JP2000215721A - Lighting system and liquid crystal device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent color unevenness and chromaticity difference. SOLUTION: In this lighting device, three colors fluorescent tubes 2A, 2B, 2C are arranged from the front of the space to the interior of that. Each color light are sequentially irradiated from these fluorescent tubes 2A, 2B, 2C. Irradiated lights are reflected to the front of the space by a reflecting film 3. Color dots 4A, 4B, 4C having same colors with the fluorescent tubes 2A, 2B, 2C respectively are formed on the reflecting film 3. But in a region 3A near the fluorescent tubes 2A, 2B, 2C, density of the color dot 4A is set lower than that of the color dots 4B, 4C, thereby color unevenness is canceled. In a region 3B of the reflecting film 3, density of the color dot 4A is set higher than that of the color dots 4B, 4C, thereby chromaticity difference is canceled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a lighting device provided with a plurality of light sources for respective colors, and a liquid crystal device using the same.

[0002]

2. Description of the Related Art Conventionally, liquid crystal devices for displaying various images using liquid crystals have been used for various devices, but in recent years, color display has been desired.

As one method of performing color display, there is a method utilizing time division, which is disclosed in Japanese Patent Publication No. 63-041078.

FIG. 5 is a cross-sectional view showing an example of the structure of a liquid crystal device which performs color display using such time division, and FIG. 6 is a block diagram showing the entire configuration of the liquid crystal device.

A liquid crystal device 20 shown in FIG. 5 includes a liquid crystal panel P for displaying various information by using liquid crystal, and a backlight device B ₃ disposed behind the liquid crystal panel P to illuminate the panel P. , Is provided.

Among them, a gate line and a source line are formed on the liquid crystal panel P in a known manner, and each pixel has:
TFTs connected to those lines are respectively arranged. As shown in FIG. 6, around the liquid crystal panel P, a shift register RG, a gate circuit G2, and a scanning circuit SC are provided.
The shift register RG is connected to the TFT via a gate circuit G2 and a source line, and the scanning circuit SC is connected to the TFT via a gate line.

The backlight device B ₃ has a transparent light guide plate 1 as shown in FIG. 5, and emits B-color light (blue light) along the side surface 1 a of the light guide plate 1. The single-wavelength fluorescent tube 2A for irradiating the inside, the single-wavelength fluorescent tube 2B for irradiating R color light (red light), and the single-wavelength fluorescent tube 2C for irradiating G color light (green light) are sequentially moved away from the liquid crystal panel P. (I.e., from the front side to the back side of the light guide plate 1). And these fluorescent tubes 2A, 2
B and 2C are sequentially turned on / off for each divided time by the changeover switch SW2 shown in FIG. The reflection films 6 and 3 are arranged on the other side surface 1d and the back surface 1b of the light guide plate 1 so as to reflect each color light irradiated inside the light guide plate 1 toward the liquid crystal panel P. Have been.

As shown in FIG. 6, when the color signals S _R ′, S _G ′ and S _B ′ of the three primary colors RGB are sent, the signals for one screen are temporarily stored in the memory 21. The signal is transferred to the memory 22 by the synchronizing signal SY1 and the clock signal CL1 before the signal for the next one screen is transmitted. The signal for one screen is a clock signal C
By L2, the data is stored in the shift register RG every ３ hour of one screen time.

In this state, when the vertical scanning signal SY2 is sent to the gate circuit G2 or the scanning circuit SC, the gate circuit G2 is opened, and the signal stored in the shift register RG is sequentially applied to the TFT. A signal is applied from the scanning circuit SC to each gate line, and the TFT is appropriately turned on. As a result, the above-described signal is applied to predetermined pixels, and a colorless image corresponding to a specific color (for example, B color) is displayed on the liquid crystal panel P.

At this time, only the fluorescent tube 2A of a specific color (for example, B color) is turned on by the changeover switch SW2, and the image displayed on the liquid crystal panel P is recognized as a B color image.

[0011] Then, by sequentially displaying the monochrome images of each of the RGB colors by such a method, the images are recognized as a full-color image.

