JP2007206585A - Electro-optical device and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electro-optical device including color filters of four colors, which is capable of improving the display luminance of red on a display screen. <P>SOLUTION: The electro-optical device includes a display panel and a light source. The display panel includes a plurality of sun-pixels, each of which is provided with one of a first color layer of red, a second color layer of blue, and third and fourth color layers of two kinds of colors, arbitrarily selected from among hues ranging from blue to yellow. The light source comprises a first light source emitting blue light, a blue wavelength conversion means for converting a part of blue light to yellow light, and a second light source emitting red light and emits a combined light of blue light, yellow light, and red light to the display panel. Thus display luminance of red on the display screen can be improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electro-optical device such as a liquid crystal display device.

  An electro-optical device typified by a liquid crystal display device is a display such as a liquid crystal display panel including an illumination device that emits white light and three color filters such as red (R), green (G), and blue (B). Color display is performed by the panel. The illumination device illuminates the display panel by transmitting the emitted white light to the display panel. For example, a white LED (Light Emitting Diode) capable of emitting white light is used as a light source in the illumination device. The white LED is composed of a blue LED that emits blue light and a YAG (yttrium, aluminum, garnet) phosphor. The blue light emitted from the blue LED excites the YAG phosphor and generates yellow light. White light emitted from the white LED is a mixture of blue light emitted from the blue LED and yellow light generated by exciting the YAG phosphor.

  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 R, G, and B on the chromaticity diagram. In general, in the color reproduction range defined by the color triangle, the saturation of the green color is low, and sufficient color reproducibility cannot be obtained.

  Therefore, recently, a liquid crystal display device having a four-color filter in which two green color filters are added to a red and blue color filter has come out.

  In Patent Document 1 below, LEDs that emit blue light and LEDs that emit red light are used, and blue light, red light, and green light obtained by wavelength conversion of blue light are mixed. Thus, an illumination device that generates white light is described.

JP 2000-275636 A

  However, in the liquid crystal display device including the four color filters obtained by adding two green color filters to the red and blue color filters, the display range of the green color can be expanded. The white point on the display screen tends to shift to the green side. In addition, when a white LED is used as the light source of the illumination device, the luminance of red light is low, and when the red color filter is applied, the luminance of red light is lower than that of other colors. End up.

  The present invention has been made in view of the above points. In an electro-optical device including four color filters, the red display luminance is improved and the white point on the display screen is shifted to the green side. It is a problem to suppress.

  In one aspect of the present invention, the electro-optical device includes a plurality of sub-pixels, and is arbitrarily selected from among a red first colored layer, a blue second colored layer, and a hue from blue to yellow. A display panel including any one of the third and fourth colored layers in the sub-pixel, a first light source that emits blue light, and blue that converts part of the blue light into yellow light A light source that includes a light wavelength conversion unit and a second light source that emits red light, and that emits white light, which is a combined light of the blue light, the yellow light, and the red light, to the display panel.

  The electro-optical device is a liquid crystal display device, for example, and includes a display panel such as a liquid crystal display panel and a light source. The display panel includes a plurality of sub-pixels, and the third and fourth colors arbitrarily selected from a red first colored layer, a blue second colored layer, and a hue from blue to yellow. One of two types of colored layers is provided in the sub-pixel. The light source is, for example, a light source unit provided in a lighting device, a first light source that emits blue light, a blue light wavelength conversion unit that converts part of the blue light into yellow light, and red light. A second light source that emits light is emitted, and the combined light of the blue light, the yellow light, and the red light is emitted to the display panel. Thereby, even when the red color filter, that is, the first colored layer is applied, the luminance of the red light can be increased, and the red display luminance on the display screen can be improved.

  In a preferred embodiment of the electro-optical device, the wavelength of the red light peak is set in a range of 630 to 650 nm.

  In another aspect of the electro-optical device, the second light source is a semiconductor light emitting element that emits red light, and a change in temperature is detected so that the luminance of the red light always becomes a predetermined luminance. Adjust to. Thereby, the illuminating device can hold | maintain a predetermined spectral characteristic with respect to a temperature change.

  In a preferred embodiment of the electro-optical device, the third colored layer is a green colored layer, and the fourth colored layer is a yellow-green colored layer.

  In a preferred embodiment of the electro-optical device, the third colored layer has a wavelength peak of transmitted light at 485-535 nm, and the fourth colored layer has a wavelength peak of transmitted light of 500-. 590 nm.

