JPH09197373A - Display device and driving method thereof - Google Patents

Abstract

(57) An object of the present invention is to provide a full-color display device which is thin, has high resolution, and is light stable, and a driving method thereof. According to the present invention, a multicolor light emitting means optically connected to at least one position of an end face of a light guide plate, and a light shielding means for controlling light emission from the multicolor light emitting means on a main surface of the light guide plate. And a light-emission driving unit that sequentially lights the multicolor light-emitting unit for each emission wavelength, and a light-shielding driving unit that controls the transmittance of the light-shielding unit at the time of lighting for each emission wavelength. Is. [Effect] With a relatively simple structure, a display device capable of full color display with high brightness, thin film and low power consumption can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device using a solid-state light emitting element used for a display or the like, and more particularly to a full color display device which is thin, has high resolution and is highly stable.

[0002]

2. Description of the Related Art Today, notebook personal computers, mobile phones, liquid crystal monitors and the like are rapidly spreading. Along with this, society's demands for color display devices that display and output the operating states of electronic devices and image information are increasing. For example, in a display device using liquid crystal, an image is displayed by the liquid crystal and a light source for its backlight so that it can be used even in an environment with little light such as at night or indoors. An example of such a display device is an Electro
Luminescence (hereinafter referred to as EL)
Alternatively, a display using a backlight such as a cold cathode tube using a direct type or a sidelight type may be used.

However, E is used as the backlight of the display device.
When L is used, it is a planar light emitting light source by itself, and although it is suitable for thinning, it has a problem that the emission brightness is dark and the life is short. In particular, when used as a backlight for a color liquid crystal or the like, further high brightness and uniformity are required, and a wide selection range of emission colors is required, which is a problem. When a cold cathode tube using the sidelight system is used, it is possible to display using a liquid crystal device with the diffusion plate and the fluorescent tube as the light source. The planar light source, which is the backlight, can be made brighter than the emission brightness itself EL, but the fluorescent lamp has a small outer shape, which is as large as 4 to 8 mm, and the device structure becomes large. When the outer shape of the fluorescent tube is reduced, the emission brightness is extremely reduced. In addition, there is a problem that the life is short, a booster circuit, a stabilizing circuit, etc. are required, and the driving circuit becomes complicated and large.

On the other hand, as a light source of a display device, a light emitting element (hereinafter referred to as an LED), which is a solid-state light emitting element, is used as a light emitting source having a relatively long life and capable of downsizing and thinning the display device. Can be mentioned. As a full-color display device using such a light-emitting element, a full-color display 63-4
No. 3177 etc. are mentioned. An example of a color display device using such an LED is shown in FIGS. As shown in FIG. 5, a plurality of LEDs 601 having wavelengths of blue, green and red are respectively arranged on a plane, and the output light is reflected by the reflection material 603 and diffused by the diffusion film 604 to form a surface light emitter of the liquid crystal device. A full color display can be performed by selecting the three wavelengths of red, blue and green output from the LEDs by using a liquid crystal device and passing them through a color filter.

[0005]

However, in order to display a full color through the color filter, it is necessary to use at least three picture elements of each RGB to form one pixel, which is a big problem for high brightness and high definition. It was a point. In addition, since a photolithography technique is used to form a color filter, there is a problem that the cost becomes high in order to obtain a large screen and high definition. Further, the light transmission loss inevitably a color filter component for being displayed with a color filter having a colored layer emitting surface becomes dark occurs. In particular, since the liquid crystal device itself also shields light to some extent, there is a problem in that only about 3 to 5% of the light output from the light emitting means is used and the brightness is significantly lowered. If an attempt is made to compensate for the light transmission loss of the color filter by increasing the luminance of the light emitting element, the heat generated from the light emitting means may cause problems such that the light shielding means cannot be controlled as desired and power consumption increases. Further, it has not been put into practical use because it has a problem that the life of the light emitting element is shortened and the wavelength of the light emitting element is deviated as the power consumption increases.

When the constituent materials of the light emitting elements for respectively emitting the RGB light are different, the difference in the materials causes a difference in the brightness due to the life of the light emitting elements, the deviation in the emission wavelength due to heat generation, the heating between the light emitting elements due to the difference in the power consumption, and the like. Problems such as color misregistration occur due to different deterioration rates. In particular, when the display device is formed as a panel display that is made smaller, thinner, brighter, and driven at high speed, the light emitting means and the light shielding means are arranged in close contact with each other, and each influence of the light shielding means and the light emitting means itself is affected. It cannot be ignored. SUMMARY OF THE INVENTION It is an object of the present invention to provide a display device that solves the above-mentioned problems and has a thin screen, high brightness, high reliability, and low power consumption, and has a large screen and high definition full color display.

