Patent Application
20240079429
This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2022-0111689, filed on Sep. 2, 2022, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.
The disclosure relates to an image sensor and an electronic apparatus including the same.
Image sensors generally sense the color of incident light by using a color filter. However, a color filter may have low light utilization efficiency because the color filter absorbs light of colors other than the intended color of light. For example, in the case of a red-green-blue (RGB) color filter is used, only ⅓ of the incident light is transmitted therethrough and the other part of the incident light, that is, ⅔ of the incident light, is absorbed. Thus, the light utilization efficiency is only about 33%, and most of the light loss in the image sensor occurs in a color filter. Accordingly, a method of separating colors by using each pixel in an image sensor without using a color filter has been attempted.
Provided is an image sensor including a color separation lens array capable of separating incident light according to wavelengths and condensing separated light.
Provided is an image sensor including a color separation lens array having less performance variation according to a chief ray angle.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.
According to an aspect of the disclosure, there is provided an image sensor including: a sensor substrate including a plurality of pixel unit groups, each of the plurality of pixel unit groups including a first pixel, a second pixel, a third pixel, and a fourth pixel arranged in a Bayer pattern; and a color separating lens array configured to separate incident light according to wavelengths and condense the light onto each of the first pixel, the second pixel, the third pixel and the fourth pixel, wherein the color separating lens array incudes a plurality of pixel corresponding groups respectively corresponding to the plurality of unit pixel groups, each of the plurality of pixel corresponding groups including a first pixel corresponding region corresponding to the first pixel, a second pixel corresponding region corresponding to the second pixel, a third pixel corresponding region corresponding to the third pixel, and a fourth pixel corresponding region corresponding to the fourth pixel, and each of the first pixel corresponding region, the second pixel corresponding region, the third pixel corresponding region and the fourth pixel corresponding region including a plurality of nanoposts, wherein the plurality of pixel corresponding groups including a central group located at a center of the color separating lens array and a plurality of peripheral groups located away from the center of the color separating lens array, and wherein relative positional relationships among the nanoposts in the first pixel corresponding region, the second pixel corresponding region, the third pixel corresponding region and the fourth pixel corresponding region in each of the plurality of peripheral groups are different from each other.
Each of the first pixel, the second pixel, the third pixel and the fourth pixel may include four photosensitive cells arranged in a 2×2 array.
The relative positional relationships among the nanoposts for each of the plurality of pixel corresponding groups is configured according to a chief ray angle and an azimuth that are defined according to a position of the peripheral group on the image sensor.
The fourth pixel may be adjacent to the third pixel in a first direction, the first pixel may be adjacent to the third pixel in a second direction that is perpendicular to the first direction, the second pixel may be adjacent to the third pixel in a diagonal direction, and the third pixel may be a red pixel, the first pixel and the fourth pixel may be green pixels, and the second pixel may be a blue pixel.
Based on the relative positional relationships between the nanoposts of the first pixel corresponding region, the second pixel corresponding region, the third pixel corresponding region and the fourth pixel corresponding region in the central group, one or more of the nanoposts in the first pixel corresponding region, the second pixel corresponding region, the third pixel corresponding region and the fourth pixel corresponding region are shifted in the peripheral group with respect to the central group.
The one or more of the nanoposts of the first pixel corresponding region in the peripheral group are shifted in the second direction, wherein a shifted displacement of the one or more of the nanoposts of the first pixel corresponding region is proportional to (CRA/CRA_max)*sin φ, and wherein CRA_max denotes a maximum value of a chief ray angle of light incident on the color separating lens array, CRA denotes a chief ray angle at a position of the one or more shifted nanopost, and φ denotes an azimuth at the position of the one or more shifted nanopost based on an axis that passes through the center of the color separating lens array and is in parallel with the first direction.
The one or more nanoposts of the fourth pixel corresponding region in the peripheral group are shifted in the first direction, wherein a shifted displacement of the fourth pixel corresponding region is proportional to (CRA/CRA_max)*cos φ, where CRA_max denotes a maximum value of a chief ray angle of light incident on the color separating lens array, CRA denotes a chief ray angle at a position of the one or more shifted nanopost, and φ denotes an azimuth at the position of the one or more shifted nanopost based on an axis that passes through the center of the color separating lens array and is in parallel with the first direction.
The one or more nanoposts of the second pixel corresponding region in the peripheral group are shifted in the first direction and the second direction, wherein a shifted displacement of the one or more nanoposts of the second color separating lens in the first direction is proportional to (CRA/CRA_max)*cos φ, wherein a shifted displacement one or more nanoposts of the second color separating lens in the second direction is proportional to (CRA/CRA_max)*sin φ, and wherein CRA_max denotes a maximum value of a chief ray angle of light incident on the color separating lens array, CRA denotes a chief ray angle at a position of the one or more shifted nanopost, and φ denotes an azimuth at the position of the one or more shifted nanopost based on an axis that passes through the center of the color separating lens array and is in parallel with the first direction.
One or more nanoposts located at a boundary between different pixel corresponding regions from among the first pixel corresponding region, the second pixel corresponding region, the third pixel corresponding region and the fourth pixel corresponding region in the peripheral group are shifted by an average displacement of the nanoposts in adjacent pixel corresponding regions.
According to another aspect of the disclosure, there is provided an image sensor including: a sensor substrate including a plurality of unit pixel groups, each of the plurality of unit pixel groups having a red pixel, a first green pixel adjacent to the red pixel in a Y direction, a second green pixel adjacent to the red pixel in an X direction, and a blue pixel adjacent to the second green pixel in the Y direction; and a color separating lens array configured to separate incident light according to wavelengths and condense the light onto each of the first pixel, the second pixel, the third pixel and the fourth pixel, wherein the color separating lens array includes a plurality of pixel corresponding groups including a red pixel corresponding region, a first green pixel corresponding region, a second green pixel corresponding region, and a blue pixel corresponding region corresponding respectively to the unit pixel groups, and each of the pixel corresponding regions including a plurality of nanoposts, wherein the plurality of pixel corresponding groups include a central group located at a center of the color separating lens array and a plurality of peripheral groups located away from the center of the color separating lens array, and wherein, in peripheral groups from among plurality of peripheral groups, having an identical chief ray angle (CRA), one or more nanoposts arranged in the first green pixel corresponding region of a first peripheral group having an azimuth of 90° with respect to the central group in the X direction are shifted in +Y direction as compared with one or more nanoposts arranged in the first green pixel corresponding region of a second peripheral group having an azimuth of 45° based on the X direction.
In the peripheral groups having the identical CRA, one or more nanoposts arranged in the second green pixel corresponding region of a third peripheral group having an azimuth of 0° with respect to the central group in the X direction are shifted in +X direction as compared with one or more nanoposts arranged in the second green pixel corresponding region of a fourth peripheral group having an azimuth of 45° based on the +X direction.
In the peripheral groups having the identical CRA, one or more nanoposts arranged in the blue pixel corresponding region of a fifth peripheral group having an azimuth of 45° with respect to the central group based on the X direction are: shifted in +X direction in the fifth peripheral group as compared with one or more nanoposts arranged in the blue pixel corresponding region of a sixth peripheral group having an azimuth of 90° based on the X direction, and shifted in +Y direction in the fifth peripheral group as compared with one or more nanoposts arranged in the blue pixel corresponding region of a seventh peripheral group having an azimuth of 0° based on the X direction.
In the plurality of peripheral groups, one or more nanoposts arranged in the first green pixel corresponding region of an eighth peripheral group having an azimuth of 90° with respect to the central group based on the X direction and having a first CRA are shifted in +Y direction in the eight peripheral group, as compared with one or more nanoposts arranged in the first green pixel corresponding region of a ninth peripheral group having an azimuth of 90° based on the X direction and having a second CRA that is less than the first chief ray angle
In the plurality of peripheral groups, one or more nanoposts arranged in the first green pixel corresponding region of a tenth peripheral group having an azimuth of 0° with respect to the central group based on the X direction and having the first CRA are shifted in +X direction in the tenth peripheral group, as compared with one or more nanoposts arranged in the second green pixel corresponding region of a eleventh peripheral group having an azimuth of 0° based on the X direction and having the second CRA that is less than the first chief ray angle
In the plurality of peripheral groups, one or more nanoposts arranged in the blue pixel corresponding region of a twelfth peripheral group having an azimuth of 45° with respect to the central group based on the X direction and having the first CRA are shifted in a direction away from the central group in the corresponding peripheral group, as compared with one or more nanoposts arranged in the blue pixel corresponding region of a thirteenth peripheral group having an azimuth of 45° based on the X direction and having the second CRA that is less than the first CRA
According to another aspect of the disclosure, there is provided an image sensor including: a sensor substrate including a plurality of pixel unit groups, each of the plurality of pixel unit groups including a first pixel, a second pixel, a third pixel, and a fourth pixel arranged in a Bayer pattern; and a color separating lens array configured to separate incident light according to wavelengths and condense the light onto each of the first pixel, the second pixel, the third pixel and the fourth pixel, wherein the color separating lens array includes a plurality of pixel corresponding groups respectively corresponding to the plurality of unit pixel groups, each of the plurality of pixel corresponding groups including a first pixel corresponding region corresponding to the first pixel, a second pixel corresponding region corresponding to the second pixel, a third pixel corresponding region corresponding to the third pixel, and a fourth pixel corresponding region corresponding to the fourth pixel, and each of the first pixel corresponding region, the second pixel corresponding region, the third pixel corresponding region and the fourth pixel corresponding region including a plurality of nanoposts, wherein the plurality of pixel corresponding groups including a central group located at a center of the color separating lens array and a plurality of peripheral groups located away from the center of the color separating lens array, and wherein an amount of variation in position of the nanoposts in the first pixel corresponding region, the second pixel corresponding region, the third pixel corresponding region and the fourth pixel corresponding region of the peripheral group with respect to the central group are different from each other.