  In another aspect of the electro-optical device, the wavelength of the blue light peak is set to 455 nm, the maximum transmittance of the second colored layer is 77%, and the transmittance of the third colored layer Is set to 66%. Thereby, it is possible to improve the red display luminance on the display screen, and to suppress the white point from shifting to the green side without causing the observer to feel a decrease in luminance.

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

  In still another aspect of the present invention, the illumination device includes a first light source that emits blue light, a blue light wavelength conversion unit that converts part of the blue light into yellow light, and a first light source that emits red light. A light source including two light sources, and emits a combined light of the blue light, the yellow light, and the red light. Thereby, the brightness | luminance of red light can be made high.

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

[Configuration of liquid crystal display device]
First, the configuration and the like of the liquid crystal display device 100 according to the present embodiment will be described with reference to FIGS.

  FIG. 1 is a plan view schematically showing a schematic configuration of a liquid crystal display device 100 according to the present 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), G1 (green 1), B (blue), and G2 (green 2) represents one sub-pixel SG, and R, G1, B, A sub-pixel SG of 1 row and 4 columns corresponding to G2 represents one display pixel AG. Here, G1 (green 1) and G2 (green 2) are two kinds of hues selected from hues from blue to yellow. In the present embodiment, as an example, G1 (green 1) generally indicates pure green indicated by G, and G2 (green 2) indicates yellowish green.

  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 an illumination device 10, a liquid crystal display panel 30, a diffusion sheet 14, a prism sheet 15, and a reflection sheet 16. 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. The liquid crystal used for the liquid crystal layer 4 is, for example, a TN (Twisted Nematic) type liquid crystal. The illumination device 10 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 present embodiment is a liquid crystal display device for color display configured using four colors of R, G1, B, and G2, and an α-Si TFT (Thin Film Transistor) as a switching element. This is an active matrix driving type liquid crystal display device using elements.

  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 33 b, 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. 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 referred to as “black matrix”, hereinafter simply abbreviated as “BM”), R, G1, B , G2 color layers 6R, 6G1, 6B, 6G2 and the common electrode 8 and the like. The BM is formed at a position that partitions the sub-pixels SG for each color. In the following description or drawings, when a component is shown without specifying the colors of R, G1, B, and G2, it is simply written as “colored layer 6”, and R, G1, B, and G2 In the case of showing the components by distinguishing colors, for example, “colored layer 6R” is used. The sub-pixels SG for each color of R, G1, B, and G2 include R, G1, B, and G2 colored layers 6R, 6G1, 6B, and 6G2, respectively. The colored layers 6R, 6G1, 6B, and 6G2 of R, G1, B, and G2 function as color filters for the respective colors. 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 emits light L to the end surface 11 c of the light guide plate 11. The light source unit 12 includes a plurality of LEDs 13.

  In FIG. 3, the top view of the illuminating device 10 is shown. The LED 13 includes a white LED 13a and a red LED 13b. The white LED 13a includes a blue LED that emits blue light and a YAG (yttrium, aluminum, garnet) phosphor. Blue light emitted from the blue LED excites the YAG phosphor to generate yellow light. The red LED 13b can emit red light. That is, the light L emitted from the light source unit 12 is a mixture of blue light emitted from the blue LED, yellow light generated by exciting the YAG phosphor with the blue light, and red light emitted from the red LED 13b. It is white light which is the synthesized light.

  Light L emitted from the light source unit 12 enters the light guide plate 11 through an end surface (hereinafter referred to as “light incident end surface”) 11 c of the light guide plate 11, and is repeatedly reflected on the light output surface 11 a and the reflection surface 11 b of the light guide plate 11. Change direction. When the angle between the light exit surface 11 a of the light guide plate 11 and the light L exceeds the critical angle, the light L exits from the light exit surface 11 a of the light guide plate 11 toward the liquid crystal display panel 30. The light L is emitted from the reflective surface 11b of the light guide plate 11 when the angle formed between the reflective surface 11b of the light guide plate 11 and the light L exceeds a critical angle. However, the light emitted from the reflection surface 11 b of the light guide plate 11 is reflected by the reflection sheet 16 that reflects the light and returned to the inside of the light guide plate 11.