[0007]

According to the present invention, there is provided a multicolor light emitting means optically connected to at least one position on an end surface of a light guide plate, and light emitted from the multicolor light emitting means on the main surface of the light guide plate. A light-shielding device for controlling light-shielding, comprising:
A display device having a light emission drive means for sequentially lighting the multi-color light emission means for each emission wavelength and a light shielding drive means for controlling the transmittance of the light shielding means at the time of lighting for each emission wavelength.
The display device also includes a correction unit that is electrically connected to the light emission drive unit and the light shielding drive unit and that changes the output value of each emission wavelength of the multicolor light emission unit with time based on previously stored data. . Further, a display device in which the light shielding means is a liquid crystal device, a display device in which the multicolor light emitting means is composed of a plurality of LED chips, the LE
The display device and the multicolor light emitting device, in which at least a part of the D chip is substantially made of gallium nitride semiconductor, include a first semiconductor having an emission wavelength of at least 430 to 490 nm and a second semiconductor having an emission wavelength of 495 nm to 560 nm. It is a display device including a semiconductor and a third semiconductor having an emission wavelength of 600 nm to 700 nm. In addition, the multicolor light emitting means emits light sequentially for each emission wavelength, and the color display corresponding to one pixel of the frame when one emission wavelength of the multicolor light emitting means emits light is adjusted by adjusting each light shielding rate of the light shielding means. A driving method of a display device for displaying, wherein the output value of the multicolor light emitting means is changed based on a correction signal for correcting each emission wavelength.

[0008]

[Advantage] By adopting the constitution of claim 1 of the present invention,
The display device can be thin and small. In addition, a full-color display device that does not require a color filter and has high brightness and high definition can be provided. In particular, it is possible to obtain a display device in which the light shielding means is extremely less affected by the heat from the multicolor light emitting means even when it is thinned and downsized.

With the configuration of claim 2 of the present invention, it is possible to correct the difference in deterioration rate of the light emitting elements constituting the multicolor light emitting means and prevent the color shift.

By adopting the constitution of claim 3 of the present invention, it is possible to obtain a display device which can be made thinner.

By adopting the constitution of claim 4 of the present invention, it is possible to obtain a color display device having a small size, high brightness and high stability.

With the structure of claim 5 of the present invention, a color display device capable of high brightness, high resolution and high speed driving can be obtained.

With the structure of claim 6 of the present invention, a full-color display device having a chromaticity distribution much wider than that of the NTSC system can be obtained.

By the method according to claim 7 of the present invention, it is possible to perform full-color display with high resolution even in the light-shielding means for which it is difficult to display intermediate colors.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of various kinds of experiments,
It was found that a display device capable of high-definition full-color display can be obtained by driving the multicolor light emitting means and the light shielding means, respectively, and the present invention has been completed. That is, unlike the display device in which one pixel is configured by using color filters of respective picture elements of RGB to display, the inventor of the present application sequentially emits the three primary colors from the multicolor light emitting means through the light guide plate and simultaneously emits one pixel. In the display device capable of full-color display, the light-shielding rate of each color is changed in accordance with an image signal to display position dots for color display with one pixel. As a result, the influence of heat from the multicolor light emitting means on the light shielding means is extremely reduced, and the RG to the light emitting element is reduced.
Since the color filter corresponding to B can be omitted, the brightness of the display device as a whole can be improved and high definition can be achieved. Further, changes in characteristics that occur when the semiconductors forming the multicolor light emitting means use different semiconductor materials for each emission wavelength can also be controlled by adjusting the light shielding time of the light shielding means.

In particular, even when the display device is formed as a panel display that is smaller and thinner, and the light emitting means and the light shielding means are arranged in close contact with each other, the heat generated by the light emitting means affects the light shielding means. The display device can be reduced.

The present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic transmission diagram showing an example of the display device of the present invention, and FIG. 2 is a schematic sectional view of the present invention showing the a-a cross section of FIG. 1. In FIGS. 1 and 2, a multicolor light emitting means 103 in which semiconductor light emitting elements capable of emitting R, G, and B are arranged on a support having a reflection function is optically connected to the light guide plate 102. A reflective material 201 that reflects light from the light emitting element is arranged on the back surface of the light guide plate 102, and a diffusion film 205 for uniformizing the light reflected from the back surface is provided on the front surface side of the light guide plate 102. . Light guide plate 10
On the upper surface of 2, there is disposed a liquid crystal device as a light shielding means 101 that is driven in synchronization with the light emitting element via a diffusion film. The liquid crystal device 101 serving as a light shielding unit includes the liquid crystal 2 between the glass serving as the translucent support 202 on which the transparent electrode 203 is formed.
The polarizing plate 206 is provided in the structure in which 04 is injected.

