Liquid crystal display device

Abstract

A liquid crystal display device includes a liquid crystal display panel in which a liquid crystal layer is disposed, a backlight that illuminates the liquid crystal display panel from the rear and includes an imaging area in which an imager is disposed, and a controller that controls brightness of the liquid crystal display panel. The liquid crystal display panel includes a display area and a dimming area provided so as to overlap with an imaging area of the backlight when the liquid crystal display panel is viewed on a plane. A dimming filter is disposed in the dimming area. The controller is configured to control driving of the liquid crystal layer in the dimming area such that a brightness when the display area is set to zero hue matches a brightness of the dimming area.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority of Japanese Patent Application No. 2023 - 222615 filed on December 28, 2023 and Japanese Patent Application No. 2024 - 165017 filed on September 24, 2024, the entire disclosures of which are incorporated herein by reference. Technical field

[0003] This application generally relates to liquid crystal display devices. Background art

[0004] Display devices having a configuration in which an imaging device is disposed behind a display (under - screen camera: CUD) are being actively developed.

[0005] For example, Japanese Patent Application Laid - Open No. 2021 - 117362 indicates that when applying CUD technology to a liquid crystal display device, a camera and an infrared (IR) light source are disposed in a part where a structural member (light guide plate of a backlight, optical sheet, etc.) in the area where the camera and the light source are to be disposed is hollowed out.

[0006] A liquid crystal panel corresponding to the area where the camera and the IR light source are disposed is provided with an occlusion area (light - shielding member) for hiding the camera and the IR light source, so that a user cannot visually recognize the camera and the IR light source. Generally, the light - shielding member is formed on a cover glass attached to the liquid crystal panel by using IR ink that blocks visible light and transmits only IR light.

[0007] However, when using conventional IR ink, when the display area displays black (zero gray level) or a low gray level, a brightness difference occurs between the occlusion area and the display area, which causes the problem that a user can clearly visually recognize the occlusion area.

[0008] The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a liquid crystal display device capable of preventing a user from visually recognizing an occlusion area. Summary of the invention

[0009] To achieve the above object, a liquid crystal display device according to a first embodiment of the present disclosure includes:

[0010] A liquid crystal display in which a liquid crystal layer is provided;

[0011] An illuminator that illuminates the liquid crystal display from behind and includes an imaging area in which an imager is provided; and

[0012] A controller that controls the brightness of the liquid crystal display, wherein

[0013] The liquid crystal display includes a display area and a dimming area, the dimming area is arranged to overlap with the imaging area of the illuminator when viewing the liquid crystal display in a plane, a dimming filter is arranged in the dimming area, and

[0014] The controller is configured to control the driving of the liquid crystal layer in the dimming area such that the brightness when the display area is set to zero tone matches the brightness of the dimming area.

[0015] It should be understood that the above general description and the following detailed description are both exemplary and explanatory, and not restrictive of the present disclosure.

[0016] According to the present disclosure, a liquid crystal display device capable of preventing a user from visually recognizing an occluded area can be provided. Description of the Drawings

[0017] The present application can be more fully understood when considering the following detailed description in conjunction with the following drawings, wherein:

[0018] Figure 1 is a diagram schematically showing a liquid crystal display device according to Embodiment 1;

[0019] Figure 2 is along Figure 1 a cross-sectional view taken along line II-II shown in

[0020] Figure 3 is a partial plan view of the liquid crystal display panel;

[0021] Figure 4 is along Figure 3 a cross-sectional view taken along line IV-IV shown in

[0022] Figure 5 is a partial cross-sectional view of a liquid crystal display panel according to Embodiment 2;

[0023] Figure 6 is a partial cross-sectional view of a liquid crystal display panel according to Embodiment 3;

[0024] Figure 7 is a partial cross-sectional view of a liquid crystal display panel according to Embodiment 4;

[0025] Figure 8 is a partial cross-sectional view of a liquid crystal display panel according to Embodiment 5;

[0026] Figure 9 is a plan view for explaining the arrangement of the dimming filter in the liquid crystal display panel according to Embodiment 5;

[0027] Figure 10 is a plan view for explaining the arrangement of the dimming filter in the liquid crystal display panel according to Embodiment 5;

[0028] Figure 11 It is a diagram for explaining a modified example of Example 5;

[0029] Figure 12A It is a diagram for explaining the first step of the manufacturing process of the dimming filter for the modified example of Example 5;

[0030] Figure 12B It is a diagram for explaining the second step of the manufacturing process of the dimming filter for the modified example of Example 5;

[0031] Figure 12C It is a diagram for explaining the third step of the manufacturing process of the dimming filter for the modified example of Example 5;

[0032] Figure 12D It is a diagram for explaining the fourth step of the manufacturing process of the dimming filter for the modified example of Example 5;

[0033] Figure 13A It is a diagram for explaining the first step of another manufacturing process of the dimming filter for the modified example of Example 5;

[0034] Figure 13B It is a diagram for explaining the second step of another manufacturing process of the dimming filter for the modified example of Example 5;

[0035] Figure 13C It is a diagram for explaining the third step of another manufacturing process of the dimming filter for the modified example of Example 5;

[0036] Figure 14 It is a partial cross-sectional view of a liquid crystal display panel according to Example 6;

[0037] Figure 15 It is a diagram for explaining the configuration of a controller according to Example 7;

[0038] Figure 16A It is a top view of the backlight;

[0039] Figure 16B Shows along Figure 16A the brightness distribution of the backlight along line B-B;

[0040] Figure 16C It is a diagram showing Figure 16A the transmittance of the liquid crystal layer at a position corresponding to line B-B;

[0041] Figure 16D It is a diagram showing Figure 16A the transmittance of the color filter and the dimming filter of the dimming area in the display area at a position corresponding to line B-B;

[0042] Figure 16E is a diagram showing the luminance of a liquid crystal display device at a position corresponding to line B-B of Figure 16A ; and

[0043] Figure 17 is a diagram for explaining a modification example. Detailed Embodiment

[0044] Hereinafter, a liquid crystal display device according to various embodiments will be described with reference to the accompanying drawings.