  The light L emitted from the light exit surface 11 a of the light guide plate 11 toward the liquid crystal display panel 30 passes through the diffusion sheet 14 and the prism sheet 15 and then passes through the liquid crystal display panel 30. The diffusion sheet 14 diffuses and emits the light L. The prism sheet 15 includes prism sheets 15a and 15b. Each of the prism sheets 15 a and 15 b has a prism shape whose cross-sectional shape is substantially triangular, and emits light L toward the liquid crystal display panel 30. The prism sheets 15a and 15b are arranged so that the ridgelines of the prism-shaped prisms are substantially perpendicular to each other. 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 according to the present embodiment 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. The liquid crystal display panel 30 uses the α-TFT element 37 as a switching element. However, the liquid crystal display panel 30 is not limited to this, and a polysilicon TFT or a TFD (Thin Film Diode) element may be used instead.

  Further, the liquid crystal display panel 30 is not limited to a liquid crystal display panel having a liquid crystal layer made of TN liquid crystal as described above. Instead, a VA (Vertical Alignment) method, an IPS (In Plane Switching) method, an FFS (Fringe) is used. It is also possible to use a liquid crystal display panel such as a field structure.

  In this embodiment, the liquid crystal display panel is used as the display panel. However, the present invention is not limited to this, and another display panel such as an electrophoretic display panel may be used instead. .

[Adjustment with red LED]
FIG. 4 is a graph showing spectral characteristics of the color filter and the illumination device. In the graph shown in FIG. 4, the horizontal axis indicates the wavelength of light, and the vertical axis indicates the transmittance of the color filter, that is, the colored layer. A graph 202 shows the spectral characteristics of the colored layer 6R, a graph 203 shows the spectral characteristics of the colored layer 6G2, a graph 204 shows the spectral characteristics of the colored layer 6G1, and a graph 205 shows the spectral characteristics of the colored layer 6B. Also, graphs obtained by normalizing the spectral characteristics of the white LED 13a and the red LED 13b in the illumination device 10 with the vertical axis as the light intensity are shown as a graph 201 and a graph 206, respectively. FIG. 5 shows a spectral characteristic of the light L emitted from the illumination device 10 as a graph 201a with the horizontal axis representing the wavelength of the light and the vertical axis representing the radiance. As can be seen from FIG. 5, the graph 201a qualitatively combines the graph 201 and the graph 206 in FIG.

  In the illumination device 10 in the liquid crystal display device 100 according to the present embodiment, unlike the illumination device in a general liquid crystal display device, as described above, a red LED is provided in addition to a white LED. As can be seen from the graph 202 and the graph 206 in FIG. 4, the magnitude of the wavelength at which the light intensity of the red LED 13b reaches a peak exists where the transmittance of the colored layer 6R is maximized. As can be seen from this, in the liquid crystal display device 100 according to the present embodiment, the red LED 13b is provided in addition to the white LED 13a as compared with the general liquid crystal display device, so that the colored layer 6R as a red color filter is provided. When applied, the brightness of red light can be increased. Thereby, the liquid crystal display device 100 according to the present embodiment can improve the red display luminance on the display screen. In addition, the wavelength which becomes the peak of the red light emitted from the red LED 13b is set within a wavelength range in which the transmittance of the colored layer 6R shown in the graph 202 is maximized, specifically within a range of 630 to 650 [nm]. It is desirable to be done.

Since the red LED has a larger temperature coefficient than the white LED, a thermistor (not shown) is installed in the vicinity of the red LED 13b. Thereby, the red LED 13b is adjusted so that the luminance of the emitted red light always becomes a predetermined luminance with respect to the temperature change. For example, when the light L has the spectral characteristics shown in FIG. 5, the adjustment is performed so that the luminance at which the red light peak becomes 0.40 [W / sr / m ² ]. By doing in this way, the light L can hold | maintain a predetermined spectral characteristic with respect to a temperature change.

  6 and 7 show the color reproduction range of the liquid crystal display device 100 according to the present embodiment in the chromaticity diagram of the International Illumination Commission (CIE).

  In FIG. 6, a color reproduction range 301 indicates a color reproduction range when the liquid crystal display device 100 according to the present embodiment uses an illumination device that uses only white LEDs as a light source, and a point P1 indicates a white point at that time. Indicates. The color reproduction range 302a indicates the color reproduction range when the illumination device 10 using the white LED 13a and the red LED 13b as the light source is used in the liquid crystal display device 100 according to the present embodiment as described above. The white point at that time is shown. At this time, the wavelength which becomes the peak of the red light emitted from the red LED 13b is set to 630 [nm], and the wavelength which becomes the peak of the blue light emitted from the blue LED in the white LED 13a is set to 450 [nm].

