JP2007226973A - Surface light-emitting device and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface light-emitting source capable of application to a liquid crystal display device of field sequential type, with a small power consumption and thinness. <P>SOLUTION: As a light source of a surface light-emitting source 20 used for the liquid crystal display device 10 of field sequential type, an LED light source 50 and an organic EL element 54 that are capable of emitting three primary colors independently are combined. By this, a surface light-emitting source 20 for field sequential purpose which combines a light-emitting diode of a color having a small power consumption and an organic EL element of a color having a small power consumption can be provided. Thereby, a liquid crystal display device 10 with a high numerical aperture and high definition, and with a small power consumption suitable for a portable electric equipment can be provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a surface light emitting device used for a liquid crystal display device, and more particularly to a surface light emitting device capable of independently emitting three primary colors and a display device using the surface light emitting device.

  As a light source of a backlight for a liquid crystal display device, a surface emitting backlight using an LED, an organic EL, or a fluorescent tube is known. Furthermore, in order to reduce the power consumption of the liquid crystal display device and to provide a portable device that is easy to carry, a surface-emitting backlight that uses these light sources alone, or a surface that uses these light sources in combination. Luminescent backlights are known.

  As a light source device combining the light sources, a light source composed of a blue LED, a rod-shaped light guide disposed so as to face the light source, and a wedge-shaped light guide plate including the rod-shaped light guide disposed on one end surface side are provided. And a lower light source device provided with a light emitting portion that is disposed further on the back side of the upper light source portion and includes an organic EL that emits yellow light only on one surface side in the upper light source portion direction. Is known (see, for example, Patent Document 1).

  In the light source device described in Patent Document 1, white light is generated by a color mixture of colored light emitted from a light source unit including a light emitting diode and colored light emitted from a light source unit including an organic EL. Accordingly, secondary excitation is not used to generate white light, and the emission color which is a complementary color can be directly emitted by the organic EL, so that a white light source having excellent energy efficiency can be obtained. It is aimed.

In addition, as a surface-emitting backlight for a liquid crystal display device adopting a field sequential method, a backlight that emits red, green, and blue light and each switching element are provided in order to achieve miniaturization and low power consumption. A data driver and a scan driver for switching corresponding to the red, green, and blue data of the pixel, and adjusting the light emission time of the red, green, and blue time-divided light to adjust the color An invention that improves the characteristics of display color by adjusting the balance is known (see, for example, Patent Document 2).
JP 2002-100229 A (FIG. 3) JP 2000-28984 A (FIG. 4)

  The light source device using the organic EL described in Patent Document 1 can be applied to a portable electronic device because the energy efficiency is good. However, in the light source device described in Patent Document 1, a white backlight light source is formed by combining a blue light emitting diode and an organic EL that emits yellow light. Therefore, there has been a problem that it cannot be applied to a field sequential type backlight that performs color display by emitting light divided in time for each of the three primary colors.

  Note that a color liquid crystal display using the field sequential method can express all colors with one pixel compared to a color liquid crystal display that uses three primary color filters to perform color display. The aperture ratio can be increased.

  Furthermore, a color liquid crystal display employing a field sequential method can increase the transmittance by about two times because a color filter is unnecessary. In addition, color liquid crystal displays that use the field sequential method are capable of high-speed moving image display, and have various advantages in that clear moving image display can be performed by performing impulse-type driving. This is a liquid crystal display method that is expected.

  In addition, in the light source device shown in FIG. 3 of Patent Document 1, since the independent organic EL and the independent light guide plate are provided, the thickness of the backlight to which the organic EL is added becomes thick. When applied to a portable device that requires a thin liquid crystal display, there has been a problem that it is difficult to reduce the thickness and size of the portable device.

  In the liquid crystal display control method of the liquid crystal display device described in Patent Document 2, in the liquid crystal display device adopting the field sequential method, the light emission luminance of the red light emitting diode used for the backlight is other blue light emitting diode and green light emitting. In view of the fact that it is lower than the light emission luminance of the diode, the display color can be displayed without increasing the number of red light emitting diodes by setting the light emission time of the red light emitting diode longer than other green light emitting diodes and blue light emitting diodes. The color passing is adjusted.