The amount of variation in position is based on a chief ray angle and an azimuth according to a position of the peripheral group in the color separating lens array, and the amount of variation in position includes a shifted distance and a shifted direction of the nanoposts in each region toward the central group.
According to another aspect of the disclosure, there is provided an electronic apparatus including: a lens assembly including one or more lenses and configured to form an optical image of an object; an image sensor configured to convert the optical image formed by the lens assembly into an electrical signal; and a processor configured to process a signal generated by the image sensor, wherein the image sensor includes: a sensor substrate including a plurality of pixel unit groups, each of the plurality of pixel unit groups including a first pixel, a second pixel, a third pixel, and a fourth pixel arranged in a Bayer pattern; and a color separating lens array configured to separate incident light according to wavelengths and condense the light onto each of the first pixel, the second pixel, the third pixel and the fourth pixel, wherein the color separating lens array includes a plurality of pixel corresponding groups respectively corresponding to the plurality of unit pixel groups, each of the plurality of pixel corresponding groups including a first pixel corresponding region corresponding to the first pixel, a second pixel corresponding region corresponding to the second pixel, a third pixel corresponding region corresponding to the third pixel, and a fourth pixel corresponding region corresponding to the fourth pixel, and each of the first pixel corresponding region, the second pixel corresponding region, the third pixel corresponding region and the fourth pixel corresponding region including a plurality of nanoposts, wherein the plurality of pixel corresponding groups including a central group located at a center of the color separating lens array and a plurality of peripheral groups located away from the center of the color separating lens array, and wherein relative positional relationships among the nanoposts in the first pixel corresponding region, the second pixel corresponding region, the third pixel corresponding region and the fourth pixel corresponding region in each of the plurality of peripheral groups are different from each other.
The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the example embodiments are merely described below, by referring to the figures, to explain aspects. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.
The disclosure will be described in detail below with reference to accompanying drawings. The example embodiments of the disclosure are capable of various modifications and may be embodied in many different forms. In the drawings, like reference numerals denote like components, and sizes of components in the drawings may be exaggerated for convenience of explanation.
Hereinafter, it will be understood that when a layer, region, or component is referred to as being “above” or “on” another layer, region, or component, it may be in contact with and directly on the other layer, region, or component, and intervening layers, regions, or components may be present.
It will be understood that although the terms “first,” “second,” etc. may be used herein to describe various components, these components should not be limited by these terms. These components are only used to distinguish one component from another. These terms do not limit that materials or structures of components are different from one another.
An expression used in the singular encompasses the expression of the plural, unless it has a clearly different meaning in the context. It will be further understood that when a portion is referred to as “comprises” another component, the portion may not exclude another component but may further comprise another component unless the context states otherwise.
Also, the terms “ . . . unit”, “ . . . module” used herein specify a unit for processing at least one function or operation, and this may be implemented with hardware or software or a combination of hardware and software.
The use of the terms of “the above-described” and similar indicative terms may correspond to both the singular forms and the plural forms.
Also, the steps of all methods described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. Also, the use of all exemplary terms (for example, etc.) is only to describe a technical spirit in detail, and the scope of rights is not limited by these terms unless the context is limited by the claims.
Referring to
The pixel array 1100 includes pixels that are two-dimensionally arranged in a plurality of rows and columns. The row decoder 1020 selects one of the rows in the pixel array 1100 in response to a row address signal output from the timing controller 1010. The output circuit 1030 outputs a photosensitive signal, in a column unit, from a plurality of pixels arranged in the selected row. To this end, the output circuit 1030 may include a column decoder and an analog-to-digital converter (ADC). For example, the output circuit 1030 may include a plurality of ADCs that are arranged respectively to columns between the column decoder and the pixel array 1100, or one ADC arranged at an output end of the column decoder. The timing controller 1010, the row decoder 1020, and the output circuit 1030 may be implemented as one chip or separate chips. A processor for processing an image signal output from the output circuit 1030 may be implemented as one chip along with the timing controller 1010, the row decoder 1020, and the output circuit 1030.
The pixel array 1100 may include a plurality of pixels PX that sense light of different wavelengths. The pixel arrangement may be implemented in various ways. The pixel array 1100 may include a color separating lens array that separates incident light according to wavelengths so that light of different wavelengths may be incident on the plurality of pixels PX.
Referring to
The color separating lens array CSLA may generate different phase profiles of the first wavelength light LA1 and the second wavelength light LA2 included in the incident light Li so that the first wavelength light LA1 may be condensed onto the first pixel PX1 and the second wavelength light LA2 may be condensed onto the second pixel PX2.
For example, referring to
Because a refractive index of a material varies depending on a wavelength of light, the color separating lens array CSLA may provide different phase profiles with respect to the first and second wavelength light LA1 and LA2. In other words, because the same material has a different refractive index according to the wavelength of light reacting with the material and a phase delay of the light that passes through the material is different according to the wavelength, the phase profile may vary depending on the wavelength. For example, a refractive index of the first pixel corresponding region R1 with respect to the first wavelength light LA1 and a refractive index of the first pixel corresponding region R1 with respect to the second wavelength light LA2 may be different from each other, and the phase delay of the first wavelength light LA1 that passed through the first pixel corresponding region R1 and the phase delay of the second wavelength light LA2 that passed through the first pixel corresponding region R1 may be different from each other. Therefore, when the color separating lens array CSLA is designed based on the characteristics of light, different phase profiles may be provided with respect to the first wavelength light LA1 and the second wavelength light LA2.
The color separating lens array CSLA may include nanoposts NP that are arranged according to a certain rule such that the first and second wavelength light LA1 and LA2 may respectively have first and second phase profiles PP1 and PP2. Here, the rule may be applied to parameters, such as the shape of the nanoposts NP, sizes (width and height), a distance between the nanoposts NP, and the arrangement form thereof, and these parameters may be determined according to a phase profile to be implemented by the color separating lens array CS LA.
A rule in which the nanoposts NP are arranged in the first pixel corresponding region R1, and a rule in which the nanoposts NP are arranged in the second pixel corresponding region R2 may be different from each other. In other words, sizes, shapes, intervals, and/or arrangement of the nanoposts NP in the first pixel corresponding region R1 may be different from those of the nanoposts NP in the second pixel corresponding region R2.
The nanoposts NP may have a shape dimension of a sub wavelength. Here, the sub-wavelength refers to a wavelength that is less than a wavelength band of light to be branched. The nanoposts NP may have a dimension that is less than a shorter wavelength of the first wavelength and the second wavelength. The nanoposts NP may have a cylindrical shape having a cross-sectional diameter of a sub wavelength. However, the shape of the nanoposts NP is not limited thereto, that is, the nanoposts NP may have an elliptical post shape or a polygonal post shape. Otherwise, the nanoposts NP may have post shapes having symmetrical or asymmetrical cross-sectional shape. The nanoposts NP are shown so that a width in the direction perpendicular to a height direction (Z-direction) is constant, that is, a cross-section parallel to the height direction has a rectangular shape, but the above shape is an example. Unlike the example, the widths of the nanoposts NP in the direction perpendicular to the height direction may not be consistent, for example, the cross-section parallel to the height direction may have a trapezoidal shape or an inversed trapezoidal shape. When the incident light Li is a visible ray, the cross-sectional diameter of the nanoposts NP may be less than, for example, 400 nm, 300 nm, or 200 nm.
In addition, a height of the nanoposts NP may be about 500 nm to about 1500 nm, which is greater than the cross-sectional diameter of the nanopost. According to an example embodiment, the nanoposts NP may be obtained by combining two or more posts stacked in the height direction (Z direction). The height of the nanoposts NP may be a few times greater than the sub wavelength to a wavelength. For example, the height of the nanoposts NP may be five times, four times, or three times or less the peak wavelength of a wavelength band separated by the color separating lens array CSLA. The nanoposts NP included in different pixel corresponding regions R1 and R2 are shown to have the identical height, but one or more example embodiments are not limited thereto, that is, the arrangement type, widths, and the number of the nanoposts NP are the examples. The widths, heights, the number, and arrangement type of the nanoposts NP may be determined to be suitable for forming the phase profile for color separation, or may be determined considering detailed processing conditions.