  As can be seen from FIG. 6, the color reproduction range 302 a has a larger red color reproduction range than the color reproduction range 301. However, the chromaticity coordinate of the white point of the point P1 is (X, Y) = (0.313, 0.338), whereas the chromaticity coordinate of the white point of the point P2a is (X, Y). = (0.334, 0.337). That is, in the liquid crystal display device 100 according to the present embodiment, when the illumination device 10 using the white LED 13a and the red LED 13b as a light source is used, the red color reproduction range is expanded, but the X coordinate of the white point is also increased. . In other words, in this case, the white color displayed on the display screen is a reddish white color.

  In FIG. 7, a color reproduction range 301 indicates a color reproduction range when the liquid crystal display device 100 according to the present embodiment uses an illumination device that uses only white LEDs as a light source, and a point P1 indicates a white point at that time. Indicates. The color reproduction range 302b indicates the color reproduction range when the illumination device 10 using the white LED 13a and the red LED 13b as the light source is used in the liquid crystal display device 100 according to the present embodiment, and the point P2b indicates the white point at that time. Show. At this time, the wavelength of the red light peak emitted from the red LED 13b is set to 650 [nm], and the wavelength of the blue light peak emitted from the blue LED in the white LED 13a is set to 450 [nm].

  As can be seen from FIG. 7, the color reproduction range 302b is larger in red color reproduction range than the color reproduction range 301, while the chromaticity coordinate of the white point of the point P2b is the white point of the point P2a. Is closer to the chromaticity coordinate of the white point of the point P1. That is, by changing the wavelength of the red light emitted from the red LED 13b from 630 [nm] to 650 [nm], the X coordinate of the white point can be reduced and displayed on the display screen. White can suppress redness.

  As can be seen from the above, in the liquid crystal display device 100 according to the present embodiment, the X coordinate of the white point of the light L is adjusted by adjusting the wavelength that is the peak of the red light emitted from the red LED 13b. Accordingly, the X coordinate of the white point on the display screen can be adjusted.

[White balance adjustment]
In the liquid crystal display device 100 according to the present embodiment described with reference to FIGS. 6 and 7, the white point P1 in the case of using the illumination device using only the white LED as the light source is accurately composed of three general RGB colors. Compared with a liquid crystal display device having a colored layer, the addition of the G2 colored layer 6G2 tends to shift to the green side. That is, the white color displayed on the display screen is a greenish white color. Therefore, in the following, in the liquid crystal display device 100 according to the present embodiment, a method for suppressing the white point from shifting to the green side when the illumination device 10 using the white LED 13a and the red LED 13b as a light source will be described.

  In order to prevent the white point from shifting to the green side, it is preferable not to reduce the green light component in the white light but to increase the blue light component. This is because green light has high visibility for human eyes, and when the green light component in white light is reduced, the observer feels that the luminance on the display screen is greatly reduced.

  8 and 10 show the color reproduction range by the liquid crystal display device 100 according to the present embodiment in the chromaticity diagram of the International Commission on Illumination (CIE).

  In FIG. 8, a color reproduction range 301 indicates a color reproduction range when the liquid crystal display device 100 according to the present embodiment uses an illumination device that uses only white LEDs as a light source, and a point P1 indicates a white point at that time. Indicates. The color reproduction range 302c indicates the color reproduction range when the illumination device 10 using the white LED 13a and the red LED 13b as the light source is used in the liquid crystal display device 100 according to the present embodiment, and the point P2c indicates the white point at that time. Show. At this time, the wavelength of the peak of red light emitted from the red LED 13b is set to 630 [nm]. In FIG. 8, the wavelength of the blue light emitted from the blue LED in the white LED 13a has a wavelength of 455 [nm], which is different from the wavelength (450 [nm]) of the blue light peak described in FIGS. Is set to

  FIG. 9 shows the spectral characteristics of the light L emitted from the illumination device 10, with the horizontal axis representing the wavelength of the light and the vertical axis representing the radiance. The graph 201b shows the spectral characteristics of the light L when the wavelength of the blue light emitted from the blue LED in the white LED 13a is 450 [nm], and the graph 201c is emitted from the blue LED in the white LED 13a. The spectral characteristics of the light L when the wavelength of the blue light peak is 455 [nm] are shown. As can be seen from FIG. 9, by changing the wavelength of the blue light emitted from the blue LED in the white LED 13a from 450 [nm] to 455 [nm], the blue light component in the light L, specifically, The component whose wavelength is 500 [nm] or less increases. That is, the color reproduction range 302c in FIG. 8 indicates the color reproduction range when the blue light component in the light L is increased compared to the color reproduction ranges 302a and 302b in FIGS.

