JP2008139528A - Electro-optical device and electronic appliance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electro-optical device capable of expanding the color reproduction range and improving the luminance. <P>SOLUTION: The electro-optical device is, for example, a liquid crystal display device and is equipped with a liquid crystal display panel and a lighting device. The lighting device illuminates the liquid crystal display panel by making the light transmit the panel. In the liquid crystal display panel, one display pixel is constituted of five sub-pixels; red (R), green (G), blue (B), yellow (Y), transparent or white (W) colors. By using the sub-pixel of Y, expansion of the color reproduction range and the suppression of the degradation in the luminance of the light of the color of G high in the human luminosity factor are achieved. By using the sub-pixel of W, degradation in the luminance over the entire part of the display screen due to the increase in the number of divisions in one display pixel can be suppressed. Also, by providing the sub-pixel of Y, in addition to the sub-pixel of W, relative degradation in the luminosity factor of Y can be suppressed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electro-optical device suitable for displaying various information.

  An electro-optical device typified by a liquid crystal display device performs color display using an illumination device that emits white light and three color filters of red (R), green (G), and blue (B). The color reproduction range that can be expressed by the electro-optical device is limited to a color triangle range defined by three color filters of RGB on the chromaticity diagram. In general, in the color reproduction range defined by the color triangle, the saturation of the yellow color is low and sufficient color reproducibility cannot be obtained. In the liquid crystal display devices disclosed in Patent Documents 1 and 2 below, one display pixel is divided into four or six subpixels, and a subpixel having a color filter of a color other than RGB, for example, yellow (Y). Is provided.

  Recently, a liquid crystal display device has been proposed in which, in addition to the three colors R, G, and B, a transparent (W) sub-pixel is added to one display pixel. In the liquid crystal display device disclosed in Patent Document 3 below, the luminance of the display screen is improved by using W sub-pixels.

  Further, in Patent Document 4 below, the liquid crystal layer of the W sub-pixel is formed by inserting the W sub-pixel in the center of the sub-pixels indicating the four colors R, G, B, and Y. A liquid crystal display device that is automatically driven by an electric field between sub-pixels indicating color is disclosed.

JP 2001-306003 A JP 2002-286927 A JP 2003-295812 A JP 2005-196166 A

  However, in the liquid crystal display devices disclosed in Patent Documents 1 and 2, one display pixel is divided into three or four subpixels of RGB, so that only a general RGB color filter is used. Compared with a liquid crystal display device provided, the aperture ratio in one sub-pixel is lowered, so that the light transmittance is lowered and the luminance of the display screen is also lowered. In addition, in the liquid crystal display device disclosed in Patent Document 3, the luminance of the display screen is improved by adding W sub-pixels, but the color reproduction range is within a color triangle range defined by three color filters of RGB. Will remain limited to. Furthermore, by adding the W sub-pixel, the human visual sensitivity is relatively reduced by R and G, and the visual sensitivity of Y for displaying R, G and a mixture of both is also relatively reduced. When displayed, the color saturation may be felt or the color becomes dull.

  Further, in the method shown in Patent Document 4, there is no counter electrode in the W sub-pixel, and the applied electric field depends on the driving state of the surrounding four-color sub-pixels, so accurate color adjustment is impossible. .

  SUMMARY An advantage of some aspects of the invention is that it provides an electro-optical device capable of accurately expanding a color reproduction range and improving luminance.

  In one aspect of the present invention, an electro-optical device includes five sub-pixels in which one display pixel is red (R), green (G), blue (B), yellow (Y), transparent, or white (W). And a lighting device that illuminates by irradiating the liquid crystal display panel with light and transmitting the liquid crystal display panel through the liquid crystal display panel.

  The electro-optical device is a liquid crystal display device, for example, and includes a liquid crystal display panel and an illumination device. The illumination device includes a light source such as an LED, and illuminates the liquid crystal display panel by irradiating and transmitting light. In the liquid crystal display panel, one display pixel includes five sub-pixels of red (R), green (G), blue (B), yellow (Y), transparent, or white (W). Specifically, the W sub-pixel has a transparent or white portion in a portion corresponding to the colored layer in the other sub-pixels. The transparent or white portion is, for example, a layer formed of a transparent resin or a layer where nothing is provided. By using the Y sub-pixel, it is possible to extend the color reproduction range and suppress the reduction of the luminance of the G-color light with high human visibility, and to use the W sub-pixel to display one display. A decrease in luminance of the entire display screen due to an increase in the number of divisions in pixels can be suppressed. Further, in the electro-optical device according to the present invention, in addition to the W sub-pixel, the Y sub-pixel can be further provided to suppress a relative decrease in the Y visibility.