[0045] Embodiment 1

[0046] As Figure 1 and Figure 2 shown, a liquid crystal display device 10 according to the present embodiment includes a liquid crystal display panel 100, a backlight 200, and a controller 300. In the present embodiment, the liquid crystal display device 10 has a CUD structure in which an imaging device is provided behind the liquid crystal display panel 100. In one example, the liquid crystal display device 10 is used as an in-vehicle display device.

[0047] In one example, the liquid crystal display panel 100 is implemented as a horizontal electric field type color liquid crystal display panel of an active matrix driven by thin film transistors (TFTs). Note that the liquid crystal display panel 100 may be implemented in a configuration such as a vertical alignment (VA) type, a twisted nematic (TN) type, or a similar vertical electric field type color liquid crystal display panel. The liquid crystal display panel 100 displays characters and / or images. As Figure 1 shown, the liquid crystal display panel 100 includes a display area 101 and a dimming area 102 provided in the display area 101. As Figure 3 shown, pixels PX and PX2 are arranged in a matrix in the display area 101. The dimming area 102 is an area for blocking the line of sight (occlusion area) so that the imaging area 202 provided on the backlight 200 is not visually recognized by the user. Therefore, as Figure 1 and Figure 2 shown, when the liquid crystal display device 10 is viewed from a plane (when viewed by the user), the dimming area 102 is provided so as to overlap with the imaging area 202 of the backlight 200, and the illumination area 201 of the backlight 200 is provided so as to overlap with the display area 101. The dimming area 102 transmits IR light and visible light. The display area 101 is an area capable of displaying characters, images, etc., and the dimming area 102 is an area that does not display characters, images, etc. Note that, for ease of understanding, for the liquid crystal display panel 100, Figure 2 only the active matrix substrate 111, the liquid crystal layer LC, the counter substrate 112, the sealing material 119, and the dimming filter 120 are shown in

[0048] As Figure 2As shown, a backlight (illuminator) 200 is disposed on the rear surface side of a liquid crystal display panel 100. The backlight 200 is implemented as an edge-lit type backlight and includes white light-emitting diode (LED) elements, a reflection sheet, a light guide plate, a diffusion sheet, a lens sheet, and a polarizing sheet (none of which are shown in the drawings). Further, by hollowing out the light guide plate, the diffusion sheet, and other optical sheets, a recess 203 is formed in the backlight 200. An imaging device 204 and an IR light source 205 are provided in the recess 203. The recess 203 in which the imaging device 204 and the IR light source 205 are provided is referred to as an "imaging area 202". Although the light guide plate and the like are not located in the imaging area 202, light from the illumination area 201 around the imaging area 202 leaks into the imaging area 202. Therefore, the in-plane luminance of the imaging area 202 (e.g., 500 cd / m 2 ) is lower than the in-plane luminance of the illumination area 201 (e.g., 12000 cd / m 2 ). Accordingly, light having a lower luminance than that of the display area 101 enters a dimming area 102 that overlaps with the imaging area 202.

[0049] A controller 300 includes a central processing unit (CPU), a memory, a power circuit, etc., and controls the liquid crystal display panel 100 and the backlight 200. In one example, the CPU executes a program stored in the memory to implement the controller 300. Specifically, the controller 300 controls a gate driver and a data driver, supplies a video signal (gray scale voltage) to a driver IC of the liquid crystal display panel 100, displays characters and / or images in the display area 101, and drives liquid crystal cells in the dimming area 102. Further, the controller 300 sends a current value signal indicating a current value to be applied to a light source to an illumination circuit of the backlight 200.

[0050] As Figure 2 and Figure 4 shown, the liquid crystal display panel 100 includes an active matrix substrate 111, a counter substrate 112, and a liquid crystal layer LC. The counter substrate 112 is attached to the active matrix substrate 111 by a sealing material 119. Further, the liquid crystal display panel 100 includes a polarizing plate 113 provided on the lower surface of the active matrix substrate 111 and a polarizing plate 114 provided on the upper surface of the counter substrate 112. In the present embodiment, the liquid crystal display panel 100 is implemented as a transmissive liquid crystal display panel. In one example, the liquid crystal display panel 100 operates in a known transverse electric field mode or vertical electric field mode.

[0051] In one example, the counter substrate 112 is implemented as a glass substrate. As Figure 4As shown, color filters 140R, 140G, and 140B, dimming filter 120, outer coating film 116, and alignment film (not shown in the figure) are provided on the main surface 112a of the counter substrate 112 opposite to the active matrix substrate 111.

[0052] In one example, the active matrix substrate 111 is implemented as a glass substrate. As Figure 3 shown, a plurality of gate lines GL, a plurality of data lines DL, switching elements SD, pixel electrodes PE, common electrodes CE, an alignment film for aligning the liquid crystal layer LC (not shown in the figure), etc. are provided on the main surface 111a of the active matrix substrate 111 opposite to the counter substrate 112. When the liquid crystal display panel 100 operates in the vertical electric field mode, the common electrode CE is provided on the counter substrate 112. Note that in Figure 4 order to facilitate understanding, the switching elements SD, pixel electrodes PE, etc. are collectively shown as the electrode forming layer 130.

[0053] As Figure 3 shown, the gate lines GL of the active matrix substrate 111 extend in the horizontal direction and are juxtaposed in the vertical direction. The data lines DL of the active matrix substrate 111 extend in the vertical direction and are juxtaposed in the horizontal direction. The gate lines GL and the data lines DL surround a set of pixel electrodes PE, common electrodes CE, and switching elements SD that form pixels PX. The gate lines GL and the data lines DL are formed of a metal such as aluminum (Al), molybdenum (Mo), etc. The gate lines GL and the data lines DL correspond to pixel lines.

