Liquid crystal display device

Abstract

To provide a liquid crystal display device capable of preventing a user from visually recognizing a blindfold area.SOLUTION: The liquid crystal display device includes: a liquid crystal display panel 100 in which a liquid crystal layer LC is arranged; a backlight which illuminates the liquid crystal display panel 100 from the back surface and includes an imaging area in which an imaging part is provided; and a control section which controls the luminance of the liquid crystal display panel 100. The liquid crystal display panel 100 includes a display area, and an extinction area provided so as to overlap with the imaging area of the backlight, when the liquid crystal display panel 100 is seen in a plan view. An extinction filter 120 is provided in the extinction area. The control section controls driving of the liquid crystal layer LC in the extinction area, so as to make the luminance when the gradation of the display area is set zero and the luminance of the extinction area coincide with each other.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a liquid crystal display device.

Background Art

[0002] The development of a display device having a configuration in which an imaging device is arranged behind the display (Camera Under Display: CUD) has been actively carried out.

[0003] In the case of applying the CUD technology to a liquid crystal display device, for example, a structural member (such as a light guide plate or an optical sheet of a backlight) in a region where a camera and an infrared (IR) light source unit are arranged has a portion cut out, and the camera and the light source unit are arranged in the cut-out portion (for example, Patent Document 1).

[0004] On the liquid crystal panel corresponding to the region where the camera and the IR light source are arranged, a hiding region (light shielding portion) is provided to hide the camera and the IR light source from being visually recognized by the user. The light shielding portion is generally formed on a cover glass bonded to the liquid crystal panel using an IR ink that shields visible light and transmits only IR light.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the case of the conventional configuration using IR ink, when the display area is displayed in black (zero gradation) or low gradation, a difference in luminance occurs between the hiding area and the display area, and the problem is that the hiding area is clearly visually recognized by the user.

[0007] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a liquid crystal display device capable of suppressing the user from visually recognizing a blind spot region.

Means for Solving the Problems

[0008] The liquid crystal display device according to the first embodiment of the present disclosure includes a liquid crystal display unit in which a liquid crystal layer is disposed, an illumination unit that illuminates the liquid crystal display unit from the back and includes an imaging region where an imaging unit is provided, and a control unit that controls the luminance of the liquid crystal display unit. The liquid crystal display unit includes a display region and a light-shielding region provided so as to overlap the imaging region of the illumination unit when the liquid crystal display unit is viewed in a plan view. A light-shielding filter is provided in the light-shielding region. The control unit is configured to control the driving of the liquid crystal layer in the light-shielding region so that the luminance when the display region is set to zero gradation coincides with the luminance of the light-shielding region.

Advantages of the Invention

[0009] According to the present disclosure, it is possible to provide a liquid crystal display device capable of suppressing the user from visually recognizing a blind spot region.

Brief Description of the Drawings

[0010]

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Embodiments for Carrying Out the Invention

[0011] Hereinafter, with reference to the drawings, a liquid crystal display device according to the present embodiment will be described.

[0012] (Embodiment 1) As shown in FIGS. 1 and 2, the liquid crystal display device 10 according to the present embodiment includes a liquid crystal display panel 100, a backlight 200, and a control unit 300. In the present embodiment, the liquid crystal display device 10 applies a CUD structure in which an imaging device is disposed behind the liquid crystal display panel 100. The liquid crystal display device 10 is used, for example, as an in-vehicle display device.

[0013] The liquid crystal display panel 100 is, for example, a horizontal electric field type color liquid crystal display panel that is actively matrix-driven by TFT (Thin Film Transistor). Note that the liquid crystal display panel 100 may be, for example, a vertical electric field type color liquid crystal display panel such as a VA (Vertical Alignment) type or a TN (Twisted Nematic) type. The liquid crystal display panel 100 displays characters or images. As shown in FIG. 1, the liquid crystal display panel 100 has a display area 101 and a light shielding area 102 provided in the display area 101. As shown in FIG. 3, pixels PX and PX2 are arranged in a matrix in the display area 101. The light shielding area 102 is an area (light shielding area) for shielding the imaging area 202 provided in the backlight 200 from being visually recognized by the user. Therefore, as shown in FIGS. 1 and 2, when the liquid crystal display device 10 is viewed in a plan view (when viewed from the user), the light shielding area 102 is provided so as to overlap the imaging area 202 of the backlight 200, and the lighting area 201 of the backlight 200 is provided so as to overlap the display area 101. Further, the light shielding area 102 transmits IR light and visible light. The display area 101 is an area capable of displaying characters, images, etc., and the light shielding area 102 is an area that does not display characters, images, etc. Note that in FIG. 2, for convenience of explanation, only the active matrix substrate 111, the liquid crystal layer LC, the counter substrate 112, the sealing material 119, and the light shielding filter 120 of the liquid crystal display panel 100 are shown.

[0014] As shown in FIG. 2, the backlight (lighting unit) 200 is disposed on the back side of the liquid crystal display panel 100. The backlight 200 is an edge light type backlight and includes a white LED (Light Emitting Diode) element, a reflective sheet, a light guide plate, a diffusion sheet, a lens sheet, and a polarizing sheet (none of which are shown). Further, a concave portion 203 is formed in the backlight 200 by cutting out optical sheets such as the light guide plate and the diffusion sheet. An imaging device 204 and an IR light source unit 205 are provided in the concave portion 203. The concave portion 203 provided with the imaging device 204 and the IR light source unit 205 is called an imaging region 202. Although the light guide plate and the like are not positioned in the imaging region 202, light from the lighting region 201 surrounding the imaging region 202 leaks into the imaging region 202. For this reason, the in-plane luminance of the imaging region 202 (for example, 500 cd / m 2 ) is lower than that of the lighting region 201 (for example, 12000 cd / m 2 ). Therefore, light having a lower luminance than that of the display region 101 is incident on the light shielding region 102 overlapping with the imaging region 202.