  In a preferred embodiment of the present invention, the electro-optical device includes a first colored region having a wavelength peak of transmitted light of one display pixel in a range of 600 nm or more and a second colored region in a range of 500 to 580 nm. A liquid crystal display panel comprising five subpixels of a third colored region in the range of 415 to 500 nm, a fourth colored region in the range of 550 to 590 nm, and a transparent or white region, and the liquid crystal display panel And an illuminating device that illuminates the light by transmitting through the liquid crystal display panel. A transparent or white area | region here is an area | region which has a transparent or white part.

  In a preferred embodiment of the electro-optical device, the peak of transmitted light in the fourth colored region is in the range of 560 to 580 nm.

  Another aspect of the electro-optical device further includes a display image conversion circuit that converts an input RGB image signal into an RGBY image signal and outputs the converted signal to the liquid crystal display panel. Thus, even when an RGB image signal is input as the image signal of the input image, the color reproduction range of the output image can be expanded to the yellow color reproduction range.

  In another aspect of the electro-optical device, the display image conversion circuit calculates a luminance signal from the RGB image signals, determines a W image signal based on the luminance signals, and the liquid crystal display panel Output to. Specifically, the display image conversion circuit obtains an RGBY image signal corresponding to the input RGB image signal from an LUT (Look Up Table), and outputs it to the liquid crystal display panel. By doing so, the color purity of the output image can be improved.

  In another aspect of the electro-optical device, the display image conversion circuit determines the luminance of the illumination device based on the luminance signal and adjusts the luminance of the illumination device. By doing in this way, the contrast of a display screen can be improved.

  In still another aspect of the invention, an electronic apparatus including the above-described electro-optical device in a display portion can be configured.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[First Embodiment]
First, the configuration of the liquid crystal display device 100 according to the first embodiment will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a plan view schematically showing a schematic configuration of the liquid crystal display device 100 according to the first embodiment. In FIG. 1, a color filter substrate 92 is disposed on the front side (observation side) of the paper, and an element substrate 91 is disposed on the back side of the paper. In FIG. 1, the vertical direction (column direction) on the paper surface is defined as the Y direction, and the horizontal direction (row direction) on the paper surface is defined as the X direction. In FIG. 1, each region corresponding to R (red), G (green), B (blue), Y (yellow), and W (transparent or white) represents one subpixel SG, and RGBYW The 1 × 5 sub-pixel SG corresponding to 1 represents one display pixel AG.

  FIG. 2 is an enlarged cross-sectional view of one display pixel AG along the cutting line AA ′ in the liquid crystal display device 100. As shown in FIG. 2, the liquid crystal display device 100 includes a liquid crystal display panel 30 and a lighting device 10. In the liquid crystal display panel 30, an element substrate 91 and a color filter substrate 92 disposed to face the element substrate 91 are bonded together via a frame-shaped sealing material 5, and liquid crystal is enclosed inside the sealing material 5. Thus, the liquid crystal layer 4 is formed. An illumination device 10 that illuminates the liquid crystal display panel 30 is provided on the outer surface of the element substrate 91 of the liquid crystal display panel 30.

  The liquid crystal display device 100 according to the first embodiment is a liquid crystal display device for color display configured using five colors of RGBYW, and an α-Si TFT (Thin Film Transistor) element is used as a switching element. This is an active matrix liquid crystal display device.

  A planar configuration of the element substrate 91 will be described. On the inner surface of the element substrate 91, a plurality of source lines 32, a plurality of gate lines 33, a plurality of α-Si TFT elements 37, a plurality of pixel electrodes 34, a driver IC 40, an external connection wiring 35, and an FPC ( Flexible Printed Circuit) 41 or the like is formed or mounted.

  As shown in FIG. 1, the element substrate 91 has a protruding region 31 that protrudes outward from one side of the color filter substrate 92, and a driver IC 40 is mounted on the protruding region 31. A terminal (not shown) on the input side of the driver IC 40 is electrically connected to one end side of the plurality of external connection wirings 35, and the other end side of the plurality of external connection wirings 35 is electrically connected to the FPC 41. It is connected. Each source line 32 is formed so as to extend in the Y direction and at an appropriate interval in the X direction, and one end side of each source line 32 is connected to an output side terminal (not shown) of the driver IC 40. Electrically connected.