A peripheral material layer having a refractive index that is different from that of the nanoposts NP may be filled among the nanoposts NP. The nanoposts NP may include a material having a higher refractive index than that of a peripheral material. For example, the nanoposts NP may include c-Si, p-Si, a-Si and a Group III-V compound semiconductor (GaP, GaN, GaAs etc.), SiC, TiO2, SiN, and/or a combination thereof. The nanoposts NP having a different refractive index from the refractive index of the peripheral material may change the phase of light that passes through the nanoposts NP. This is caused by phase delay that occurs due to the shape dimension of the sub-wavelength of the nanoposts NP, and a degree at which the phase is delayed, may be determined by a detailed shape dimension and arrangement shape of the nanoposts NP. A peripheral material of the nanoposts NP may include a dielectric material having a lower refractive index than that of the nanoposts NP. For example, the peripheral material may include SiO2 or air. However, one or more example embodiments are not limited thereto, that is, the materials of the nanoposts NP and the peripheral material may be set so that the nanoposts NP may have a lower refractive index than that of the peripheral material.
Division of regions in the color separating lens array CSLA and shapes and arrangement of the nanoposts NP may be set so that a phase profile which allows the incident light to be separated according to wavelengths and to condense to the plurality of pixels PX1 and PX2 may be obtained. The separation according to wavelength may include a color separation in the visible ray band, but is not limited thereto, that is, the wavelength band may be expanded to the visible ray to infrared ray range, or other various ranges. A first wavelength Δ1 and a second wavelength Δ2 may be in a wavelength band of infrared rays and visible rays. However, one or more embodiments are not limited thereto, and a variety of wavelength bands may be included according to the rule of arrays of the plurality of nanoposts NP. Also, an example in which two wavelengths are separated and condensed is shown. However, embodiments are not limited thereto. The incident light may be branched into three directions or more according to wavelengths and condensed.
Also, the nanoposts NP in the color separating lens array CSLA is arranged in a single layer, but the color separating lens array CSLA may have a stack structure in which the nanoposts NP are arranged in a plurality of layers.
The color arrangement shown in
The color arrangement of
The pixel array 1100 of the image sensor 1000 may include a color separating lens array so as to correspond to the above color arrangement, that is, the color separating lens array condensing light of a color corresponding to a certain pixel. That is, the division of regions and the shapes and arrangement of the nanoposts NP may be set so that wavelengths separated by the color separating lens array CSLA described above with reference to
Referring to
Each of the first to fourth pixels 111, 112, 113, and 114 may include a plurality of photosensitive cells that independently sense incident light. For example, each of the first to fourth pixels 111, 112, 113, and 114 may include first to fourth photosensitive cells c1, c2, c3, and c4. The first to fourth photosensitive cells c1, c2, c3, and c4 may be two-dimensionally arranged in the first direction (X direction) and the second direction (Y direction). For example, in each of the first to fourth pixels 111, 112, 113, and 114, the first to fourth photosensitive cells c1, c2, c3, and c4 may be arranged in a 2×2 array.
According to the example embodiment, some of the plurality of pixels each including the plurality of photosensitive cells sensing the light of the same color may be used as auto-focusing pixels. In the auto-focusing pixel, an auto-focusing signal may be obtained from a difference between output signals of adjacent photosensitive cells. For example, an auto-focusing signal in the first direction (X direction) may be generated from a difference between output signals from the first photosensitive cell c1 and the second photosensitive cell c2, a difference between output signals from the third photosensitive cell c3 and the fourth photosensitive cell c4, or a difference between a sum of the output signals from the first photosensitive cell c1 and the third photosensitive cell c3 and a sum of the output signals from the second photosensitive cell c2 and the fourth photosensitive cell c4. Also, an auto-focusing signal in the second direction (Y direction) may be generated from a difference between output signals from the first photosensitive cell c1 and the third photosensitive cell c3, a difference between output signals from the second photosensitive cell c2 and the fourth photosensitive cell c4, or a difference between a sum of the output signals from the first photosensitive cell c1 and the second photosensitive cell c2 and a sum of the output signals from the third photosensitive cell c3 and the fourth photosensitive cell c4.
In addition, a general image signal may be obtained by adding output signals from the first to fourth photosensitive cells c1, c2, c3, and c4. For example, a first green image signal may be generated by adding the output signals from the first to fourth photosensitive cells c1, c2, c3, and c4 of the first pixel 111, a blue image signal may be generated by adding the output signals from the first to fourth photosensitive cells c1, c2, c3, and c4 of the second pixel 112, a red image signal may be generated by adding the output signals from the first to fourth photosensitive cells c1, c2, c3, and c4 of the third pixel 113, and a second green image signal may be generated by adding the output signals from the first to fourth photosensitive cells c1, c2, c3, and c4 of the fourth pixel 114.
Referring to
The shapes and arrangement of the plurality of nanoposts included in the color separating lens array 130 may be set to form a phase profile that is appropriate to the wavelength separation, and the detailed shape and arrangement of the nanoposts may be adjusted according to a relative position of the pixel corresponding group 130G in which the nanoposts are included in the color separating lens array 130. This will be described in detail later with reference to
Referring to
The sensor substrate 110 may include the first pixel 111, the second pixel 112, the third pixel 113, and the fourth pixel 114 sensing light as described above with reference to
A transparent spacer layer 120 may be arranged between the sensor substrate 110 and the color separating lens array 130. According to an example embodiment, a color filter array may be further arranged between the sensor substrate 110 and the spacer layer 120. The color filter array may include a red filter, a green filter, and a blue filter, and the filters may be arranged corresponding to the color arrangement as shown in
The spacer layer 120 supports the color separating lens array 130 and may have a thickness d that satisfies a regulation about a distance between the sensor substrate 110 and the color separating lens array 130, that is, a distance between an upper surface of the sensor substrate 110 and a lower surface of the color separating lens array 130. The thickness of the spacer layer 120 may vary depending on whether the color filter array is provided between the color separating lens array 130 and the sensor substrate 110.
The spacer layer 120 may include a material transparent with respect to the visible ray, for example, a dielectric material having a lower refractive index than that of the nanoposts NP and low absorption coefficient in the visible ray band, e.g., SiO2, siloxane-based spin on glass (SOG), etc. When the peripheral material layer filled among the nanoposts NP has a higher refractive index than that of the nanoposts NP, the spacer layer 120 may include a material having a lower refractive index than that of the peripheral material layer.
A thickness d of the spacer layer 120 may be selected within a range of ht−p≤d≤ht+p. Here, ht denotes a focal length of light at the peak wavelength in a wavelength band branched by the color separating lens array 130, and p denotes a pixel pitch. In an example embodiment, the pixel pitch may be a few μm or less, for example, 2 μm or less, 1.5 μm or less, 1 μm or less, or 0.7 μm or less. The pixel pitch may be within a range of about 0.5 μm to about 1.5 μm. The thickness of the spacer layer 120 may be designed based on, for example, the center wavelength of the green light, that is, 540 nm.
When the color filter array is arranged between the sensor substrate 110 and the color separating lens array 130, in consideration of the thickness of the color filter array, the thickness of the spacer layer 120 may be set to be less than the focal length of the color separating lens array 130 with respect to the light of the center wavelength from among the wavelength bands separated by the color separating lens array 130. For example, the thickness may be set to be less than a focal length of the green light by the color separating lens array 130.
According to an example embodiment, an etch-stop layer may be further provided between the spacer layer 120 and the color separating lens array 130. The etch-stop layer may be provided to protect the spacer layer 120 that is the structure under the color separating lens array 130, during the process of manufacturing the color separating lens array 130. For example, a condition about the distance between the lower surface of the color separating lens array 130 and the upper surface of the sensor substrate 110 may be maintained due to the etch-stop layer.
Also, a protective layer for protecting the color separating lens array 130 may be further disposed on the color separating lens array 130. The protective layer may include a material functioning as an anti-reflection layer.
The first green pixel corresponding region 131 corresponds to the first green pixel 111 and may be on the first green pixel 111, the blue pixel corresponding region 132 corresponds to the blue pixel 112 and may be on the blue pixel 112, the red pixel corresponding region 133 corresponds to the red pixel 113 and may be on the red pixel 113, and the second green pixel corresponding region 134 corresponds to the second green pixel 114 and may be on the second green pixel 114. That is, the first to fourth pixel corresponding regions 131, 132, 133, and 134 of the color separating lens array 130 may be arranged respectively facing the pixels 111, 112, 113, and 114 of the sensor substrate 110. As shown in
In addition, similar to the above description with reference to
Sizes, shapes, intervals, and/or arrangement of the plurality of nanoposts NP included in the color separating lens array 130 may be determined such that the green light is separated and condensed to the first and second green pixels 111 and 114, the blue light is separated and condensed to the blue pixel 112, and the red light is separated and condensed to the red pixel 113.