[0015] The control unit 300 is composed of a CPU (Central Processing Unit), a memory, a power supply circuit, etc., and controls the liquid crystal display panel 100 and the backlight 200. The control unit 300 is realized, for example, by the CPU executing a program stored in the memory. Specifically, the control unit 300 controls the gate driver and the data driver, supplies a video signal (gray scale voltage) to the driver IC of the liquid crystal display panel 100, displays characters or images in the display region 101, and drives the liquid crystal cells in the light shielding region 102. Further, the control unit 300 transmits a current value signal representing the value of the current flowing through the light source to the lighting circuit of the backlight 200.

[0016] Next, as shown in FIGS. 2 and 4, 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 bonded 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 this embodiment, the liquid crystal display panel 100 is a transmissive liquid crystal display panel. The liquid crystal display panel 100 operates in, for example, a known horizontal electric field mode or vertical electric field mode.

[0017] The counter substrate 112 is, for example, a glass substrate. As shown in FIG. 4, a color filter 140R, 140B, 140G, a light-shielding filter 120, an overcoat film 116, and an alignment film (not shown) are provided on a main surface 112a of the counter substrate 112 facing the active matrix substrate 111.

[0018] The active matrix substrate 111 is, for example, a glass substrate. On a main surface 111a of the active matrix substrate 111 facing the counter substrate 112, as shown in FIG. 3, a pixel electrode PE, a plurality of gate wirings GL, a plurality of data wirings DL, a switching element SD, a pixel electrode PE, a common electrode CE, and an alignment film (not shown) for aligning the liquid crystal layer LC are provided. 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. In FIG. 4, for convenience of explanation, these switching elements SD, pixel electrodes PE, etc. are collectively shown as an electrode formation layer 130.

[0019] The gate wiring GL of the active matrix substrate 111 extends in the horizontal direction and is arranged side by side in the vertical direction as shown in FIG. 3. The data wiring DL of the active matrix substrate 111 extends in the vertical direction respectively and is arranged side by side in the horizontal direction. The gate wiring GL and the data wiring DL surround a set of pixel electrodes PE, a common electrode CE, and a switching element SD that form the pixel PX. The gate wiring GL and the data wiring DL are formed of a metal such as aluminum (Al) or molybdenum (Mo). The gate wiring GL and the data wiring DL correspond to pixel wirings.

[0020] The pixel electrodes PE are arranged in a matrix. The pixel electrodes PE are formed of, for example, ITO (Indium Tin Oxide). Further, the pixel electrodes PE are formed in a comb shape. The common electrode CE is also formed in a comb shape from ITO. The comb-shaped portions of the pixel electrodes PE and the comb-shaped portions of the common electrode CE are arranged alternately and parallel to each other. Thereby, a horizontal electric field parallel to the main surface 111a of the active matrix substrate 111 is generated between the comb-shaped portions of the pixel electrodes PE and the comb-shaped portions of the common electrode CE. On the other hand, when operating in the vertical electric field mode, the pixel electrodes PE and the common electrode CE are not formed in a comb shape and are arranged to face each other with the liquid crystal layer interposed therebetween. Thereby, a vertical electric field perpendicular to the main surface 111a of the active matrix substrate 111 and the counter substrate 112 is generated between the pixel electrode PE and the common electrode CE.

[0021] The switching element SD is, for example, a TFT element. The switching element SD is provided near the intersection of the gate wiring GL and the data wiring DL. The switching element SD has a gate electrode, a source electrode, a drain electrode, and a semiconductor layer (none of which are shown). The gate electrode of the switching element SD is connected to the gate wiring GL, and the source electrode of the switching element SD is connected to the data wiring DL. Further, the drain electrode of the switching element SD is connected to the pixel electrode PE. The gate electrode, the source electrode, and the drain electrode are formed of a metal such as aluminum or molybdenum. The semiconductor layer of the switching element SD is formed of amorphous silicon, an oxide containing indium (In), gallium (Ga), and zinc (Zn), etc.

[0022] The switching element SD is sequentially driven based on a scanning signal supplied from a gate driver via a gate wiring GL connected to a gate electrode. When the switching element SD is in an open state, a video signal (gray-scale voltage) supplied from a data driver is supplied to a drain electrode via a data wiring DL connected to a source electrode. Then, a predetermined horizontal electric field parallel to the main surface 111a of the active matrix substrate 111 is generated between a comb-tooth portion of a pixel electrode PE connected to the drain electrode and a comb-tooth portion of a common electrode CE, and the predetermined horizontal electric field is applied to the liquid crystal. Note that the common electrode CE is connected to a common wiring, and the potential of the common electrode CE is controlled to a predetermined potential. On the other hand, when operating in the vertical electric field mode, a predetermined vertical electric field perpendicular to the main surface 111a of the active matrix substrate 111 and the common electrode CE is generated between a pixel electrode PE portion connected to the drain electrode and the common electrode CE, and the predetermined vertical electric field is applied to the liquid crystal.

[0023] In the display area 101 of the liquid crystal display panel 100, as shown in FIG. 3, a plurality of pixels PX are arranged in a matrix. The pixel PX includes a red (R) sub-pixel SPR, a green (G) sub-pixel SPG, and a blue (B) sub-pixel SPB, and the sub-pixels SPR, SPG, and SPB are repeatedly arranged in this order. Further, in the present embodiment, the liquid crystal display panel 100 is provided with at least one pixel PX2 in the light-shielding area 102, which is the same as the sub-pixels SPR, SPG, and SPB in the display area 101. The pixel PX2 in the light-shielding area 102 is provided with a pixel electrode and a common electrode similar to those of the sub-pixels SPR, SPG, and SPB. The number of pixels PX2 provided in the light-shielding area 102 is arbitrary, and for example, m×n pixels PX2 (m and n are natural numbers) can be provided.