  Each gate line 33 includes a first wiring 33a formed so as to extend in the Y direction, and a second wiring 33b formed so as to extend in the X direction from the terminal portion of the first wiring 33a. ing. The second wiring 33 b of each gate line 33 is formed to extend in the direction intersecting each source line 32, that is, in the X direction and at an appropriate interval in the Y direction. One end of one wiring 33a is electrically connected to a terminal (not shown) on the output side of the driver IC 40. An α-TFT element 37 is provided at a position corresponding to the intersection of each source line 32 and each gate line 33 with the second wiring 33b, and each α-TFT element 37 includes each source line 32, each gate line 33, and each gate line 33. It is electrically connected to each pixel electrode 34 and the like. Each α-TFT element 37 and each pixel electrode 34 are provided at positions corresponding to each sub-pixel SG on the substrate 1 such as glass. Each pixel electrode 34 is formed of a transparent conductive material such as ITO (Indium-Tin Oxide).

  A region in which a plurality of display pixels AG are arranged in a matrix in the X and Y directions is an effective display region V (a region surrounded by a two-dot chain line). In the effective display area V, images such as letters, numbers, and figures are displayed. That is, the effective display area V indicates a display screen area in the liquid crystal display device 100. The area outside the effective display area V is a frame area 38 that does not contribute to display. An alignment film (not shown) is formed on the inner surface of each source line 32, each gate line 33, each α-TFT element 37, each pixel electrode 34, and the like.

  Next, the planar configuration of the color filter substrate 92 will be described. As shown in FIG. 2, the color filter substrate 92 is formed on a substrate 2 such as glass on a light shielding layer (generally called “black matrix”, hereinafter simply abbreviated as “BM”), R, G, B , Y colored layers 6R, 6G, 6B, 6Y, W transparent or white portion 6W, common electrode 8, and the like. The transparent or white portion 6W is, for example, a layer formed of a transparent resin or a layer provided with nothing, and transmits the light L from the lighting device 10 as it is without being colored. The BM is formed at a position that partitions each subpixel SG. In FIG. 2, for the sub-pixels SG of each color, the corresponding colors are shown with parentheses.

  In the following description or drawings, when a component is indicated without specifying the RGBY color, it is simply written as “colored layer 6”, and when the component is indicated by distinguishing the RGBY color, For example, it is written as “colored layer 6R”. The colored layers 6R, 6G, 6B, and 6Y and the transparent or white portion 6W constitute a color filter. The common electrode 8 is made of a transparent conductive material such as ITO like the pixel electrode, and is formed over substantially the entire surface of the color filter substrate 92. The common electrode 8 is electrically connected to one end side of the wiring 36 in the corner area E1 of the sealing material 5, and the other end side of the wiring 36 is electrically connected to an output terminal corresponding to the COM of the driver IC 40. It is connected to the.

  Next, the illumination device 10 will be described. The lighting device 10 includes a light guide plate 11 and a light source unit 12. The light source unit 12 has a plurality of LEDs 13 as a light source. As the plurality of LEDs 13, a single chip type white LED that excites a YAG (yttrium, aluminum, garnet) phosphor with blue light from a blue LED and emits white light thereby may be used. Alternatively, a multi-chip type that emits white light by aligning LEDs of RGB colors and simultaneously emitting and mixing light may be used. White light emitted from the plurality of LEDs 13 is emitted as light L from the light source unit 12 toward an end surface (hereinafter referred to as “light incident end surface”) 11 c of the light guide plate 11.

  The light L emitted from the light source unit 12 enters the light guide plate 11 through the light incident end surface 11c of the light guide plate 11, changes its direction by repeating reflection at the light output surface 11a and the reflection surface 11b of the light guide plate 11, and changes the direction. When the angle formed by the light exit surface 11a and the light L exceeds the critical angle, light exits from the light exit surface 11a of the light guide plate 11 toward the liquid crystal display panel 30 through the optical sheet (not shown) as illumination light L. The liquid crystal display device 100 is illuminated by the light L passing through the liquid crystal display panel 30. Thereby, the liquid crystal display device 100 can display images, such as a character, a number, and a figure, and an observer can visually recognize an image.