  Further, in the backlight used for the field sequential type liquid crystal display device, the ratio of the amount of light is set to the ratio of red: green: blue = 3: 6: 1 to maintain the white balance when viewed by a person. Can do. Therefore, when trying to balance the amount of emitted light, it is necessary to pass a large amount of current through the green light-emitting diode with low brightness, which increases the power consumption of the liquid crystal display device, which is disadvantageous for application to portable devices. There was a problem of becoming.

  On the other hand, in the case of the organic EL, there is a tendency that the blue and red power consumption is large because the light emission efficiency of blue and red tends to be lower than that of the light emitting diode.

  The present invention has been made to solve the above problems, and is applicable to a field-sequential liquid crystal display device, and has a thin surface light source with low power consumption and a liquid crystal display device using the surface light source. It is intended to provide.

  Therefore, the present invention has a configuration in which a light emitting diode and an organic EL are used in combination as a light source of a surface emitting source capable of independently emitting the three primary colors.

  According to the above surface emitting source, since the light emitting diode and the organic EL are used in combination as the light source of the surface emitting source capable of independently emitting the three primary colors, the light sources with good luminous efficiency are combined. It is possible to provide a surface light source with low power consumption.

  Embodiments of the present invention will be described below.

  The surface light emitting device according to the present invention emits light by switching, for example, three primary colors of red, green, and blue in time sequence. In addition, while the surface light emitting device emits each of the three primary colors, it is possible to apply the image of the emitted color to a field sequential type liquid crystal display device in which a liquid crystal display element forms. In the field sequential type liquid crystal display device, time-sequential color mixing is generated by repeating the image formation for each color of the red field, the green field, and the blue field in time sequence, thereby performing color screen display.

  In a portable electronic device equipped with a color liquid crystal display device, in addition to a demand for downsizing the entire liquid crystal display device including a backlight, power consumption is particularly low in order to ensure the operation time of the electronic device. Desired.

  Therefore, in the present invention, a light emitting diode and an organic EL are used in combination as a surface light source capable of independently emitting three primary colors for a field sequential type liquid crystal display device.

  As a result, it is possible to provide a field sequential surface emitting source that combines a light emitting diode with low power consumption and an organic EL with low power consumption. A liquid crystal display device with low electric power and suitable for a portable electric device can be provided.

  Further, the present invention is configured to include a compensation plate that narrows the emission spectrum of the light source and compensates for the color characteristics of the three primary colors.

  Accordingly, it is possible to provide a surface light source that emits light suitable for the backlight characteristics of the three primary colors of the field sequential method by narrowing a wide light emission spectrum emitted from a light source such as an organic EL.

  In the present invention, a blue light emitting diode and a red light emitting diode are used as the light emitting diode, and a green organic EL is used as the organic EL.

  Blue and red light emitting diodes with better luminous efficiency and lower power consumption than blue and red organic ELs are used as light sources, and green organic ELs with better luminous efficiency and lower power consumption than green light emitting diodes are used as light sources. Used as As a result, it is possible to provide a field-sequential surface-emitting source for a liquid crystal display device that consumes less power and is suitable for portable electric devices.

  In addition, the present invention includes a light guide plate that guides light emitted from the light emitting diode to the light emitting surface, and the organic EL is disposed below the light guide plate.

  Thereby, a surface emitting source can be comprised by selecting the combination with good luminous efficiency out of the combination of a light emitting diode and organic EL. Further, it is possible to provide a small surface emitting source that employs an edge light system for a light emitting diode having locally high emission luminance.

  Further, the present invention includes a light guide plate that guides light emitted from the light emitting diode to a light emitting surface, and the organic EL is formed on a lower surface of the light guide plate.

  Thereby, a surface-emitting source can be comprised by selecting the combination with good luminous efficiency among a light emitting diode and organic EL. In addition, an edge light system is adopted for a light emitting diode having locally high light emission luminance, and a small and thin surface light source can be provided.

  In addition, the present invention includes a light guide plate that guides light emitted from the light emitting diode to the light emitting surface, and the organic EL is incorporated in the light guide plate.

  Thereby, a surface-emitting source can be comprised by selecting the combination with good luminous efficiency among a light emitting diode and organic EL. In addition, an edge light system is adopted for a light emitting diode having locally high light emission luminance, and a small and thin surface light source can be provided.

  Further, in the present invention, each of the above surface emitting sources is used in a liquid crystal display device.