A pixel arrangement characteristic of the Bayer pattern may be reflected to the arrangement of the nanoposts in the pixel corresponding regions 131, 132, 133, and 134. In the Bayer pattern pixel arrangement, adjacent pixels to the blue pixel 112 and the red pixel 113 in the first direction (X direction) and the second direction (Y direction) are same as the green pixels G, whereas the adjacent pixel to the first green pixel 111 in the first direction (X direction) is the blue pixel 112 and the adjacent pixel to the first green pixel 111 in the second direction (Y direction) is the red pixel R. In addition, the adjacent pixel to the second green pixel 114 in the first direction (X direction) is the red pixel 113 and the adjacent pixel to the second green pixel 114 in the second direction (Y direction) is the blue pixel 114. In addition, adjacent pixels to the first and second green pixels 111 and 114 in four diagonal directions are green pixels, adjacent pixels to the blue pixel 112 in the four diagonal directions are the red pixels 113, and adjacent pixels to the red pixel 113 in the four diagonal directions are the blue pixels 112. Therefore, in the blue and red pixel corresponding regions 132 and 133 respectively corresponding to the blue pixel 112 and the red pixel 113, the nanoposts NP may be arranged in the form of 4-fold symmetry, and in the first and second green pixel corresponding regions 131 and 134, the nanoposts NP may be arranged in the form of 2-fold symmetry. The arrangement of nanoposts 1 in the first and second green pixel corresponding regions 131 and 134 may be rotated by 90° angle with respect to each other.
As shown in the plan view of
Referring to
In addition, the first green light phase profile PPG1 does not denote that the phase delay amount of the light that has passed through the center of the first green pixel corresponding region 131 is the largest, but when the phase of light that has passed through the first green pixel corresponding region 131 is 2π and a phase delay amount of the light that has passed through another point is greater and has a phase value of 2π or greater, the first green light phase profile PPG1 may denote a value remaining after subtracting 2π, that is, wrapped phase profile. For example, when the phase of light that has passed through the first green pixel corresponding region 131 is 2π and the phase of light that has passed through the center of the blue pixel corresponding region 132 is 3π, the phase in the blue pixel corresponding region 132 may be remaining π after subtracting π (n=1) from 3π.
Also, the blue light that has passed through the color separating lens array 130 may have a blue light phase profile PPB that is largest at the center of the blue pixel corresponding region 132 and reduces away from the center of the blue pixel corresponding region 132. In detail, immediately after passing through the color separating lens array 130, the phase of the blue light is the largest at the center of the blue pixel corresponding region 132 and reduced as a concentric circle away from the center of the blue pixel corresponding region 132, the phase is the smallest at the centers of the first and second green pixel corresponding regions 131 and 134 in the X direction and the Y direction and the smallest at the center of the red pixel corresponding region 133 in the diagonal direction. When the phase of the blue light at the center of the blue pixel corresponding region 132 is 2π, the phase at the centers of the first and second green pixel corresponding regions 131 and 134 may be about, for example, about 0.9π to about 1.1π, and the phase at the center of the red pixel corresponding region 133 may be less than that at the centers of the first and second green pixel corresponding regions 131 and 134, for example, about 0.5π to about 0.9π.
The green light incident on the first green pixel corresponding region 131 and the vicinity of the first green pixel corresponding region 131 is condensed to the first green pixel 111 by the color separating lens array 130, and the green light from the blue and red pixel corresponding regions 132 and 133, in addition to the first green pixel corresponding region 131, is also incident on the first green pixel 111. That is, according to the phase profile of the green light described above with reference to
The blue light is condensed onto the blue pixel 112 by the color separating lens array 130, and the blue light from the pixel corresponding regions 131, 132, 133, and 134 is incident on the blue pixel 112. In the phase profile of the blue light described above, the blue light that has passed through a blue light condensing region BL that is obtained by connecting centers of four red pixel corresponding regions 133 adjacent to the blue pixel corresponding region 132 at apexes is condensed onto the blue pixel 112. Therefore, as shown in
Referring to
Referring to
In the phase profile of the red light described above with reference to
The green light incident on the second green pixel corresponding region 134 and the vicinity of the second green pixel corresponding region 134 proceeds similarly to the green light incident on the first green pixel corresponding region 131 and the vicinity of the first green pixel corresponding region 131, and as shown in
The color separating lens array 130 satisfying the above phase profile and performance described above may be automatically designed through various types of computer simulations. For example, the structures of the pixel corresponding regions 131, 132, 133, and 134 may be optimized through a nature-inspired algorithm such as a genetic algorithm, a particle swarm optimization algorithm, an ant colony optimization algorithm, etc., or a reverse design based on an adjoint optimization algorithm.
The structures of the green, blue, and red pixel corresponding regions may be optimized while evaluating performances of a plurality of candidate color separating lens arrays based on evaluation factors such as color separation spectrum, optical efficiency, signal-to-noise ratio, etc. when designing the color separating lens array 130. For example, the structures of the green, blue, and red pixel corresponding regions may be optimized in a manner that a target numerical value of each evaluation factor is determined in advance and the sum of the differences from the target numerical values of a plurality of evaluation factors is reduced. Alternatively, the performance may be indexed for each evaluation factor, and the structures of the green, blue, and red pixel corresponding regions may be optimized so that a value representing the performance may be maximized.
An incidence angle of the light incident on the image sensor 1000 is typically defined as a chief ray angle (CRA). A chief ray denotes a light ray starting from a point of the object and arriving at the image sensor 1000 by passing through a center of an objective lens. The CRA denotes an angle formed by the chief ray with respect to an optical axis, and is generally equal to an incident angle of the chief ray incident on the image sensor 1000. For example, the chief ray of the light starting from a point on the optical axis of the objective lens is incident perpendicularly to the center portion of the image sensor 1000, and in this case, the CRA is 0°. As the starting point is away from the optical axis of the objective lens, the CRA increases and the light is incident on the edge of the image sensor 1000. From the viewpoint of the image sensor 1000, the CRA of the light incident on the center portion of the image sensor 1000 is 0° and the CRA of the incident light gradually increases away from the center of the image sensor 1000.
However, the color separating lens array 130 described above may generally have a directivity with respect to the incident light. In other words, the color separating lens array 130 efficiently operates with respect to the light incident on the color separating lens array within a certain angle range, but when the incidence angle is away from the certain angle range, the color separation performance of the color separating lens array 130 may degrade. Accordingly, when the nanoposts NP of the color separating lens array 130 have the same arrangement form in the entire area of the image sensor 1000, the color separation efficiency is not consistent throughout the entire area of the image sensor 1000 and may vary depending on regions in the image sensor 1000. Thus, the quality of the image provided by the image sensor 1000 may degrade.
In addition, when the plurality of pixels 111, 112, 113, and 114 each have a plurality of photosensitive cells, there may be a signal difference between the plurality of photosensitive cells corresponding to the identical pixel and is referred to as a channel difference. The channel difference may occur due to the structural variation that may be generated during a manufacturing processes and may also occur due to the CRA. Also, the light of different wavelengths has different focal lengths, and the channel difference due to the CRA may also vary depending on the wavelengths. The channel difference may degrade image quality obtained from the image sensor 1000. The channel difference may cause an error when an automatic focusing signal is generated. As described above with reference to
The image sensor 1000 according to the example embodiment may be designed so that the arrangement type of the nanoposts NP of the color separating lens array 130 may vary considering the CRA of the incident light, which varies depending on the location on the image sensor 130. For example, the arrangement of the nanoposts NP included in the plurality of pixel corresponding regions 131, 132, 133, and 134 of the color separating lens array 130 may be differently adjusted according to relative positional relationship based on the center of the color separating lens array 130. An azimuth and color, as well as the CRA, may be considered in aligning the nanoposts NP.
Referring to
Referring to
As shown in the example in
Referring to
In the peripheral group PG, arrows and displacement indicated in the first pixel corresponding region 131, the second pixel corresponding region 132, and the fourth pixel corresponding region 134 are indicated based on the third pixel corresponding region 133. In the third pixel corresponding region 133, s indicates that the peripheral group PG is misaligned with facing pixel group 110G by s, unlike the central group CG. For the convenience of description, s is indicated in the third pixel corresponding region 133, but the first to fourth pixel corresponding regions 131, 132, 133, and 134 may be shifted in a certain direction by a certain distance with respect to the first to fourth pixels 111, 112, 113, and 114 facing thereof. s will be described later with reference to
The relative positional relationship may be different between the peripheral groups PG at different locations. For example, the relative positional relationship may be different between the peripheral groups PG at different locations as indicated by different r or φ. That is, in one peripheral group PG, relative positional relationship among the nanoposts of the first pixel corresponding region 131, the nanoposts of the second pixel corresponding region 132, the nanoposts of the third pixel corresponding region 133, and the nanoposts of the fourth pixel corresponding region 134 is different from the relative positional relationship among the nanoposts of the first pixel corresponding region 131, the nanoposts of the second pixel corresponding region 132, the nanoposts of the third pixel corresponding region 133, and the nanoposts of the fourth pixel corresponding region 134 in another peripheral group PG at different location.
