JP2011141567A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device in which transmission display using light that a backlight emits and reflective display using external light are made possible without sectioning each display pixel into a transmission display area and a reflective display area, and which can obtain high display quality. <P>SOLUTION: A light guide plate 13 has optical characteristics that the color temperature of the light from a C-light source which is reciprocated on the light guide plate 13 is lower than the color temperature of a C-light source. A color filter 7R corresponding to a red component, a color filter 7G corresponding to a green component and a color filter 7B corresponding to a blue component have optical characteristics set so that the color temperature of the composite light composed of the light when the light from the C-light source is reciprocated on the color filter 7R corresponding to the red component, the light when the light from the C-light source is reciprocated on the color filter 7G corresponding to the green component and the light when the light from the C-light source is reciprocated on the color filter 7B corresponding to the blue component, is higher than the color temperature of the C-light source. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device that includes a sidelight-type backlight and is capable of display using light emitted from the sidelight-type backlight and display using external light.

  In recent years, transmissive display that performs display using illumination light from a backlight disposed behind a liquid crystal panel, and external light that has been incident from the front of the liquid crystal panel and once passed through the liquid crystal layer of the liquid crystal panel are reflected, and again There has been developed a liquid crystal display device that can be used for both a reflective display that emits light from the front of a liquid crystal panel through a liquid crystal layer and performs display. For example, in Patent Document 1, each display pixel is divided into two regions, and a pixel electrode in one region is formed of only a transparent material, and a pixel electrode in the other region is included in a reflective material. In this way, each display pixel can be formed to be transmissive display and reflective display.

JP 2004-93715 A

  However, when each display pixel is divided into a transmissive display area and a reflective display area, the display area available for each display is halved, so the available light is also halved, resulting in a dark display. There was a problem that would decrease.

  Therefore, the present invention enables display using light emitted from the backlight and display using external light without dividing each display pixel into a transmissive display area and a reflective display area, and also provides high display quality. An object of the present invention is to provide a liquid crystal display device capable of obtaining the above.

In order to achieve the above object, a liquid crystal display device according to a first aspect of the present invention is a display in which a color filter corresponding to a red component and a color filter corresponding to a green component are arranged. A liquid crystal panel having a pixel and a display pixel in which a color filter corresponding to a blue component is disposed, a reflective layer that reflects light, and a light guide plate disposed between the reflective layer and the liquid crystal panel; A sidelight-type backlight having a liquid crystal panel, and the reflective layer so that external light reflected by the reflective layer is irradiated to the liquid crystal panel through the light guide plate; The external light that has passed through the light guide plate in order is reflected, and the light guide plate has an optical characteristic that the color temperature of light from the C light source that reciprocates the light guide plate is lower than the color temperature of the C light source. Corresponding to the red component A color filter corresponding to the green component, and a color filter corresponding to the blue component, the light when the light from the C light source reciprocates the color filter corresponding to the red component, and the light from the C light source The color temperature of the combined light consisting of the light when the light reciprocates the color filter corresponding to the green component and the light when the light from the C light source reciprocates the color filter corresponding to the blue component, The optical characteristics are set so as to be higher than the color temperature of the C light source.
The invention according to claim 2 is the liquid crystal display device according to claim 1, wherein the backlight includes a light emitting element that emits light toward an end surface of the light guide plate, and the light emitting element includes: The light from the light emitting element that has passed once through the color filter corresponding to the red component and the light from the light emitting element that has passed through the color filter corresponding to the green component once and the color filter corresponding to the blue component once. It is characterized in that it emits light having a color temperature of light synthesized from the light from the light emitting element equal to that of a C light source.
According to a third aspect of the present invention, there is provided a liquid crystal display device corresponding to a display pixel having a color filter corresponding to a red component, a display pixel having a color filter corresponding to a green component, and a blue component. A sidelight type comprising: a liquid crystal panel having a display pixel on which the color filter is disposed; a reflective layer that reflects light; and a light guide plate disposed between the reflective layer and the liquid crystal panel. Backlight, and the reflective layer sequentially passes through the liquid crystal panel and the light guide plate so that external light reflected by the reflective layer is irradiated to the liquid crystal panel through the light guide plate. The light guide plate has an optical characteristic that white light from a predetermined light source that reciprocates the light guide plate is colored in a predetermined color, the color filter corresponding to the red component, and the green color Compatible with ingredients When the white light reciprocates the color filter corresponding to the green component and the light when the white light reciprocates the color filter corresponding to the red component, and the color filter corresponding to the blue component The optical characteristics are set so that the coloration of the combined light composed of the light of the above and the light when the white light reciprocates through the color filter corresponding to the blue component is a complementary color of the predetermined color It is characterized by that.
According to a fourth aspect of the present invention, in the liquid crystal display device according to any one of the first to third aspects, a display pixel in which a color filter corresponding to the red component is arranged and a color filter corresponding to the green component A display pixel in which the aperture ratio is equal to a display pixel in which the color filter corresponding to the blue component is disposed.