  Accordingly, it is possible to provide a field sequential type liquid crystal display device which consumes less power and is suitable for a portable electric device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view schematically showing a liquid crystal display device 10 in which a surface light emitting device 20 having an organic EL 54 incorporated in an edge light type light guide plate 52 and an optical sheet 60 are provided on the back surface of a liquid crystal display element 70. It is. FIG. 2 is a cross-sectional view schematically showing the surface light emitting device 120 having the organic EL 154 under the edge light type light guide plate 152 and the liquid crystal display device 110 provided with the optical sheet 60.

  As shown in FIG. 1, the liquid crystal display device 10 includes a liquid crystal display element 70 that forms a display screen by adjusting the amount of transmitted light for each pixel, and the three primary colors from the lower surface of the liquid crystal display element 70 independently. The light-emitting device includes a surface light-emitting device 20 that can be irradiated in a time-sharing manner, and an optical sheet 60 that adjusts the irradiation direction and color tone of light emitted from the surface light-emitting device.

  For example, the surface light emitting device 20 can independently emit three primary colors of red, green, and blue. The three primary colors that emit light may emit three colors of yellow, magenta, and cyan instead of emitting the three colors red, green, and blue described below. In the following description, the three primary colors are used for convenience, but the emitted light is not limited to the three primary colors, and other colors may be added.

  The surface light source 20 is a light emitting unit capable of independently emitting light of the three primary colors, and can be used for, for example, a field sequential type color liquid crystal display device. A color liquid crystal display employing a field sequential method can obtain higher resolution and a higher aperture ratio than a color liquid crystal display that performs color display using three primary color filters. Accordingly, the transmittance of the liquid crystal is increased and low power consumption can be realized.

  The surface light emitting device 20 includes, for example, an LED light source 50 including a red light emitting diode that emits red light and a blue light emitting diode that emits blue light, and the light emitted from the LED light source 50 is incident from the side surface, and the incident light is The entire surface of the liquid crystal is provided with a light guide plate 52 that guides and outputs the light as much as possible, and a reflective layer 58 that reflects the light reaching the lower surface of the light guide plate 52.

Further, the surface light emitting device 20 is provided with a cap 59 on the back surface thereof to prevent the life of the organic EL 54 from being shortened by contact of moisture in the atmosphere with the organic EL 54. The cap 59 can be filled with, for example, N ₂ and a desiccant can be enclosed to enhance the moisture-proof effect on the organic EL 54.

  In the first embodiment of the present invention, the organic EL 54 is incorporated in the light guide plate 52. By incorporating the organic EL 54 into the light guide plate 52, the liquid crystal display device 10 can be made thin, and the electronic device can be miniaturized when applied to a portable electronic device.

  The light emission colors of the LED light source 50 and the organic EL 54 may be any combination of red, green, and blue colors, or any combination of yellow, magenta, and cyan colors. However, when there is the following relationship between the LED light source and the organic EL 54, a combination of colors to be used may be selected.

  For example, when a red light emitting diode and a blue light emitting diode are used as the LED light source 50, an element that emits green light is used as the organic EL 54.

  In general, in a backlight used in a field sequential type color liquid crystal display device, white balance can be maintained when the ratio of the amounts of light emission colors is red: green: blue = 3: 6: 1. Therefore, it is necessary to increase the amount of green light emission. However, if this is left as it is, the power consumption for causing the green light-emitting diode to emit light increases, and the operation time of the electronic device is limited when applied to a portable electronic device. This causes the problem of being

  On the other hand, organic EL tends to have a large power consumption of elements emitting red and blue colors. Therefore, by using the organic EL as the green light source and the surface light emitting device 20 using the LED light sources as the red and blue light sources, the LED light source is used for all colors or the organic EL is used for all colors. The power consumption of the surface emitting source 20 can be reduced as compared with the case where is used.

  Then, by incorporating the surface light emitting device 20 into a portable electronic device, an electronic device having a long operation time can be provided. In addition, by using LED light sources for red and blue light sources and organic EL for green light sources, high NTSC ratio (National ・ Television ・ System ・ Committe ・ Ratio) was compared with the triangular area of NTSC standard color crossing coordinates. Power consumption can be reduced while maintaining high contrast with an area ratio (%) and an index indicating the vividness of color.