According to an example embodiment, in one peripheral group PG, relative positional relationship among the nanoposts in the first to fourth pixel corresponding regions 131, 132, 133, and 134 may vary depending on the color of adjacent pixel corresponding region. For example, a distance between a center of the entire arrangement of nanoposts in the first pixel corresponding region 131 and a center of the entire arrangement of nanoposts in the second pixel corresponding region 132 may be different from a distance between the center of the entire arrangement of nanoposts in the first pixel corresponding region 131 and a center of the entire arrangement of nanoposts in the third pixel corresponding region 133. According to an example embodiment, in one peripheral group PG, at least two distances between the centers of the nanoposts arranged in adjacent pixel regions may be different from each other. According to an example embodiment, at least two of the distance between the center of the nanoposts of the first pixel corresponding region 131 and the center of the nanoposts of the second pixel corresponding region 132, the distance between the center of the nanoposts of the first pixel corresponding region 131 and the center of the nanoposts of the third pixel corresponding region 133, the distance between the center of the nanoposts of the second pixel corresponding region 132 and the center of the nanoposts of the fourth pixel corresponding region 134, and the distance between the center of the nanoposts of the third pixel corresponding region 133 and the center of the nanoposts of the fourth pixel corresponding region 134 may be different from each other. A degree of difference may vary depending on the position of the peripheral group PG.
The nanoposts of the first pixel corresponding region 131, the second pixel corresponding region 132, and the fourth pixel corresponding region 134 in the peripheral group PG are relatively shifted with respect to the third pixel corresponding region 133, as compared with the central group CG. In azimuth locations shown in the drawings, the nanoposts of the first pixel corresponding region 131, the second pixel corresponding region 132, and the fourth pixel corresponding region 134 in the peripheral group PG are relatively further shifted in the direction away from the third pixel corresponding region 133 when compared with the relative positional relationship among the first to fourth pixel corresponding regions 131, 132, 133, and 134 in the central group CG. For example, at a different azimuth location, the nanoposts of the first pixel corresponding region 131, the second pixel corresponding region 132, and the fourth pixel corresponding region 134 in the peripheral group PG are relatively further shifted in the direction close to the third pixel corresponding region 133 when compared with the relative positional relationship among the first to fourth pixel corresponding regions 131, 132, 133, and 134 in the central group CG. That is, the shifted distance and direction may be determined according to the CRA and the azimuth φ. That is, the shifted distance and distance may be determined by the distance r and the azimuth φ from the center C of the color separating lens array 130. Here, the distance r and the azimuth φ are described to be about the center of the peripheral group PG, but are not limited thereto. The distance r and the azimuth φ may be defined for each of the nanoposts in the peripheral group PG. A detailed value of the shifted distance of the nanoposts may be determined by the distance r and the azimuth φ representing the position of each nanopost, or may be determined by the distance r and the azimuth φ representing the center location of the corresponding peripheral group PG.
The nanoposts in the first pixel corresponding region 131, the second pixel corresponding region 132, and the fourth pixel corresponding region 134 may be further shifted in the direction away from the center C of the color separating lens array 130, with respect to the nanoposts of the third pixel corresponding region 133. As indicated by the arrows, the nanoposts of the second pixel corresponding region 132 in the peripheral group PG may be shifted in the direction away from the center C with respect to the nanoposts of the third pixel corresponding region 133 in the color separating lens array 130, the nanoposts of the first pixel corresponding region 131 may be shifted in the direction away from the axis (X-axis) that is parallel to the first direction while passing through the center C of the color separating lens array 130 with respect to the nanoposts of the third pixel corresponding region 133, and the nanoposts of the fourth pixel corresponding region 134 may be shifted in the direction away from the axis (Y-axis) that is parallel to the second direction while passing through the center C of the color separating lens array 130 with respect to the nanoposts of the third pixel corresponding region 133. The shifted distance may be in proportional to the distance r from the center C of the color separating lens array 130 of the corresponding peripheral group PG (or nanopost to be shifted), in other words, CRA.
The shift may be carried out in order to reduce the channel difference as described above. To do this, the nanoposts included in one pixel corresponding region are shifted together. For example, the nanoposts configured to operate as one lens covering the four photosensitive cells c1, c2, c3, and c4 shown in
In the peripheral group PG, the displacement of the nanoposts in the first pixel corresponding region 131 may be expressed by (0, Δy), the displacement of the nanoposts in the second pixel corresponding region 132 may be expressed by (Δx, Δy), and the displacement of the nanoposts in the fourth pixel corresponding region 134 may be expressed by (Δx, 0). Here, the displacement is based on the relative positional relationship between the nanoposts of the first to fourth pixel corresponding regions 131, 132, 133, and 134 in the central group CG.
The displacement (0, Δy) of the first pixel corresponding region 131 may satisfy following condition:
Δy=(gb0)*(CRA/CRA_max)*sin φ
Here, gb0 denotes a real number equal to or greater than 0 (zero), CRA_max denotes a CRA maximum value, CRA denotes a chief ray angle, and φ denotes an azimuth.
The displacement (Δx, 0) of the fourth pixel corresponding region 134 may satisfy the following condition:
Δx=(gr0)*(CRA/CRA_max)*cos φ
Here, gr0 denotes a real number equal to or greater than 0 (zero), CRA_max denotes a CRA maximum value, CRA denotes a chief ray angle, and φ denotes an azimuth.
The displacement (Δx, Δy) of the second pixel corresponding region 132 may satisfy following condition:
Δx=(b0)*(CRA/CRA_max)*cos φ
Δy=(b0)*(CRA/CRA_max)*sin φ
Here, b0 denotes a real number equal to or greater than 0, CRA_max denotes a CRA maximum value, CRA denotes a chief ray angle, and φ denotes an azimuth.
In the above equations, the constants of gb0, gr0, and b0 may be set to represent the desired channel difference at the position where the CRA has maximum value. The combination of the above values is not limited to one example, but may have various combinations.
The above equations are examples and may be changed. For example, the suggested displacements are linearly in proportional to the CRA, but are not limited thereto, and may be in proportional in another functional relationship, e.g., a non-linear relationship.
Referring to the drawings, as compared with the relative positional relationship between the nanoposts NP in the first to fourth pixel corresponding regions 131, 132, 133, and 134 in the central group CG shown in
The nanoposts NP of the second pixel corresponding region 132, that is, the blue pixel corresponding region, are shifted by bx_0 in +X direction. bx_0 denotes (b0)*(CRA/CRA_max).
The nanoposts NP in the fourth pixel corresponding region 134, that is, the second green pixel corresponding region, are shifted by grx_0 in the +X direction, and the shifted distance grx_0 is (gr0)*(CRA/CRA_max).
According to an example embodiment, bx_0 and grx_0 are in proportional to the CRA. Therefore, when
Also, in the peripheral group PG having the azimuth of 0°, when the relative positional relationship among the first to fourth pixel corresponding regions 131, 132, 133, and 134 in the peripheral group PG having a first CRA is compared with the relative positional relationship among the first to fourth pixel corresponding regions 131, 132, 133, and 134 in the peripheral group PG having a second CRA that is less than the first CRA, the second pixel corresponding region 132 and the fourth pixel corresponding region 134 may be described as follows.
In the peripheral groups PG having the azimuth of 0°, the nanoposts NP of the second pixel corresponding region 132 in the peripheral group PG having the first CRA may be further shifted in +X direction in the corresponding peripheral group PG, as compared with the relative positional relationship among the nanoposts NP of the second pixel corresponding region 132 in the peripheral group PG having the second CRA that is less than the first CRA.
In the peripheral groups PG having the azimuth of 0°, the nanoposts NP of the fourth pixel corresponding region 134 in the peripheral group PG having the first CRA may be further shifted in +X direction in the corresponding peripheral group PG, as compared with the relative positional relationship among the nanoposts NP of the fourth pixel corresponding region 134 in the peripheral group PG having the second CRA that is less than the first CRA.
The nanoposts NP of the first pixel corresponding region 131, that is, the first green pixel corresponding region, are shifted by gby_45 in +Y direction, and gby_45 denotes (gb0)*(CRA/CRA_max)sin 45°.
The nanoposts NP of the fourth pixel corresponding region 134, that is, the second green pixel corresponding region, are shifted by grx_45 in +X direction. grx_45 denotes (gr0)*(CRA/CRA_max)cos 45°. The nanoposts NP of the second pixel corresponding region 132 are shifted by bx_45 in +X direction and by_45 in +Y direction. bx_45 is (b0)*(CRA/CRA_max)cos 45°, and by_45 is (b0)*(CRA/CRA_max)sin 45°.
