1. Field
Apparatuses and methods consistent with the exemplary embodiments relate to a display panel and a display apparatus including the same, and more particularly, to a display panel including a color filter polarizing layer and a polarizing layer and a display apparatus including the same.
2. Description of the Related Art
A liquid crystal display (LCD) panel includes first and second substrates having a liquid crystal layer formed therebetween, and a polarizing film for polarizing light incident on the first and second substrates. Also, the LCD panel includes a color filter layer in order to represent color with light. As the incident light passes through the polarizing film and the color filter layer, the optical efficiency of the light becomes lowered. Meanwhile, the LCD panel may further include a dual brightness enhance film (DBEF) at a light-incident side so as to compensate for light loss due to polarization.
The polarizing film and the DBEF increase manufacturing costs of the LCD panel or the display apparatus and make a manufacturing process complicated.
One or more exemplary embodiments provide a display panel and a display apparatus including the same, in which manufacturing costs are decreased and a manufacturing process is simplified.
According to another aspect of an exemplary embodiment, there is provided a display panel having improved optical efficiency and a display apparatus including the same.
The foregoing and/or other aspects may be achieved by providing a display panel with a liquid crystal layer, including first and second substrates which are disposed opposite to each other; a color filter polarizing layer which is formed on a surface of one of the first and second substrates between the first and second substrates, and includes a metal linear grid arranged at different pitches to emit a first polarized component of incident light with different colors; and a polarizing layer formed on an opposite surface to the surface of one of the first and second substrates.
The polarizing layer may further include a polarizing film transmitting a second polarized component different from the first polarized component.
The display panel may further include a pixel layer formed on the surface of one of the first and second substrates and including a pixel including a plurality of sub pixels, and at least three sub pixels each corresponding to the different arranged pitches of the metal linear grid.
The metal linear grid may include a red metal linear grid, a green metal linear grid and a blue metal linear grid, and every pitch of the red metal linear grid may be formed so that every pitch is shorter than ½ of a red light wavelength, the green metal linear grid is formed so that every pitch is shorter than ½ of a green light wavelength, and the blue metal linear grid is formed so that every pitch is shorter than ½ of a blue light wavelength.
The metal linear grid may include a first metal layer, an insulating layer, and a second metal layer stacked in sequence.
A height of the metal linear grid may be larger than a width thereof.
The color filter polarizing layer may further include a dielectric layer stacked beneath the metal linear grid.
According to another aspect of an exemplary embodiment, there is provided a display apparatus including a display apparatus having a liquid crystal layer, including a display panel which includes first and second substrates which are disposed opposite to each other, a color filter polarizing layer which is formed on a surface of one of the first and second substrates between the first and second substrates, and includes a metal linear grid arranged with different pitches to emit a first polarized component of incident light with different colors, and a polarizing layer formed on a surface opposite to the surface of one of the first and second substrates; and a backlight assembly which emits light to the display panel.
The above and/or other aspects will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings, in which:
Below, exemplary embodiments will be described in detail with reference to accompanying drawings so as to be easily realized by a person having ordinary knowledge in the art. The exemplary embodiments may be embodied in various forms without being limited to the exemplary embodiments set forth herein. Descriptions of well-known parts are omitted for clarity, and like reference numerals refer to like elements throughout.
As shown therein, a display panel 1000 in this exemplary embodiment includes first and second substrates 100 and 200 opposite to each other, and a color filter polarizing layer 300, a pixel layer 400 and a liquid crystal layer 500 arranged in sequence between the first and second substrates 100 and 200, and a polarizing film 600 arranged on an outside surface of the second substrate 200. The display panel 1000 including the liquid crystal layer 500 may be used in a television, home appliances such as a monitor, a cellular phone, a portable multimedia player (PMP), a Netbook, a notebook computer, a mobile terminal such as an E-book terminal or the like, a display apparatus for exhibition and advertisement, etc.