  Next, the function of the light guide plate 52 will be described. When red and blue light is incident on the side surface of the light guide plate 52 from the LED light source 50, the incident light travels while reflecting the inside of the light guide plate 52. The light radiated into the edge light type light guide plate 52 reaches the upper surface or the lower surface of the light guide plate 52 while traveling through the light guide plate 52. Of the light reaching the upper surface of the light guide plate 52, the light incident on the upper surface of the light guide plate 52 at an angle greater than the critical angle is emitted from the surface of the light guide plate 52 on the liquid crystal display element 70 side. The light emitted at this time is emitted at a shallow angle due to refraction. The critical angle is a constant determined according to the ratio of the refractive index of the light guide plate 52 and the external substance. Light incident at an angle less than the critical angle with respect to the upper surface of the light guide plate 52 is totally reflected inside the upper surface of the light guide plate 52 and passes through the light guide plate 52 again.

  On the other hand, the light that has reached the lower surface of the light guide plate 52 is totally reflected by the reflection layer 58 provided on the lower surface of the light guide plate 52 and passes through the light guide plate 52 again. As described above, internal reflection is repeated, and most of the light incident from the side surface of the light guide plate 52 is emitted to the liquid crystal display element 70 side.

  In addition, the prism 56 which reflects the light irradiated to the lower surface of the light guide plate 52 to the liquid crystal display element 70 side is appropriately disposed so that the amount of light output from the liquid crystal display element 70 of the light guide plate 52 is made more uniform. May be. The prisms 56 may be arranged concentrically according to the distance from the LED light source 50, or may be arranged more densely as the distance from the LED light source 50 increases.

  Further, in order to make the amount of light emitted from the surface of the light guide plate 52 on the liquid crystal display element 70 side more uniform, the lower surface of the light guide plate 52 is tapered from the side surface on the LED light source 50 side to the opposite side surface. You may make it a shape.

  Next, the configuration of the optical sheet 60 will be described. The optical sheet 60 has a dot print 62 that changes the direction of light with a shallow angle output from one surface of the light guide plate 52 on the liquid crystal side by refraction, and further diffuses the light output from the light guide plate 52 in all directions. The diffusion member 64 that reduces the spots, and the light diffused in all directions by the diffusion member 64 is caused to stand in the X direction and the Y direction, and the incident light is condensed in the vertical direction, and the user starts the liquid crystal display device 10 from the vertical direction. Prism sheets 66X and 66Y that work to increase the brightness when viewed, and a compensation plate 68 that narrows the wide emission spectrum emitted by the light source such as the organic EL 54 and compensates for the backlight characteristics of the three primary colors suitable for the field sequential method. It has. Note that a plurality of compensation plates 68 may be provided in order to perform color compensation of the three primary colors, or may be selected so as to perform compensation of colors that pass through the liquid crystal.

  Next, the configuration of the liquid crystal display element 70 will be described. The liquid crystal display element 70 is composed of polarizing plates 72 and 92 that transmit light of vibration components in one direction out of the light emitted from the surface light emitting device 20, glass substrates 74 and 90 that hold a liquid crystal layer 84, and pixels. A pixel electrode 76 and a common electrode 88 for applying a voltage to the liquid crystal. A TFT, a pixel electrode, and an alignment film (not shown) are formed on the surface of the glass substrate 74. Further, a common electrode 88 and an alignment film (not shown) are formed on the surface of the counter glass substrate 90.

  When the liquid crystal display element 70 is a normally white mode display element, the polarization characteristics of the polarizing plate 72 and the polarization characteristics of the liquid crystal aligned on the lower surface of the liquid crystal layer 84 are matched. The normally white mode liquid crystal display element refers to a liquid crystal display device that has a high light transmittance when no voltage is applied and a low light transmittance when a voltage is applied. Since the liquid crystal molecules are arranged in a 90-degree twisted arrangement according to the respective orientation directions, by matching the polarization characteristics of the polarizing plate 92 with the polarization characteristics of the liquid crystal aligned on the upper surface of the liquid crystal layer 84, The light rotated 90 degrees along the liquid crystal molecules is transmitted through the polarizing plate 92 and output from the liquid crystal display element 70.