[0054] The pixel electrodes PE are arranged in a matrix form. In one example, the pixel electrodes PE are formed of indium tin oxide (ITO). The pixel electrodes PE are formed in a comb shape. The common electrode CE is formed in a comb shape by ITO. The combs of the pixel electrodes PE and the combs of the common electrode CE are alternatively arranged parallel to each other. Therefore, a lateral electric field parallel to the main surface 111a of the active matrix substrate 111 is generated between the combs of the pixel electrodes PE and the combs of the common electrode CE. At the same time, when operating in the vertical electric field mode, the pixel electrodes PE and the common electrodes CE are not formed in a comb shape, but are arranged to face each other across the liquid crystal layer. Therefore, a vertical electric field perpendicular to the main surfaces 111a of the counter substrate 112 and the active matrix substrate 111 is generated between the pixel electrodes PE and the common electrodes CE.

[0055] In one example, the switching element SD is implemented as a TFT element. The switching element SD is disposed near the intersection of the gate line GL and the data line DL. The switching element SD includes a gate, a source, a drain, and a semiconductor layer (none of which are shown in the drawings). The gate of the switching element SD is connected to the gate line GL, and the source of the switching element SD is connected to the data line DL. The drain of the switching element SD is connected to the pixel electrode PE. The gate, source, and drain are formed of a metal such as aluminum, molybdenum, etc. The semiconductor layer of the switching element SD is formed of amorphous silicon, an oxide including indium (In), gallium (Ga), zinc (Zn), etc.

[0056] Based on the scan signal provided via the gate line GL connected to the gate from the gate driver, the switching element SD is sequentially driven. When the switching element SD is in the off state, the video signal (gray scale voltage) provided from the data driver is supplied to the drain via the data line DL connected to the source. In addition, a predetermined lateral electric field parallel to the main surface 111a of the active matrix substrate 111 is generated between the comb teeth of the pixel electrode PE connected to the drain and the comb teeth of the common electrode CE, and the predetermined lateral electric field is applied to the liquid crystal. Note that the common electrode CE is connected to the common line, and the potential of the common electrode CE is controlled to a predetermined potential. At the same time, when operating in the vertical electric field mode, a predetermined vertical electric field perpendicular to the common electrode CE and the main surface 111a of the active matrix substrate 111 is generated between the common electrode CE and the pixel electrode PE connected to the drain, and the predetermined vertical electric field is applied to the liquid crystal.

[0057] As Figure 3 shown, in the display area 101 of the liquid crystal display panel 100, a plurality of pixels PX are arranged in a matrix form. Each pixel PX includes a red (R) sub-pixel SPR, a green (G) sub-pixel SPG, and a blue (B) sub-pixel SPB. The sub-pixels SPR, SPG, and SPB are repeatedly arranged in this order. In the present embodiment, the liquid crystal display panel 100 further includes at least one pixel PX2 similar to the sub-pixels SPR, SPG, and SPB of the display area 101 in the dimming area 102. The pixel PX2 in the dimming area 102 includes pixel electrodes and common electrodes similar to the sub-pixels SPR, SPG, and SPB. The number of pixels PX2 provided in the dimming area 102 can be determined as needed. For example, m×n (where m and n are natural numbers) of pixels PX2 can be provided.

[0058] As Figure 3 shown, in the present embodiment, like the pixels PX in the display area, the switching element SD, the pixel electrode PE, the common electrode CE, etc. are provided in the pixels PX2 of the dimming area 102. In addition, the pixels PX2 in the dimming area 102 can control the liquid crystal layer LC and adjust the transmittance of the liquid crystal layer LC.

[0059] In Figure 3 , pixels PX and PX2 arranged in a pixel row are connected to a common gate line GL. In addition, pixels PX2 arranged in the same sub-pixel column as sub-pixel SPR are connected to a common data line DL. This also applies to the sub-pixel columns same as sub-pixels SPG and SPB. When pixel PX2 is not set in the dimming area and not driven, the number of pixels PX connected to the data line and gate line passing through the dimming area decreases. Therefore, from the perspective of the outputs of the gate driver and data driver, the load capacity changes, and the delay states of the scan signal and data signal transmitted through various lines change. These changes are very likely to cause deterioration of the display quality, such as uneven brightness. From the perspective of preventing deterioration of the display quality, Figure 3 the present embodiment shown in

[0060] The dimming filter 120 provided in the dimming area 102 is a filter for attenuating light entering from the backlight 200. The dimming filter 120 is provided throughout the dimming area 102. The dimming filter 120 transmits visible light and infrared light, including near-infrared light. The optical density (OD) value of the dimming area 102 provided with the dimming filter 120 is 1.49 - 3.10 (transmittance: 0.08% - 3.2%). As Figure 4 shown, the dimming filter 120 is formed by stacking two sub-filters 120R and 120B. In the present embodiment, an example of a configuration using color filters of red and blue is described. The sub-filter is formed of the same material as the color filters commonly used in liquid crystal display devices. Two-color color filters are selected from the red, green, and blue color filters used in the liquid crystal display device as needed.

[0061] The black matrix (BM) commonly used in liquid crystal display devices does not transmit light in the near-infrared region. In contrast, the transmittance of the near-infrared region of each of red, green, and blue used in the color filter is very high (>90%). Therefore, by forming the dimming filter 120 using the color filter resist used in the liquid crystal display device, the dimming filter 120 can attenuate light in the visible light region (380 - 780 nm) and transmit light in the infrared region (especially the near-infrared region (800 - 2500 nm)). Preferably, the dimming filter 120 can transmit light having the wavelength of an IR light source, such as light having a wavelength of 940 nm.

[0062] Note that the color combination of the sub - filters used as the dimming filter 120 can be determined as needed. For example, a red sub - filter and a green sub - filter can be stacked, or a green sub - filter and a blue sub - filter can be stacked. In addition, sub - filters of three colors, namely red, green, and blue, can be stacked. Here, when the user observes the liquid crystal display panel 100, the color of the sub - filter closest to the user, that is, the sub - filter directly provided on the counter substrate 112, is visually recognized by the user. Therefore, preferably, the stacking order of the sub - filters is selected according to the use of the liquid crystal display device 10.