  According to the present invention, display using light emitted from a backlight and display using external light can be performed without dividing each display pixel into a transmissive display area and a reflective display area, and high display quality can be achieved. Can be obtained.

Disassembled perspective view of liquid crystal display device Side view of liquid crystal display device Expanded sectional view of the liquid crystal panel Schematic diagram showing the arrangement of pixel electrodes Color filter placement example Explanatory drawing of the locus of the light from the light emitting element guided by the light guide plate Illustration of backscattering caused by diffuser Enlarged sectional view of the prism Explanatory drawing of the locus of light reflected by the prism part Illustration of the direction of each optical axis Explanatory drawing of the relationship between the spectral intensity of the light before reciprocating the light guide plate and the spectral intensity of the light after reciprocating the light guide plate Explanatory drawing of spectral transmittance in color filter of each color component Explanatory drawing of the relationship between the color temperature of the light from the C light source before reciprocating the color filter and the color temperature of the combined light of each light from the C light source reciprocating the color filter of the corresponding color component Modification of light emitting element Variation of spectral transmittance in color filter of each color component

  The liquid crystal display device according to the present invention enables display by external light by reflecting external light with the sidelight-type backlight in addition to the light-emitting display that performs display by emitting the sidelight-type backlight. As shown in FIGS. 1 and 2, the liquid crystal panel 1, the light source unit 15 that irradiates illumination light toward one surface of the liquid crystal panel 1, and the light source unit 15 and the liquid crystal panel 1 are arranged. The condensing unit 27, the retardation plate 33 disposed between the condensing unit 27 and the liquid crystal panel 1, the reflective polarizing plate 32 disposed between the retardation plate 33 and the liquid crystal panel 1, A first diffusion plate arranged between the reflective polarizing plate and the liquid crystal panel; and a second diffusion plate arranged between the light collecting unit and the light source unit. .

  As shown in FIG. 3, the liquid crystal panel 1 includes a pair of transparent substrates 2 and 3 which are arranged to face each other with a predetermined gap therebetween, and a liquid crystal layer 11 sealed in the gap between the pair of transparent substrates 2 and 3. And a pair of polarizing plates 12 and 13 disposed so as to sandwich the pair of transparent substrates 2 and 3 and the transmission axes thereof are orthogonal to each other.

  The first transparent substrate 3 out of the pair of transparent substrates 2 and 3 is extended and arranged on the side facing the second transparent substrate 2 so as to be parallel to each other as shown in FIG. The plurality of signal lines SL, the plurality of scanning lines GL extending so as to intersect with the plurality of signal lines SL, and the plurality of scanning lines GL are arranged so as to correspond to the intersections of the signal lines SL and the scanning lines GL. A plurality of pixel electrodes 4 made of a transparent conductive film such as ITO, and a plurality of TFTs (thin film transistors) 5 disposed so as to correspond to the pixel electrodes 4 are formed. That is, a plurality of pixel electrodes 4 are arranged in a matrix so that the pixel electrodes 4 are arranged on the respective display pixels. A scanning line GL is formed corresponding to each pixel row so that a gate signal can be supplied to the TFT 5 for each pixel row, and a display signal voltage can be supplied to the pixel electrode 4 via the TFT 5. A signal line SL is formed corresponding to each pixel column.