[0024] As shown in FIG. 3, in the present embodiment, in the light-shielding area 102 as well, a switching element SD, a pixel electrode PE, a common electrode CE, etc. are provided in the same manner as the pixels PX in the display area. For the pixels PX2 in the light-shielding area 102, the liquid crystal layer LC can be controlled, and the transmittance of the liquid crystal layer LC can be adjusted.

[0025] In FIG. 3, the pixels PX and PX2 arranged in one pixel row are connected to a common gate wiring GL. Also, the pixels PX2 arranged in the same sub-pixel column as the sub-pixel SPR are connected to a common data wiring DL. The same applies to the same sub-pixel columns as the sub-pixels SPG and SPB. When the pixel PX2 is not arranged in the dimming area and not driven, the number of pixels PX connected to the gate wiring and data wiring passing through the dimming area decreases. For this reason, the load capacitance seen from the outputs of the gate driver and data driver changes, and the delay states of the scanning signal and data signal transmitted through each wiring change. As a result, there is a high possibility that the display image quality deteriorates, such as the occurrence of luminance unevenness. The present embodiment shown in FIG. 3 is a preferable form from the viewpoint of not deteriorating the display image quality.

[0026] The dimming filter 120 provided in the dimming area 102 is a filter for attenuating the light incident from the backlight 200. The dimming filter 120 is provided over the entire dimming area 102. The dimming filter 120 transmits visible light and infrared light including near infrared. Also, the OD (Optical Density) value of the dimming area 102 where the dimming filter 120 is provided is 1.49 to 3.10 (transmittance 0.08% to 3.2%). Also, as shown in FIG. 4, the dimming filter 120 is configured by laminating two sub-filters 120R and 120B. In the present embodiment, a configuration using R-color and B-color color filters is taken as an example. The sub-filter is formed of the same material as the color filter generally used in a liquid crystal display device. Of the R-color, G-color, and B-color color filters used in the liquid crystal display device, any two-color color filters are selected.

[0027] The black matrix (BM) generally used in a liquid crystal display device does not transmit light in the near-infrared region. In contrast, each of the RGB colors used in a color filter has a high transmittance (>90%) in the near-infrared region. Therefore, by forming the light attenuation filter 120 using a color filter resist used in a liquid crystal display device, the light attenuation filter 120 can attenuate light in the visible light region (380 to 780 nm) and transmit light in the infrared region, particularly in the near-infrared region (800 to 2500 nm). It is preferable that the light attenuation filter 120 can transmit light having the wavelength of an IR light source, for example, light having a wavelength of 940 nm.

[0028] Note that the combination of the colors of the sub-filters used as the light attenuation filter 120 is arbitrary. For example, an R-color sub-filter and a G-color sub-filter, or a G-color sub-filter and a B-color sub-filter may be laminated. Further, three RGB-color sub-filters may be laminated. Here, when the user observes the liquid crystal display panel 100, the color of the sub-filter located closest to the user, that is, provided immediately above the counter substrate 112, is visually recognized by the user. Therefore, it is preferable to select the order of laminating the sub-filters according to the use of the liquid crystal display device 10.

[0029] The sub - filters 120R and 120B of the light - reducing filter 120 may be formed of the same material as the color filters used in the display area 101 or may be formed of different materials. Since the materials can be made common, it is preferable to use the same material. In this embodiment, since the film thicknesses of the R - color sub - filter 120R and the B - color sub - filter 120B are thinner than those of the color filters in the display area 101, it is necessary to perform film formation and patterning in a process different from that of the color filters in the display area 101. In this regard, as another method of forming color filters with different resist thicknesses in the display area 101 and the light - reducing area 102, by using a multi - tone mask capable of exposing with different light amounts in multiple steps, it is possible to form the light - reducing filter 120 and the color filters in the display area 101 in the same process. By exposing the color - filter resist at an intermediate amount with a multi - tone mask, color filters with different thicknesses can be formed after development.

[0030] Also, in this embodiment, the thickness of the light - reducing filter 120 is formed to be the same as the thickness of the color filters of the pixels provided in the display area 101. Thereby, the cell gap G1 in the display area 101 and the cell gap G2 in the light - reducing area 102 can be made the same. When the cell gap G1 and the cell gap G2 are the same, the liquid - crystal layer LC in the pixel PX2 in the light - reducing area 102 can be controlled in the same manner as the control of the liquid - crystal layer LC in the pixel PX in the display area 101, which is preferable.

[0031] When the light - reducing filter 120 is configured by laminating two sub - filters 120R and 120B, the thickness of each sub - filter 120R and 120B is set to half of the thickness of the color filters in the display area 101, and the thickness when the two layers are laminated is made the same as that of the color filters. Note that as long as the attenuation rate required for the light - reducing filter 120 can be achieved, the thicknesses of the sub - filters 120R and 120B are arbitrary. For example, if the thickness of the light - reducing filter 120 is the same as the thickness of the color filters in the display area, the thicknesses of the sub - filters 120R and 120B may be different from each other.