The color filter polarizing layer 300 and the pixel layer 400 are formed in sequence on the first substrate 100, and a polarizing film 600 is formed on the second substrate 200. As shown in
The color filter polarizing layer 300 is formed on the first substrate 100, and the pixel layer 400 for controlling the liquid crystal array and displaying an image is formed on the color filter polarizing layer 300. The color filter polarizing layer 300 includes the metal linear grid 310 arranged with different pitches so that first polarized component of the incident light can be emitted as light of different color. The polarizing film 600 transmits light of a second polarized component different from the first polarized component. On the metal linear grid 310, a planarization layer 100-1 is formed for protecting and leveling the metal linear grid 310. The metal linear grid 310 included in the color filter polarizing layer 300 will be described below in detail.
The pixel layer 400 formed on the planarization layer 100-1 includes a plurality of pixels (not shown) for changing the liquid crystal array filled in the liquid crystal layer 500 on the basis of a control signal received from the exterior, and each pixel includes a plurality of sub pixels 410. In this exemplary embodiment, the sub pixels 410 represent the smallest unit pixels in which video signal values corresponding to red, green and blue are input, and a unit, which includes a plurality of sub pixels 410 and expresses one video signal, is regarded as the pixel. The sub pixel 410 includes a thin film transistor (TFT) 411 as a switching device, and a pixel electrode 412. The sub pixel 410 has a two-dimensional spatial concept as well as a physical concept including the TFT 411 and the pixel electrode 412.
On the planarization layer 100-1 of the first substrate 100, the gate electrode 411-1 is formed. The gate electrode 411-1 may be a single or multiple layers containing metal. On the same layer as the gate electrode 411-1, there are further formed a gate line (not shown) connected to the gate electrode 411-1 and arranged in a transverse direction of the display panel 1000, and a gate pad (not shown) connected to a gate driver (not shown) and transmitting a driving signal to the gate line. Also, on the same layer as the gate electrode 411-1, a sustain electrode 413 is formed for building electric charges up.
On the first substrate 100, a gate insulating layer 411-2 containing silicon nitride (SiNx) or the like covers the gate electrode 411-1 and the sustain electrode 413.
On the gate insulating layer 411-2 of the gate electrode 411-1, a semiconductor layer 411-3 containing amorphous silicon or the like semiconductor is formed. On the semiconductor layer 411-3, an ohmic contact layer 411-4 containing n+ hydrogenated amorphous silicon or the like material highly doped with silicide or n-type impurities is formed. Further, the ohmic contact layer 411-4 is removed in a channel portion between a source electrode 411-5 and a drain electrode 411-6 to be described later.
On the ohmic contact layer 411-4 and the gate insulating layer 411-2, data wiring lines 411-5 and 411-6 are formed. The data wiring lines 411-5 and 411-6 may also be a single or multiple layer containing metal. The data wiring lines 411-5 and 411-6 includes a data line (not shown) formed in a vertical direction and intersecting a gate line (not shown) to form the sub pixel 410, a source electrode 411-5 branched from the data line and extended to an upper portion of the ohmic contact layer 411-4, and a drain electrode 411-6 separated from the source electrode 411-5 and formed on an upper portion of the ohmic contact layer 411-4 opposite to the source electrode 411-5.
On the data wiring lines 411-5 and 411-6 and the semiconductor layer 411-3 that is not covered with the data wiring lines 411-5 and 411-6, a passivation layer 411-7 is formed. At this time, silicon nitride or the like inorganic insulting film may be further formed between the passivation layer 411-7 and the TFT 411, thereby securing the reliability of the TFT 411.
Typically, the pixel electrode 412 formed on the passivation layer 411-7 contains indium tin oxide (ITO) or indium zinc oxide (IZO), or the like transparent conductive material. The pixel electrode 412 is electrically connected to the source electrode 411-5.
On the planarization layer 100-1 of the second substrate 200, the black matrix 200-1 is formed in a region corresponding to the TFT 411 of the first substrate 100. Generally, the black matrix 200-1 serves to divide the sub pixels 410 and prevent the TFT 411 from being exposed to external light. The black matrix 200-1 contains a photosensitive organic material with black dye. As the black dye, carbon black, titanium oxide or the like is used.
On the black matrix 200-1, an overcoat layer 200-2 is formed for leveling and protecting the black matrix 200-1. As the overcoat layer 200-2, an acrylic epoxy material is typically used.