  The first transparent substrate 3 is provided with auxiliary capacitance lines HL corresponding to the respective pixel rows, and an auxiliary capacitance is provided for each display pixel by an insulating film disposed between the auxiliary capacitance line HL and the pixel electrode 4. Cs is formed. The auxiliary capacitance line HL is set to the same potential as the counter electrode 6 described later.

  Each TFT 5 includes a gate electrode formed on the substrate surface of the first transparent substrate 3, a gate insulating film made of a transparent insulator formed so as to cover the gate electrode, and the gate insulation. An i-type semiconductor film formed on the gate insulating film so as to face the gate electrode through the film, and a drain electrode formed on both sides of the i-type semiconductor film via the n-type semiconductor film, respectively And a source electrode. Each TFT 5 has a source electrode connected to the corresponding pixel electrode 4, a gate electrode connected to the corresponding scanning line, and a drain electrode connected to the corresponding signal line.

  On the other hand, in the second transparent substrate 2 of the pair of transparent substrates 2 and 3, an area roughly corresponding to the pixel electrode 4 is opened on the side facing the first transparent substrate 3 as shown in FIG. The light shielding layer (not shown), the color filter 7, and the counter electrode 6 are formed in order from the lower layer side. The light shielding layer can be formed of a light shielding metal film or resin film, and is formed so that the area of the opening through which light is transmitted becomes equal for each display pixel. That is, the liquid crystal panel 1 is set so that the aperture ratio is equal for each display pixel. The color filter 7 includes a red color filter 7R corresponding to the red component, a green color filter 7G corresponding to the green component, and a blue color filter 7B corresponding to the blue component. For example, as shown in FIG. A color filter of a corresponding color component is arranged for each. The counter electrode 6 is made of a transparent conductive film such as ITO, and is formed so that it can be set to the same potential between the display pixels. For example, the counter electrode 6 is formed in a single film so as to cover the color filter 7 in each display pixel. The spectral transmittance characteristics of each color component in the color filter will be described later.

  Here, alignment films 8 and 9 for controlling the initial alignment state of the liquid crystal molecules in the liquid crystal layer 11 are applied on the pixel electrode 4 and the counter electrode 6 in each display pixel, respectively. For example, the alignment films 8 and 9 are subjected to an alignment process so that the liquid crystal molecules of the liquid crystal layer 11 are twisted and aligned at a twist angle of 90 ° when no voltage is applied between the pixel electrode 4 and the counter electrode 6. Has been.

  The pair of transparent substrates 2 and 3 are joined together by a frame-shaped sealing material 10 disposed so as to surround the image display area where the plurality of pixel electrodes 4 are disposed as described above. The liquid crystal constituting the liquid crystal layer 11 described above is sealed in the enclosed region.

  By the way, as shown in FIGS. 1 and 2, the liquid crystal panel 1 is disposed so that the first transparent substrate 3 protrudes from one side of the second transparent substrate 2, and the driver circuit 14 is disposed on the protruding portion 3a. Is installed. The driver circuit 14 is electrically connected to a plurality of terminals formed in the projecting portion 3a, and supplies a scanning signal to each scanning line GL and supplies a display signal voltage to each signal line SL via these terminals. Furthermore, a common voltage is supplied to each auxiliary capacitance line HL and the counter electrode 6.

  The driver circuit 14 controls the voltage applied to the liquid crystal layer 11 through the pixel electrode 4 and the counter electrode 6 to change the tilt angle or azimuth angle of the liquid crystal molecules with respect to the transmission axes of the pair of polarizing plates 12 and 13. The amount of light transmitted through the liquid crystal panel 1 is controlled for each display pixel.

  As shown in FIGS. 1 and 2, the light source unit 15 is a so-called sidelight-type backlight, and is a plate that is disposed so as to face the liquid crystal panel 1 and has an area larger than the image display area in the liquid crystal panel 1. A light guide plate 16 made of a transparent member, a reflection plate 19 disposed so as to face the light guide plate 16, and a plurality of light emitting elements 20 that irradiate light toward any one end surface of the light guide plate 16. It has.

  The plurality of light emitting elements 20 emit light when the liquid crystal display device performs transmissive display using light emitted from the light source unit 15. Each of the light emitting elements 20 includes a red LED that emits red component light and a green component. A green LED that emits blue light and a blue LED that emits blue component light. Note that the plurality of light emitting elements 20 are preferably configured so that light emission / non-light emission can be controlled as appropriate according to the brightness in the usage environment of the liquid crystal display device.