[0063] The sub - filters 120R and 120B of the dimming filter 120 can each be formed of the same material as the color filters used in the display area 101, or can be formed of different materials. Since the same material can be used, it is preferred to use the same material. Note that in this embodiment, the thicknesses of the red sub - filter 120R and the blue sub - filter 120B are less than the thickness of the color filters in the display area 101. Therefore, a process different from that for the color filters in the display area 101 must be used to form and pattern the red sub - filter 120 and the blue sub - filter 120B. In this regard, as another method for forming color filters with different resist thicknesses for the display area 101 and the dimming area 102, the dimming filter 120 and the color filters in the display area 101 can be formed using the same process by using a multi - level mask that allows exposure at multiple light intensity levels. By exposing the color filter resist to medium - intensity light using the multi - level mask, color filters with different thicknesses after development can be formed.

[0064] In this embodiment, the thickness of the dimming filter 120 is formed to be the same as the thickness of the color filters of the pixels provided in the display area 101. Therefore, the cell gap G1 in the display area 101 and the cell gap G2 in the dimming area 102 can be made the same. Preferably, the cell gap G1 and the cell gap G2 are the same because in this case, the liquid crystal layer LC in the pixel PX2 in the dimming area 102 can be controlled in the same manner as the liquid crystal layer LC in the pixel PX in the display area 101.

[0065] When obtaining the dimming filter 120 by stacking two layers of sub - filters 120R and 120B, the thickness of each of the sub - filters 120R and 120B is set to be half of the thickness of the color filter in the display area 101, and the thickness when stacking two layers is the same as the thickness of one of the color filters. Note that if the attenuation rate required for the dimming filter 120 can be achieved, the thickness of each of the sub - filters 120R and 120B can be set as needed. For example, if the thickness of the dimming filter 120 is the same as the thickness of the color filter in the display area 101, the thicknesses of the sub - filters 120R and 120B can be different from each other.

[0066] The light entering the dimming area 102 from the back of the liquid crystal display panel 100 is attenuated at each of the polarizing plate, the electrode formation layer, the liquid crystal layer, the color filter, and the polarizing plate. In this embodiment, the OD value of the dimming area 102 is adjusted so that the brightness calculated when driving the pixel PX2 in the dimming area 102 exceeds the black brightness of the display area 101. Therefore, by reducing the driving voltage of the pixel PX2, the transmittance of the liquid crystal layer LC can be easily reduced, and thus the brightness of the dimming area 102 can be matched with the black brightness of the display area 101. In one example, it is described that the measured value of the black brightness of the display area 101 is 0.5 cd / m 2 and the measured value of the light entering the dimming area 102 is 500 cd / m 2 . In this case, the dimming area 102 is configured such that the brightness calculated when driving the pixel PX2 in the dimming area 102 exceeds 0.5 cd / m 2 . Then, the driving voltage is adjusted by reducing the voltage applied to the pixel PX2 so that the brightness of the dimming area 102 becomes 0.5 cd / m 2 . Note that in this specification, the term "match" allows for errors and includes cases where the brightness difference is within ±10%.

[0067] In this embodiment, except for the color filter, the sub - pixels SP in the display area 101 and the pixels in the dimming area 102 have the same configuration. Therefore, for common components, the attenuation rate is the same, and thus it has the advantage that it is easier to simulate the attenuation rate in the dimming area 102.

[0068] Therefore, in this embodiment, the dimming filter 120 is provided in the dimming area 102. In addition, the liquid crystal layer LC in the dimming area 102 is driven and controlled to transmit the light from the backlight 200. As a result, the brightnesses of the dimming area 102 and the display area 101 are matched. Therefore, according to the liquid crystal display device 10 of this embodiment, the user can be prevented from visually recognizing the dimming area 102.

[0069] Embodiment 2

[0070] Hereinafter, the liquid crystal display device 10 according to Embodiment 2 is described. The difference between this embodiment and the above-described Embodiment 1 is that the cell gap G3 of the dimming region 102 is smaller than the cell gap G1 of the display region 101. Features common to Embodiment 1 are denoted by the same reference numerals, and their detailed description is omitted.

[0071] As Figure 5 shown, the dimming filter 122 of this embodiment is also formed by stacking a green sub-filter 122G and a blue sub-filter 122B. In this embodiment, as Figure 5 shown, the dimming filter 122 is formed thicker than the color filter of the display region 101. Compared with Embodiment 1, it is preferable to form a thicker dimming filter 122 because doing so can increase the attenuation rate of the dimming filter 112. Here, the cell gap G3 is a gap into which the liquid crystal layer LC can be introduced. When the same driving voltage as that of the pixel PX in the display region 101 is used, the electric field applied to the liquid crystal layer LC can be strengthened in a narrower cell gap, and the response time can be improved.

[0072] Note that in this embodiment, the color combination of the sub-filters can also be determined as needed. In addition, the number of sub-filters is not limited to two, and may also be three. In particular, it is preferable to stack sub-filters of three colors, namely red, green, and blue, because doing so reduces the color difference from the black color in the display region 101.

[0073] When the sub-filter has the same thickness as the color filter in the display region 101 and is formed of the same material as the color filter in the display region 101, since the sub-filter of the dimming filter 122 can be formed using the process for manufacturing the color filter in the display region 101, it has the advantage of being easy to manufacture.

[0074] Also in this embodiment, the dimming filter 122 is disposed in the dimming region 102. In addition, the liquid crystal layer LC in the dimming region 102 is driven and controlled to transmit light from the backlight 200. In particular, in this embodiment, the dimming filter 122 is formed thicker, and thus, the attenuation rate of the dimming filter 122 can be increased. Therefore, the user can be prevented from visually recognizing the dimming region 102.