[0032] The light incident on the light attenuation region 102 from the back of the liquid crystal display panel 100 is attenuated by the polarizing plate, the electrode formation layer, the liquid crystal layer, the color filter, and the polarizing plate, respectively. In the present embodiment, the OD value and the like of the light attenuation region 102 are adjusted so that the calculated luminance when the pixel PX2 in the light attenuation region 102 is driven exceeds the black luminance of the display region 101. Thereby, by lowering the driving voltage of the pixel PX2, the transmittance of the liquid crystal layer LC can be easily lowered, so that the luminance of the light attenuation region 102 can be made to coincide with the black luminance of the display region 101. For example, the actually measured value of the black luminance of the display region 101 is 0.5 cd / m 2 and the actually measured value of the light incident on the light attenuation region 102 is 500 cd / m 2 is taken as an example. In this case, the light attenuation region 102 is configured so that the calculated luminance when the pixel PX2 in the light attenuation region 102 is driven exceeds 0.5 cd / m 2 And by lowering the voltage applied to the pixel PX2, the driving voltage is adjusted so that the luminance of the light attenuation region 102 becomes 0.5 cd / m 2 Note that in this specification, "coincide" allows for an error and also includes cases where the luminance difference is within ±10%.

[0033] Also, in the present embodiment, the sub-pixel SP of the display region 101 and the pixel of the light attenuation region 102 have the same configuration except for the color filter. Therefore, for the common components, the attenuation rate is the same, so there is an advantage that the simulation of the attenuation rate in the light attenuation region 102 becomes easy.

[0034] As described above, in the present embodiment, the light attenuation filter 120 is provided in the light attenuation region 102, and further, the liquid crystal layer LC in the light attenuation region 102 is driven and controlled to transmit the light from the backlight 200, so that the luminance of the light attenuation region 102 and the display region 101 is made to coincide. As a result, according to the liquid crystal display device 10 of the present embodiment, it is possible to suppress the user from visually recognizing the light attenuation region 102.

[0035] (Embodiment 2) The liquid crystal display device 10 according to Embodiment 2 will be described below. The difference between this embodiment and the above-described Embodiment 1 is that the cell gap G3 of the light-shielding region 102 is smaller than the cell gap G1 of the display region 101. For features common to Embodiment 1, the same reference numerals are given and detailed descriptions are omitted.

[0036] Also in this embodiment, as shown in FIG. 5, the light-shielding filter 122 is formed by overlapping the G-color sub-filter 122G and the B-color sub-filter 122B. In this embodiment, as shown in FIG. 5, the light-shielding filter 122 is formed thicker than the color filter in the display region 101. Compared with Embodiment 1, by forming the light-shielding filter 122 thicker, the attenuation rate of the light-shielding filter 122 can be increased, which is preferable. Here, the cell gap G3 is a gap in which the liquid crystal layer LC can be filled. Also, when using the same driving voltage as that of the pixel PX in the display region 101, a narrower cell gap can strengthen the electric field applied to the liquid crystal layer LC and increase the liquid crystal response speed.

[0037] Note that also in this embodiment, the combination of the colors of the sub-filters is arbitrary. Furthermore, the number of sub-filters is not limited to two and may be three. In particular, when overlapping the three sub-filters of R, G, and B, the color difference from the black color in the display region 101 becomes small, which is preferable.

[0038] Also, when the sub-filter has the same thickness as the color filter in the display region 101 and is formed of the same material, the sub-filter of the light-shielding filter 122 can also be formed in the process of manufacturing the color filter in the display region 101, which has the advantage of facilitating manufacturing.

[0039] Also in this embodiment, a light-shielding filter 122 is provided in the light-shielding region 102, and further, the liquid crystal layer LC in the light-shielding region 102 is driven and controlled to transmit the light from the backlight 200. In particular, in this embodiment, since the light-shielding filter 122 can be formed thick, the attenuation rate of the light-shielding filter 122 can be increased. Thereby, it is possible to suppress the user from visually recognizing the light-shielding region 102.

[0040] (Embodiment 3) The liquid crystal display device according to Embodiment 3 will be described below. What is different between this embodiment and the above-described Embodiments 1 and 2 is that a concave portion 112b is provided on the main surface 112a of the counter substrate 112, and a light reduction filter 123 is partially provided in this concave portion 112b. For the features common to the above-described embodiments, the same reference numerals are given and detailed descriptions are omitted.

[0041] Also in this embodiment, as shown in FIG. 6, the light reduction filter 123 is formed by stacking sub-filters 123R and 123B. In this embodiment, the light reduction filter 123 is formed thicker than the color filters 140R, 140G, and 140B in the display area 101. In this embodiment, a concave portion 112b is provided on the surface of the counter substrate 112 facing the active matrix substrate 111. Therefore, the thickness T1 in the display area 101 of the counter substrate 112 is larger than the thickness T2 in the light reduction area 102 (T1>T2).

[0042] Further, the light reduction filter 123 is provided in the concave portion 112b of the counter substrate 112. For this reason, there is an advantage that the light reduction filter 123 can be formed thicker and the attenuation rate of the light reduction filter 123 can be easily increased. In addition to this, as shown in FIG. 6, the cell gap G2 in the light reduction area 102 can be made the same as the cell gap G1 in the display area 101. Thereby, the liquid crystal layer LC in the pixel PX2 in the light reduction area 102 can be controlled in the same manner as the liquid crystal layer LC in the pixel PX in the display area 101.

[0043] Note that also in this embodiment, the combination of the colors of the sub-filters is arbitrary. Further, the number of sub-filters is not limited to two and may be three. In particular, when three sub-filters of R, G, and B are stacked, it is preferable because the color difference from the black color in the display area 101 becomes small.

[0044] In addition, when the sub-filter has the same thickness as the color filter in the display area 101 and is formed of the same material and in the same stacking order, the sub-filter of the dimming filter 123 can also be formed in the process of manufacturing the color filter in the display area 101, which has the advantage of facilitating manufacturing.