  As shown in FIG. 6, the light guide plate 16 guides the light of each color component irradiated from the light emitting element 20 toward the end surface 17 of the light guide plate 16 to face the liquid crystal panel 1 on the main surface 18 a (hereinafter referred to as the main surface 18 a). The light is irradiated from the first main surface 18a) toward the liquid crystal panel 1. Here, for example, a plurality of linear grooves GB are formed on the other main surface 18b (hereinafter, referred to as “second main surface 18b”) facing the first main surface 18a by the light emitting element 20. It is formed so as to be parallel to the end face 17 irradiated with light. The cross-sectional shape of the groove GB is formed such that, for example, two sides GB1 and GB2 sandwiching the apex angle have different inclination angles with respect to the first main surface 18a of the light guide plate 16. Specifically, it is formed so that the inclination angle of one side GB1 located on the side where the light emitting element 20 is arranged is larger than that of the other one side GB2.

  Then, as shown by a broken line in FIG. 6, the light guide plate 16 reflects the light from the light emitting element 20 incident from the end surface 17 on the inner surface, and the liquid crystal panel 1 from the first main surface 18 a of the light guide plate 16. Ejected towards. The light guide plate 16 can be formed of a transparent material such as acrylic having a refractive index larger than air, for example, a refractive index of about 1.5.

  The reflection plate 19 reflects the light leaking from the second main surface 18b of the light guide plate 16 out of the light from the light emitting element 20 toward the light guide plate 16, and passes through the liquid crystal panel 1 and the light guide plate 16. The outside light is reflected again toward the light guide plate 16 and the liquid crystal panel 1. That is, the reflective plate 19 improves the light use efficiency when the liquid crystal display device performs transmissive display using light emitted from the light emitting element 20, while the liquid crystal display device uses external light. When performing reflective display, it functions as a reflector that reflects external light. In addition, the reflector 19 can use what deposited metals, such as silver and aluminum, on the glass substrate or the plastic substrate, for example.

  The second diffusion plate 35 reduces in-plane variation of the light emitted from the light guide plate 16 by diffusing the light emitted from the first main surface 18a of the light guide plate 16, and has a haze value of 55 to 55. It consists of a transparent sheet in which light scattering particles are dispersed so as to be 85%. As shown in FIG. 7, the second diffusion plate 35 backscatters a part of the external light L that has passed through the liquid crystal panel 1. Therefore, the second diffusion plate 35 is formed by the liquid crystal display device. It also functions as an auxiliary reflector when performing reflective display using outside light.

  The condensing unit 27 condenses the light so that the light emitted from the light guide plate 16 toward the liquid crystal panel 1 and diffused by the second diffusion plate 35 is directed more efficiently to the liquid crystal panel 1. The first prism array 28 and the second prism array 30 made of a transparent sheet-like member made of The first prism array 28 is formed so that a plurality of linear prism portions 29 are parallel to each other on one surface. The first prism array 28 is arranged so that the extending directions of the plurality of prism portions 29 are orthogonal to the extending directions of the plurality of grooves GB formed in the light guide plate 16, for example. The second prism array 30 is formed such that a plurality of linear prism portions 31 are parallel to each other on one surface. The second prism array 30 is arranged such that the extending directions of the plurality of prism portions 31 are parallel to the extending directions of the plurality of grooves GB formed in the light guide plate 16, for example. In addition, as shown in FIG. 8, each prism part 29 and 31 is an isosceles triangle shape symmetrical with respect to the normal line HD of the liquid crystal panel 1, respectively, and the vertex angle is in the range of 80 ° to 100 °. The cross-sectional shape is preferably set to 90 °.

  As shown in FIG. 9, the prism arrays 28 and 30 sequentially reflect a part of the external light L that has passed through the liquid crystal panel 1 on the inclined surfaces that constitute the prism portions 29 and 31. The prism arrays 28 and 30 also function as auxiliary reflectors when the liquid crystal display device performs reflection display using external light.