[0075] Embodiment 3

[0076] Hereinafter, a liquid crystal display device according to Embodiment 3 is described. This embodiment is different from the above-described Embodiments 1 and 2 in that a concave portion 112b is provided on the main surface 112a of the counter substrate 112, and the dimming filter 123 is partially provided in the concave portion 112b. Features common to the above-described embodiments are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0077] As Figure 6 shown, the dimming filter 123 of this embodiment is formed by stacking sub-filters 123R and 123B. In this embodiment, the dimming filter 123 is formed thicker than the color filters 140R, 140G, and 140B in the display area 101. In this embodiment, the concave portion 112b is provided on the surface of the counter substrate 112 opposite to the active matrix substrate 111. Accordingly, the thickness T1 of the counter substrate 112 in the display area 101 is greater than the thickness T2 in the dimming area 102 (T1 > T2).

[0078] The dimming filter 123 is provided in the concave portion 112b of the counter substrate 112. Accordingly, it is advantageous that a thicker dimming filter 123 can be formed and the attenuation rate of the dimming filter 123 can be easily increased. In addition, as Figure 6 shown, the cell gap G2 in the dimming area 102 can be made the same as the cell gap G1 in the display area 101. Accordingly, the liquid crystal layer LC in the pixel PX2 in the dimming area 102 can be controlled in the same manner as the liquid crystal layer LC in the pixel PX.

[0079] Note that, in this embodiment, the color combination of the sub-filters can also be determined as needed. In addition, the number of sub-filters is not limited to two, and may also be three. In particular, it is preferable to stack sub-filters of three colors, namely red, green, and blue, because this reduces the color difference from the black in the display area 101.

[0080] When the sub-filters have the same thickness as the color filters in the display area 101, are formed of the same material, and have the same stacking order, it is also advantageous because the sub-filters of the dimming filter 123 can be formed using the process for manufacturing the color filters in the display area 101, thus facilitating manufacturing.

[0081] Embodiment 4

[0082] Hereinafter, a liquid crystal display device according to Embodiment 4 is described. This embodiment is different from the above-described Embodiment 1 in that the sub-pixels SPR, SPG, and SPB in the display area 101 are defined by the black matrix BM. Features common to the above-described embodiments are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0083] As Figure 7As shown, the sub-pixels SPR, SPG, and SPB of the display area 101 are defined by the black matrix BM. In this case, as Figure 7 shown, the black matrix BM is disposed in the dimming area 102 in the same manner as in the display area 101.

[0084] The black matrix BM is disposed in the dimming area 102 in the same manner as in the display area 101. Therefore, since the pattern of the black matrix BM also exists in the dimming area 102, the user can be prevented from visually recognizing the dimming area 102.

[0085] Embodiment 5

[0086] Hereinafter, a liquid crystal display device according to Embodiment 5 will be described. In the above embodiment, the dimming filters disposed in the dimming area 102 are the same in the pixel PX2. However, in the present embodiment, each pixel PX2 disposed in the dimming area 102 includes a dimming filter having a different sub-filter combination. Features common to the above embodiment are denoted by the same reference numerals, and their detailed description is omitted.

[0087] As Figure 8 shown, in the pixel PX2, any one of a dimming filter 125 including a combination of a red sub-filter 125R and a blue sub-filter 125B, a dimming filter 126 including a combination of a blue sub-filter 126B and a green sub-filter 126G, and a dimming filter 127 including a combination of a green sub-filter 127G and a red sub-filter 127R is provided.

[0088] In one example, as Figure 9 shown, the dimming filters 125-127 are arranged side by side in stripes. Note that the present disclosure is not limited to the configuration arranged in stripes, and as Figure 10 shown, a configuration in which the dimming filters 125-127 are arranged in a matrix is also possible.

[0089] In the liquid crystal display panel of the present embodiment, a dimming filter 125 having a combination of a red sub-filter 125R and a blue sub-filter 125B, a dimming filter 126 having a combination of a blue sub-filter 126B and a green sub-filter 126G, and a dimming filter 127 having a combination of a green sub-filter 127G and a red sub-filter 127R are provided. Therefore, the color difference between the black tones of the dimming area 102 and the display area 101 can be reduced. Therefore, the user can be prevented from visually recognizing the dimming area 102.

[0090] Modification Example of Embodiment 5

[0091] In Figure 9 and Figure 10In [the reference], an example of a configuration in which the dimming filters 125 - 127 are arranged in stripes or a matrix is described. However, the present disclosure is not limited thereto, and the dimming region 102 is divided into sections each including a plurality of pixels PX2, for example, a 3×3 section of pixels PX2, and each section is provided with the same color filter; for example, one section is provided with the dimming filter 125 having a combination of a red sub-filter and a blue sub-filter, and an adjacent section is provided with the dimming filter 126 having a combination of a blue sub-filter and a green sub-filter, and such a configuration is acceptable.

[0092] As Figure 11 shown, the dimming filters are formed such that a boundary portion 128 where color filter resists of three colors are stacked is provided at the boundary where the dimming filter 125 and the dimming filter 126 contact, and such a configuration is acceptable. Note that Figure 11 illustrates the substrate 112 and the dimming filters 125, 126, and 127. As Figure 11 shown, a portion of the sub-filter 126G of the dimming filter 126 adjacent to the dimming filter 125 is provided to overlap with the dimming filter 125. The boundary portion 128 where color filter resists of three colors are stacked is formed by setting the edge of the green sub-filter 126G not included in the dimming filter 125 to overlap with the dimming filter 125. Preferably, the boundary portion 128 includes color filters of three colors because this can reduce the color difference from the black in the display region 101. Similarly, preferably, the dimming filters are formed such that boundary portions 128 where color filter resists of three colors are stacked are also provided at the boundary where the dimming filter 126 and the dimming filter 127 contact and at the boundary where the dimming filter 127 and the dimming filter 125 contact.