According to an example embodiment, gby_45, grx_45, bx_45, by_45 are all in proportional to the CRA. Therefore, when
The nanoposts NP of the first pixel corresponding region 131 are further shifted in +Y direction as compared with the central group CG, the nanoposts NP of the fourth pixel corresponding region 134 are further shifted in +X direction as compared with the central group CG, and the nanoposts NP of the second pixel corresponding region 132 are further shifted in a direction of vector sum of +X direction and +Y direction.
Also, in the peripheral group PG having the azimuth of 45°, when the relative positional relationship among the first to fourth pixel corresponding regions 131, 132, 133, and 134 in the peripheral group PG having a first CRA is compared with the relative positional relationship among the first to fourth pixel corresponding regions 131, 132, 133, and 134 in the peripheral group PG having a second CRA that is less than the first CRA, the first pixel corresponding region 131, the second pixel corresponding region 132 may be described as follows with respect to the fourth pixel corresponding region 134.
In the peripheral groups PG having the azimuth of 45°, the nanoposts NP of the first pixel corresponding region 131 in the peripheral group PG having the first CRA may be further shifted in +Y direction in the corresponding peripheral group PG, as compared with the relative positional relationship among the nanoposts NP of the first pixel corresponding region 131 in the peripheral group PG having the second CRA that is less than the first CRA.
In the peripheral groups PG having the azimuth of 45°, the nanoposts NP of the fourth pixel corresponding region 134 in the peripheral group PG having the first CRA may be further shifted in +X direction in the corresponding peripheral group PG, as compared with the relative positional relationship among the nanoposts NP of the fourth pixel corresponding region 134 in the peripheral group PG having the second CRA that is less than the first CRA.
In the peripheral groups PG having the azimuth of 45°, the nanoposts NP of the second pixel corresponding region 132 in the peripheral group PG having the first CRA may be further shifted in the direction away from the central group CG in the corresponding peripheral group PG, as compared with the relative positional relationship among the nanoposts NP of the second pixel corresponding region 132 in the peripheral group PG having the second CRA that is less than the first CRA.
When comparing
From among the peripheral groups PG having the same CRA, the nanoposts NP in the fourth pixel corresponding region 134 of the peripheral group PG having the azimuth of 0° may be further shifted in +X direction in the corresponding peripheral group PG, as compared with the relative positional relationship among the nanoposts NP of the fourth pixel corresponding region 134 in the peripheral group PG having the azimuth of 45°.
The nanoposts NP of the first pixel corresponding region 131 are shifted by gby_90 in +Y direction, and gby_90 is (gb0)*(CRA/CRA_max).
The nanoposts NP of the second pixel corresponding region 132 are shifted by by_90 in +Y direction, and by_90 is (b0)*(CRA/CRA_max).
According to an example embodiment, by_90 and gby_90 are in proportional to the CRA. Therefore, when
The nanoposts NP of the first pixel corresponding region 131 may be further shifted in +Y direction as compared with the central group CG, and the nanoposts NP of the second pixel corresponding region 132 may be further shifted in +Y direction as compared with the central group CG.
Also, in the peripheral group PG having the azimuth of 90°, when the relative positional relationship among the first to fourth pixel corresponding regions 131, 132, 133, and 134 in the peripheral group PG having a first CRA is compared with the relative positional relationship among the first to fourth pixel corresponding regions 131, 132, 133, and 134 in the peripheral group PG having a second CRA that is less than the first CRA, the first pixel corresponding region 131 and the second pixel corresponding region 132 may be described as follows.
In the peripheral groups PG having the azimuth of 90°, the nanoposts NP of the first pixel corresponding region 131 in the peripheral group PG having the first CRA may be further shifted in +Y direction in the corresponding peripheral group PG, as compared with the relative positional relationship among the nanoposts NP of the first pixel corresponding region 131 in the peripheral group PG having the second CRA that is less than the first CRA.
In the peripheral groups PG having the azimuth of 90°, the nanoposts NP of the second pixel corresponding region 132 in the peripheral group PG having the first CRA may be further shifted in +Y direction in the corresponding peripheral group PG, as compared with the relative positional relationship among the nanoposts NP of the first pixel corresponding region 131 in the peripheral group PG having the second CRA that is less than the first CRA.
Also, when comparing
From among the peripheral groups PG having the same CRA, the nanoposts NP in the first pixel corresponding region 131 of the peripheral group PG having the azimuth of 90° may be further shifted in +Y direction in the corresponding peripheral group PG, as compared with the relative positional relationship among the nanoposts NP of the first pixel corresponding region 131 in the peripheral group PG having the azimuth of 45°.
Also, when comparing
From among the peripheral groups PG having the same CRA, the nanoposts NP arranged in the second pixel corresponding region 132 of the peripheral group PG having the azimuth of 45° may be further shifted in +Y direction in the corresponding peripheral group PG, as compared with the relative positional relationship of the nanoposts NP arranged in the second pixel corresponding region 132 of the peripheral group PG having the azimuth of 0°, and may be further shifted in +X direction in the corresponding peripheral group PG, as compared with the relative positional relationship of the nanoposts NP arranged in the second pixel corresponding region 132 of the peripheral group PG having the azimuth of 90°.
In the description with reference to
The descriptions with reference to
Referring to
The shifted type of the nanoposts may be considered to be substantially symmetrical with respect to the X-axis and Y-axis. When the first quadrant is between the azimuth of 0° to 90°, the second quadrant is between the azimuth of 90° to 180°, the third quadrant is between the azimuth of 180° to 270°, and the fourth quadrant is between the azimuth of 270° to 360°, the arrangement of the nanoposts in the first quadrant is substantially symmetrical with the arrangement of the nanoposts in the second quadrant with respect to the Y-axis and substantially symmetrical with the arrangement of the nanoposts in the fourth quadrant with respect to the X-axis. Also, the arrangement type of the nanoposts in the second quadrant is substantially symmetrical with the arrangement type of the nanoposts in the first quadrant based on the Y-axis and substantially symmetrical with the arrangement type of the nanoposts in the third quadrant based on the X-axis.
Here, ‘substantially symmetrical’ denotes that the symmetrical degree allows four quadrants may represent the same color separation performance although the arrangements are not completely symmetrical.
In case that the nanoposts in the first quadrant are moved by one pixel pitch in the X direction, the arrangement of the nanoposts in the first quadrant are symmetrical with the arrangement of nanoposts in the second quadrant with respect to that the Y-axis. Also, in case that the nanoposts in the first quadrant are moved by one pixel pitch in the Y direction, the nanoposts in the first quadrant are symmetrical with the nanoposts in the fourth quadrant with respect to the X-axis. Similarly, in case that the nanoposts in the third quadrant are moved by one pixel pitch in the X direction, the nanoposts in the third quadrant are symmetrical with the nanoposts in the fourth quadrant with respect to the Y-axis. Also, in case that the nanoposts in the third quadrant are moved by one pixel pitch in the Y direction, the nanoposts in the third quadrant are symmetrical with the nanoposts in the second quadrant with respect to the X-axis.
The shift of the nanoposts described above with reference to
As briefly mentioned above, in the description with reference to
Among the pixel corresponding groups, the central group CG is aligned with a facing unit pixel group 110G. That is, the first to fourth pixel corresponding regions 131, 132, 133, and 134 of the central group CG may be respectively aligned with the first to fourth pixels 111, 112, 113, and 114 in the unit pixel group 110G.
The peripheral group PG may be shifted from the facing unit pixel group 110G. The shifted direction is a direction toward the center of the color separating lens array 130, and the shifted distance is in proportional to the CRA. The shifted distance s may be represented by following equation.
According to an example embodiment, s=d×tan(CRA′)
Here, d denotes a minimum straight distance between the lower surface of the color separating lens array 130 and the upper surface of the sensor substrate, and CRA′ denotes an incident angle of light incident on the sensor substrate 110.
According to an example embodiment, CRA′ may have following relation with CRA, that is, the incident angle of light that is incident on the color separating lens array 130.
According to an example embodiment, CRA′=sin−1(n×sin CRA)
Here, n denotes an effective refractive index of material layers arranged between the color separating lens array 130 and the sensor substrate 110.
Such shifting of the first to fourth pixel corresponding regions 131, 132, 133, and 134 included in the peripheral group PG is performed considering that the color separation efficiency of the color separating lens array 130 may be shown to be high within a certain angle range as described above. In the peripheral group PG having increased CRA, the first to fourth pixel corresponding regions 131, 132, 133, and 134 are shifted according to the direction of the incident angle of light, and then, the color separation may be effectively performed at the position having the large CRA.