  In the liquid crystal display device 100, G1, G2,..., Gm−1, Gm (m is a natural number) are generated by the driver IC 40 based on the signal and power from the FPC 41 side connected to the main board or the like of the electronic device. The gate lines 33 are sequentially selected one by one in order, and a gate signal of a selection voltage is supplied to the selected gate lines 33, while the other non-selected gate lines 33 are not selected. A voltage gate signal is provided. Then, the driver IC 40 applies source signals corresponding to display contents to the pixel electrodes 34 located at positions corresponding to the selected gate lines 33, respectively, corresponding S1, S2,..., Sn-1, Sn ( n is a natural number) and is supplied through the α-TFT element 37. As a result, the alignment state of the liquid crystal layer 4 is controlled, and the display state of the liquid crystal display device 100 is switched to the non-display state or the intermediate display state.

  Although the liquid crystal display device 100 is shown as a completely transmissive liquid crystal display device, the present invention is not limited to this, and a transflective liquid crystal display device may be used instead. FIG. 3 shows a configuration of the sub-pixel SG in the transflective liquid crystal display device. In this case, a reflective layer 41 that reflects light is provided on the pixel electrode 34 of each subpixel SG. As an example of this aspect, as shown in FIG. 3A, the reflective layer 41 is formed so as to have an opening 42. The opening 42 becomes a transmission region that transmits the light L from the illumination device 10. Alternatively, as shown in FIG. 3B, the subpixel SG may be divided into two regions, the reflective layer 41 is formed only on one side, and the reflective layer 41 is not formed on the other side. In this case, the region 43 where the reflective layer 41 is not formed becomes a transmissive region that transmits the light L from the illumination device 10.

  Furthermore, although the α-TFT element 37 is used as the switching element as shown in FIG. 1, the present invention is not limited to this, and a polysilicon TFT or a TFD (Thin Film Diode) element can be used instead. .

(Spectral distribution and chromaticity diagram)
FIG. 4 shows the relationship between the transmittance of the colored layer 6 and the wavelength of light in the liquid crystal display device 100 according to the first embodiment. The horizontal axis represents the light wavelength [nm], and the vertical axis represents the transmittance of the colored layer.

  In FIG. 4, graphs 301R, 301G, 301B, and 301Y indicate the transmittances of the RGBY colored layers 6R, 6G, 6B, and 6Y, respectively. As can be seen from the graphs 301R, 301G, 301B, 301Y, the transmittance of each of the RGBY colored layers 6 has the property that the transmittance is highest in the wavelength range of each color of RGBY. Therefore, in the liquid crystal display device 100 according to the first embodiment, when displaying each color of RGBY, it is possible to perform color display by transmitting only the light in which the colored layer of each color is in the wavelength range of each color. Here, when the graph 301Y is seen, it can be seen that it has a region 350 overlapping the graph 301G. That is, the Y colored layer 6Y and the G colored layer 6G have portions where the transmission wavelength regions overlap.

  FIG. 5 shows a color reproduction range by the liquid crystal display device according to the first embodiment in a chromaticity diagram of the International Commission on Illumination (CIE). In FIG. 5, a color reproduction range 401 is a color reproduction range based on the wavelength sensitivity characteristic of the human eye, and indicates a color reproduction range that can be recognized by humans. A color reproduction range 402 indicated by a triangular broken line is a color reproduction range achieved by a liquid crystal display device having a colored layer composed of only three general RGB colors. On the other hand, a color reproduction range 451 indicated by a rectangular solid line is a color reproduction range achieved by the liquid crystal display device 100 according to the first embodiment. A color reproduction range 411 indicates a yellow color reproduction range.

  As can be seen from the fact that the yellow color reproduction range becomes the color reproduction range 411 in FIG. 5, the color reproduction range is 402 in a liquid crystal display device having a colored layer consisting of only three general RGB colors. Therefore, it was difficult to display a yellowish color. On the other hand, the color reproduction range 451 achieved by the liquid crystal display device according to the first embodiment is wider than the color reproduction range 402, and particularly extends to the yellow color reproduction range 411. It has a nice shape. In other words, the liquid crystal display device 100 according to the first embodiment can expand the color reproduction range, in particular, the yellow color reproduction range.