On the overcoat layer 200-2, a common electrode 200-3 is formed. The common electrode 200-3 is made of a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), etc. The common electrode 200-3, together with the pixel electrode 412 of the first substrate 100, directly apply a voltage to the liquid crystal layer 500.
As shown therein, the metal linear grid 310 is shaped like a bar arranged in certain direction on the first substrate 100. The metal linear grid 310 is periodically arranged with a certain height (H) and width (W). The cycle, i.e., the pitch of the metal linear grid 310 is controlled differently according to desired colors of light.
If a pitch of a diffraction grid is adjusted to be equal to or shorter than ½ of the wavelength of the light, a diffraction wave is not formed but only transmitted light and reflected light exist. As shown therein, when the incident light passes through the metal linear grid 310 shaped like a slit, the first polarized component of the incident light, which is perpendicular to the metal linear grid 310, is transmitted through the first substrate 100, but a second polarized component, which is perpendicular to the metal linear grid 310, becomes reflected light which is reflected once again. That is, the incident light passing through the color filter polarizing layer 300 is polarized with respect to a certain direction. Meanwhile, air may be formed in between the metal linear grids 310.
The red metal linear grid 310-R is arranged such that every pitch is shorter than ½ of a red light wavelength, the green metal linear grid 310-G is arranged such that every pitch is shorter than ½ of a green light wavelength, and the blue metal linear grid 310-B is arranged such that every pitch is shorter than ½ of a blue light wavelength. Thus, each pitch of the metal linear grids 310-R, 310-G and 310-B is adjusted in accordance with the sub pixels 410-R, 410-G and 410-B, so that the wavelength of the incident light can be controlled to thereby allow the sub pixels 410 to emit light of different colors, respectively.
The pitch of the red metal linear grid 310-R is shorter than ½ of the red light wavelength, i.e., about 330˜390 nm, and the incident light is separated into a red light spectrum having a first polarized component while passing through the red metal linear grid 310-R. The pitch of the green metal linear grid 310-G is shorter than ½ of the green light wavelength, i.e., about 250˜290 nm, and the incident light is separated into a green light spectrum having the first polarized component. The pitch of the blue metal linear grid 310-B may be set up to be shorter than ½ of the blue light wavelength, i.e., about 220˜240 nm. The light passing through the blue metal linear grid 310-B is separated into a blue light spectrum having the first polarized component. In other words, the pitches of the metal linear grid 310 are decreased in order of the red metal linear grid 310-R, the green metal linear grid 310-G and the blue metal linear grid 310-B. The pitch of the metal linear grid 310 may be adjusted in accordance with light wavelengths of color desired to be emitted from the display panel 1000, and light of yellow, cyan and magenta may be emitted instead of the foregoing light of red, green and blue.
As shown in
The principle that colored light is emitted from the metal layer 311, 315 of the metal linear grid 310 is based on Plasmon that free electrons in metal are collectively oscillated. Nano-sized metal shows Plasmon resonance on a surface of the metal due to the oscillation of the free electrons. The surface Plasmon resonance is collective charge density oscillation of the electrons on the surface of a metal thin film, and a surface Plasmon wave caused by the surface Plasmon resonance is a surface electromagnetic wave propagating along a boundary surface between the metal and the dielectric material adjacent to the metal. As a kind of surface electromagnetic wave propagating along the boundary surface between metal and the dielectric material, the surface Plasmon wave corresponds to a wave generated when light incident to the metal surface and having a certain wavelength is not totally reflected and causes a surface wave. If the metal linear grid 310 including the first metal layer 311, the insulating layer 313 and the second metal layer 315 is arranged in the form of slits in a certain cycle, the color of emitted light is varied depending on the cycle.
According to this exemplary embodiment, the metal linear grid 310 is configured to make white light filter into individual colors throughout a visible light region. This is to achieve a nano oscillator for quantum-Plasmon-quantum conversion within a certain oscillation wavelength, which enhances a pass bandwidth and makes compactness possible as compared with other color filtering methods. Also, the filtered light has already been naturally polarized, so that it can be directly applied to an LCD panel or the like without any separate polarizing layer.
