Patent Application
20210239881
This application claims the benefit of and priority to Korean Application No. 10-2020-0012725, filed Feb. 3, 2020, the disclosure of which is incorporated herein in its entirety by reference.
The present invention relates to a lens assembly construct comprising a plurality of lenses stacked along an optical axis and a barrel accommodating the same, and to a smart device having the lens assembly construct.
With the recent increase in the demand for a maximized area of a display of smart devices, a so-called hole-in-active-area (HIAA) structure has been adopted in which a hole is made in an active area of a display and a camera lens is placed under it. In this case, in order to minimize display loss of the smart device due to the lens module, it is necessary to minimize the size of the hole corresponding to the front camera lens.
In a conventional HIAA structure of a smart device, a lens module is disposed under a hole of a display where, as shown in
The object of the present invention is to minimize the loss of the display area due to a lens of a camera in a HIAA-structured smart device in which a hole is made in an active area of the display and a camera lens is installed under it.
The problem to be solved by the present invention is not limited thereto, and may be variously extended without departing from the spirit and scope of the present invention.
In order to solve the problem, a lens assembly construct used for a smart device according to an embodiment of the present invention comprises a plurality of lenses stacked along an optical axis and a barrel accommodating the plurality of lenses, wherein the plurality of lenses comprise a first lens positioned closest to a subject side, and the head of the barrel is positioned below the center of the front surface of the first lens, wherein the first lens comprises an effective aperture portion and a flange portion, and a coating layer in which one or more dielectric layers are laminated is formed on the effective aperture portion, and wherein a colored area is formed in the surface of the first lens, on at least a part of the flange portion of the first lens except the effective aperture portion on which the coating layer of the first lens is formed, by heating the first lens higher than a first temperature, making a dye permeate through the pores of the surface, and then lowering the temperature below the first temperature to make the dye permeate into the surface of the first lens for coloring.
In an example, the plurality of lenses may comprise a second lens positioned below and adjacent to the first lens, and a stop of the lens assembly construct may be positioned above the front surface of the second lens.
In an example, the head of the barrel may be at least 0.3 mm below the center of the front surface of the first lens.
In an example, the entire flange portion except the effective aperture portion on which the coating layer of the first lens is formed may be permeated with the dye for coloring.
In an example, the coating layer may be an anti-reflective coating layer.
In an example, the linear coefficient of thermal expansion of the dielectric layer may be lower than the linear coefficient of thermal expansion of the first lens. In addition, the linear coefficient of thermal expansion of the first lens may be 5×10−5/° C. or higher, and the linear coefficient of thermal expansion of the dielectric layer may be 1×10−5/° C. or lower.
In an example, the transmittance of light in the wavelength range of the visible light region of the portion of the first lens on which the colored area is formed may be 40% or lower, and the transmittance of light in the wavelength range of the visible light region of the portion of the first lens on which the colored area is not formed may be 90% or higher.
In an example, the front surface of the first lens may have a convex shape protruding toward the subject side, and the first lens may be made of plastic.
In an example, the plurality of lenses may include three or more single lenses.
In an example, the color of the dye may be black.
A lens assembly construct used for a smart device according to another embodiment of the present invention comprises a plurality of lenses stacked along an optical axis and a barrel accommodating the plurality of lenses, wherein the plurality of lenses comprise a first lens positioned closest to a subject side, and the head of the barrel is positioned below the center of the front surface of the first lens, wherein the first lens comprises an effective aperture portion and a flange portion, and the flange portion comprises an inclined portion, and wherein a colored layer is formed by printing on at least a part of the front surface of the inclined portion by spraying a paint.
In an example, a stop of the lens assembly construct may be positioned above the rear surface of the first lens.
In an example, the head of the barrel may be at least 0.3 mm below the center of the front surface of the first lens.
In an example, the colored layer may be formed by printing on at least a part of the front surface and at least a part of the rear surface of the inclined portion with a paint.
In an example, the colored layer may be formed by printing on an end portion of the effective aperture portion of the first lens with a paint.