  Compared with a general liquid crystal display device having a colored layer composed of only three colors of RGB, as described above, in the liquid crystal display device according to the first embodiment, one sub-pixel includes RGB sub-pixels. In addition to SG, the structure has Y and W sub-pixels SG. In a general liquid crystal display device having a colored layer composed of only three colors of RGB, one display pixel is composed of RGB sub-pixels SG, and is thus divided into three. On the other hand, in the liquid crystal display device according to the first embodiment, one display pixel is composed of RGBYW sub-pixels SG and is thus divided into five. Therefore, the liquid crystal display device 100 according to the first embodiment partitions each sub-pixel SG when viewed from the entire display screen as compared with a liquid crystal display device having a colored layer composed of only three colors of RGB. As the BM formed at the position increases, the aperture ratio in each sub-pixel SG also decreases, so that the light transmittance decreases and the luminance also decreases.

  However, in the liquid crystal display device 100 according to the first embodiment, as described above, the Y colored layer 6Y and the G colored layer 6G have portions where the transmission wavelength regions overlap. The light of the color where the transmission wavelength region overlaps can be transmitted through both the colored layer 6Y and the colored layer 6G. In other words, by dividing one display pixel into five parts, the light of one subpixel SG is compared with the area of the subpixel in a liquid crystal display device having a colored layer composed of only three general RGB colors. Even if the transmittance is reduced, the light of the color where the transmissive region overlaps can be emitted from both the sub-pixel SG having the colored layer 6Y and the sub-pixel SG having the colored layer 6G. The light of G color has high human visibility. Accordingly, by emitting light in the wavelength region of a part of the G color through the Y sub-pixel SG, it is possible to suppress a decrease in luminance of the G color light having high human visibility.

  Further, in the liquid crystal display device 100 according to the first embodiment, although one display pixel is divided into five, one of the subpixels SG is a W subpixel SG. Since the W sub-pixel SG has the transparent or white portion 6W, the light L emitted from the illumination device 10 can be transmitted as it is without being absorbed by the transparent or white portion 6W. Therefore, by using the W sub-pixel SG, the luminance of the display pixel can be improved, and thus the luminance of the entire display screen can be improved. As can be seen from the above, in the liquid crystal display device according to the first embodiment, the decrease in luminance of the entire display screen caused by one display pixel being divided into five can be transmitted through the light L as it is. This can be suppressed by using the subpixel SG.

  In addition, when a W subpixel is additionally provided in a liquid crystal display device having a color layer composed of only three colors of RGB, the luminance of the display screen is improved, but the W subpixel SG is added. As a result, the human visibility is relatively lowered in R and G. For this reason, the visibility of Y in which R, G, and both are mixedly displayed is also relatively lowered, and the saturation is felt when displayed, or the color becomes dull. On the other hand, in the liquid crystal display device 100 according to the first embodiment, since the Y sub-pixel SG is further provided in addition to the W sub-pixel SG, a relative decrease in the Y visibility can be suppressed.

  In summary, the liquid crystal display device 100 according to the first embodiment uses a Y sub-pixel SG as compared with a liquid crystal display device having a colored layer composed of only three general RGB colors. Display screen by increasing the number of divisions in one display pixel by expanding the reproduction range and suppressing a decrease in luminance of light of G color with high human visibility and using W subpixel SG A reduction in the overall luminance can be suppressed. Further, in the liquid crystal display device 100 according to the first embodiment, since the Y sub-pixel SG is further provided in addition to the W sub-pixel SG, a relative decrease in the Y visibility can be suppressed.

  As an image signal input to the liquid crystal display device 100 according to the first embodiment, for example, RGBY image signals may be directly input from the outside, or RGB image signals may be input from the outside. It may be input and converted into RGBY image signals. At this time, the liquid crystal layer in the W sub-pixel SG is always in a state of completely transmitting light.

  Next, in the liquid crystal display device 100, a case where image signals of each color of RGB are converted into image signals of each color of RGBY will be described.

  FIG. 6 is a schematic diagram of the liquid crystal display device 100 according to the first embodiment. In the liquid crystal display device 100, when the input RGB color image signals are converted into RGBY color image signals, the liquid crystal display device 100 includes a display image conversion circuit 612. The display image conversion circuit 612 has a function of converting RGB color image signals output from an external display image output source 611 such as a personal computer into RGBY color image signals and outputting them to the liquid crystal display panel 30. Have.