[0012]

[SUMMARY OF THE INVENTION Incidentally, the inventors, each color fluorescent tubes 2A of the backlight device B ₃ described above,
2B and 2C were individually turned on, and the luminance distribution of each color was examined. FIG. 7 is a diagram showing a luminance distribution for each color in the conventional backlight device, in which reference numeral 23A is a line showing the luminance distribution of the B-color fluorescent tube 2A, and reference numeral 23B is a line of the R-color fluorescent tube 2B. This is a line indicating the luminance distribution, and reference numeral 23C is G
It is a line showing the luminance distribution of the color fluorescent tube 2C. The horizontal axis represents the distance from the fluorescent tubes 2A, 2B, 2C to the luminance measurement point, and the vertical axis represents the luminance ratio. According to the findings,
In the case of the B-color fluorescent tube 2A arranged closest to the liquid crystal panel P, the brightness is significantly higher in the vicinity of the fluorescent tube 2A (a portion of about 10 to 15 mm) than in other portions,
It was confirmed that color unevenness occurred.

When the luminance of each color in a portion (20 to 150 mm) apart from the fluorescent tubes 2A, 2B and 2C is compared, the luminance of B color (see reference numeral 23A) is equal to the luminance of R and G colors (reference numeral 23B). And reference numeral 23C).
It was confirmed that a chromaticity difference between the mixed colors occurred.

An illuminating device for making the brightness of white light uniform is disclosed in Japanese Patent Application Laid-Open No. 08-220535. Such a device, as shown in FIG.
, And a white fluorescent tube 24 is arranged around the light guide plate 1. A reflection sheet (not shown) is attached to the back of the light guide plate 1, and the reflection sheet has a fluorescent tube 2.
White dots (those having a uniform reflection characteristic in substantially the entire wavelength region of visible light; not shown) are formed such that the arrangement density increases as the distance from the dot 4 increases. However, in such a method, although the luminance of white light can be made uniform, the luminance of each color light cannot be made uniform, and the occurrence of color unevenness and chromaticity difference in a liquid crystal device using the above-described time division is not achieved. Cannot be eliminated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lighting device for preventing the occurrence of color unevenness.

Another object of the present invention is to provide a lighting device for preventing occurrence of a chromaticity difference.

Still another object of the present invention is to provide a liquid crystal device which prevents color unevenness and chromaticity difference from occurring.

[0018]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and has a transparent light guide and a light guide which is disposed at a position facing at least one side surface of the light guide. A light source that irradiates light inside the light guide; and a first reflecting member that is disposed on a back surface of the light guide and reflects light emitted by the light source toward a front side of the light guide. In the lighting device, the first light source is arranged in order from the front side to the rear side along the one side surface.
A light source for color, a light source for second color and a light source for third color,
And at least in the vicinity of the light source, a second color member and a third color member having the same color as the second color light source and the third color light source have the same color as the first color light source. The color members are arranged at a higher density than the first color member, and the luminance of the illumination light from the first color light source in the vicinity of the light source is set to be small.

According to the present invention, there is provided a liquid crystal device including the above-described lighting device and a liquid crystal element arranged along the lighting device, wherein the liquid crystal device is synchronized with the sequential display of an image. Then, the illumination device emits illumination light of each color to display a full-color image.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.
An embodiment of the present invention will be described.

The illuminating device according to the present invention includes a transparent light guide ₁ as shown by reference numeral B ₁ in FIG. 1, for example, and is provided at a position facing at least one side surface 1 a of the light guide 1. The light source 2 for irradiating light inside the light guide 1 is disposed. A first reflecting member 3 is disposed on a back surface 1b of the light guide 1, and is configured to reflect light emitted by the light source 2 toward a front surface 1c of the light guide 1. I have.

Here, the light source 2 is a first color light source 2.
A, a second color light source 2B and a third color light source 2C, and these light sources 2A, 2B, 2C
A is arranged in order from the front 1c side to the back side 1b along the line a.