  When an image is displayed by setting the brightness of each pixel of the liquid crystal display element 70, a scan electrode driving circuit provided outside the liquid crystal display element 70 is connected to a scan electrode (not shown) of the liquid crystal display element 70. ) Are sequentially selected one by one, and a voltage corresponding to the brightness of the pixel is applied to the selected scan electrodes. When a voltage is applied, a voltage is applied between the pixel electrode 76 and the common electrode 88 via the TFT, and the liquid crystal molecules rotate to a position corresponding to the voltage. In the state where no voltage was applied, all of the light transmitted through the polarizing plate 72 was rotated 90 degrees along the liquid crystal molecules. However, a part of the light transmitted through the polarizing plate 72 was directly polarized because the liquid crystal molecules were rotated. The plate 92 is reached. Since the polarization direction of the polarizing plate 92 is 90 degrees different from the polarization direction of the polarizing plate 72, the light directly transmitted through the liquid crystal layer 84 is not output to the outside of the liquid crystal display element 70, and only the portion of the pixel electrode 76 transmits light. The transmittance decreases and darkens. By creating a similar situation for all the pixel electrodes 76, an image can be displayed on the liquid crystal display device 10.

  In the field sequential type liquid crystal display device, the surface light-emitting device 20 emits light by sequentially switching the three primary colors (for example, red, green, and blue), and the liquid crystal display element 70 emits light while emitting each of the three primary colors. An image of the color that is present is formed. By repeating this for each color of the red field, the green field, and the blue field, a color screen display can be performed by time-mixing.

  Next, the liquid crystal display device 110 in which the organic EL 154 is provided below the edge light type light guide plate 52 will be described with reference to FIG. The same components as those described in FIG. 1 are denoted by the same reference numerals and description thereof is omitted. As shown in FIG. 2, the liquid crystal display device 110 includes a liquid crystal display element 70 that forms a display screen by adjusting the amount of transmitted light for each pixel, and the three primary colors are independent from the lower surface of the liquid crystal display element 70. The surface light source 120 can be irradiated in a time-sharing manner, and an optical sheet 60 that adjusts the irradiation direction and color tone of light emitted from the surface light source 120.

  The surface light emitting device 120 is a light emitting unit capable of independently emitting light of the three primary colors, and can be used for, for example, a field sequential type color liquid crystal display device. The surface light emitting device 120 includes, for example, an LED light source 50 composed of a red light emitting diode and a blue light emitting diode, and light emitted from the LED light source 50 is incident from the side surface, and the incident light is incident on the entire surface of the liquid crystal side as much as possible. A light guide plate 152 that guides and outputs the light so as to have a uniform amount of light, a glass substrate 153 that forms the organic EL 154, and a reflective layer 58 that reflects light transmitted from the lower surface of the light guide plate 152 and light emitted from the organic EL. I have. In addition, the surface light emitting device 120 includes a cap 59 that prevents the life of the organic EL 154 from being shortened by contact of moisture in the atmosphere with the organic EL 154 on the back surface thereof.

  Next, the configuration of the optical sheet 60 will be described. The optical sheet 60 reduces the unevenness of light quantity by diffusing light with a shallow angle output from one surface of the light guide plate 152 on the liquid crystal side and diffusing the light output from the light guide plate 152 in all directions. The diffusing member 64 and the light diffused in all directions by the diffusing member 64 stand in the X direction and the Y direction to collect the incident light in the vertical direction, and the user sees the liquid crystal display device 110 from the vertical direction. Prism sheets 66X and 66Y that work to increase brightness, and a compensation plate 68 that narrows the wide emission spectrum emitted from the light source such as the organic EL 54 and compensates for the backlight characteristics of the three primary colors suitable for the field sequential method. . Note that a plurality of compensation plates 68 may be provided in order to perform color compensation of the three primary colors, or may be selected so as to perform compensation of colors that pass through the liquid crystal.

  Next, the function of the light guide plate 152 will be described. When red and blue light from the LED light source 50 is incident on the side surface of the light guide plate 152, the incident light travels while reflecting the inside of the light guide plate 152. The light radiated into the edge light type light guide plate 152 reaches the upper surface or the lower surface of the light guide plate 152 while traveling through the light guide plate 152. Of the light reaching the upper surface of the light guide plate 152, the light incident on the upper surface of the light guide plate 152 at an angle greater than the critical angle is emitted from the surface of the light guide plate 152 on the liquid crystal display element 70 side. The light emitted at this time is emitted at a shallow angle due to refraction. Light incident at an angle less than the critical angle with respect to the upper surface of the light guide plate 152 is totally reflected inside the upper surface of the light guide plate 152 and passes through the light guide plate 152 again.