Accordingly, the display panel 100 can generate polarized colored light through one color filter polarizing layer 300 instead of the existing polarizing film and color filter. Also, light that is not transmitted through the first substrate 100 is not absorbed but is instead reflected from the first metal layer 311 of the metal linear grid 310, making it likely to be reflected again toward the display panel 1000. That is, the total optical efficiency is improved so that the conventional dual brightness enhance film (DBEF) can be omitted.
If light enters through the bottom of the first substrate 100 and exits through the second substrate 200, the light of only the first polarized component enters the liquid crystal layer 500, and the light of the second polarized component is reflected from the first substrate 100. Typically, a backlight assembly (not shown) emitting light under the display panel 1000 includes a reflective plate that reflects light reflected from the first substrate 100 toward the display panel 1000 again. Metal contained in the metal linear grid 310 may have high reflectivity so that more much light can be recycled by the reflective plate and enter the first substrate 100, i.e., more much light of the second polarized component can enter the reflective plate. For example, the metal linear grid 310 may include metal having high reflectivity, such as Al, Ag, Cu, etc. Thus, if the highly-reflective metal causes the reflectivity of the metal linear grid 310, it is possible to omit the dual brightness enhance film (DBEF) used in the conventional display panel. Accordingly, there is an effect on reducing production costs of the display panel 1000, and it is possible to make the display apparatus including the display panel 1000 thin and lightweight.
As shown therein, the color filter polarizing layer 300 may further include a dielectric layer 320 formed under the metal linear grid 310. The dielectric layer 320 may be made of a material similar to the first substrate 100, and may contain MgF2. The dielectric layer 320 may be provided in the form of a film coupled to the first substrate 100. Here, the dielectric layer 320 may replace the first substrate 100 or may be omitted.
As shown therein, the display panel 1000 may further include a light absorbing layer 330 formed on the metal linear grid 310 included in the first substrate 100 and absorbing light. If external light enters the display panel 1000 and is reflected again, there are problems that a contrast ratio of the display panel 1000 may be lowered and picture quality may be deteriorated due to the reflection of light. To prevent these problems, the first substrate 100 according to this exemplary embodiment includes the light absorbing layer 330 on the metal linear grid 310 in order to absorb undesired external light.
The light absorbing layer 330 may contain metal having low reflectivity, and or may include or be configured with carbon, chrome oxide, etc. for absorbing the light.
Alternatively, the light absorbing layer 330 may be formed not on the first substrate 100 but beneath the second substrate 200. That is, the external light is intercepted by the light absorbing layer and thus prevented from entering the display panel 1000.
As shown in
Then, as shown in
After forming the metal linear grid 310, as shown in
Then, as shown in
Thereafter, if
As shown therein, the display panel 1000 according to this exemplary embodiment includes a polarizing film 600 formed on the outer surface of the firs substrate 100, and a color filter polarizing layer 300 formed on the second substrate 200. In other words, the color filter polarizing layer 300 may be arranged on not the pixel layer 400 but on the substrate formed with the black matrix 200-1. If light enters through the bottom of the first substrate 100, the light of second polarized component passed through the polarizing film 600 passes through the liquid crystal layer 500, and then emits as the light of the first polarized component with different colors while passing through the color filter polarizing layer 300. Each of the color filter polarizing layer 300 and the polarizing film 600 may be selectively formed on the same or different substrates as the pixel electrode 400. Of course, light may enter though the second substrate 200 and exit through the first substrate 100.
In this exemplary embodiment, because the metal linear grid 310 is formed on the second substrate 200 through which the light exits, the metal linear grid 310 may contain metal having low reflectivity so as to suppress reflection of external light and absorb the light. The metal linear grid 310 may undergo additional processes for decreasing the reflectivity of the metal, or may include or be configured with carbon, chrome oxide, etc. for absorbing the light.
In the meantime, the metal linear grid 310 according to another exemplary embodiment may include metal having high strength in consideration of external impacts. For example, the second metal linear grid 610 may contain MoW or the like alloy, or may contain conductive polymer capable of performing substantially the same function as the metal layer.