[0045] (Embodiment 4) The liquid crystal display device according to Embodiment 4 will be described below. What is different in this embodiment from Embodiment 1 described above is that the sub-pixels SPR, SPG, and SPB in the display area 101 are defined by the black matrix BM. For the features common to the above-described embodiments, the same reference numerals are given and detailed descriptions are omitted.

[0046] As shown in FIG. 7, the sub-pixels SPR, SPG, and SPB in the display area 101 are defined by the black matrix BM. In this case, as shown in FIG. 7, for the dimming area 102 as well, the black matrix BM is arranged in the same manner as in the display area 101.

[0047] The black matrix BM is also arranged in the dimming area 102 in the same manner as in the display area 101. Thereby, since the pattern of the black matrix BM also exists in the dimming area 102, it is possible to suppress the user from visually recognizing the dimming area 102.

[0048] (Embodiment 5) The liquid crystal display device according to Embodiment 5 will be described below. In the above-described embodiments, the dimming filter provided in the dimming area 102 has a configuration common among the pixels PX2, but in this embodiment, the pixels PX2 provided in the dimming area 102 each have a dimming filter with a different combination of sub-filters. For the features common to the above-described embodiments, the same reference numerals are given and detailed descriptions are omitted.

[0049] As shown in FIG. 8, for pixel PX2, a dimming filter 125 combining a red sub-filter 125R and a blue sub-filter 125B, a dimming filter 126 combining a blue sub-filter 126B and a green sub-filter 126G, or a dimming filter 127 combining a green sub-filter 127G and a red sub-filter 127R is provided.

[0050] Further, as shown in FIG. 9, for example, the dimming filters 125 to 127 are arranged side by side in a stripe pattern. Note that the dimming filters 125 to 127 are not limited to the stripe arrangement, and may be arranged in a matrix pattern as shown in FIG. 10.

[0051] In the liquid crystal display panel of the present embodiment, a dimming filter 125 combining a red sub-filter 125R and a blue sub-filter 125B, a dimming filter 126 combining a blue sub-filter 126B and a green sub-filter 126G, and a dimming filter 127 combining a green sub-filter 127G and a red sub-filter 127R are arranged. Thereby, the color difference in black color between the dimming region 102 and the display region 101 can be reduced. Therefore, it is possible to suppress the user from visually recognizing the dimming region 102.

[0052] (Modification of Embodiment 5) In FIGS. 9 and 10, the configuration in which the dimming filters 125 to 127 are arranged in a stripe pattern or a matrix pattern is described as an example, but the present invention is not limited thereto. In the dimming region 102, a section including a plurality of pixels PX2, for example, a section including 3×3 pixels PX2, is divided, and the inside of the section is the same color filter, for example, a dimming filter 125 combining a red sub-filter and a blue sub-filter, and an adjacent section may be a dimming filter 126 combining a blue sub-filter and a green sub-filter.

[0053] Also, as shown in FIG. 11, it may be formed such that at the boundary where the light-shielding filter 125 and the light-shielding filter 126 are in contact, there is a boundary portion 128 where three-color color filter resists are overlapped. Note that FIG. 11 shows the counter substrate 112 and the light-shielding filters 125, 126, and 127. As shown in FIG. 11, a part of the sub-filter 126G of the light-shielding filter 126 adjacent to the light-shielding filter 125 is provided so as to overlap the light-shielding filter 125. By providing the end of the sub-filter 126G of the G color not included in the light-shielding filter 125 so as to overlap, a boundary portion 128 where three-color color filter resists are overlapped is formed. Since the boundary portion 128 has three-color color filters, the color difference from black in the display region 101 is reduced, which is preferable. Similarly, it is preferable that the boundary where the light-shielding filter 126 and the light-shielding filter 127 are in contact and the boundary where the light-shielding filter 127 and the light-shielding filter 125 are in contact are also formed so as to have a boundary portion 128 where three-color color filter resists are overlapped.

[0054] Next, a process for manufacturing the light-shielding filters 125, 126, and 127 formed so as to have a boundary portion 128 where three-color color filter resists are overlapped will be described. FIG. 12 shows an example of manufacturing the light-shielding filters 125, 126, and 127 in four steps, and FIG. 13 shows an example of manufacturing in three steps. Here, the light-shielding filters 125, 126, and 127 are formed by overlapping color filter resists on the counter substrate 112. Therefore, FIGS. 12 and 13 are shown upside down compared to FIG. 11.

[0055] FIG. 12(a) shows the first step of forming the sub-filter 127G of the G color. First, as shown in the left figure, a G-color color filter resist is applied and formed on the counter substrate 112. Next, as shown in the right figure, an exposure process is performed in which a portion other than the portion where the sub-filter 127G of the G color on the G-color color filter resist is to be formed is covered with a photomask and irradiated with ultraviolet light to cure the G-color color filter resist, and then a developing process is performed to remove the uncured portion, whereby the sub-filter 127G of the G color is formed. When the first step is completed, the process proceeds to the second step.

[0056] FIG. 12(b) shows the second step of forming the R-color sub-filters 125R and 127R. As shown in the left figure of FIG. 12(b), an R-color color filter resist is formed on the opposed substrate 112 on which the G-color sub-filter 127G is formed. Thereby, a layer of the R-color color filter resist for forming the R-color sub-filter 125R is formed on the opposed substrate 112, and a layer of the R-color color filter resist for forming the R-color sub-filter 127R is formed on the G-color sub-filter 127G. Next, as shown in the right figure, portions other than the portions where the R-color sub-filters 125R and 127R are to be formed on the R-color color filter resist are covered with a photomask and exposed, and then developed, whereby the R-color sub-filters 125R and 127R are formed at once. When the second step is completed, the process proceeds to the third step.