The shift as the relative positional relationship between the adjacent pixel corresponding regions described above with reference to
The first to fourth pixel corresponding regions 131, 132, 133, and 134 included in the peripheral group PG may be entirely shifted by a distance s toward the center C, with respect to the first to fourth pixels 111, 112, 113, and 114 included in the unit pixel group 110G facing the peripheral group PG. That is, the center of the entire arrangement of the nanoposts in the first pixel corresponding region 131 may be misaligned as much as the distance s, not being overlapped with the center of the first pixel 111. The center of the entire arrangement of the nanoposts in each of the second pixel corresponding region 132, the third pixel corresponding region 133, and the fourth pixel corresponding region 134 is also misaligned as much as the distance s with respect to the center of each of the second pixel 112, the third pixel 113, and the fourth pixel 114. Also, at the shifted position, some of the first to fourth pixel corresponding regions 131, 132, 133, and 134 in each peripheral group PG may be shifted with respect to one pixel corresponding region, that is, the relative positional relationship of the first to fourth pixel corresponding regions 131, 132, 133, and 134 may be differently adjusted for each peripheral group PG.
Here, ‘adjusting of the relative positional relationship’ denotes shifting of the nanoposts in some pixel corresponding regions of each peripheral group PG, except for the basic displacement, that is, the shifting of the entire nanoposts by the distance s toward the center C in each peripheral group PG.
The direction of the basic displacement s is a direction toward the center C, and the direction of adjusting the relative positional relationship is a direction away from the center C. The numerical range of the basic displacement may be greater than the numerical range of the relative positional relationship adjustment described above with reference to
For example, from among the peripheral groups PG having the same azimuth, the nanoposts of the second pixel corresponding region 132 in the peripheral group PG having the first CRA may be further shifted toward the center than the nanoposts of the second pixel corresponding region 132 in the peripheral group PG having the second CRA that is less than the first CRA, vice versa, or may be similar to the nanoposts of the second pixel corresponding region 132 in the peripheral group PG having the second CRA. The above relationship may depend upon the basic displacement s and the relative positional relationship adjusting displacement in the corresponding peripheral group PG.
The nanoposts NP may each have a stacked structure in which a first nanopost NP1 and a second nanopost NP2 are stacked. The second nanopost NP2 stacked on the first nanopost NP1 may be shifted toward the center C of the color separating lens array 130. The shifted degree may increase in proportional to the CRA.
The shapes of the nanoposts NP are obtained by stacking the first nanoposts NP1 and the second nanoposts NP2 to be out of line with each other according to the CRA as described above with reference to
The example shapes of the nanoposts NP may be applied along with the relative shift among the pixel corresponding regions 131, 132, 133, and 134 in the peripheral group PG described above with reference to
The first, second, third, and fourth pixels are respectively a green pixel Gb, a blue pixel B, a red pixel R, and a green pixel Gr, and
According to an example embodiment, a numerical value 1 indicated on the longitudinal axis is a reference value, for example, may be a signal value from one channel in the pixel corresponding to the central group. In
The processor ED20 may control one or more elements (hardware, software elements, etc.) of the electronic apparatus ED01 connected to the processor ED20 by executing software (program ED40, etc.), and may perform various data processes or operations. As a part of the data processing or operations, the processor ED20 may load a command and/or data received from another element (sensor module ED76, communication module ED90, etc.) to a volatile memory ED32, may process the command and/or data stored in the volatile memory ED32, and may store result data in a non-volatile memory ED34. The processor ED20 may include a main processor ED21 (central processing unit, application processor, etc.) and an auxiliary processor ED23 (graphic processing unit, image signal processor, sensor hub processor, communication processor, etc.) that may be operated independently from or along with the main processor ED21. The auxiliary processor ED23 may use less power than that of the main processor ED21, and may perform specified functions.
The auxiliary processor ED23, on behalf of the main processor ED21 while the main processor ED21 is in an inactive state (sleep state) or along with the main processor ED21 while the main processor ED21 is in an active state (application executed state), may control functions and/or states related to some (display device ED60, sensor module ED76, communication module ED90, etc.) of the elements in the electronic apparatus ED01. The auxiliary processor ED23 (image signal processor, communication processor, etc.) may be implemented as a part of another element (camera module ED80, communication module ED90, etc.) that is functionally related thereto.
The memory ED30 may store various data required by the elements (processor ED20, sensor module ED76, etc.) of the electronic apparatus ED01. The data may include, for example, input data and/or output data about software (program ED40, etc.) and commands related thereto. The memory ED30 may include the volatile memory ED32 and/or the non-volatile memory ED34.
The program ED40 may be stored as software in the memory ED30, and may include an operation system ED42, middleware ED44, and/or an application ED46.
The input device ED50 may receive commands and/or data to be used in the elements (processor ED20, etc.) of the electronic apparatus ED01, from outside (user, etc.) of the electronic apparatus ED01. The input device ED50 may include a microphone, a mouse, a keyboard, and/or a digital pen (stylus pen).
The sound output device ED55 may output a sound signal to outside of the electronic apparatus ED01. The sound output device ED55 may include a speaker and/or a receiver. The speaker may be used for a general purpose such as multimedia reproduction or record play, and the receiver may be used to receive a call. The receiver may be coupled as a part of the speaker or may be implemented as an independent device.
The display device ED60 may provide visual information to outside of the electronic apparatus ED01. The display device ED60 may include a display, a hologram device, or a projector, and a control circuit for controlling the corresponding device. The display device ED60 may include a touch circuitry set to sense a touch, and/or a sensor circuit (pressure sensor, etc.) that is set to measure a strength of a force generated by the touch.
The audio module ED70 may convert sound into an electrical signal or vice versa. The audio module ED 70 may acquire sound through the input device ED50, or may output sound via the sound output device ED55 and/or a speaker and/or a headphone of another electronic apparatus (electronic apparatus ED02, etc.) connected directly or wirelessly to the electronic apparatus ED01.
The sensor module ED76 may sense an operating state (power, temperature, etc.) of the electronic apparatus ED01, or an outer environmental state (user state, etc.), and may generate an electrical signal and/or data value corresponding to the sensed state. The sensor module ED76 may include a gesture sensor, a gyro-sensor, a pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an infrared (IR) ray sensor, a vivo sensor, a temperature sensor, a humidity sensor, and/or an illuminance sensor.
The interface ED77 may support one or more designated protocols that may be used in order for the electronic apparatus ED01 to be directly or wirelessly connected to another electronic apparatus (electronic apparatus ED02, etc.) The interface ED77 may include a high-definition multimedia interface (HDMI), a universal serial bus (USB) interface, an SD card interface, and/or an audio interface.
The connection terminal ED78 may include a connector by which the electronic apparatus ED01 may be physically connected to another electronic apparatus (electronic apparatus ED02, etc.). The connection terminal ED78 may include an HDMI connector, a USB connector, an SD card connector, and/or an audio connector (headphone connector, etc.).
The haptic module ED79 may convert the electrical signal into a mechanical stimulation (vibration, motion, etc.) or an electric stimulation that the user may sense through a tactile or motion sensation. The haptic module ED79 may include a motor, a piezoelectric device, and/or an electric stimulus device.
The camera module ED80 may capture a still image and a video. The camera module ED80 may include a lens assembly including one or more lenses, the image sensor 1000 described above, image signal processors, and/or flashes. The lens assembly included in the camera module ED80 may collect light emitted from an object that is an object to be captured.
The power management module ED88 may manage the power supplied to the electronic apparatus ED01. The power management module ED88 may be implemented as a part of a power management integrated circuit (PMIC).
The battery ED89 may supply electric power to components of the electronic apparatus ED01. The battery ED89 may include a primary battery that is not rechargeable, a secondary battery that is rechargeable, and/or a fuel cell.
The communication module ED90 may support the establishment of a direct (wired) communication channel and/or a wireless communication channel between the electronic apparatus ED01 and another electronic apparatus (electronic apparatus ED02, electronic apparatus ED04, server ED08, etc.), and execution of communication through the established communication channel. The communication module ED90 may be operated independently from the processor ED20 (application processor, etc.), and may include one or more communication processors that support the direct communication and/or the wireless communication. The communication module ED90 may include a wireless communication module ED92 (cellular communication module, a short-range wireless communication module, a global navigation satellite system (GNSS) communication module) and/or a wired communication module ED94 (local area network (LAN) communication module, a power line communication module, etc.). From among the communication modules, a corresponding communication module may communicate with another electronic apparatus via a first network ED09 (short-range communication network such as Bluetooth, WiFi direct, or infrared data association (IrDA)) or a second network ED99 (long-range communication network such as a cellular network, Internet, or computer network (LAN, WAN, etc.)). Such above various kinds of communication modules may be integrated as one element (single chip, etc.) or may be implemented as a plurality of elements (a plurality of chips) separately from one another. The wireless communication module ED92 may identify and authenticate the electronic apparatus ED01 in a communication network such as the first network ED98 and/or the second network ED99 by using subscriber information (international mobile subscriber identifier (IMSI), etc.) stored in the subscriber identification module ED96.