In an example, the front surface of the first lens may have a convex shape protruding toward the subject side, and the first lens may be made of plastic.
In an example, the plurality of lenses may include three or more single lenses.
In an example, the color of the paint may be black.
A smart device according to an embodiment of the present invention comprises a display having a hole in an active area and a lens assembly construct, wherein the lens assembly construct is disposed under the hole.
According to the present invention, by forming a colored area in the area of a front portion exposed out of the barrel except for an effective aperture portion in a first lens of the lens assembly construct positioned closest to a subject side, a structure is achieved that allows blocking entry of unnecessary light thanks to the colored area to a certain area of the front portion of the first lens without a barrel. That is, the lens assembly construct according to the present invention can exhibit an effect of reduction in the external diameter, which corresponds to the breadth of the barrel, compared with a conventional lens module with the HIAA structure, thereby achieving minimizing a display loss.
Hereinafter, examples of the present invention are described in detail with reference to the attached drawings so that a person having ordinary skill in the technical field to which the present invention pertains can easily carry out the invention. The attached drawings and the following descriptions relate to preferred forms among various forms for the purpose of illustrating the characteristics of the present invention. The present invention can be implemented in various different forms and is not limited to the examples described herein.
In the present invention, a smart device may be, for example, a smartphone or a tablet PC, but is not limited thereto, and may include a portable device that includes a display and can function as a camera.
A lens assembly construct according to the present invention may be disposed under a hole made in a display active area of a smart device, but is not limited thereto and can be applied in any form that can be used in a smart device. Among the plurality of lenses constituting the lens assembly construct of the present invention, the lens positioned closest to a subject side may have a colored portion formed in at least a part of an area of a front portion exposed out of the barrel except for an effective aperture portion. The colored portion may be formed as a colored area by color permeation with a dye to be described below, or may be formed as a colored layer by color printing with a paint to be described below.
Referring to
Each of the plurality of lenses may comprise plastic. More specifically, the lens may consist of one of PC (polycarbonate), COC (cyclo olefin copolymer) and COP (cyclo olefin polymer) or comprise at least one of them. The types of the plastic material constituting the lenses are not limited thereto, and different known plastic materials may be used.
Meanwhile, a lens assembly construct according to an example of the present invention may comprise a barrel having an inner space for accommodating the plurality of lenses, with open upper and lower portions. The head of the barrel may be a front portion of an outer circumference of the barrel that faces the subject side and may be positioned below the center of the front surface of the first lens 110. For example, the head of the barrel may be at least 0.3 mm below the center of the front surface of the first lens. In an example, a stop of the lens assembly construct may be positioned above the front surface of the second lens 120. In another example, a stop of the lens assembly construct may be positioned above the rear surface of the first lens.
In contrast, in the conventional lens module shown in
By comparison, in the lens assembly construct of the present invention, assuming that the diameter of the effective aperture portion 111 is about 1.2 mm, and that the diameter of the exposed portion 113 in the front surface of the inclined portion of the first lens that is exposed out of the barrel is about 0.1 mm, the outer diameter of the barrel head is about 1.4 mm, which requires making a hole with a diameter of about 1.4 mm or greater in the display. This achieves an effect of reduction in the external diameter by about 0.6 mm compared with a convention lens module with the HIAA structure, thereby achieving minimizing display loss.
A colored portion is formed in at least a part of the area except the effective aperture portion of the first lens. In an embodiment of forming a colored portion, it is possible to form a colored portion by permeating a dye into at least a part of the flange portion of the lens for coloring. In another embodiment of forming a colored portion, it is possible to form a colored layer by printing in color at least a part of the front surface of the lens with a paint.