  As shown in FIG. 10, the reflective polarizing plate 32 has a transmission axis 32a and a reflection axis 32b in directions orthogonal to each other, and transmits and reflects light of a polarization component parallel to the transmission axis 32a in incident light. The light of the polarization component parallel to the axis 32b is reflected. Note that, in the reflective polarizing plate 32, the transmission axis 32 a of the reflective polarizing plate 32 is parallel to the transmission axis 13 a of the polarizing plate 13 disposed on the reflective polarizing plate 32 side of the pair of polarizing plates 12 and 13. It is arranged to be. Of the pair of polarizing plates 12 and 13, the transmission axis 12 a of the polarizing plate 12 is disposed so as to be orthogonal to the transmission axis 13 a of the polarizing plate 13 as described above. It can set suitably according to orientation mode.

  The phase difference plate 33 has a slow axis 33a and a fast axis 33b in directions orthogonal to each other, and the slow axis 33a and the fast axis 33b are in relation to the transmission axis 32a and the reflection axis 32b of the reflective polarizing plate 32. It arrange | positions so that it may become an angle of 45 degrees. The phase difference plate 33 gives a phase difference of ¼ wavelength between the light having the polarization component parallel to the slow axis 33a and the light having the polarization component parallel to the fast axis 33b. The optical constant is set.

  As described above, the reflective polarizing plate 32 and the retardation plate 33, and further the reflective plate are arranged, so that the light from the light emitting element 20 via the light guide plate 16 is transmitted with respect to the transmission axis 13a of the polarizing plate 13. The light irradiated toward the liquid crystal panel 1 with the polarization plane in the orthogonal direction is once reflected by the reflective polarizing plate 32, converted into light parallel to the transmission axis 13a of the polarizing plate 13, and then returned to the liquid crystal panel 1. Irradiation can be performed, and the utilization efficiency of light from the light-emitting element can be improved.

  The first diffuser plate 34 is for preventing the occurrence of moire between the display pixels in the liquid crystal panel 1 and the prism arrays 28 and 30 in the light condensing unit 27, and has a haze value of 20 to 50%. Thus, it consists of a transparent sheet in which light scattering particles are dispersed. Since the first diffusing plate 34 backscatters part of the external light that has passed through the liquid crystal panel 1 in the same manner as the second diffusing plate 35, the first diffusing plate 34 has the liquid crystal display. It also functions as an auxiliary reflector when the device performs reflective display using external light.

  In the liquid crystal display device as described above, when the applied voltage is controlled so that the liquid crystal layer 11 in the liquid crystal panel 1 can transmit light, the external light passes through the liquid crystal panel 1 regardless of whether or not the light emitting element 20 emits light. The light can pass through the light guide plate 16 and can enter the light guide plate 16. However, the external light incident on the light guide plate 16 sequentially passes through the first main surface 18a and the second main surface 18b of the light guide plate 16. The light passes through and is reflected by the reflection plate 19, and then passes through the second main surface 18 b and the first main surface 18 a of the light guide plate 16 in order and returns to the liquid crystal panel 1 again. That is, in the above-described liquid crystal display device, each display pixel is not divided into a transmissive display area and a reflective display area, and external light is used in addition to transmissive display using light emitted from each light emitting element 20. It is also possible to perform display, that is, reflective display.

  Further, in the liquid crystal display device as described above, in addition to the reflection of the external light at the reflection plate 19 in the light source unit 15, the first diffusion plate 34, the second diffusion plate 35, the prism arrays 28, 30 and the like are used. Part of the light is reflected in an auxiliary manner. For this reason, a plurality of reflection surfaces exist between the liquid crystal panel 1 and the reflection plate 19, and the image of the liquid crystal panel 1 projected onto the reflection plate 19 by external light can be blurred. Therefore, even if there is a certain distance between the liquid crystal panel 1 and the reflection plate 19, it is possible to prevent the image displayed on the liquid crystal panel 1 from being viewed as a double image and improve the display quality. be able to.