[0057] FIG. 12(c) shows the third step of forming the B-color sub-filters 125B and 126B. First, a B-color color filter resist is applied to the recesses on the R-color sub-filter 125R formed in the R-color color filter resist layer and the recesses formed on the opposed substrate 112. Thereby, a layer of the B-color color filter resist for forming the B-color sub-filters 125B and 126B is formed. Next, the portions where the B-color sub-filters 125B and 126B are to be formed on the B-color color filter resist are exposed, and then developed, whereby the B-color sub-filters 125B and 126B are formed at once. When the third step is completed, the process proceeds to the fourth step.

[0058] FIG. 12(d) shows the fourth step of forming the G-color sub-filter 126G. First, a G-color color filter resist is applied to the recesses on the B-color sub-filter 126B formed on the surface of the color filter resist layer. Thereby, a layer of the G-color color filter resist for forming the G-color sub-filter 126G is formed. Next, the portion of the G-color color filter resist is exposed and then developed to form the G-color sub-filter 126G. Through the above four steps, the light reduction filters 125, 126, and 127 are manufactured. Here, at the boundary between the light reduction filter 125 and the light reduction filter 127, a boundary portion 128 is formed where the three-color color filter resists are overlapped by the ends of the light reduction filters 125 and 127. Also, at the boundary between the light reduction filter 127 and the light reduction filter 126, a boundary portion 128 is formed where the three-color color filter resists are overlapped by the ends of the light reduction filters 127 and 126. Further, at the boundary between the light reduction filter 126 and the light reduction filter 125, a boundary portion 128 is formed where the three-color color filter resists are overlapped by the ends of the light reduction filters 126 and 125. The light reduction filters 125, 126, and 127 manufactured by the four steps are such that the first layer formed on the counter substrate 112 is formed by the three-color sub-filters 125R, 127G, and 126B, and the second layer formed by laminating on the first layer is formed by the three-color sub-filters 125B, 127R, and 126G. And different-color sub-filters 125B, 127R, and 126G are formed on the sub-filters 125R, 127G, and 126B of the first layer, respectively. Conversely, if the light reduction filter has a structure in which the first layer is formed with three-color sub-filters and the second layer is laminated with three-color sub-filters of colors different from those of the first layer, it is manufactured by the above four steps.

[0059] Next, an example of manufacturing the dimming filters 125, 126, and 127 in three steps will be described with reference to FIG. 13. FIG. 13(a) shows the first step of forming the G-color sub-filters 127G and 126G. First, as shown in the left figure, a G-color color filter resist is applied and formed into a film on the opposing substrate 112. Next, as shown in the right figure, an exposure process is performed in which portions other than those where the G-color sub-filters 127G and 126G are to be formed on the G-color color filter resist are covered with a photomask and irradiated with ultraviolet light to cure the G-color color filter resist, and then a developing process is performed to remove the uncured portions, whereby the G-color sub-filters 127G and 126G are formed at once. Here, the G-color sub-filters 127G and 126G are formed adjacent to each other, and the left half of the G-color color filter resist layer formed in a trapezoidal shape by the developing process is taken as the G-color sub-filter 127G, and the right half is taken as the G-color sub-filter 126G. Therefore, the stacking order is different from that of the dimming filter 126 shown in FIG. 12(d) manufactured in the four steps described above. When the first step is completed, the process proceeds to the second step.

[0060] FIG. 13(b) shows the second step of forming the R-color sub-filters 125R and 127R. As shown in the left figure of FIG. 13(b), an R-color color filter resist is formed into a film on the opposing substrate 112 on which the G-color sub-filters 127G and 126G are formed. As a result, a layer of the R-color color filter resist for forming the R-color sub-filter 125R is formed on the opposing substrate 112, and a layer of the R-color color filter resist for forming the R-color sub-filter 127R is formed on the G-color sub-filters 127G and 126G. Next, as shown in the right figure, portions other than those where the R-color sub-filters 125R and 127R are to be formed on the R-color color filter resist are covered with a photomask and exposed, and then a developing process is performed, whereby the R-color sub-filters 125R and 127R are formed at once. When the second step is completed, the process proceeds to the third step.

[0061] Figure 13(c) shows the third step of forming the B-color sub-filters 125B and 126B. First, a B-color color filter resist is applied to the recesses on the R-color sub-filter 125R formed on the R-color color filter resist layer and the recesses formed on the counter substrate 112. Thereby, a layer of the B-color color filter resist for forming the B-color sub-filters 125B and 126B is formed. Next, the portions for forming the B-color sub-filters 125B and 126B on the B-color color filter resist are exposed, and then the B-color sub-filters 125B and 126B are formed at once by performing a development process. Through the above three steps, the dimming filters 125, 126, and 127 are manufactured. As described above, the stacking order of the dimming filter 126 is opposite to that in Fig. 12(d), and the G-color sub-filter 126G and the B-color sub-filter 126B are stacked on the counter substrate 112 in this order. At the boundary between the dimming filter 125 and the dimming filter 127, a boundary portion 128 is formed where the three-color color filter resists are overlapped by the ends of the dimming filters 125 and 127. Also, at the boundary between the dimming filter 127 and the dimming filter 126, a boundary portion 128 is formed where the three-color color filter resists are overlapped by the ends of the dimming filters 127 and 126. Further, at the boundary between the dimming filter 126 and the dimming filter 125, a boundary portion 128 is formed where the three-color color filter resists are overlapped by the ends of the dimming filters 126 and 125. In the manufacturing method of Fig. 12, four steps are required: the step of forming a G-color color filter resist on the counter substrate 112, the step of forming an R-color color filter resist, the step of forming a B-color color filter resist, and the step of forming a G-color color filter resist again. In contrast, in the manufacturing method of Fig. 13, the step of forming the G-color color filter resist for the second time can be omitted, and the manufacturing can be simplified. The dimming filters 125, 126, and 127 manufactured through the three steps are such that the first layer formed on the counter substrate 112 is formed by the two-color sub-filters 125R, 127G, and 126G, and the second layer formed by stacking on the first layer is formed by the two-color sub-filters 125B, 127R, and 126B.Then, different - colored sub - filters 125B, 127R, and 126B are formed on the sub - filters 125R, 127G, and 126G of the first layer respectively. Conversely, if it is a dimming filter with a structure in which two - colored sub - filters are formed in the first layer and two - colored sub - filters of colors different from those in the first layer are laminated in the second layer respectively, it is manufactured by the above - mentioned three steps.