(Light-shielding means 101) The light-shielding means 101 used in the present invention controls the light-shielding rate by an information signal in which light emitted from the multicolor light emitting means 103 via the light guide plate 102 is synchronized with the multicolor light emitting means 103. It is a thing. Specifically, it can be formed by using various kinds of liquid crystals, dielectric mirrors and the like. In the present invention, the light emission color and brightness of each pixel are determined by the light blocking rate of the light blocking unit 103. As such a light shielding means, a ferroelectric liquid crystal (Ferroe liquid crystal) having a ferroelectric property by using a nematic liquid crystal or a smectic liquid crystal is used.
lectric liquid crystal)
A liquid crystal device formed by being sandwiched between translucent supports 202 such as borosilicate glass or alumina having a transparent electrode 203 such as iO ₂ is preferably used. For driving, an active matrix using a thin film diode or TFT or a simple matrix can be mentioned.

In the present invention, the liquid crystal 20 is used as the light shielding means 101.
When 4 is used, if the ultraviolet light component is contained in the light emitted from the multicolor light emitting means 103, the characteristics of the light shielding means 101 may be deteriorated due to breaking of the double bond of the polymer liquid crystal. . In severe cases, it does not function as the light blocking means 101, so the light blocking means 101 and the multicolor light emitting means 103.
It is preferable to provide an ultraviolet absorbing layer between and. Examples of such an ultraviolet absorbing layer include a resin film and glass containing an ultraviolet absorbing material. Alternatively, the light guide plate may be made to contain an ultraviolet absorber. When glass is used as the ultraviolet absorbing layer, it may be used also as a translucent support for holding the liquid crystal.

(Light Guide Plate 102) As the light guide plate 102 used in the present invention, the light from the multicolor light emitting means 103 is efficiently guided and formed into a planar shape, and the heat generated from the multicolor light emitting means is directly transmitted to the light shielding means 101. It is required to have excellent transmittance and heat resistance and to be uniformly formed. Further, the shape of the light guide plate 102 can be various shapes such as a rectangle and a polygon as desired. Specific constituent materials include acrylic resin, polycarbonate resin,
Examples thereof include glass. The thickness of the light guide plate 102 increases as the thickness of the plate increases, but it is preferable that the thickness of the light guide plate 102 be 1 mm or more and 10 mm or less depending on the arrangement and type of the light emitting elements forming the multicolor light emitting means. By embedding the light emitting element in the end surface of the light guide plate, the light guide plate 102 and the multicolor light emitting means 103 are optically connected. In addition, if the light guide plate is a quadrangle, it goes without saying that the multicolor light emitting means 103 may be connected to all four end faces, and the number of LEDs that are light emitting elements forming the multicolor light emitting means 103 is also limited. Not a thing.

Further, it is preferable to provide, on the lower side and the side surface of the light guide plate 102, a reflecting material 201 for reflecting the light traveling while reflecting inside the light guide plate in the light emitting surface direction without waste.
The shape and size of the reflecting material 201 are not specified as long as they scatter the light from the multicolor light emitting means 103 into the light guide plate, and the reflecting material 201 also serves as a case-shaped member for holding the light guide plate 102 or the light guide plate. It can also be processed on the surface. In addition, in order to make the surface light emitted uniformly using the light guide plate, the reflective material 2
01 may have a stripe shape, and the surface area of the reflective material 201 may be reduced as the area approaches the multicolor light emitting means so that the surface luminance becomes constant. Further, by arranging the light emitting elements that form the multicolor light emitting means 103, the shape of the reflecting material 201 can be appropriately changed so that the light emission becomes uniform in a planar manner. further,
By forming irregularities on the surface of the light guide plate that is in contact with the reflecting material, it is possible to further scatter the light from the multicolor light emitting means and to make uniform light emission. The reflective material 201 preferably has a reflectance of 95% or more with respect to the light emitted from the multicolor light emitting means, and more preferably 98% or more. Further, since it is provided on the light guide plate, the thickness is preferably 3 mm or less, more preferably 1 mm or less in consideration of the arrangement with the light shielding means 101 and the like provided thereon. The material of the reflective material satisfying the above-mentioned reflectance is polyethylene terephthalate resin, polycarbonate resin, barium titanate as a reflective material in a resin such as polypropylene resin,
Examples thereof include a film-shaped member formed by containing aluminum oxide, titanium oxide, silicon oxide, calcium phosphate and the like. In addition, a metal film of Al, Ag, Cu or the like is used as the light guide plate 10.
It may be formed on the surface 2 by plating or sputtering. Further, a foamed polyester or the like containing a white pigment is processed into a film. These reflecting materials are made of silicon resin, epoxy resin, etc.
Can be attached to 2.