  By the way, in the light source unit 15, the light guide plate 16 has the inclined surface as described above so that the light from the light emitting element 20 irradiated on the end surface 17 is emitted from the first main surface 18 a toward the liquid crystal panel 1. A groove GB is formed. Therefore, the light passes through the first main surface 18a and the second main surface 18b of the light guide plate 16 in order and is reflected by the reflection plate 19, and then the second main surface 18b of the light guide plate 16 and the first main surface 18b. The external light that passes through the surface 18a in sequence and returns to the liquid crystal panel 1 again has a stray light intensity that increases as the light has a shorter wavelength in the visible light region, and a stray light intensity that increases as the light has a longer wavelength. Becomes smaller. Therefore, the external light Lin from the liquid crystal panel 1 toward the light guide plate 16 becomes yellowish or reddish light Lout when traveling from the light guide plate 16 to the liquid crystal panel 1 as shown in FIG. ing.

  Therefore, in the present embodiment, the spectral transmittance characteristics of light are adjusted with respect to the color filter 7 corresponding to each color component in accordance with the change in color of the external light caused by the external light reciprocating the light guide plate 16. .

  Specifically, assuming that the external light has a spectral characteristic equal to that of the C light source, the color temperature of the external light from the light guide plate 16 toward the liquid crystal panel 1 after reciprocating the light guide plate 16 in this case is the reason described above. Therefore, the color temperature is lower than the color temperature of the C light source. Therefore, the color temperature of the combined light obtained by combining the light from the C light source that reciprocates the red color filter 7R, the light from the C light source that reciprocates the green color filter 7G, and the light from the C light source that reciprocates the blue color filter 7B is obtained. By adjusting the spectral transmittance characteristics with respect to the color filter 7 corresponding to each color component so that the color temperature is higher than the color temperature of the C light source, the wavelength between the wavelength regions generated by reciprocating the light guide plate 16 is adjusted. Correct the transmitted light amount difference.

  For example, as indicated by an arrow A in FIG. 12, by adjusting the transmission intensity in the blue wavelength region in the color filter 7G corresponding to the green component, the absorption wavelength region in the color filter 7B in which the transmission intensity corresponds to the blue component. In the CIE1931 chromaticity diagram, the coordinate point of the composite light Lt as described above is set so as to be higher than the transmission intensity in the absorption wavelength region in the color filter 7R corresponding to the transmission intensity and the red component. As shown in FIG. 13, it is set so as to be on the blue side (higher color temperature side) than the coordinate point of the C light source. At this time, in order to maintain the color itself of the color filter 7G corresponding to green, the transmission intensity in the red wavelength region in the color filter 7G corresponding to the green component is readjusted as indicated by an arrow B in FIG. Also good.

  Thus, by adjusting the spectral transmittance characteristics of the color filter, typically, the color filter 7, the light guide plate 16, the reflection plate 19, the light guide plate 16, and the color filter 7 in the order of the external light. The color temperature of the white display at the time of white display can be approximated to the C light source, and the display quality in the reflective display using external light can be further improved.

  By the way, in the above-described case, in order to obtain a high luminance display using external light when the light emitting element 20 is not emitting light, the transmittance in the peak wavelength region in the color filter 7B corresponding to the blue component is obtained. On the other hand, the color temperature adjustment is performed without relatively reducing the transmittance in the peak wavelength region in the color filter 7G corresponding to the green component and the transmittance in the peak wavelength region in the color filter 7R corresponding to the red component. In other words, even after the color temperature is adjusted, in the visible light region (approximately 380 nm to 780 nm), the transmittance at the peak wavelength Gp in the color filter 7G corresponding to the green component and the color filter 7R corresponding to the red component. The color temperature is adjusted so that the transmittance at the peak wavelength Rp is higher than the transmittance at the peak wavelength Bp in the color filter 7B corresponding to the blue component. This is because the transmittance at the peak wavelength Gp in the color filter 7G corresponding to the green component and the peak in the color filter 7R corresponding to the red component with respect to the transmittance at the peak wavelength Bp in the color filter 7B corresponding to the blue component. It is possible to set the coordinate point of the composite light Lt as described above to be on the blue side (higher color temperature side) than the coordinate point of the C light source by reducing the transmittance at the wavelength Rp. However, in this case, the light use efficiency is lowered, and the display quality is lowered.