As shown therein, the display panel 1000 in this exemplary embodiment further includes an additional polarizing layer 700 beneath the color filter polarizing layer 300 to transmit the first polarized component. The additional polarizing layer 700 may include an additional metal linear grid 710 that contains substantially the same metal as metal contained in the metal linear grid 310 and is arranged in the same direction as the metal linear grid 310. The additional metal linear grid 710 is arranged in the same direction as the metal linear grid 310, and thus transmits the first polarized component. The light of the first polarized component passed through the additional polarizing layer 700 is emitted with red, blue and green colors while passing through the color filter polarizing layer 300.
The metal layer contained in the additional metal linear grid 710 may contain highly-reflective metal, e.g., at least one of Al, Ag and Cu. Further, a light absorbing layer may be further provided on the metal layer and absorb external light.
The display panel 1000 may further include a printed circuit board mounted with a gate driving integrated chip (IC) and a data chip film package although they are not shown. Also, a compensation film (not shown) may be further provided outside the first substrate 100 and the second substrate 200.
As shown therein, the display apparatus 1 includes the display panel 1000, the backlight assembly 2000, accommodating containers 3100, 3200, 3300 accommodating the display panel 1000 and the backlight assembly 2000, and a video provider 4000.
The display panel 1000 includes the first substrate 100, the second substrate 200 opposite to the first substrate 100, the liquid crystal layer (not shown) interposed between the first substrate 100 and the second substrate 200, and a panel driver 800 for driving the pixel layer 400 to display a video signal. The panel driver 800 may include a gate driving IC 810, a data chip film package 820, and a printed circuit board 830.
The first substrate 100 and the second substrate 200 may be formed with the pixel layer 400, the color filter polarizing layer 300, the polarizing film 600, the black matrix 200-1, the common electrode 200-3, etc. The color filter polarizing layer 300 polarizes the incident light entering the first substrate 100, and the polarizing film 600 polarizes light exiting through the display panel 1000.
The display panel 1000 receives external light and controls intensity of light passing through the liquid crystal layer interposed between the first substrate 100 and the second substrate 200, thereby displaying an image.
The gate driving IC 810 is integrated and formed on the first substrate 100, and connected to each gate line (not shown) formed on the first substrate 100. Further, the data chip film package 820 may be connected to each data line (not shown) formed on the first substrate 100. Here, the data chip film package 820 may include a tape automated bonding (TAB) tape where a semiconductor chip is adhered to a wiring pattern formed on a base film by TAB technology. As an example of the chip film package, a tape carrier package (TCP), a chip on film (COF), etc. may be used.
Meanwhile, the printed circuit board 830 may be mounted with driving components for inputting a gate driving signal to a gate driving IC 931 and for inputting a data driving signal to a data chip film package 820.
The backlight assembly 2000 may include a light guide plate 2200 for guiding light, first and second light sources 2300a and 2300b for emitting light, a reflective sheet 2400 placed beneath the light guide plate 2200, and one or more optical sheets 2100.
The light guide plate 2200 serves to guide the light to be supplied to the display panel 1000. The light guide plate 2200 may be made of transparent plastic panel such as acryl, and guide light emitted from the first and second light sources 2300a and 2300b to travel toward the display panel 1000 formed on the light guide plate 2000. On the rear of the light guide plate 2200, there may be various patterns for changing a traveling direction of the light entering the inside of the light guide plate 2200 toward the display panel 1000.
As shown in the drawing, the first light source 2300a and the second light source 2300b may include a light emitting diode (LED) as a point light source. The light source is not limited to the LED, and may include a line light source such as a cold cathode fluorescent lamp (CCFL) or a hot fluorescent lamp (HCFL). The first light source 2300a and the second light source 2300b are electrically connected with an inverter (not shown) supplying power, and receive the power.
The reflective sheet 2400 is provided under the light guide plate 2200 and reflects the light emitted under the light guide plate 2200 upward. Specifically, the light, which is not reflected by a fine dot pattern formed on the back of the light guide plate 2200, is reflected again toward the light guide plate 2200, thereby decreasing loss in the light entering the display panel 1000 and enhancing uniformity of light transmitting through the exit surface of the light guide plate 2200.