  However, as can be seen from FIG. 8, the chromaticity of B and the chromaticity of G1 in the color reproduction range 302c are different from the chromaticity of B and the chromaticity of G1 in the color reproduction range 301.

  In FIG. 10, a color reproduction range 301 indicates a color reproduction range when the liquid crystal display device 100 according to the present embodiment uses an illumination device that uses only white LEDs as a light source, and a point P1 indicates a white point at that time. Indicates. The color reproduction range 302d indicates the color reproduction range when the illumination device 10 using the white LED 13a and the red LED 13b as the light source is used in the liquid crystal display device 100 according to this embodiment, and the point P2d indicates the white point at that time. Show. At this time, the wavelength that is the peak of red light emitted from the red LED 13b is set to 630 [nm], and the wavelength that is the peak of blue light emitted from the blue LED in the white LED 13a is set to 455 [nm]. The color reproduction range 302d indicates the color reproduction range when the transmittances of the colored layer 6B and the colored layer 6G1 are increased by 10 [%] compared to the color reproduction range 302c in FIG. That is, in this case, the maximum value of the transmittance of the colored layer 6B and the maximum value of the transmittance of the colored layer 6G1 are 70 [%, which is the maximum value of the transmittance of the colored layer 6B shown by the graphs 205 and 204 in FIG. ], A value increased by 10 [%] compared to the maximum value of 60% of the transmittance of the colored layer 6G1, that is, the maximum value of the transmittance of the colored layer 6B and the colored layer 6G1 in this case The maximum values of transmittance are 77 [%] and 66 [%], respectively.

  As can be seen from FIG. 10, the chromaticity of B and the chromaticity of G1 in the color reproduction range 302d hardly differ from the chromaticity of B and the chromaticity of G1 in the color reproduction range 301. Further, the chromaticity coordinate of the white point of the point P2d is mainly smaller in the Y coordinate of the white point than the chromaticity coordinate of the white point of the point P1. That is, the chromaticity coordinate of the white point of the point P2d is not shifted to the green side compared to the chromaticity coordinate of the white point of the point P1.

  As can be seen from the above, in the liquid crystal display device 100 according to the present embodiment, the red LED 13b is added to the white LED 13a as the light source of the illuminating device 10, and the wavelength of the blue light peak in the white LED 13a and the transmission of the colored layer 6B. By adjusting all of the maximum value of the rate and the maximum value of the transmittance of the colored layer 6G1, it is possible to improve the red display luminance on the display screen and without causing the observer to feel a decrease in luminance. The white point can be prevented from shifting to the green side.

[Modification]
In the above-described embodiment, the white LED 13a is composed of a blue LED that emits blue light and a YAG (yttrium, aluminum, garnet) phosphor. However, the present invention is not limited to this. A white LED using the above phosphor may be used as the white LED 13a. Even in this case, the adjustment method of the present invention described above can be used.

[Other embodiments]
In the above description, R, G1, B, and G2 have been described as the colors (colored regions) of the colored layer functioning as a color filter. However, the application of the present invention is not limited to this, and other four colors are used. One display pixel can also be constituted by a colored region.

  Specifically, the four colored areas are blue colored areas (also referred to as “first colored areas”) in a visible light area (380 to 780 nm) in which the hue changes according to the wavelength. A colored region having a red hue (also referred to as a “second colored region”) and two colored regions selected from hues from blue to yellow (“third colored region”, “fourth colored region”). Also called “colored region”. 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
-The colored region of the blue hue is from violet to blue-green, more preferably from indigo to blue.
-The colored region of red hue is from orange to red.
-One coloring area | region selected by the hue from blue to yellow is blue to green, More preferably, it is blue green to green.
-The other coloring area | region selected by the hue from blue to yellow is green to orange, More preferably, it is green to yellow. Or it is green to yellowish green.

  Here, the same hue is not used for each colored region. For example, when a green hue is used in two colored regions selected from hues of blue to yellow, the other uses a blue or yellowish green hue for one green.