  The transmission intensity in the blue wavelength region in the color filter 7G corresponding to the green component can be an average transmittance between approximately 380 nm and 450 nm. Further, the transmission intensity in the absorption wavelength region in the color filter 7B corresponding to the blue component can be an average transmittance between approximately 500 nm and 780 nm. Further, the transmission intensity in the absorption wavelength region in the color filter 7R corresponding to the red component can be an average transmittance between approximately 380 nm and 580 nm. Further, the transmission intensity in the red wavelength region in the color filter 7G corresponding to the green component can be an average transmittance between approximately 620 nm and 780 nm.

  Further, the spectral transmittance in the color filter 7B corresponding to the blue component is B (λ), the spectral transmittance in the color filter 7G corresponding to the green component is G (λ), and the spectral transmittance in the color filter 7G corresponding to the red component. When R (λ) is R (λ), the white reflection spectrum W2 (λ) by these color filters alone takes into account the possibility that light will pass through color filters corresponding to different color components in the forward and backward paths of light. , [Equation 1].

  The relationship between the reflection spectrum W2 (λ) and the coordinates (x, y) on the CIE 1931 chromaticity diagram can be expressed as [Equation 2].

  Here, X, Y, and Z indicate tristimulus values in the XYZ color system. Further, x (λ), y (λ), and z (λ) indicate color matching functions in the XYZ color system. S (λ) represents the spectral distribution of the C light source.

  In this way, when the spectral transmittance characteristics of the light of the filter 7 corresponding to each color component are adjusted, the spectral characteristics of the light from the light source unit 15 corresponding to the adjustment, that is, the light guide plate in the darkroom environment. It is preferable to adjust the spectral characteristics of the light emitted from the light emitting element 20 emitted from the 16 first main planes 18a.

  For example, the light from the light source unit 15 once transmitted through the red color filter 7R adjusted as described above, the light from the light source unit 15 once transmitted through the green color filter 7G adjusted as described above, and the same as described above. The spectrum of the light from the light source unit 15 is set so that the color temperature of the combined light obtained by combining the light from the light source unit 15 once transmitted through the blue color filter 7G adjusted in this way becomes equal to the color temperature of the C light source, for example. It is preferable to adjust the characteristics. By adjusting in this way, it is possible to maintain a high display quality in the display using light emitted from the light emitting element 20 even when the display quality in the external light is improved.

  In the above-described embodiment, the liquid crystal alignment mode is TN in which the liquid crystal molecules of the liquid crystal layer 11 are twisted and aligned at a twist angle of 90 ° when no voltage is applied between the pixel electrode 4 and the counter electrode 6. Although the case where the mode is set has been described, the alignment mode of the liquid crystal is not limited to the TN mode. For example, the liquid crystal molecules of the liquid crystal layer 11 when no voltage is applied between the pixel electrode 4 and the counter electrode 6. The liquid crystal molecules may be aligned vertically to the substrate surface, and a voltage may be applied between the pixel electrode 4 and the counter electrode 6 to form a vertical alignment type alignment mode in which liquid crystal molecules are tilted.

  In the above-described embodiment, a configuration in which the alignment state of liquid crystal molecules is controlled by a vertical electric field has been described. However, a configuration in which the alignment state of liquid crystal molecules is controlled by a horizontal electric field may be used.

  In the above-described embodiment, the case where each light-emitting element 20 includes a red LED, a green LED, and a blue LED has been described. However, each light-emitting element 20 is resin-molded as illustrated in FIG. A blue LED 22 is arranged at the center of the inner bottom surface of a box-shaped housing 21 having one open surface, and a red fluorescent material in the form of fine particles on a transparent material 24 such as a transparent resin. Alternatively, a fluorescent layer (hereinafter referred to as a red / green fluorescent layer) 23 in which 25 and a green fluorescent material 26 are dispersed at a predetermined ratio may be filled. Since it is possible to use a single LED that emits light for each light emitting element 20, even if light emission / non-light emission is frequently switched according to the brightness in the usage environment, a more stable operation can be obtained. This is preferable.

  In the above-described embodiment, by adjusting the transmission intensity in the blue wavelength region in the color filter 7G corresponding to the green component, the coordinate point of the synthesized light Lt is on the blue side (higher color temperature) than the coordinate point of the C light source. The coordinate point of the synthesized light Lt is bluer than the coordinate point of the C light source by adjusting the transmission intensity in the blue wavelength region in the color filter 7R corresponding to the red component. You may set so that it may become the side (high color temperature side).