Further, at least 3A in the vicinity of the light source 2,
7A, as shown in FIGS. 2 to 4, the same color as the second color light source 2B and the third color light source 2C (ie,
The second color member 4B and the third color member 4C have substantially the same spectral characteristics as those of the color light sources 2B and 2C. The first color light source 2A has the same color as the first color light source 2A. They are arranged at a higher density than the member 4A, and are set so that the brightness of the illumination light from the first color light source 2A in the vicinity 3A, 7A of the light source 2 becomes smaller.

In this case, at least the vicinity 3 of the light source 2
A and 7A may be provided with the second color member 4B and the third color member 4C, and may not be provided with the first color member 4A (FIG. 3).
And FIG. 4), the first color member 4A, the second color member 4B, and the third color member 4C.
May be arranged together (see FIG. 2).
In the example shown in FIG. 3, for example, when the first color light source 2A emits blue light, the second color light source 2B emits red light, and the third color light source 2C emits green light, A red color member 4B and a green color member 4C may be arranged in the vicinity 3A of the light source 2.

Further, the color members 4A, 4A for these colors are used.
B and 4C may have reflection characteristics and may be formed on the surface of the first reflection member 3 (see FIGS. 2 and 3), have transmission characteristics, and It may be arranged on the front face 1c (see FIG. 4).

On the other hand, as shown in FIG. 2, the first color member 4A, the second color member 4B and the third color member 4C are also arranged at a portion 3B remote from the light source 2. In addition, the arrangement density of the first color member 4A in the portion 3B remote from the light source 2 is higher than the arrangement density of each of the second color member 4B and the third color member 4C. May be. Here, these color members 4A, 4B, and 4C for each color have reflection characteristics and are formed on the surface of the first reflection member 3. However, it is needless to say that the present invention is not limited thereto. The members 4A, 4B, and 4C have transmission characteristics,
The light guide 1 may be arranged on the front face 1c.

Further, as described above, the color member 4 for each color is used.
Instead of arranging A, 4B, and 4C in the portion 3B remote from the light source 2, * color tone and tube current value of the first color light source 2A, the second color light source 2B, and the third color light source 2C May be adjusted to eliminate the chromaticity difference between the first to third colors. * The second light reflecting member 5 is disposed so as to cover the light source 2, and the light source 2 emits light. Light is reflected to the light guide 1 side, and a color member for the first color having a reflection characteristic is arranged on the surface of the second reflection member 5 (not shown), and the first to third color members are provided. The chromaticity difference may be eliminated. * A color member for a first color having transmission characteristics is arranged on the one side surface 1a arranged so that the light source 2 is opposed (not shown), The chromaticity difference between the first to third colors may be eliminated.

In this case, as shown in FIG. 3, a white member 4D having a uniform reflection characteristic in substantially the entire wavelength region of visible light is provided on the first reflection member 3 so that the arrangement density increases as the distance from the light source 2 increases. It may be arranged on the surface of.

The combination of the first color, the second color, and the third color is “red, green, blue”, “blue,
Red, green, green, blue, red, blue, green,
"Red", "Green, Red, Blue", "Red, Blue, Green"
Any combination may be used. In addition, the first
The combination of the color, the second color and the third color is “yellow, magenta, cyan”, “cyan, yellow, magenta”, “magenta, cyan, yellow”, “cyan, magenta, yellow”, “magenta, Any combination of “yellow, cyan” and “yellow, cyan, magenta” may be used.

The light guide 1 may be a plate-like member made of acrylic or the like.

Furthermore, a single-wavelength fluorescent tube may be used for each color light source 2A, 2B, 2C.

By the way, as shown in FIG. 1, the liquid crystal device 10 may be constructed by disposing the liquid crystal element P along the above-mentioned illumination device B _1.
In synchronization with the sequential display of images, the lighting device B ₁
Then, full-color images may be displayed by irradiating each color illumination light and utilizing time division.

Next, effects of the present embodiment will be described.

According to this embodiment, at least in the vicinity 3A, 7A of the light source 2, the second color member 4B and the third color member 4C have a higher density than the first color member 4A. 3A, 7 near the light source 2
Since the brightness of the illumination light from the first color light source 2A in A is set to be small, color unevenness in the vicinity 3A, 7A of the light source 2 can be eliminated.