  On the other hand, out of the light reaching the lower surface of the light guide plate 152, the light incident on the lower surface of the light guide plate 152 at an angle greater than the critical angle is emitted from the surface on the organic EL 154 side from the light guide plate 152. The light incident on the lower surface of the light guide plate 152 at an angle equal to or less than the critical angle is totally reflected inside the lower surface of the light guide plate 152 and passes through the light guide plate 152 again.

  The light emitted from the lower surface of the light guide plate 152 is totally reflected by the reflection layer 58 provided on the lower surface of the organic EL 154, enters the light guide plate 152 again, and passes through the inside of the light guide plate 152. In this way, reflection is repeated, and most of the light incident from the side surface of the light guide plate 152 is emitted to the liquid crystal display element 70 side.

  Further, similarly to the light guide plate 52 shown in FIG. 1, a prism 56 for appropriately reflecting the light irradiated on the lower surface of the light guide plate 152 to the upper surface on the liquid crystal display element 70 side is disposed, and the liquid crystal display element 70 of the light guide plate 152 is arranged. You may comprise so that the light quantity of the light output from the side may be made more uniform.

  Further, in order to make the amount of light output from the liquid crystal display element 70 side of the light guide plate 152 more uniform, the lower surface of the light guide plate 152 is tapered from the side surface on the LED light source 50 side to the opposite side surface. It may be.

  In the example illustrated in FIG. 2, the organic EL 154 is disposed at a position apart from the lower portion of the light guide plate 152. However, the organic EL 154 may be formed directly on the lower surface of the light guide plate 152. By forming the organic EL 154 on the lower surface of the light guide plate 152, the liquid crystal display device 110 can be thinned, and the electronic device can be miniaturized when applied to a portable electronic device.

  The light emission colors of the LED light source 50 and the organic EL 154 may be any combination of red, green, and blue colors, and may be any combination of yellow, magenta, and cyan colors. By using the organic EL as the light source and using the LED light sources as the red and blue light sources, the surface emitting source 120 is configured to use the LED light source for all colors or the organic EL for all colors. Compared with the case, the power consumption of the surface emitting source 120 can be reduced. Therefore, an electronic device having a long operation time can be provided by incorporating the surface emitting source 120 into a portable electronic device. Further, by using LED light sources for red and blue light sources and organic EL for green light sources, it is possible to reduce power consumption while maintaining a high NTSC ratio and high contrast.

  Since the surface emitting source according to the present invention can emit light of the three primary colors independently, it can be applied to a high-definition field sequential type liquid crystal display device having a high aperture ratio. Further, according to the present invention, a thin field sequential type backlight for a liquid crystal display device with low power consumption can be provided.

Sectional drawing which shows typically the liquid crystal display device using the surface emitting device of the structure which incorporated organic EL in the light-guide plate. Sectional drawing which shows typically the liquid crystal display device which provided organic EL in the lower part of the light-guide plate.

Explanation of symbols

10, 110 Liquid crystal display device 20, 120 Surface emitting source 50 LED light source 52, 152 Light guide plate 54 154 Organic EL
56 Prism 58 Reflective layer 59 Cap 60 Optical sheet 62 Dot printing 64 Diffusion member 66X, 66Y Prism sheet 68 Compensation plate 70 Liquid crystal display element 72, 92 Polarizing plate 74, 90, 153 Glass substrate 76 Pixel electrode 84 Liquid crystal layer 88 Common electrode

Claims (6)

  A surface light-emitting device using a combination of a light-emitting diode and an organic EL as a light source of a surface-emitting source capable of independently emitting three primary colors.   The surface light emitting device according to claim 1, further comprising a compensation plate that narrows a light emission spectrum of the light source and compensates for color characteristics of three primary colors.   The surface light-emitting device according to claim 1, wherein a blue light-emitting diode and a red light-emitting diode are used as the light-emitting diode, and a green organic EL is used as the organic EL.   The surface light emission according to any one of claims 1 to 3, further comprising a light guide plate that guides light emitted from the light emitting diode to a light emitting surface, wherein the organic EL is provided below the light guide plate. apparatus.   The surface light-emitting device according to claim 1, further comprising: a light guide plate that guides light emitted from the light emitting diode to a light emitting surface, wherein the organic EL is incorporated in the light guide plate.   A liquid crystal display device comprising: the surface light-emitting device having the structure described in any one of claims 1 to 5; and a liquid crystal display element provided on a light-emitting surface of the surface light-emitting device.

Images