  The display image output circuit 612 includes an arithmetic processing unit 612a such as a CPU (Central Processing Unit) and a storage unit 612b such as a RAM (Random Access Memory). The arithmetic processing unit 612a converts the RGB image signals 61R, 61G, 61B of the input image output from the display image output source 611 into RGBY color image signals 62R, 62G, 62B, 62Y. The storage unit 612b is provided with an LUT (Look Up Table) in which image signals of RGB colors having a predetermined intensity are associated with image signals of RGBY colors having a corresponding intensity. For example, when an RGB image signal for displaying only the Y color is input to the arithmetic processing unit 612a, for example, an RGB image signal with an intensity of R = 0, G = 100, and B = 100, The arithmetic processing unit 612a stores the RGBY color image signals (for example, R = 0, G = 10, B = 10, Y = 100) having the intensity corresponding to the intensity of the RGB color image signals, and the storage unit 612b. The obtained RGBY color image signals are output to the liquid crystal display panel 30. As a result, not only the RGB colors but also the Y color can be displayed on the display screen of the liquid crystal display panel 30. In this way, the color reproduction range of the output image can be expanded to the color reproduction range of the yellow color even when an RGB image signal is input as the image signal of the input image. it can.

[Second Embodiment]
Next, a liquid crystal display device 100a according to a second embodiment of the present invention will be described. FIG. 7 is a schematic diagram showing a liquid crystal display device 100a according to the second embodiment. The display image conversion circuit 612 in the liquid crystal display device 100a according to the second embodiment not only converts the RGB color image signals output from the display image output source 611 such as a personal computer into RGBY color image signals. , W image signals are also converted and output to the liquid crystal display panel 30.

  In the same manner as described in the first embodiment, the display image output circuit 612 converts the RGB color image signals into RGBY color image signals to expand the color reproduction range. At this time, the arithmetic processing unit 612a further calculates a luminance signal from the input RGB color image signals, and outputs the W color image signal determined based on the luminance signals to the liquid crystal display panel 30. To do. Expression (1) shown below is a general expression for calculating the luminance signal Y_sig and the color difference signals I and Q from the intensity of each color of RGB. In Expression (1), the intensity of each color of RGB is Ra, Ga, and Ba, respectively. Specifically, the arithmetic processing unit 612a detects the intensity of each RGB color from the input RGB image signal, and then determines the luminance signal Y_sig of Expression (1) based on the detected intensity of each RGB color. The luminance signal Y_sig is calculated using the equation for obtaining

  The arithmetic processing unit 612a determines the W image signal based on the calculated luminance signal Y_sig, and outputs the determined W image signal to the liquid crystal display panel 30. In this way, the gradation of the liquid crystal layer in the W sub-pixel SG can be adjusted according to the input image, and the output image can be displayed with an appropriate luminance according to the input image.

  As described above, the liquid crystal display device 100a according to the second embodiment can adjust the gradation of the liquid crystal layer in the W sub-pixel SG based on the luminance signal Y_sig. It is possible to display with appropriate brightness. Therefore, it is possible to improve the color purity of the output image, rather than making the liquid crystal layer in the W sub-pixel SG always transmit light.

[Third embodiment]
Next, a liquid crystal display device 100b according to a third embodiment of the present invention is described. FIG. 8 is a schematic diagram of a liquid crystal display device 100b according to the third embodiment. The difference between the liquid crystal display device 100b according to the third embodiment and the liquid crystal display device 100 according to the first embodiment is that the display image conversion circuit 612 supplies a control signal 62BL to the illumination device 10. . Specifically, the display image conversion circuit 612 adjusts the luminance of the light L emitted from the light source unit 12 of the lighting device 10 by supplying the control signal 62BL to the LED 13 of the lighting device 10.

  The arithmetic processing unit 612a of the display image conversion circuit 612 determines the control signal 62BL based on the luminance signal Y_sig obtained from the previous equation (1). For example, based on the luminance signal Y_sig, when it is determined that the ratio of display pixels having high luminance is high in one display image, adjustment is performed to increase the luminance of the light L, while low in one display image. When it is determined that the ratio of display pixels having luminance is large, adjustment is performed to lower the luminance of the light L. At this time, the W sub-pixel SG may have the liquid crystal layer in a completely transmissive state, or, as described in the liquid crystal display device 100a according to the second embodiment, the gradation may be changed based on the luminance signal Y_sig. It may be changed.