First, in one embodiment, a method of forming a colored area by having at least a part of the flange portion of the lens permeated with a dye for coloring is described. A coating layer in which one or more dielectric layers are laminated may be formed on the effective aperture portion of the lens. Then, the lens may be heated higher than a first temperature, a dye may be made to permeate through the pores of the surface, and then the temperature may be lowered below the first temperature to make the dye permeate into the interior of the surface of the lens for coloring on at least a part of the flange portion of the lens except the effective aperture portion on which the coating layer is formed. Or, in another embodiment, the lens may be permeated with a dye at the same time as the heating of the lens. Here, the first temperature may be room temperature, which may be a temperature between 20° C. and 30° C. Or, the first temperature may be a temperature between 0° C. and 60° C. However, the range of the first temperature is not limited to the above-mentioned examples and may include other temperature ranges. Then, the lens may be dried and cleaned. By the processes, the coating layer acts as a mask on the dye, and thus, the dye permeates only the portion of the lens on which the coating layer is not formed, which allows easy formation of the colored layer in the surface of the lens except the effective aperture portion.
It is also possible to have the entire flange portion except the effective aperture portion on which the coating layer is formed permeated with a dye for coloring. Through this, light that enters via an unintended optical path can be effectively absorbed to prevent occurrence of internal reflection more effectively.
A coating layer formed by laminating at least one dielectric layer on the effective aperture portion of the lens may be an anti-reflective coating layer. When the anti-reflective coating layer is formed on the effective aperture portion, it restricts the reflection of light that enters or comes out the effective aperture portion. This restricts introduction of light via unwanted paths, to more effectively prevent occurrence of internal reflection.
The coating layer formed on the effective aperture portion of the lens may be formed by laminating at least one dielectric layer by vacuum deposition where deposition material is vaporized or sublimated in vacuum by a heating device to be deposited on an object. The dielectric layer may comprise, for example, at least one of SiO2, Al2O2 and TiO2, but is not limited thereto, and it may comprise other known components of a dielectric layer.
After the processes of forming the coating layer on the effective aperture portion of the lens and color-permeating the dye, a dielectric layer may be additionally laminated on the surface of the lens. Accordingly, an additional process to improve the performance of the lens can be carried out even after the formation of the colored area.
With reference to
However, if the material 401 has a low linear coefficient of thermal expansion, the dye 402 may not permeate the material, because the pores do not open sufficiently. For this reason, even when the dye 402 is applied after materials having different linear coefficients of thermal expansion have been heated at the same temperature, the dye 402 may permeate and color only the surface of the material having a high linear coefficient of thermal expansion, thereby forming a colored layer inside the surface, but the dye 402 may not permeate the surface of the material having a low linear coefficient of thermal expansion, failing to form a colored layer.
Accordingly, the linear coefficient of thermal expansion of the dielectric layer may preferably be lower than the linear coefficient of thermal expansion of the lens. In particular, the linear coefficient of thermal expansion of the dielectric layer may be lower than the linear coefficient of thermal expansion of the portion of the lens on which a colored area is formed. Accordingly, even when the dye is applied after the coating layer consisting of at least one dielectric layer is heated together with the lens, only the portion of the lens on which a colored area is to be formed is colored with the dye, without coloring the coating layer, to prevent interference with the light passing through the effective aperture portion. More preferably, the linear coefficient of thermal expansion of the lens may be 5×10−5/° C. or higher to 5×10−4/° C. or lower, and the linear coefficient of thermal expansion of the dielectric layer may be 1×10−7° C. or higher to 1×10−5/° C. or lower.
A colored area may also be formed by immersing the lens in a dye. In this case, it makes it easy for the dye to permeate the entire flange portion except for the effective aperture portion, where the coating layer acts as a mask to prevent the permeation of the dye. In an example, immersing the lens in a dye may be performed for the period of 10 minutes or more to 60 minutes or less. By immersing the lens in the dye for the period of 10 minutes or more, it is possible to easily form the colored area inside and, by immersing the lens in the dye for the period of 60 minutes or less, it is possible to prevent the dye from being laminated to form an unnecessary layer on the surface of the lens.
The temperature of the dye may be 60° C. or higher to 90° C. or lower. When the temperature of the dye is in that range, it is possible to heat the lens to a temperature higher than the first temperature, which is room temperature for example, without a separate device or process.