[0093] Next, a process for manufacturing the dimming filters 125, 126, and 127 is provided, and the dimming filters are formed such that a boundary portion 128 where color filter resists of three colors are stacked is included. Figures 12A - 12D illustrates an example of manufacturing the dimming filters 125, 126, and 127 in four steps, and Figures 13A - 13C illustrates an example of manufacturing the dimming filters 125, 126, and 127 in three steps. Here, the dimming filters 125, 126, and 127 are formed by stacking color filter resists on the substrate 112. Therefore, Figures 12A - 12D and Figures 13A - 13C are vertically inverted with respect to Figure 11 the vertical.

[0094] Figure 12AShows the first step of forming the green sub-filter 127G. First, as shown in the left figure, a green color filter resist is applied to the counter substrate 112 to form a layer. Next, as shown in the right figure, the portions of the green color filter resist other than the portion to form the green sub-filter 127G are covered with a photomask, and an exposure process of irradiating infrared light is performed to cure the green color filter resist. Then, a development process is performed to remove the uncured portions. Thus, the green sub-filter 127G is formed. After the first step is completed, the second step is performed.

[0095] Figure 12B Shows the second step of forming the red sub-filters 125R and 127R. As Figure 12B shown in the left figure, a red color filter resist is formed on the counter substrate 112 on which the green sub-filter 127G is formed. As a result, a red color filter resist layer for forming the red sub-filter 125R is formed on the counter substrate 112, and a red color filter resist layer for forming the red sub-filter 127R is formed on the green sub-filter 127G. Next, as shown in the right figure, the portions of the red color filter resist other than the portions to form the red sub-filters 125R and 127R are covered with a photomask, and an exposure process is performed. Then, a development process is performed. Thus, the red sub-filters 125R and 127R are formed. After the second step is completed, the third step is performed.

[0096] Figure 12C Shows the third step of forming the blue sub-filters 125B and 126B. First, a blue color filter resist is applied to the recesses on the red sub-filter 125R formed on the red color filter resist layer and the recesses formed on the counter substrate 112. As a result, a blue color filter resist layer for forming the blue sub-filters 125B and 126B is formed. Next, the portions of the blue color filter resist to form the blue sub-filters 125B and 126B are exposed, and then a development process is performed. Thus, the blue sub-filters 125B and 126B are formed. After the third step is completed, the fourth step is performed.

[0097] Figure 12DShows the fourth step of forming the green sub - filter 126G. First, a green color - filter resist is applied to the recesses on the blue sub - filter 126B formed on the surface of the color - filter resist layer. As a result, a green color - filter resist layer for forming the green sub - filter 126G is formed. Next, a part of the green color - filter resist is exposed and then developed. Thus, the green sub - filter 126G is formed. The dimming filters 125, 126, and 127 are manufactured by performing the above four steps. Here, the boundary portion 128 where three - color color - filter resists are stacked is formed by the ends of the dimming filters 125 and 127 at the boundary between the dimming filter 125 and the dimming filter 127. In addition, the boundary portion 128 where three - color color - filter resists are stacked is formed by the ends of the dimming filters 127 and 126 at the boundary between the dimming filter 127 and the dimming filter 126. In addition, the boundary portion 128 where three - color color - filter resists are stacked is formed by the ends of the dimming filters 126 and 125 at the boundary between the dimming filter 126 and the dimming filter 125. Under the manufacture of the dimming filters 125, 126, and 127 by four steps, the first layer formed on the substrate 112 is formed of three - color sub - filters 125R, 127G, and 126B, and the second layer stacked on the first layer is formed of three - color sub - filters 125B, 127R, and 126G. The sub - filters 125B, 127R, and 126G are formed on the sub - filters 125R, 127G, and 126B of the first layer and are accordingly different in color from the sub - filters 125R, 127G, and 126B of the first layer. In other words, if the dimming filter has a structure in which three - color sub - filters are formed on the first layer and three - color sub - filters different from those of the first layer are stacked on the second layer, the dimming filter is manufactured by the above four steps.

[0098] Next, with reference to Figures 13A - 13C Examples of manufacturing the dimming filters 125, 126, and 127 in three steps are described. Figure 13AShows the first step of forming the green sub - color filters 127G and 126G. First, as shown in the left figure, a green color - filter resist is applied onto the substrate 112 to form a layer. Next, as shown in the right figure, the portions of the green color - filter resist other than the portions where the green sub - color filters 127G and 126G are to be formed are covered with a photomask, and an exposure process of irradiating infrared light is performed to cure the green color - filter resist. Then, a developing process is performed to remove the uncured portions. Thus, the green sub - color filters 127G and 126G are formed. Here, the green sub - color filters 127G and 126G are formed adjacent to each other. The left half of the green color - filter resist formed in a trapezoidal shape by the developing process is defined as the green sub - color filter 127G, and the right half is defined as the green sub - color filter 126G. Therefore, the stacking order is different from Figure 12D the stacking order of the dimming filter 126 manufactured by the above four steps as shown. After the first step is completed, the second step is carried out.

[0099] Figure 13B Shows the second step of forming the red sub - color filters 125R and 127R. As Figure 13B shown in the left figure, a red color - filter resist is formed on the substrate 112 where the green sub - color filters 127G and 126G are formed. As a result, a red color - filter resist layer for forming the red sub - color filter 125R is formed on the substrate 112, and a red color - filter resist layer for forming the red sub - color filter 127R is formed on the green sub - color filters 127G and 126G. Next, as shown in the right figure, the portions of the red color - filter resist other than the portions where the red sub - color filters 125R and 127R are to be formed are covered with a photomask, and an exposure process is performed. Then a developing process is carried out. Thus, the red sub - color filters 125R and 127R are formed. After the second step is completed, the third step is carried out.