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

In the above, a wide range of color reproducibility by the colored areas of four colors has been described in terms of hue, but as another specific example, it can be expressed as follows with the wavelength of light transmitted through the colored areas.
The blue colored region is a colored region having a wavelength peak of light transmitted through the colored region at 415 to 500 nm, preferably at 435 to 485 nm.
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.
-One colored region selected by hue from blue to yellow is a colored region having a wavelength peak of 485-535 nm of light transmitted through the colored region, preferably a colored region having a wavelength of 495-520 nm. .
The other colored region selected with a hue from blue to yellow is a colored region having a wavelength peak of light transmitted through the colored region of 500-590 nm, preferably 510-585 nm, or 530- This is a colored region at 565 nm.

  In the case of transmissive display, this wavelength is a numerical value obtained by illuminating light from the illumination device through the color filter. In the case of reflective display, the value is obtained by reflecting external light.

As another specific example, when a colored region of four colors is expressed by an x, y chromaticity diagram, it is as follows.
The blue colored region is a colored region where x ≦ 0.151 and y ≦ 0.200, preferably a colored region where 0.134 ≦ x ≦ 0.151 and 0.034 ≦ y ≦ 0.200.
The red colored region is a colored region satisfying 0.520 ≦ x and y ≦ 0.360, and preferably a colored region satisfying 0.550 ≦ x ≦ 0.690 and 0.210 ≦ y ≦ 0.360.
-One of the colored areas selected in hues from blue to yellow is a colored area where x ≦ 0.200 and 0.210 ≦ y, preferably a colored area where 0.080 ≦ x ≦ 0.200 and 0.210 ≦ y ≦ 0.759 is there.
-The other colored region selected with a hue from blue to yellow is a colored region in the range of 0.257 ≦ x, 0.450 ≦ y, preferably a colored region in the range of 0.257 ≦ x ≦ 0.520, 0.450 ≦ y ≦ 0.720 is there.

  In the case of transmissive display, the x, y chromaticity diagram is a numerical value obtained by illuminating light from the illumination device through the color filter. In the case of reflective display, the value is obtained by reflecting external light.

  These four colored areas can be applied within the above-described range when the sub-pixel includes a transmission area and a reflection area.

Specific examples of the configuration of the above four colored regions include the following.
・ Colored areas of red, blue, green, and blue-green ・ Colored areas of red, blue, green, and yellow ・ Colored areas of red, blue, dark green, and yellow ・ Hue is red and blue , Emerald, yellow coloring area / hue is red, blue, deep green, yellow green coloring area / hue is red, blue green, dark green, yellow green coloring area
[Electronics]
Next, an embodiment in which the liquid crystal display device according to this embodiment is used as a display device of an electronic apparatus will be described.

  As the image signals input to the liquid crystal display device 100 according to the present embodiment, for example, image signals of each color of R, G1, B, and G2 may be directly input from the outside, or each of RGB colors may be input. An image signal may be input from the outside and converted to an image signal of each color of R, G1, B, and G2.

  Here, 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 R, G1, B, and G2 will be described.

  FIG. 11 is a circuit block diagram of a schematic configuration showing the overall configuration of the present embodiment. An electronic apparatus shown here includes the liquid crystal display device 100 and a control unit 610. The control unit 610 includes a display information output source 611, a display image conversion circuit 612, and a timing generator 614.

  In the liquid crystal display device 100, when the input RGB image signals are converted into R, G1, B, and G2 image signals, the display image conversion circuit 612 outputs an external display image such as a personal computer. The RGB color image signals output from the source 611 are converted into R, G1, B, and G2 color image signals and output to the liquid crystal display panel 30.

  The display image conversion 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, and 61B of the input image output from the display image output source 611 into the R, G1, B, and G2 image signals 62R, 62G1, 62B, and 62G2. Convert to 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 colors R, G1, B, and G2 corresponding thereto. ing. For example, when an RGB image signal for displaying the G2 color is input to the arithmetic processing unit 612a, for example, an RGB color image signal having an intensity of R = 0, G = 100, and B = 100, the calculation is performed. The processing unit 612a has R, G1, B, and G2 color image signals having an intensity corresponding to the RGB image signal intensity (for example, R = 0, G1 = 10, B = 10, G2 = 100). Are obtained from the LUT of the storage unit 612b, and the obtained image signals of the respective colors R, G1, B, and G2 are output to the liquid crystal display panel 30. As a result, not only the RGB colors but also the G2 color can be displayed on the display screen of the liquid crystal display panel 30. 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 G2 color reproduction range.