Further, the first color member 4A, the second color member 4B and the third color member 4C are also arranged at a portion 3B remote from the light source 2, and When the arrangement density of the first color member 4A in the separated portion 3B is higher than the arrangement densities of the second color member 4B and the third color member 4C, the light source 2 The luminance of the illumination light from each of the color light sources 2A, 2B, and 2C in the portion 3B away from the light source can be equalized, and the chromaticity difference between the first to third colors can be eliminated.

Further, such a chromaticity difference can be eliminated by adjusting the color tone and the tube current value of the first color light source 2A, the second color light source 2B and the third color light source 2C. * A second reflection member 5 is disposed so as to cover the light source 2 so that light emitted by the light source 2 is reflected toward the light guide 1, and a first color having a reflection characteristic is provided. It can also be achieved by arranging a color member for color on the surface of the second reflection member 5. * The color member for first color having transmission characteristics is provided on the one side surface 1 a on which the light source 2 is arranged to face. Can also be achieved.

Further, when a white member 4D having a uniform reflection characteristic in substantially the entire wavelength region of visible light is arranged on the surface of the first reflection member 3 so that the arrangement density increases as the distance from the light source 2 increases. Can obtain uniform optical characteristics. Here, as described above, the color member 4 for each color is used.
When A, 4B, and 4C are used, the amount of reflected light is (the amount of first color light × the arrangement density of the first color member 4A) + (the amount of second color light × the arrangement of the second color member 4B). (Density) + (light amount of third color light × color member for third color 4C)
Of the white member 4 as described above.
The amount of reflected light when D is used is (the amount of first color light + the amount of second color light + the amount of third color light) × (arrangement density of white member 4D). Since the arrangement density can be set higher than in the case of using the color members 4A, 4B, 4C for the respective colors, the irradiation light amount of the illumination device can be increased.

On the other hand, when the above-described lighting device is applied to a liquid crystal device, a full-color image with little color unevenness and chromaticity difference can be displayed.

[0039]

The present invention will be described below in more detail with reference to examples.

[0040] Example 1 In this example, you create a lighting device B ₁ of the edge type shown in FIGS.

That is, a transparent light guide plate (light guide) 1 made of acryl is used, and a single-wavelength fluorescent tube for blue (a first color light source) is arranged along the side surface 1a in a position facing the side surface 1a. 2), a single-wavelength fluorescent tube for red (the light source for the second color) 2B, and a single-wavelength fluorescent tube for green (the light source for the third color) 2C are arranged so that each color light is irradiated inside the light guide plate 1. did.

A side reflection film 6 is adhered to the other side surface 1d facing the fluorescent tubes 2A, 2B, 2C, and a main reflection film 3 as a first reflection member is also adhered to the back surface 1b of the light guide plate 1. The irradiated light was reflected to the front surface 1c side of the light guide plate 1.

As shown in FIG. 2, the main reflection film 3 has a large number of blue dots (color members for first color) 4A and red dots (color members for second color) 4A having reflection characteristics.
B and green dots (color member for third color) 4C are printed, but in the vicinity 3A of the fluorescent tubes 2A, 2B, 2C, the arrangement density of the red dots 4B and the green dots 4C is equal,
In addition, the density of the blue dots 4A is set higher than that of the blue dots, and the luminance of the blue illumination light in the portion 3B is reduced. Also, a portion 3B separated from the fluorescent tubes 2A, 2B, 2C
Are green dot 4C, red dot 4
B and the blue dot 4A were increased in this order. Further, for each of the dots 4A, 4B, and 4C of each color, the arrangement density becomes higher as the distance from the fluorescent tubes 2A, 2B, and 2C increases.

According to this embodiment, color unevenness in the vicinity 3A of the fluorescent tube could be eliminated, chromaticity difference could be eliminated, and luminance could be made uniform.

Further, when the above-described lighting device was applied to a liquid crystal device, a full-color image with little color unevenness and chromaticity difference was obtained.