[0100] Figure 13C Shows the third step of forming the blue sub - color filters 125B and 126B. First, a blue color - filter resist is applied to the recesses formed on the red sub - color filter 125R formed on the red color - filter resist layer and the recesses formed on the green sub - color filter 126G. As a result, a blue color - filter resist layer for forming the blue sub - color filters 125B and 126B is formed. Next, the portions of the blue color - filter resist where the blue sub - color filters 125B and 126B are to be formed are exposed, and then a developing process is carried out. Thus, the blue sub - color filters 125B and 126B are formed. The dimming filters 125, 126, and 127 are manufactured by performing the above three steps. Note that, as described above, the stacking order of the dimming filter 126 is the same as Figure 12DThe stacking order in [it] is reversed, and the green sub - color - filter 126G and the blue sub - color - filter 126B are stacked on the counter - substrate 112 in sequence. The boundary portion 128 where the color - filter resists of three colors are stacked is formed by the ends of the dimming filters 125 and 127 at the boundary between the dimming filter 125 and the dimming filter 127. In addition, the boundary portion 128 where the color - filter resists of three colors are stacked is formed by the ends of the dimming filters 127 and 126 at the boundary between the dimming filter 127 and the dimming filter 126. In addition, the boundary portion 128 where the color - filter resists of three colors are stacked is formed by the ends of the dimming filters 126 and 125 at the boundary between the dimming filter 126 and the dimming filter 125. Using Figures 12A - 12D The manufacturing method [it] requires four steps, namely, the step of forming the green color - filter resist on the counter - substrate 112, the step of forming the red color - filter resist, the step of forming the blue color - filter resist, and the step of further forming the green color - filter resist. In contrast, using Figures 13A - 13C The manufacturing method [it], the step of forming the second green color - filter resist can be omitted, and the manufacturing can be simplified. By manufacturing the dimming filters 125, 126, and 127 in three steps, the first layer formed on the counter - substrate 112 is formed by two - color sub - color - filters 125R, 127G, and 126G, and the second layer formed on the first layer is formed by two - color sub - color - filters 125B, 127R, and 126B. The sub - color - filters 125B, 127R, and 126B are formed on the sub - color - filters 125R, 127G, and 126G of the first layer, and are respectively different in color from the sub - color - filters 125R, 127G, and 126G of the first layer. In other words, if the dimming filter has a structure in which two - color sub - color - filters are formed on the first layer and two - color sub - color - filters respectively different from those of the first layer are stacked and formed on the second layer, the dimming filter is manufactured by the above three steps.

[0101] Embodiment 6

[0102] Hereinafter, a liquid - crystal display device according to Embodiment 6 is described. The difference between this embodiment and the above - mentioned embodiments is that a larger number of dimming filters having a specific combination of sub - color - filters are arranged. Features common to the above - mentioned embodiments are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0103] In the dimming region 102 of this embodiment, as Figure 14As shown, a dimming filter 125 having a combination of a red sub-filter 125R and a blue sub-filter 125B, a dimming filter 126 having a combination of a blue sub-filter 126B and a green sub-filter 126G, and a dimming filter 127 having a combination of a green sub-filter 127G and a red sub-filter 127R are provided for each pixel PX2, respectively.

[0104] In this embodiment, starting from the left figure of Figure 14 , the dimming filter 126 is disposed behind the dimming filter 125. The dimming filter 125 having a combination of a red sub-filter 125R and a blue sub-filter 125B is disposed behind the dimming filter 126 again. Next, the dimming filter 127 having a combination of a green sub-filter 127G and a red sub-filter 127R is disposed. Therefore, a larger number of dimming filters 125 having a combination of a red sub-filter 125R and a blue sub-filter 125B are set. Therefore, the hue of R + B can be enhanced.

[0105] In this case, similar to Embodiment 5, the dimming filters 125 - 127 may be arranged in stripes or in a matrix. The dimming filters 125 - 127 may also be randomly set.

[0106] Therefore, by increasing the number of settings of the dimming filters including a specific combination, the hue of the reflected light and the transmitted light in the dimming region 102 can be changed. By changing the hue according to the use of the liquid crystal display device 10, the user can be prevented from visually recognizing the dimming region 102.

[0107] Embodiment 7

[0108] Hereinafter, a liquid crystal display device according to Embodiment 7 is described. The difference between this embodiment and the above-described embodiments is that the driving voltage applied to the pixels PX2 in the dimming region 102 varies according to the brightness distribution of the backlight 200. Features common to the above-described embodiments are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0109] First, Figure 16A A top view of the backlight is shown. Figure 16B The brightness distribution of the backlight 200 along the line B - B of Figure 16A is shown. Figure 16C is a diagram showing the transmittance of the liquid crystal layer at a position corresponding to the line B - B of Figure 16A . Figure 16D is a diagram showing the transmittance of the color filter of the display region 101 and the dimming filter 120 of the dimming region 102 at a position corresponding to the line B - B; and Figure 16E shows the brightness of the liquid crystal display device 10 at a position corresponding to the line B - B.

[0110] As Figure 16B shown, there is a position-based inconsistency in the brightness of the backlight 200. Specifically, the brightness gradually decreases towards the outer center of the imaging region 202. To address the slope of the brightness decrease, as Figure 16C shown, in the dimming region 102 corresponding to the imaging region 202, the driving voltage of the pixel PX2 is changed according to the brightness distribution, such that the transmittance of the liquid crystal layer gradually increases. As a result, the transmittance of the liquid crystal layer LC in the dimming region 102 is corrected.

[0111] Specifically, as Figure 15 shown, the controller 301 of the present embodiment includes a display controller 311, a memory 312, and a backlight controller 313.

[0112] The memory 312 of the controller 301 stores the correction values of the voltages to be applied to each pixel PX2 as a look-up table. The correction values are created based on the brightness distribution measured in advance in the imaging region 202. Figure 16B An example of the brightness distribution is shown in. The display controller 311 generates an input video signal, the look-up table stored in the memory 312, and a corrected video signal. Next, the display controller 311 provides the corrected video signal to the driver IC of the liquid crystal display panel 100. The backlight controller 313 sends a current value signal representing the current value to be applied to the light source to the lighting circuit of the backlight 200 based on a pulse width modulation (PWM) signal.