  The timing generator 614 has a hard switch or a soft switch for switching the timing mode, and generates the clock signal CLK from the luminance signal of the image signal. The driving sequence of the LED driving circuit 51 for each color of RGB described above is controlled so as to match the clock signal CLK determined by the timing generator 614.

  Next, a specific example of an electronic apparatus to which the liquid crystal display device 100 according to this embodiment can be applied will be described with reference to FIG.

  First, an example in which the liquid crystal display device 100 according to the present invention is applied to a display unit of a portable personal computer (so-called notebook personal computer) will be described. FIG. 12A is a perspective view showing the configuration of this personal computer. As shown in the figure, a personal computer 710 includes a main body 712 having a keyboard 711 and a display 713 to which the liquid crystal display device 100 according to the present invention is applied.

  Next, an example in which the liquid crystal display device 100 according to the present invention is applied to a display unit of a mobile phone will be described. FIG. 12B 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 device 100 according to the present invention is applied.

  Note that, as an electronic apparatus to which the liquid crystal display device 100 according to the present invention can be applied, in addition to the personal computer shown in FIG. 12A and the mobile phone shown in FIG. Type / monitor direct-view type video tape recorder, car navigation device, pager, electronic notebook, calculator, word processor, workstation, videophone, POS terminal, digital still camera, etc.

It is a top view of the liquid crystal display device concerning this embodiment. It is sectional drawing of the liquid crystal display device which concerns on this embodiment. It is a top view of the illuminating device which concerns on this embodiment. It is a graph which shows the spectral characteristic of a color filter and an illuminating device. It is a graph which shows the spectral characteristic of the illuminating device which concerns on this embodiment. It is a chromaticity diagram of the International Commission on Illumination (CIE) showing the color reproduction range. It is a chromaticity diagram of the International Commission on Illumination (CIE) showing the color reproduction range. It is a chromaticity diagram of the International Commission on Illumination (CIE) showing the color reproduction range. It is a graph which shows the spectral characteristic of the illuminating device which concerns on this embodiment. It is a chromaticity diagram of the International Commission on Illumination (CIE) showing the color reproduction range. 1 is a circuit block diagram of an electronic apparatus to which a liquid crystal display device according to an embodiment is applied. It is a figure which shows the example of the electronic device to which the liquid crystal display device of this embodiment is applied.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 12 Light source part, 13a White LED, 13b Red LED, 14 Diffusion sheet, 15 Prism sheet, 10 Illumination device, 30 Liquid crystal display panel, 100 Liquid crystal display device

Claims (8)

A plurality of sub-pixels are provided, and a red-colored first colored layer, a blue-based second colored layer, and colors of the third and fourth colors arbitrarily selected from hues from blue to yellow A display panel including any one of the layers in the sub-pixel;
A first light source that emits blue light, a blue light wavelength conversion unit that converts part of the blue light into yellow light, and a second light source that emits red light, the blue light and the yellow light. And a light source that emits the combined light of the red light to the display panel.   2. The electro-optical device according to claim 1, wherein a wavelength at which the red light reaches a peak is set within a range of 630 to 650 nm. The second light source is a semiconductor light emitting element that emits red light,
The electro-optical device according to claim 1, wherein a change in temperature is detected and adjustment is performed so that the luminance of the red light always becomes a predetermined luminance. The third colored layer is a green colored layer,
The electro-optical device according to claim 1, wherein the fourth colored layer is a yellow-green colored layer. The third colored layer has a wavelength peak of transmitted light at 485-535 nm,
4. The electro-optical device according to claim 1, wherein the fourth colored layer has a wavelength peak of transmitted light in a range of 500 to 590 nm. The wavelength of the blue light peak is set to 455 nm,
6. The electro-optical device according to claim 4, wherein a maximum value of the transmittance of the second colored layer is set to 77%, and a maximum value of the transmittance of the third colored layer is set to 66%. .   An electronic apparatus comprising the electro-optic device according to claim 1 in a display unit. A light source comprising: a first light source that emits blue light; a blue light wavelength conversion unit that converts part of the blue light into yellow light; and a second light source that emits red light;
An illumination device that emits combined light of the blue light, the yellow light, and the red light.

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