Example 2 In this example, the lighting device shown in FIGS. 1 and 3 was prepared.

That is, in the main reflection film 3, in the vicinity 3A of the fluorescent tube, a large number of red dots 4B and green dots 4C having reflection characteristics are arranged so as to have the same arrangement density, and blue dots 4A are arranged. Instead, the luminance of the blue illumination light in such a portion was reduced.

The color tone and the tube current of the fluorescent tubes 2A, 2B, 2C are adjusted so that the chromaticity difference between blue, red and green is eliminated.

Further, in the portion 3B of the main reflection film 3 away from the fluorescent tube, each color dot 4A, 4B, 4C
Were not arranged, and many white dots 4D as white members were arranged. As the distance from the fluorescent tubes 2A, 2B, and 2C increases, the area per one white dot 4D is increased and the pitch is reduced, so that the arrangement density is increased and the luminance is made uniform.

According to this embodiment, the same effects as those of the first embodiment are obtained. Further, the irradiation light amount could be increased as compared with the first embodiment.

[0051] Example 3 In this example, we create a lighting apparatus B ₂ shown in FIG.

That is, the lighting curtain 7 is arranged on the front surface 1c side of the light guide plate 1, and in the vicinity 7A of the fluorescent tube in the lighting curtain 7, a large number of red dots 4B and green dots 4C having transmission characteristics are arranged at a density. They were arranged so as to be equal, and the brightness of the blue illumination light in such a portion was reduced without arranging the blue dots 4A. Also, no dots were formed on the portion 7B of the lighting curtain 7 away from the fluorescent tube or on the main reflection film 3. Other configurations were the same as those of the second embodiment.

According to this embodiment, the same effect as that of the first embodiment is obtained.

[0054]

As described above, according to the present invention,
At least in the vicinity of the light source, the second color member and the third color member are arranged at a higher density than the first color member, and the second color member and the third color member are arranged near the light source from the first color light source in the vicinity of the light source. Since the brightness of the illumination light is set to be small, color unevenness near the light source can be eliminated.

The first color member, the second color member,
The color member for color and the color member for third color are also arranged at a portion distant from the light source, and the arrangement density of the first color member at the portion distant from the light source is determined by the second color.
When the arrangement density of the color member for color and the color member for third color is higher than each other, it is possible to equalize the luminance of the illumination light from each color light source in a portion distant from the light source,
The chromaticity difference between the first to third colors can be eliminated.

Furthermore, the elimination of the chromaticity difference can be achieved by: * the first color light source, the second color light source, and the third color light source.
It can also be achieved by adjusting the color tone or tube current value of the color light source. * A second reflecting member is arranged so as to cover the light source, and the light emitted by the light source is reflected toward the light guide 1. So that the first color member having a reflection characteristic is replaced with the second color member.
It can also be achieved by arranging it on the surface of a reflection member. * It can also be achieved by arranging a color member for a first color having transmission characteristics on the one side surface where the light source is arranged to face.

Further, when a white member having a uniform reflection characteristic in substantially the entire wavelength region of visible light is arranged on the surface of the first reflection member so that the arrangement density increases as the distance from the light source increases, Optical characteristics can be obtained.

On the other hand, when the above-described lighting device is applied to a liquid crystal device, a full-color image with little color unevenness and chromaticity difference can be displayed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an embodiment of a structure of a lighting device according to the present invention.

FIG. 2 is a diagram illustrating an example of the arrangement of dots of each color.

FIG. 3 is a diagram for explaining another example of the arrangement of each color dot.

FIG. 4 is a view for explaining still another example of the arrangement of each color dot.

FIG. 5 is a cross-sectional view illustrating an example of a conventional structure of a liquid crystal device that performs color display using time division.

FIG. 6 is a block diagram showing the overall configuration of the liquid crystal device of FIG.

FIG. 7 is a diagram showing a luminance distribution for each color in a conventional backlight device.

FIG. 8 is a diagram illustrating an example of a structure of a conventional lighting device.