The dye used for color permeation may have a color that absorbs light in the wavelength range of the visible light region. For example, it may be blue, red, yellow, orange, or violet. Here, the wavelength range of the visible light region may be a range of 400 nm or higher to 700 nm or lower. In an example, the color of the dye 202 may be black. In addition, the dye may be a disperse dye and may be obtained by mixing dyes of various colors. For example, a disperse dye may be obtained by mixing the following five categories of dyes.
(1) Blue dyes:
Dianix Blue AC-E, Dianix Blue RNE (C.I. Disperse Blue 91), Dianix Blue GRE (C.I. Disperse Blue 81), Sumikaron Blue E-R (C.I. Disperse Blue 91), and Kayaron Polyester Blue GR-E (C.I. Disperse Blue 81)
(2) Red dyes:
Dianix Red AC-E, Diaceliton Fast Red R (C.I. Disperse Red 17), Diaceliton Fast Scarlet R (C.I. Disperse Red 7), Diaceliton Fast Pink R (C.I. Disperse Red 4), Sumikaron Rubin SE-RPD, and Kayaron Polyester Rubin GL-SE200 (C.I. Disperse Red 73)
(3) Yellow dyes:
Dianix Yellow AC-E, Dianix Yellow YL-SE (C.I. Disperse Yellow 42), Sumikaron Yellow SE-RPD, Diaceliton Fast Yellow GL (C.I. Disperse Yellow 33), Kayaron Fast Yellow GL (C.I. DisPerth Yellow 33), and Kayaron Microester Yellow AQ-LE
(4) Orange dyes:
Dianix Orange B-SE200 (C.I. Disperse Orange 13), Diaceliton Fast Orange GL (C.I. Disperse Orange 3), Miketon Polyester Orange B (C.I. Disperse Orange 13), Sumikaron Orange SE-RPD, and Sumikaron Orange SE-B (C.I. Disperse Orange 13)
(5) Violet dyes:
Dianix Violet 5R-SE (C.I. Disperse Violet 56) and Sumikaron Violet E-2RL (C.I.
Disperse Violet 28).
The transmittance of light in the wavelength range of the visible light region of the portion of the lens on which the colored area is formed may be 40% or lower, and the transmittance of light in the wavelength range of the visible light region of the portion of the lens on which the colored area is not formed may be 90% or higher. Here, the method for measuring the transmittance of light in the wavelength range of the visible light region may be by measuring the ratio of the intensity of the incident light after the light in the wavelength range of the visible light region has been projected to the intensity of the projected light over the entire wavelength range of the visible light region. If the transmittance of the light in the entire wavelength range of the visible light region is at a particular level or higher, it can be said that the transmittance of the light in the wavelength range of the visible light region is equal to or higher than the particular level. If the transmittance of the light in the entire wavelength range of the visible light region is at a particular level or lower, it can be said that the transmittance of the light in the wavelength range of the visible light region is equal to or lower than the particular level.
When a colored area is formed on the lens by permeating a dye, only one processing is required even when both surfaces of the lens are processed, which is advantageous in terms of both cost and time. In addition, because a colored layer can be formed regardless of the shape of the lens, the colored area can be formed easily even when the lens comprises a gate cutting portion or has an unusual shape with a side surface portion, such as the shape of a D-cut lens. Further, because a dye permeates into the lens for coloring, it does not affect the thickness of the lens; thus, it does not interfere with precise assembling of a lens assembly construct even when the colored layer is formed.
According to another embodiment, with reference to
The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as ‘comprise’ or ‘have’ are intended to mean that the stated characteristics, numbers, steps, operations, constituents, parts or a combination thereof are present, and should not be understood to preclude the possibility of addition or presence of one or more of other characteristics, numbers, steps, operations, constituents, parts or a combination thereof.
Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as those commonly understood by a person having ordinary skill in the art to which the present invention belongs. A term defined in a commonly used dictionary should be interpreted as having a meaning consistent with a meaning in the context of the related technology, and should not be interpreted to have an ideal or excessively formal meaning unless explicitly defined in this application.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2020-0012725 | Feb 2020 | KR | national |