  For example, as indicated by an arrow C in FIG. 15, by adjusting the transmission intensity in the blue wavelength region in the color filter 7R corresponding to the red component, the absorption wavelength region in the color filter 7B in which the transmission intensity corresponds to the blue component. In the CIE1931 chromaticity diagram, the coordinate point of the composite light Lt as described above is set to be higher than the transmission intensity in the absorption wavelength region in the color filter 7G corresponding to the green transmission component and the green component. As shown in FIG. 13, it is set so as to be on the blue side (higher color temperature side) than the coordinate point of the C light source.

  In this case, the transmission intensity in the blue wavelength region in the color filter 7G corresponding to the red component can be an average transmittance between approximately 380 nm and 450 nm. Further, the transmission intensity in the absorption wavelength region in the color filter 7B corresponding to the blue component can be an average transmittance between approximately 500 nm and 780 nm. Further, the transmission intensity in the absorption wavelength region of the color filter 7G corresponding to the green component can be an average transmittance between approximately 380 nm to 450 nm and approximately 650 nm to 780 nm.

1 Liquid crystal panel 2, 3 Transparent substrate 4 Pixel electrode 5 TFT
7 Color filter 11 Liquid crystal layer 12, 13 Polarizing plate 15 Light source part (side light type backlight)
16 Light guide plate 19 Reflector 20 Light emitting element

Claims (4)

A liquid crystal panel having a display pixel having a color filter corresponding to a red component, a display pixel having a color filter corresponding to a green component, and a display pixel having a color filter corresponding to a blue component When,
A sidelight-type backlight having a reflective layer that reflects light, and a light guide plate disposed between the reflective layer and the liquid crystal panel;
With
The reflective layer reflects the external light that has passed through the liquid crystal panel and the light guide plate in order so that the external light reflected by the reflective layer is irradiated to the liquid crystal panel through the light guide plate. ,
The light guide plate has an optical characteristic that the color temperature of light from the C light source that reciprocates the light guide plate is lower than the color temperature of the C light source,
The color filter corresponding to the red component, the color filter corresponding to the green component and the color filter corresponding to the blue component are:
Light from when the light from the C light source reciprocates through the color filter corresponding to the red component, light from when the light from the C light source reciprocates through the color filter corresponding to the green component, and from the C light source So that the color temperature of the combined light consisting of the light when reciprocating the color filter corresponding to the blue component is higher than the color temperature of the C light source,
A liquid crystal display device characterized in that optical characteristics are set. The backlight has a light emitting element that emits light toward an end face of the light guide plate,
The light emitting element includes a color filter corresponding to the light and the blue component from the light emitting element that has passed once through the color filter corresponding to the green component and the light from the light emitting element that has passed through the color filter corresponding to the red component once. 2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device emits light having a color temperature equal to a color temperature of a C light source, which is obtained by combining light from the light emitting element that has passed through the light source once. A liquid crystal panel having a display pixel having a color filter corresponding to a red component, a display pixel having a color filter corresponding to a green component, and a display pixel having a color filter corresponding to a blue component When,
A sidelight-type backlight having a reflective layer that reflects light, and a light guide plate disposed between the reflective layer and the liquid crystal panel;
With
The reflective layer reflects the external light that has passed through the liquid crystal panel and the light guide plate in order so that the external light reflected by the reflective layer is irradiated to the liquid crystal panel through the light guide plate. ,
The light guide plate has an optical characteristic that white light from a predetermined light source that reciprocates the light guide plate is colored in a predetermined color,
The color filter corresponding to the red component, the color filter corresponding to the green component and the color filter corresponding to the blue component are:
The light when the white light reciprocates the color filter corresponding to the red component, the light when the white light reciprocates the color filter corresponding to the green component, and the white light corresponds to the blue component The colored light of the combined light consisting of the light when reciprocating the color filter is a complementary color of the predetermined color,
A liquid crystal display device characterized in that optical characteristics are set.   A display pixel in which a color filter corresponding to the red component is arranged, a display pixel in which a color filter corresponding to the green component is arranged, and a display pixel in which a color filter corresponding to the blue component is arranged have an aperture ratio. The liquid crystal display device according to claim 1, wherein the liquid crystal display devices are equal to each other.

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