Further, it is preferable to provide a diffusion film 205 on the upper surface of the light guide plate 102, which functions to scatter light from the light guide plate 102 to make the brightness uniform. As such a diffusion film 205, it is necessary to have a high light transmittance and efficiently diffuse light, and it is preferable that the diffusion film 205 has a transmittance of 50% or more, and more preferably 70% or more. Examples of the material of the diffusion film 205 include a transparent polycarbonate film or polyester film having high heat resistance, coated with refractive fine particle resin beads or translucent inorganic fine particles, and further embossed. In addition, by forming irregularities on the surface of the light guide plate 102 that is in contact with the diffusion film 205, it is possible to prevent interference fringes that are formed due to the diffusion film 205 sticking to the light guide plate 102. It should be noted that the diffusion film 205 can be made to have a shade by containing a white pigment in inverse proportion to the distance from the multicolor light emitting means 103 for uniform brightness.

In the present invention, the multicolor light emitting means 103
That the end face of the light guide plate 102 is optically connected means that light emitted by the multicolor light emitting means 103 is introduced from the end part of the light guide plate. Specifically, the multicolor light emitting means 103
Not only is the light-emitting element constituting the above described embedded in the light-guide plate, but the light-emitting element is bonded by a light-transmissive resin or the like, or the light emission of the light-emitting element is guided to the end face of the light-guide plate by using an optical fiber or the like.

(Multicolor Light Emitting Means 103) As the multicolor light emitting means 103 used in the present invention, a semiconductor light emitting element having a different emission wavelength is arranged on a substrate having a reflection function. The light-emitting element forming the multicolor light-emitting means 103 is formed of GaA on the substrate by a liquid phase growth method, a MOCVD method or the like.
1N, ZnS, ZnSe, SiC, GaP, GaAlA
s, AlInGaP, InGaN, GaN, AlInG
A material in which a semiconductor such as aN is formed as a light emitting layer is preferably used. Examples of the semiconductor structure include a homo structure, a hetero structure, and a double hetero structure having a MIS junction and a PN junction. The emission wavelength can be selected from ultraviolet light to infrared light depending on the material of the semiconductor layer and its degree of mixed crystal. A plurality of light emitting elements may be used for each emission wavelength, or a light emitting element in which light emitting layers having a plurality of emission wavelengths are formed on one substrate may be used. In the present invention, the light emission output of a light emitting element that emits one emission wavelength is 200 μW
The output of 300 μW or more is more preferable. When the light emitting output of the LED, which is a light emitting element, is less than 200 μW, even if the number of LEDs constituting the multicolor light emitting means 103 optically connected to the end face of the light guide plate 102 is increased, sufficient brightness is obtained. This is because it tends to be difficult to obtain a light source of planar light emission.

The multicolor light emitting means 103 of the present invention is
It is necessary to display at high speed in synchronization with the light shielding means 101.
As such a specific semiconductor material, gallium nitride-based compound semiconductors are preferably used for semiconductors that emit green and blue light, and gallium-aluminum-arsenic-based semiconductors and aluminum-indium-based semiconductors are used for red.
It is preferable to use a gallium / phosphorus-based semiconductor. If desired, a plurality of LED chips having different wavelengths can be used. For example, one blue color and two green colors and two red colors can be used. A light emitting element as a multicolor light emitting means of a full color display device has a red emission wavelength of 600 nm to 700 nm, a green emission wavelength of 495 nm to 565 nm, and a blue emission wavelength of 430 in order to widen the color range.
It is preferably from nm to 490 nm.