The antenna module ED97 may transmit or receive the signal and/or power to/from outside (another electronic apparatus, etc.). An antenna may include a radiator formed as a conductive pattern formed on a substrate (PCB, etc.). The antenna module ED97 may include one or more antennas. When the antenna module ED97 includes a plurality of antennas, from among the plurality of antennas, an antenna that is suitable for the communication type used in the communication network such as the first network ED98 and/or the second network ED99 may be selected by the communication module ED90. The signal and/or the power may be transmitted between the communication module ED90 and another electronic apparatus via the selected antenna. Another component (RFIC, etc.) other than the antenna may be included as a part of the antenna module ED97.
Some of the elements may be connected to one another via the communication method among the peripheral devices (bus, general purpose input and output (GPIO), serial peripheral interface (SPI), mobile industry processor interface (MIPI), etc.) and may exchange signals (commands, data, etc.).
The command or data may be transmitted or received between the electronic apparatus ED01 and the external electronic apparatus ED04 via the server ED08 connected to the second network ED99. Other electronic apparatuses ED02 and ED04 may be the devices that are the same as or different kinds from the electronic apparatus ED01. All or some of the operations executed in the electronic apparatus ED01 may be executed in one or more devices among the other electronic apparatuses ED02, ED04, and ED08. For example, when the electronic apparatus ED01 has to perform a certain function or service, the electronic apparatus ED01 may request one or more other electronic apparatuses to perform some or entire function or service, instead of executing the function or service by itself. One or more electronic apparatuses receiving the request execute an additional function or service related to the request and may transfer a result of the execution to the electronic apparatus ED01. To do this, for example, a cloud computing, a distributed computing, or a client-server computing technique may be used.
The lens assembly 1170 may collect light emitted from an object that is to be captured. The lens assembly 1170 may include one or more optical lenses. The lens assembly 1170 may include a path switching member which switches the optical path toward the image sensor 1000. According to whether the path switching member is provided and the arrangement type with the optical lens, the camera module ED80 may have a vertical type or a folded type. The camera module ED80 may include a plurality of lens assemblies 1170, and in this case, the camera module ED80 may include a dual camera module, a 360-degree camera, or a spherical camera. Some of the plurality of lens assemblies 1170 may have the same lens properties (viewing angle, focal distance, auto-focus, F number, optical zoom, etc.) or different lens properties. The lens assembly 1170 may include a wide-angle lens or a telephoto lens.
The actuator 1180 may drive the lens assembly 1170. At least some of the optical lens and the path switching member included in the lens assembly 1170 may be moved by the actuator 1180. The optical lens may be moved along the optical axis, and when the distance between adjacent lenses is adjusted by moving at least some of the optical lenses included in the lens assembly 1170, an optical zoom ratio may be adjusted.
The actuator 1180 may adjust the position of any one of the optical lenses in the lens assembly 1170 so that the image sensor 1000 may be located at the focal length of the lens assembly 1170. The actuator 1180 may drive the lens assembly 1170 according to an AF driving signal transferred from the AF controller 1130.
The flash 1120 may emit light that is used to strengthen the light emitted or reflected from the object. The flash 1120 may emit visible light or infrared-ray light. The flash 1120 may include one or more light-emitting diodes (red-green-blue (RGB) LED, white LED, infrared LED, ultraviolet LED, etc.), and/or a Xenon lamp. The image sensor 1000 may be the image sensor 1000 described above with reference to
The image sensor 1000 includes the color separating lens array 130 described above, and each pixel may include a plurality of photosensitive cells forming a plurality of channels, for example, the plurality of photosensitive cells arranged in a 2×2 array. Some of the pixels may be used as AF pixels, and the image sensor 1000 may generate an AF driving signal from the signals from the plurality of channels in the AF pixels. From among the nanoposts in the color separating lens array included in the image sensor 1000, the arrangement type of the nanoposts of the periphery portion is adjusted so that the channel difference may be reduced, and thus, an accuracy of the AF driving may be improved.
The image stabilizer 1140, in response to a motion of the camera module ED80 or the electronic apparatus ED01 including the camera module ED80, moves one or more lenses included in the lens assembly 1170 or the image sensor 1000 in a certain direction or controls the operating characteristics of the image sensor 1000 (adjusting of a read-out timing, etc.) in order to compensate for a negative influence of the motion. The image stabilizer 1140 may sense the movement of the camera module ED80 or the electronic apparatus ED01 by using a gyro sensor or an acceleration sensor arranged in or out of the camera module ED80. The image stabilizer 1140 may be implemented as an optical type.
The AF controller 1130 may generate the AF driving signal from signal values sensed from the AF pixels in the image sensor 1000. The AF controller 1130 may control the actuator 1180 according to the AF driving signal.
The memory 1150 may store some or entire data of the image obtained through the image sensor 1000 for next image processing operation. For example, when a plurality of images are obtained at a high speed, obtained original data (Bayer-patterned data, high resolution data, etc.) is stored in the memory 1150, and a low resolution image is only displayed. Then, original data of a selected image (user selection, etc.) may be transferred to the image signal processor 1160. The memory 1150 may be integrated with the memory ED30 of the electronic apparatus ED01, or may include an additional memory that is operated independently.
The ISP 1160 may perform image treatment on the image obtained through the image sensor 1000 or the image data stored in the memory 1150. The image treatments may include a depth map generation, a three-dimensional modeling, a panorama generation, extraction of features, an image combination, and/or an image compensation (noise reduction, resolution adjustment, brightness adjustment, blurring, sharpening, softening, etc.). The image signal processor 1160 may perform controlling (exposure time control, read-out timing control, etc.) of the elements (image sensor 1000, etc.) included in the camera module ED80. The image processed by the image signal processor 1160 may be stored again in the memory 1150 for additional process, or may be provided to an external element of the camera module ED80 (e.g., the memory ED30, the display device ED60, the electronic apparatus ED02, the electronic apparatus ED04, the server ED08, etc.). The image signal processor 1160 may be integrated with the processor ED20, or may be configured as an additional processor that is independently operated from the processor ED20. When the image signal processor 1160 is configured as an additional processor separately from the processor ED20, the image processed by the image signal processor 1160 undergoes through an additional image treatment by the processor ED20 and then may be displayed on the display device ED60.
The AF controller 1130 may be integrated with the image signal processor 1160. The image signal processor 1160 may generate the AF signal by processing signals from the AF pixels of the image sensor 1000, and the AF controller 1130 may convert the AF signal into a driving signal of the actuator 1180 and transfer the signal to the actuator 1180.
The electronic apparatus ED01 may further include one or a plurality of camera modules having different properties or functions. The camera module may include elements similar to those of the camera module ED80 of
The image sensors according to the example embodiments may be applied to various electronic apparatuses.
The image sensor 1000 according to the example embodiments may be applied to a mobile phone or a smartphone, a tablet or a smart tablet, a digital camera or a camcorder, a laptop computer, or a television or a smart television. For example, the smartphone or the smart tablet may include a plurality of high-resolution cameras each including a high-resolution image sensor. Depth information of objects in an image may be extracted, out focusing of the image may be adjusted, or objects in the image may be automatically identified by using the high-resolution cameras.
Also, the image sensor 1000 may be applied to a smart refrigerator, a surveillance camera, a robot, a medical camera, etc. For example, the smart refrigerator may automatically recognize food in the refrigerator by using the image sensor, and may notify the user of an existence of a certain kind of food, kinds of food put into or taken out, etc. through a smartphone. Also, the surveillance camera may provide an ultra-high-resolution image and may allow the user to recognize an object or a person in the image even in dark environment by using high sensitivity. The robot may be input to a disaster or industrial site that a person may not directly access, to provide the user with high-resolution images. The medical camera may provide high-resolution images for diagnosis or surgery, and may dynamically adjust a field of view.
Also, the image sensor 1000 may be applied to a vehicle. The vehicle may include a plurality of vehicle cameras arranged on various locations, and each of the vehicle cameras may include the image sensor according to the example embodiment. The vehicle may provide a driver with various information about inside the vehicle or around the vehicle by using the plurality of vehicle cameras, and may automatically recognize an object or a person in the image to provide information required to the autonomous travel.
Because the color separating lens array included in the image sensor described above may separate the incident light by wavelengths and condense the separated light without absorbing or blocking the incident light, the light utilization efficiency of an image sensor may be improved.
Also, the nanoposts of the color separating lens array are designed considering the light that is incident on the periphery portion of the image sensor at an angle, and thus, the performance degradation according to the incident angle may be reduced and the quality of images obtained by the image sensor may be improved. For example, the nanoposts of the color separating lens array are configured to take in to account light that is incident on the periphery portion of the image sensor in a slant manner.
While the image sensor and the electronic apparatus including the image sensor have been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims. The example embodiments should be considered in descriptive sense only and not for purposes of limitation. Therefore, the scope of the disclosure is defined not by the detailed description of the disclosure but by the appended claims, and all differences within the scope will be construed as being included in the disclosure.
It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0111689 | Sep 2022 | KR | national |