[0113] Although as Figure 16B shown, there is a position-based inconsistency in the brightness of the backlight 200, but as Figure 16C shown, the transmittance of the liquid crystal layer LC in the dimming region 102 is corrected by changing the driving voltage of the pixel PX2 according to the brightness distribution. As Figure 16D shown, the transmittance within the dimming region 102 is substantially constant. In the display region 101, as Figure 16B shown, the brightness is high, but as Figure 16C shown, the transmittance of the liquid crystal is low. In addition, the transmittance of the color filter is higher than that of the dimming filter. Combining these features, the brightness within the plane can be made uniform, as Figure 16E shown.

[0114] Therefore, according to the present embodiment, by changing the voltage applied to the pixel PX2 according to the brightness distribution, the brightness inconsistency in the dimming region 102 can be suppressed, and the user can be further prevented from visually recognizing the dimming region.

[0115] The embodiments according to the present disclosure have been described above, but the present disclosure is not limited to these embodiments. For those skilled in the art, various changes, modifications, combinations, etc. will be obvious.

[0116] In addition, various embodiments can be combined. For example, the controller described in Embodiment 7 can be combined with the configurations of Embodiments 1-6. In addition, the feature including the black matrix described in Embodiment 4 can be combined with the configurations of Embodiment 2 or 3. In addition, the number of combinations can be set as needed, and the black matrices described in Embodiments 2 and 4 can be combined. In addition, the features of the controller described in Embodiment 7 can also be combined.

[0117] In the above embodiments, a configuration example is described in which the cell gap of the dimming region 102 is the same as or narrower than the cell gap G1 of the display region 101, but the present disclosure is not limited thereto. For example, as Figure 17 shown, the thickness of the dimming filter 120 of Embodiment 1 can be formed to be thinner than the thicknesses of the color filters 140R, 140G, and 140B. Therefore, the cell gap of the dimming region 102 can be formed to be wider than the cell gap of the display region.

[0118] In Embodiment 3, a configuration example is described in which the concave portion 112b is provided on the pair of substrates 112 and the cell gaps G1 and G4 are the same. However, the present disclosure is not limited thereto. Embodiments 3 and 2 can be combined, and the cell gap of the dimming region 102 can be made narrower than the cell gap G1 of the display region 101. Conversely, while ensuring the thickness of the dimming filter 123, the cell gap of the dimming region 102 can be made larger than the cell gap G1 of the display region 101.

[0119] In the above embodiments, an example in which the backlight is implemented as an edge-lit backlight is described, but the present disclosure is not limited thereto. For example, a configuration in which the backlight is implemented as a local dimming backlight is possible.

[0120] For purposes of explanation, some example embodiments have been described above. Although the above discussion has given specific embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the broader spirit and scope of the invention. Therefore, the specification and drawings should be regarded as illustrative rather than restrictive. Accordingly, this detailed description should not be considered restrictive, and the scope of the invention is defined only by the included claims and all equivalents to which those claims are entitled.

Claims

1. A liquid crystal display device, comprising: a liquid crystal display having a liquid crystal layer disposed therein; an illuminator which illuminates the liquid crystal display from behind and includes an imaging area provided with an imager; and A controller that controls the brightness of the liquid crystal display, wherein The liquid crystal display comprises a display area and a dimming area, the dimming area is arranged to overlap with the imaging area of ​​the illuminator when the liquid crystal display is viewed in a planar manner, a dimming filter is arranged in the dimming area, and The controller is configured to control driving of the liquid crystal layer in the dimming area so that the brightness when the display area is set to a zero tone matches the brightness of the dimming area. 2 . The liquid crystal display device according to claim 1 , wherein the dimming filter transmits light in a visible light region and a near infrared region.

3. The liquid crystal display device according to claim 1, wherein: In the dimming filter, at least two color filters of a red color filter, a green color filter, and a blue color filter are stacked, and an OD value of the dimming area where the dimming filter is disposed is 1.49-3.

10.

4. The liquid crystal display device according to claim 3, wherein: The thickness of the dimming filter is the same as the thickness of the color filter arranged in the display area.

5. The liquid crystal display device according to claim 3, wherein: The thickness of the dimming filter is greater than the thickness of the color filter disposed in the display area.

6. The liquid crystal display device according to claim 1, wherein: A cell gap of the liquid crystal layer in the dimming area is narrower than a cell gap of the liquid crystal layer in the display area.

7. The liquid crystal display device according to claim 1, wherein: The cell gap of the liquid crystal layer in the dimming area is the same as the cell gap of the liquid crystal layer in the display area.

8. The liquid crystal display device according to claim 1, wherein The dimming filter is disposed on a substrate, and The thickness of the substrate in the region where the dimming filter is provided is thinner than the thickness of the region where the display region is formed.

9. The liquid crystal display device according to claim 1, wherein The dimming area is divided by a plurality of pixels. In the dimming filter, two color filters among a red color filter, a green color filter, and a blue color filter are stacked, The adjacent pixels include dimming filters in which the combination of the two color filters stacked on each other is different, and A boundary portion is provided at a boundary between adjacent dimming filters, in which three color filters are stacked, namely, a red color filter, a green color filter, and a blue color filter.

10. The liquid crystal display device according to claim 9, wherein: Among the multiple dimming filters arranged in the dimming area, the first layer is formed by three color filters, namely the red color filter, the green color filter and the blue color filter, and the second layer is formed by three color filters, namely the red color filter, the green color filter and the blue color filter.

11. The liquid crystal display device according to claim 9, wherein: Among the plurality of dimming filters arranged in the dimming area, a first layer is formed by the two color filters among the red color filter, the green color filter and the blue color filter, and a second layer is formed by the two color filters among the red color filter, the green color filter and the blue color filter.

Images