One or more optical sheets 2100 are provided on the top of the light guide plate 2200 and serve to diffuse and condense the light transmitted from the light guide plate 2200. The optical sheets 2100 may further include a diffusion sheet, a prism sheet, a protection sheet, etc. The diffusion sheet may be placed between the light guide plate 2200 and the prism sheet, and diffuses incident light from the light guide plate 2200 to thereby prevent the light from being partially concentrated. The prism sheet may include triangular prisms regularly arranged on the top thereof, and serve to condense the light diffused by the diffusion sheet in a direction perpendicular to the display panel 1000. The protection sheet may be formed on the prism sheet, to protect the surface of the prism sheet, and diffuse the light and thus uniformly distribute the light.
The accommodating container may include a lower accommodating container 3100, a middle accommodating container 3200 and an upper accommodating container 3300. The lower accommodating container 3100 may accommodate the reflective sheet 2400, the first and second light sources 2300a and 2300b, the light guide plate 2200, and one or more optical sheets 2100. The lower accommodating container 3100 may be made of metal having a strength capable of withstanding an external shock and ground ability.
The video provider 4000 connects with the display panel 1000 and provides a video signal. Although not shown in
First, at operation S10, the color filter polarizing layer 300 including the metal linear grid 310 arranged at different pitches to make the first polarized component of the light exit the display apparatus with different colors are formed on the first substrate 100. At this time, the metal linear grid 310 may include the red metal linear grid arranged such that every pitch is shorter than ½ of a red light wavelength, the green metal linear grid arranged such that every pitch is shorter than ½ of a green light wavelength, and the blue metal linear grid arranged such that every pitch is shorter than ½ of a blue light wavelength. Of course, the metal linear grid may be arranged or formed with pitches different from the above in accordance with the colors of the light. The metal linear grid 310 may be formed by stacking the first metal layer 311, the insulating layer 313 and the second metal layer 315 in sequence and applying the sputtering process thereto.
Beneath the metal linear grid 310 may be provided the dielectric layer 320, and on the metal linear grid 310 may be provided the light absorbing layer 330 for suppressing reflection of light.
Characteristics of metal forming the metal linear grid 310, i.e., reflectivity or strength of the metal may be varied depending on whether the metal linear grid 310 is formed on the substrate for incident light or on the substrate for exiting light.
On the color filter polarizing layer 300, the pixel layer 400 including the plurality of sub pixels 410 is formed at operation S20. Alternatively, the pixel layer 400 may be formed on the substrate different from the color filter polarizing layer 300, i.e., the second substrate 200.
On the second substrate 200 having no pixel layer 400, the black matrix 200-1, the overcoat layer 200-2 and the common electrode 200-3 are formed.
Then, at operation S30, the first substrate 100 and the second substrate 200 are encapsulated, and the liquid crystal is injected between the first substrate 100 and the second substrate 200.
At operation S40, the polarizing film 600 is attached to the outer surface of the second substrate 200 having no color filter polarizing layer 300, thereby transmitting the second polarized component of light different from the first polarized component. With this process, the display panel 1000 is completed.
Next, the video provider 4000 capable of supplying video data to the sub pixels 410 and the panel driver 800 for driving the pixel layer 400 are connected to the substrate, and assembled to the backlight assembly 2000 including the light sources 2300a and 2300b, thereby completing the display apparatus 1 as shown in
As described above, according to an exemplary embodiment, there are provided a display panel and a display apparatus comprising the same, in which manufacturing costs are decreased and a manufacturing process is simplified.
According to another exemplary embodiment, there are provided a display panel having improved optical efficiency and a display apparatus comprising the same.
Although a few exemplary embodiments have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these exemplary embodiments without departing from the principles and spirit of the inventive concept, the scope of which is defined in the appended claims and their equivalents.
Number | Date | Country | Kind |
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10-2011-0037632 | Apr 2011 | KR | national |
This application claims the benefit of U.S. Provisional Patent Application No. 61/442,394, filed on Feb. 14, 2011 in the United States Patent and Trademark Office and Korean Patent Application No. 10-2011-0037632, filed on Apr. 22, 2011 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference.
Number | Date | Country | |
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61442394 | Feb 2011 | US |