[0062] (Embodiment 6) The liquid - crystal display device according to Embodiment 6 will be described below. What is different in this embodiment from the above - described embodiments is that many dimming filters with a specific combination of sub - filters are arranged. For the features common to the above - described embodiments, the same reference numerals are given and detailed descriptions are omitted.

[0063] In the dimming region 102 of this embodiment, for each pixel PX2, as shown in FIG. 14, a dimming filter 125 combining an R - colored sub - filter 125R and a B - colored sub - filter 125B, a dimming filter 126 combining a B - colored sub - filter 126B and a G - colored sub - filter 126G, and a dimming filter 127 combining a G - colored sub - filter 127G and an R - colored sub - filter 127R are respectively provided.

[0064] In this embodiment, from the left in FIG. 14, the dimming filter 126 is arranged next to the dimming filter 125. Next to the dimming filter 126, a dimming filter 125 combining an R - colored sub - filter 125R and a B - colored sub - filter 125B is arranged again. Subsequently, a dimming filter 127 combining a G - colored sub - filter 127G and an R - colored sub - filter 127R is arranged. Therefore, the number of arrangements of the dimming filter 125 combining an R - colored sub - filter 125R and a B - colored sub - filter 125B can be increased. Thereby, the color tone of R + B can be strengthened.

[0065] In this case, the dimming filters 125 to 127 may be arranged in a stripe shape or in a matrix shape, similar to Embodiment 5. Furthermore, the dimming filters 125 to 127 may be arranged randomly.

[0066] In this way, by increasing the number of arrangements of the dimming filters in a specific combination, the hue of the reflected light or transmitted light in the dimming region 102 can be changed. The hue can be changed according to the use of the liquid crystal display device 10, and the dimming region 102 can be prevented from being visually recognized.

[0067] (Embodiment 7) The liquid crystal display device according to Embodiment 7 will be described below. The difference between this embodiment and the above-described embodiments is that the drive voltage applied to the pixel PX2 in the dimming region 102 is varied according to the luminance distribution of the backlight 200. For features common to the above-described embodiments, the same reference numerals are given and detailed description is omitted.

[0068] First, FIG. 16(a) shows a top view of the backlight. FIG. 16(b) shows the luminance distribution of the backlight 200 taken along line B-B in FIG. 14(a). FIG. 16(c) is a diagram showing the transmittance of the liquid crystal layer at a position corresponding to line B-B in FIG. 16(a). Further, FIG. 16(d) is a diagram showing the transmittance of the color filter in the display region 101 and the dimming filter 120 in the dimming region 102 at a position corresponding to line B-B, and FIG. 16(e) shows the luminance of the liquid crystal display device 10 at a position corresponding to line B-B.

[0069] As shown in FIG. 16(b), there is non-uniformity in the luminance of the backlight 200 depending on the position. Specifically, the luminance gradually decreases toward the center of the periphery of the imaging region 202. Corresponding to the inclination of this luminance decrease, as shown in FIG. 16(c), in the dimming region 102 corresponding to the imaging region 202, the transmittance of the liquid crystal layer LC in the dimming region 102 is corrected by changing the drive voltage of the pixel PX2 according to the luminance distribution so as to gradually increase the transmittance of the liquid crystal layer.

[0070] Specifically, as shown in FIG. 15, the control unit 301 of this embodiment includes a display control unit 311, a storage unit 312, and a backlight control unit 313.

[0071] The storage unit 312 of the control unit 300 stores, as a look-up table, the correction value of the voltage applied to each pixel PX2 created based on the luminance distribution within the imaging region 202 measured in advance as shown in FIG. 16(b). The display control unit 311 generates a corrected video signal from the input video signal and the look-up table stored in the storage unit 312. Subsequently, the display control unit 311 supplies the corrected video signal to the driver IC of the liquid crystal display panel 100. The backlight control unit 313 transmits a current value signal representing the value of the current flowing through the light source to the lighting circuit of the backlight 200 based on a PWM (Pulse Width Modulation) signal.

[0072] As shown in FIG. 16(b), there is non-uniformity in the luminance of the backlight 200 depending on the position. However, as shown in FIG. 16(c), by changing the driving voltage of the pixel PX2 according to the luminance distribution, the transmittance of the liquid crystal layer LC in the light-shielding region 102 is corrected. As shown in FIG. 16(d), the transmittance within the light-shielding region 102 is substantially constant. Also, within the display region 101, the luminance is high as shown in FIG. 16(b), but the transmittance of the liquid crystal is low as shown in FIG. 16(c). Further, the transmittance of the color filter is high compared to the light-shielding filter. Considering these together, as shown in FIG. 16(e), the luminance can be made uniform within the plane.