  In the liquid crystal display device according to the third embodiment, the brightness of the light L emitted from the illumination device 10 is adjusted in accordance with the input image signal, so that bright images are displayed brighter and dark images are displayed darker. And the contrast of the display screen can be improved.

[Modification]
In the above description, RGBY is described as the color (colored region) of the colored layer functioning as a color filter. However, the application of the present invention is not limited to this, and one pixel is formed by other four colored regions. It can also be configured.

  In this case, the four colored regions are red-colored colored regions (also referred to as “first colored regions”) in the visible light region (380 to 780 nm) whose hue changes depending on the wavelength, and green-based colored regions. Colored area of hue (also referred to as “second colored area”), colored area of blue hue (also referred to as “third colored area”), colored area of yellow hue (also referred to as “fourth colored area”) Consists of. Here, the term “system” is used. For example, if it is a blue system, the color is not limited to a pure blue hue, and includes a blue-violet color, a blue-green color, and the like. If it is a red hue, it is not limited to red but includes orange. These colored regions may be composed of a single colored layer, or may be composed of a plurality of colored layers having different hues. In addition, although these colored regions are described in terms of hue, the hue can be set by changing the saturation and lightness as appropriate.

The specific hue range is, for example,
-The colored region of red hue is from orange to red.
-The colored region of the blue hue is from violet to blue-green, more preferably from indigo to blue.

  Thereby, a wider range of color reproducibility than the conventional RGB colored region can be realized.

Also, in the above description, a wide range of color reproducibility by the colored areas of four colors has been described in terms of hue, but below, when expressed in terms of the wavelength of light transmitted through the colored areas, it is as follows from FIG.
The red colored region is a colored region having a wavelength peak of light transmitted through the colored region of 600 nm or more, and preferably a colored region of 605 nm or more.
The green colored region is a colored region having a wavelength peak of light transmitted through the colored region in the range of 500 nm to 580 nm, preferably a colored region in the range of 510 to 570 nm.
The blue colored region is a colored region having a peak of the wavelength of light transmitted through the colored region at 415 to 500 nm, preferably a colored region at 435 to 485 nm.
The yellow colored region is a colored region having a wavelength peak of light transmitted through the colored region of 550 to 590 nm, and preferably a colored region of 560 to 580 nm.

  In addition, when the colored region of 4 colors in this example is used, you may use a fluorescent tube, organic EL, etc. other than the above-mentioned LED as a light source of RGBW for a backlight.

However, among the RGBW light sources, the following are preferable as the RGB light sources.
-B has a peak wavelength of emitted light at 435 nm to 485 nm-G has a peak wavelength of emitted light at 520 nm to 545 nm-R has a peak wavelength of emitted light at 610 nm to 650 nm And if a color filter is appropriately selected according to the wavelength of the RGB light source, a wider range of color reproducibility can be obtained.

  Moreover, you may use the light source which has a some peak so that a wavelength may come to a peak at 450 nm and 565 nm, for example.

  Next, modified examples of the liquid crystal display devices 100 to 100b according to the embodiments will be described. Specifically, this modification is a modification of the arrangement configuration of the sub-pixels SG in the display pixel AG.

  9A to 9D are plan views illustrating modifications of the arrangement configuration of the sub-pixels SG in the display pixel AG. The hatched areas indicate the areas of the sub-pixels SG of the respective colors. FIG. 9A shows an arrangement configuration of the sub-pixels SG described above. The arrangement configuration of the sub-pixels SG in one display pixel AG is not limited to the arrangement configuration shown in FIG. 9A. Instead, the arrangement configuration shown in FIGS. 9B to 9D may be adopted. it can.

  In the arrangement shown in FIG. 9B, as shown in the figure, the W sub-pixel SG has an L-shape and is in contact with the RGBY sub-pixels SG. Therefore, when such an array configuration is adopted, the observer sees the brightness of each color of RGBY equally improved. In the arrangement shown in FIGS. 9A and 9B, the RGBYW sub-pixels SG are arranged in stripes, so that the display state of the sub-pixels SG such as the gate line 33 and the source line 32 is controlled. Thus, the wiring configuration of the liquid crystal display panel 30 can be simplified.