[Explanation of symbols]

Reference Signs List 1 light guide plate (light guide) 2A single wavelength fluorescent tube for blue (light source for first color) 2B single wavelength fluorescent tube for red (light source for second color) 2C single wavelength fluorescent tube for green (light source for third color) 3 Main reflective film (first reflective member) 4A Blue dot (color member for first color) 4B Red dot (color member for second color) 4C Green dot (color member for third color) 4D White dot (white member) 5 second reflecting member 10 the liquid crystal device B ₁ illumination device B ₂ illumination device P crystal panel (liquid crystal device)

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yoshihiro Onitsuka 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H091 FA02Z FA14Z FA23Z FA41Z FA42Z FB02 FD01 FD04 FD24 GA11 LA15 LA20 5G435 AA02 AA04 BB12 BB15 CC09 CC12 DD09 DD14 EE27 FF03 FF08 GG26 GG27

Claims (13)

[Claims] 1. A transparent light guide, a light source disposed at a position facing at least one side surface of the light guide to irradiate light inside the light guide, and a light guide on a back surface of the light guide. A first reflecting member disposed to reflect light emitted by the light source toward the front side of the light guide, wherein the light source includes a light source, A first color light source arranged in order from the side to the back side;
A light source for a second color and a light source for a third color, and at least in the vicinity of the light source, a color member for a second color having the same color as the light source for the second color and the light source for the third color;
The color member for color is arranged at a higher density than the color member for the first color of the same color as the light source for the first color, and the luminance of the illumination light from the light source for the first color in the vicinity of the light source is reduced. An illuminating device set to: 2. The color member for the second color and the color member for the third color are arranged at least in the vicinity of the light source, and the color member for the first color is not arranged. The lighting device according to claim 1. 3. The color member for the first color, the color member for the second color, and the color member for the third color are arranged at least in the vicinity of the light source. The lighting device according to claim 1. 4. The illumination according to claim 1, wherein each of the color members has a reflection characteristic and is formed on a surface of the first reflection member. apparatus. 5. The illuminating device according to claim 1, wherein the color member for each color has transmission characteristics, and is arranged in front of the light guide. . 6. The color member for the first color, the color member for the second color, and the color member for the third color are disposed at a portion separated from the light source, and the first color member at a portion separated from the light source. The lighting device according to claim 4, wherein an arrangement density of the one-color member is higher than an arrangement density of each of the second-color member and the third-color member. 7. The first color light source, the second color light source, and the third color light source are adjusted to adjust the color tone and the tube current value.
The lighting device according to any one of claims 1 to 5, wherein a chromaticity difference between a color and a third color is eliminated. 8. A color for a first color having a reflection characteristic, wherein a second reflection member is disposed so as to cover the light source, so that light emitted by the light source is reflected toward the light guide. The lighting device according to any one of claims 1 to 5, wherein a member is disposed on a surface of the second reflecting member. 9. The color member for a first color having a transmission characteristic is arranged on the one side surface where the light source is arranged so as to face the light source. The lighting device according to claim 1. 10. A white member having a uniform reflection characteristic in substantially the entire wavelength region of visible light is arranged on the surface of the first reflection member so that the arrangement density increases as the distance from the light source increases. The lighting device according to any one of claims 7 to 9. 11. The first color, the second color, and the third color.
The color combinations are "red, green, blue", "blue, red, green", "green, blue, red", "blue, green, red", "green, red, blue", "red, blue, The lighting device according to any one of claims 1 to 10, wherein the lighting device is a combination of any of "green". 12. The first color, the second color, and the third color.
The color combinations are "yellow, magenta, cyan", "cyan, yellow, magenta", "magenta, cyan, yellow", "cyan, magenta, yellow", "magenta, yellow, cyan", "yellow, cyan, The lighting device according to any one of claims 1 to 10, wherein the lighting device is any combination of "magenta". 13. The lighting device according to claim 1, further comprising: a liquid crystal device arranged along the lighting device, wherein the liquid crystal device sequentially displays an image. A liquid crystal device that emits illumination light of each color from the illumination device in synchronization with the display device to display a full-color image.