[0073] Therefore, according to the present embodiment, by changing the voltage applied to the pixel PX2 according to the luminance distribution, it is possible to suppress the non-uniformity of the luminance within the light-shielding region 102 and further suppress the user from visually recognizing the light-shielding region.

[0074] Although the present disclosure has been described in accordance with each embodiment, the present disclosure is not limited to these. It is obvious to those skilled in the art that various changes, improvements, combinations, etc. are possible.

[0075] Also, each embodiment can be combined with each other. For example, it is also possible to combine the control unit described in Embodiment 7 with the configurations of Embodiments 1 to 6. Further, it is also possible to combine the configuration including the BM described in Embodiment 4 with the configuration of Embodiment 2 or 3. Also, the number of combinations is arbitrary, and it is also possible to combine the BM described in Embodiment 2 and Embodiment 4 and then combine the configuration of the control unit described in Embodiment 7.

[0076] In the above-described embodiments, an example has been given in which the cell gap of the light-shielding region 102 is the same as or narrower than the cell gap G1 of the display region 101, but the present invention is not limited thereto. For example, as shown in FIG. 17, the thickness of the light-shielding filter 120 of Embodiment 1 is formed thinner than the color filters 140R, 140G, and 140B. Thereby, it is also possible to form the cell gap of the light-shielding region 102 wider as compared with the cell gap of the display region.

[0077] In Embodiment 3, an example has been given in which the concave portion 112b is provided on the counter substrate 112 and the cell gaps G1 and G4 are made the same, but the present invention is not limited thereto. By combining Embodiment 3 and Embodiment 2, it is possible to make the cell gap of the light-shielding region 102 narrower than the cell gap G1 of the display region 101. Conversely, while securing the thickness of the light-shielding filter 123, a configuration in which the cell gap of the light-shielding region 102 is made larger than the cell gap G1 of the display region 101 is also possible.

[0078] In the above-described embodiments, an example has been given in which the backlight is an edge-light type backlight, but the present invention is not limited thereto. For example, the backlight can also be a local dimming backlight.

Explanation of Reference Numerals

[0079] 10 Liquid crystal display device, 100 Liquid crystal display panel, 101 Display area, 102 Light-shielding area, 111 Matrix substrate, 112 Counter substrate, 111a, 112a Main surface, 112b, 203 Concave portion, 113, 114 Polarizing plate, 116 Overcoat film, 119 Sealant, 120, 122, 123, 125, 126, 127 Light-shielding filter, 120R, 120B, 122G, 122B, 123R, 123B, 125R, 125B, 126B, 126G, 127G, 127R Sub-filter, 128 Boundary portion, 130 Electrode formation layer, 140R, 140G, 140B Color filter, 200 Backlight, 201 Lighting area, 202 Imaging area, 204 Imaging device, 205 IR light source, 300, 301 Control unit, 311 Display control unit, 312 Memory unit, 313 Backlight control unit, BM Black matrix, CE Common electrode, G1~G4 Cell gap, LC Liquid crystal layer, PE Pixel electrode, PX, PX2 Pixel, SD Switching element

Claims

1. A liquid crystal display section in which a liquid crystal layer is disposed; An illumination section that illuminates the liquid crystal display section from the back and includes an imaging region where an imaging section is provided; A control section that controls the luminance of the liquid crystal display section, wherein the liquid crystal display section includes a display region and a light-shielding region provided so as to overlap the imaging region of the illumination section when the liquid crystal display section is viewed in plan, and a light-shielding filter is provided in the light-shielding region, and the control section is configured to control driving of the liquid crystal layer in the light-shielding region so as to make the luminance when the display region is at zero gradation coincide with the luminance of the light-shielding region, A liquid crystal display device.

2. The light-shielding filter transmits light in a visible light region and a near-infrared region, The liquid crystal display device according to Claim 1.

3. At least two color filters among R, G, and B are laminated in the light-shielding filter, and an OD value of the light-shielding region where the light-shielding filter is provided is 1.49 or more and 3.10 or less, The liquid crystal display device according to Claim 1.

4. A film thickness of the light-shielding filter is the same as a film thickness of a color filter provided in the display region, The liquid crystal display device according to Claim 3.

5. The film thickness of the light-shielding filter is thicker than the film thickness of the color filter provided in the display region, The liquid crystal display device according to Claim 3.

6. A cell gap of the liquid crystal layer in the light-shielding region is narrower than a cell gap of the liquid crystal layer in the display region, The liquid crystal display device according to Claim 1.

7. The cell gap of the liquid crystal layer in the light-shielding region is the same as the cell gap of the liquid crystal layer in the display region, The liquid crystal display device according to Claim 1.

8. The light-shielding filter is provided on a substrate, and a thickness of the substrate in a region where the light-shielding filter is provided is thinner than a thickness of a region where the display region is formed, The liquid crystal display device according to Claim 1.

9. The light-shielding region is partitioned by a plurality of pixels, two color filters among R, G, and B are laminated in the light-shielding filter, adjacent pixels include light-shielding filters in which combinations of the two laminated color filters are different from each other, and a boundary portion where three color filters of R, G, and B are overlapped is provided at a boundary between adjacent light-shielding filters, The liquid crystal display device according to Claim 1.

10. The plurality of the light-shielding filters arranged in the light-shielding region are such that the first layer is formed of three color filters of R, G, and B, and the second layer is formed of three color filters of R, G, and B. The liquid crystal display device according to claim 9.

11. The plurality of the light-shielding filters arranged in the light-shielding region are such that the first layer is formed of two color filters out of R, G, and B, and the second layer is formed of two color filters out of R, G, and B. The liquid crystal display device according to claim 9.

Images