  In the arrangement shown in FIG. 9C, the RGBY sub-pixels SG are arranged in a square shape, and the W sub-pixel SG is arranged at the center thereof. When such an arrangement is adopted, the central portion of the display pixel AG in which the W sub-pixel SG is arranged becomes brighter, so that the luminance of the display pixel AG itself appears to be improved as viewed from the observer. The same effect can be obtained with the arrangement configuration of the delta arrangement shown in FIG.

  Further, in FIGS. 9A to 9D, the area of the W sub-pixel SG may be different from the area of the sub-pixels SG of other colors, that is, RGBY. This is because the W sub-pixel SG is only for improving the luminance of the display pixel AG.

[Electronics]
Next, specific examples of electronic devices to which the liquid crystal display devices 100 to 100b according to the above-described embodiments can be applied will be described with reference to FIG.

  First, an example in which the liquid crystal display devices 100 to 100b according to the embodiments are applied to a display unit of a portable personal computer (so-called notebook personal computer) will be described. FIG. 10A is a perspective view showing the configuration of this personal computer. As shown in the figure, the personal computer 710 includes a main body 712 having a keyboard 711 and a display 713 to which the liquid crystal display devices 100 to 100b according to the present invention are applied.

  Next, an example in which the liquid crystal display devices 100 to 100b according to each embodiment are applied to a display unit of a mobile phone will be described. FIG. 10B is a perspective view showing the configuration of this mobile phone. As shown in the figure, the cellular phone 720 includes a plurality of operation buttons 721, a reception port 722, a transmission port 723, and a display unit 724 to which the liquid crystal display devices 100 to 100b according to the present invention are applied.

  As electronic devices to which the liquid crystal display devices 100 to 100b according to the embodiments can be applied, in addition to the personal computer shown in FIG. 10A and the mobile phone shown in FIG. , Viewfinder type / monitor direct view type video tape recorder, car navigation device, pager, electronic notebook, calculator, word processor, workstation, videophone, POS terminal, digital still camera, and the like.

1 is a plan view of a liquid crystal display device according to a first embodiment. 1 is a cross-sectional view of a liquid crystal display device according to a first embodiment. It is a top view of the sub pixel of the liquid crystal display device concerning a 1st embodiment. It is a figure which shows the spectrum distribution of the liquid crystal display device which concerns on 1st Embodiment. It is an xy chromaticity diagram of the International Commission on Illumination (CIE) showing a chromaticity range. 1 is a schematic diagram of a liquid crystal display device according to a first embodiment. It is a schematic diagram of the liquid crystal display device which concerns on 2nd Embodiment. It is a schematic diagram of the liquid crystal display device which concerns on 3rd Embodiment. It is a top view of the sub pixel which shows the modification of the liquid crystal display device of each embodiment. It is a figure which shows the example of the electronic device to which the liquid crystal display device of each embodiment is applied.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 Light guide plate, 12 Light source part, 13 LED, 10 Illumination device, 30 Liquid crystal display panel, 100 Liquid crystal display device

Claims (7)

A liquid crystal display panel in which one display pixel includes five sub-pixels of red (R), green (G), blue (B), yellow (Y), transparent, or white (W);
An illuminating device that performs illumination by irradiating the liquid crystal display panel with light and transmitting the liquid crystal display panel;
An electro-optical device comprising: A first colored region having a wavelength peak of transmitted light of one display pixel in a range of 600 nm or more, a second colored region in a range of 500 to 580 nm, and a third colored region in a range of 415 to 500 nm; A liquid crystal display panel composed of a fourth colored region in the range of 550 to 590 nm, and five sub-pixels of a transparent or white region,
An illumination device that illuminates the liquid crystal display panel by irradiating light and transmitting the liquid crystal display panel;
An electro-optical device comprising:   The electro-optical device according to claim 2, wherein a peak of transmitted light of the fourth colored region is in a range of 560 to 580 nm.   4. The electrical apparatus according to claim 1, further comprising a display image conversion circuit that converts an input RGB image signal into an RGBY image signal and outputs the RGBY image signal to the liquid crystal display panel. 5. Optical device.   The display image conversion circuit calculates a luminance signal from the RGB image signals, determines a W image signal based on the luminance signals, and outputs the W image signal to the liquid crystal display panel. 4. The electro-optical device according to claim 3.   The electro-optical device according to claim 5, wherein the display image conversion circuit determines the luminance of the illumination device based on the luminance signal and adjusts the luminance of the illumination device.   An electronic apparatus comprising the electro-optic device according to claim 1 in a display unit.

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