It is preferable that the multicolor light emitting means 103 is arranged on a support body in which a groove is formed so that it can be arranged without a gap from the end surface of the light guide plate 102 and into which each LED chip of the light emitting element can be fitted. Specifically, polycarbonate, polyethylene, acrylic, urethane, vinyl chloride, nylon, and polyethylene terephthalate are preferable as the material of the support that can be formed by heat welding. Further, the support efficiently reflects the light traveling toward the end face support of the light guide plate 102, and
In order to make the light incident on, it is preferable that it is colored white. In addition, the amount of heat generated from the light emitting elements forming the multicolor light emitting means 103 increases. Therefore, the light emitting element may be arranged on the common substrate via the heat conducting member. The heat conducting member is required to have good heat conductivity. Specifically, 0.0
1cal / cm ² / cm / ℃ or more preferably preferably 0.5cal / cm ² / cm / ℃ above. Examples of materials satisfying these conditions include iron, copper, aluminum, copper containing iron, copper containing tin, and ceramics with a metallized pattern.

(Driving Means 301, 302) The driving means used in the present invention are the light emitting driving means 301 for sequentially emitting light for each emission wavelength of the multicolor light emitting means, and the multicolor light emitting means 1.
03, and the light-shielding drive means 302 used for changing the light-shielding rate of each color in one pixel in accordance with an image signal so that one pixel expresses multiple colors. Specifically, as shown in FIG. 4, the emission wavelengths of RGB, which are time-divided, are further expressed by the light-shielding ratio of the light-shielding unit to express the gradation and mixed color of the emission colors. Note that the multicolor light emitting element is RG
In order to display in B time division, light may be emitted continuously or in pulses. Therefore, due to the afterimage phenomenon of the human eye, the color of the pixel is determined by the respective shading rates of RGB of one pixel. As such a driving means, C
It can be configured by driving the light shielding means 101 and the multicolor light emitting means 103 at high speed by a synchronous circuit using a PU.

(Correction Means 303) As the correction means used in the present invention, the difference in the deterioration rate caused by the different semiconductor materials of the light emitting elements of the multicolor light emitting means is stored in advance in the ROM or the like, and the correction rate is increased with time. It is used to correct the change in the light emission output of the color light emitting element. The corrected value is fed back to the light emission drive means and the output variation due to the difference in deterioration rate is added to drive the multicolor light emission means. The output variation may be corrected for all the light emitting elements, or may be corrected with reference to the output of the light emitting element having the highest brightness. Therefore, the luminance of each wavelength of the multicolor light emitting element may be corrected while being measured by the sensor or may be automatically corrected by a predetermined correction value. Such a correction unit can be variously configured by a CPU having various arithmetic circuits.

[0029]

【Example】

[Example 1] A back reflector was formed by screen-printing a white reflective member containing barium titanate dispersed in an acrylic binder on one surface of an acrylic plate having a thickness of 2 mm and curing it. Next, the acrylic plate on which the back reflector is formed is cut into a rectangle of 10 × 8 cm, all the end faces (cut faces) of the acrylic plate are polished, and then the end face to which the multicolor light emitting means is optically connected is removed. By forming a side reflector of Al on the polished surface, a light guide plate on which the reflector was formed was obtained.

Each LE of the light emitting element constituting the multicolor light emitting means
The D chip has InGaN (emission wavelength of 525 nm) and InG as semiconductors of the green, blue and red light emitting layers, respectively.
It was constructed using aN (emission wavelength 470 nm) and GaAlAs (emission wavelength 660 nm). Specifically, for a semiconductor wafer for an LED chip that emits red light, P-type GaAlAs is continuously grown on a P-type gallium-arsenide substrate by the temperature difference liquid crystal growth method, and N-type GaAlAs is grown on it. , P-type GaAlAs, which is a light emitting region, is formed.
A semiconductor wafer that emits blue and green light has a thickness of 400
N-type and P-type gallium nitride compound semiconductors are formed on a μm sapphire substrate by MOCVD growth method at 5 μm and 1 μm, respectively.
m is deposited to form a heterostructure PN junction. The P-type gallium nitride semiconductor is formed by annealing after being doped with Mg which is a P-type dopant, and the emission wavelength is controlled by changing the In content.

Each of the wafers thus formed is 350
After making a square angle and fixing the LED chip of RGB as a light emitting element on a common support body using Ag paste, it electrically connected. The common support constituting the multi-color light emitting means was integrally formed by thermosetting 10 g of polycarbonate resin containing 6 g of silicon oxide. The integrally formed support body is formed in a rectangular parallelepiped according to the size of the end surface of the light guide plate, and has three holes so that the light emitting elements can be arranged respectively. After the light guide plate and the multicolor light emitting means were optically connected using a translucent resin, a white diffusion layer, which was an embossed film of polycarbonate, was disposed over the entire light emitting surface of the light guide plate.

On the other hand, SnO is formed on a glass substrate, which is a light-transmissive substrate, by sputtering to form a light shielding means.
TFTs were formed on the _two transparent electrodes by using the plasma CVD method. Next, the end portion was sealed with a sealing material so that the ferroelectric liquid crystal could be injected between the translucent supports, and then the ferroelectric liquid crystal was injected between the translucent supports. A light blocking means was formed by disposing a polarizing plate on the liquid crystal panel thus formed. The light shielding means arranged on the light guide plate to which the multicolor light emitting means is optically connected and the multicolor light emitting means connected to the light guide plate respectively use a one-chip microcomputer, and the light shielding means and the multicolor light emitting means are driven by the driving means. Were driven in synchronization with each other. When the display device thus produced was connected to a power source to emit white light, it was 78 cd / m ² at (0.29, 0.31) in the chromaticity coordinate of the Kelly chart. The display device was made to emit light in a time-divisional manner by flowing RBG pulse signals, respectively, while the light-shielding means controlled the light-shielding rate for each emission wavelength according to the image signal as shown in FIG. It was confirmed that a high-definition moving image can be displayed by this display device.

(Embodiment 2) A constitution similar to that of Embodiment 1 is made except that the light emission drive means is electrically connected to a correction means for storing a correction value of the deterioration rate in advance. Example 1 and Example 2
When each of the examples was driven for 2000 hours, light was emitted with good color balance in any of the examples up to 1000 hours. When driving for a long time such as over 2000 hours,
GaAlAs used in the multicolor light emitting means of Example 1.
The red light output from the semiconductor is reduced by 30%, while
The green and blue light output from the InGaN semiconductor is 1
It decreased by 0%. When multicolor light emission was performed, the chromaticity coordinates of the Kelly chart were (0.27, 0.29), and the white balance was lost. The display device of Example 2 remained (0.29, 0.31) in the chromaticity coordinates of the Kelly chart.

[0034]

As described above, the display device of the present invention can be a display device capable of full-color display with high brightness, thin film and low power consumption with a relatively simple structure.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a display device of the present invention.

FIG. 2 is a schematic cross-sectional view of aa of the display device of the present invention shown in FIG.

FIG. 3 is a block diagram showing a configuration of the present invention.

FIG. 4 is a driving method using the display device of the present invention.

FIG. 5 is a schematic perspective view of a display device shown for comparison with the present invention.

6 is a bb schematic sectional view of the display device for comparison shown in FIG.

[Explanation of symbols]

 101 ... Shading means 102 ... Light guide plate 103 ... Multicolor light emitting means 201 ... Reflecting material 202 ... Translucent support 203 ... -Transparent electrode 204-Liquid crystal 205-Diffusion film 206-Polarizing plate 301-Emission driving means 302-Shading driving means 303- Correcting means 601 LED 602 Light guide plate 603 Reflecting material 604 Diffusing film

Claims (7)

[Claims] 1. A multicolor light emitting means optically connected to at least one location of an end surface of the light guide plate, and a light shielding means for controlling light emission from the multicolor light emitting means on the main surface of the light guide plate. A display device comprising: a light emission drive means for sequentially turning on the multicolor light emitting means for each emission wavelength; and a light shielding drive means for controlling the transmittance of the light shielding means at the time of lighting for each emission wavelength. Display device. 2. A correction means which is electrically connected to the light emission drive means and the light shield drive means and which changes the output value of each emission wavelength of the multicolor light emission means with time based on previously stored data. Item 2. A display device according to item 1. 3. The display device according to claim 1, wherein the light shielding means is a liquid crystal device. 4. The display device according to claim 1, wherein said multicolor light emitting means is composed of a plurality of LED chips. 5. The display device according to claim 4, wherein at least a part of the LED chip is substantially made of a gallium nitride semiconductor. 6. The multicolor light emitting means is at least 430.
495n with a first semiconductor having an emission wavelength of 490nm
a second semiconductor having an emission wavelength of m to 560 nm and 6
The display device according to claim 1, further comprising a third semiconductor having an emission wavelength of 00 nm to 700 nm. 7. The multicolor light emitting means is caused to sequentially emit light for each light emission wavelength, and a color display corresponding to one pixel of a frame when one emission wavelength of the multicolor light emitting means emits light is adjusted by each light shielding rate of the light shielding means. A method of driving a display device for performing mixed color display, wherein the output value of the multicolor light emitting means is changed based on a correction signal for correcting each emission wavelength.