JPS61217084A - Image display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image display device, and more particularly to an image display device that includes a liquid crystal display element and a surface light source element and is suitable for color display.

[Conventional technology]

When constructing a transmissive display element using liquid crystal, a surface light source that emits light uniformly over the entire surface is attached behind the display element in order to improve display contrast. Furthermore, in order to construct a dynamic image display device using the various liquid crystal display elements described above, means for driving the liquid crystal display elements, means for an interface, etc. are required.

[Problem that the invention seeks to solve]

Incidentally, in recent years, in image display devices using liquid crystal display elements such as those described above, it has become necessary to increase the screen size and, in particular, to reduce the pixel size for color display.

As the screen size increases, the overall weight of the device increases, and the uniformity of the light emission intensity of the surface light source tends to be lost. Furthermore, as the pixel size is reduced to improve resolution, the number density of driving wiring increases, requiring further miniaturization, and at the same time, the assembly work becomes troublesome.

[Means for solving problems]

In view of the above-mentioned problems, the present invention realizes weight reduction by making the entire device thinner, realizes the high and uniform light emission intensity of a surface light source, and further reduces the assembly work of the device. This was done to make it easier.

That is, according to the present invention, there is provided a flat image display device in which a liquid crystal display element, a surface light source element, and a driving element are sequentially laminated, and the end portion of the driving wiring between the liquid crystal layer and the indicator is formed by three layers. The surface light source element includes a plurality of types of light sources emitting different colors of light that are arranged facing at least one side edge of a translucent substrate. (h) The driving element includes a printed wiring board, and (h) an end of the driving wiring of the liquid crystal display element is connected to the printed wiring of the driving element across the surface light source element. ,
An image display device is provided.

Hereinafter, specific examples of the image display device of the present invention will be described with reference to the drawings.

FIG. 1 is an exploded perspective view showing a specific example of the device of the present invention, and FIGS. 2 and 3 are a partial sectional view taken along the line 1--2 and a partial sectional view taken along the line 2--2 in an undisassembled state.

In the figure, 2 is a liquid crystal display element, 4 is a surface light source element, and 6 is a driving element.

The liquid crystal display element 2 is made up of two transparent glass plates 8.degree. 10 maintained at an appropriate distance by interposing a neutralizer 12, and a liquid crystal layer 14 is formed in the gap. Although not shown, a polarizing plate is attached to the glass plate 8.10. Transparent electrodes 16 and 18 are formed on the surface of the glass plate 8° IO on the liquid crystal layer 14 side, respectively. The liquid crystal display element 2 of this specific example is driven by an XY matrix. The transparent electrode 16 is a line-shaped electrode extending in the X direction, and a large number of these are arranged in parallel. Further, similarly, the transparent electrode 18 is a line-shaped electrode rotating in the Y direction, and a large number of these are arranged in parallel. The width of the transparent electrodes 16 and 18 is, for example, about 0.3 to 0.55 gm. These transparent electrodes 16.18 are, for example, 0.04 to 0.0
They are arranged at intervals of about 6 dews.

A mask layer 17 made of an opaque material is formed between a large number of linear transparent electrodes 16 on the surface of the glass plate 8 facing the liquid crystal layer 14 . Further, on the surface of the second glass plate 10 facing the liquid crystal layer 14, a mask layer 19 made of an opaque material is formed between a large number of linear transparent electrodes 18.

Mask layer 17.19 can be formed by printing, plating, sputtering, etc. before or after forming transparent electrode 16.18.

Half of the electrodes 16 extend to the right in FIG. 1 to form a driving wiring 20, and the end of the wiring 20 is connected to the front side A of the two sides along the X direction of the glass plate 8. It extends to the vicinity of. The other half of the electrode 16 extends to the left in FIG. It extends to the vicinity of side B. In addition, electrode 1
Half of the wiring 22 crosses over to the glass plate 8 side at the end of the front side C of the two sides along the X direction of the glass plate 10, and the wiring 22 is The end portion is wired to extend to the vicinity of side A of the glass plate 80. Electrode 1
The other half of 8 is formed at the end of the back side of the two sides along the X direction of the glass plate 10, and similarly extends to the glass plate B side to form the driving wiring 23. The end of the wiring 23 extends to the vicinity of the side B of the glass plate 8. By arranging the ends of the driving wiring for the liquid crystal display element 2 in two directions in this manner, the wiring can be connected without directly crossing the light source (described later) of the surface light source element 4, which is convenient for maintenance and inspection of the light source. It is advantageous to leave the reeds open in at least one direction.

The surface light source element 4 has end face transparent light guide members 24 and 25 corresponding to two sides along the Y direction of the light transmitting substrate 26 joined together, and faces the light guide members 24 and 25 in the Y direction. along the red surface light source 28-1°29-1. Green (G) light source 28-2.29-2, and blue (B) light source 28-3.
29-3, the linear light source 28
-1 to 3.29 -1 to 3 each have 7 rectors and 30
．． 31, so that the amount of light from the light source effectively enters into the translucent light guiding member 24, 25 from the end face thereof and is guided into the translucent substrate 26. A light diffusion layer 32 is attached to the upper surface of the transparent substrate 26 as shown in FIG. 2, and a light diffusion layer 32 is attached to the lower surface of the substrate 26 as shown in FIG. A light scattering reflection layer 34 is attached to the surface.

Further, as shown in FIG. 3, a light reflective layer is provided on the end faces of the transparent substrate 26 corresponding to two sides along the X'':)5 direction.

The material for the transparent substrate 26 is preferably synthetic resin due to its light weight and other aspects, but glass may also be used. The synthetic resin is preferably a single or copolymer of polymethyl methacrylate, polystyrene, polycarbonate, polyester, polysilicon, and the like.

The shape of the substrate 26 is a parallel flat plate, and its size is preferably equal to or slightly larger than the size of the liquid crystal layer 14 of the liquid crystal display element 2.

The material of the light-transmitting light guiding members 24 and 25 is the same as the light-transmitting substrate 26.
The material may be the same as that of Note that the transparent substrate 26 and the transparent light guide members 24 and 25 can be formed integrally. Light sources 28-1 to 3.2 of translucent light guiding member 24°25
The end surface on the side facing 9-1 to 9-3 is a smooth surface. Although the end surface may be a flat surface, it is formed as a concave cylindrical surface along each light source, and its original axis is transparent from each end surface. At about 173 points along the length of the optical substrate 26 in the X direction, the substrate 26
It is preferable to intersect with the bottom surface of. This allows the amount of light from the light source to reach the entire interior of the substrate 26 almost uniformly.

The light diffusing layer 32 contains an appropriate light diffusing agent.

For example, titanium oxide particles can be used as the light diffusing agent. Further, instead of the light diffusing agent, a material in which fine air bubbles are dispersed may be used. The thickness of the light diffusion layer 32 is, for example, approximately several 10 μm. Further, the light scattering reflection layer 34 is formed by depositing or plating a metal such as aluminum on a rough surface having irregularities of about 10 to several 10 μm, for example. As a means for roughening the surface, for example, mechanically providing unevenness, or coating a smooth surface with particles having a size of about 10 to several tens of micrometers can be exemplified. Furthermore, the light scattering reflection layer 34 can also be obtained by vapor depositing or plating a metal such as aluminum on the surface of a layer formed in the same manner as the light diffusion layer 32 described above.

The light-transmitting substrate 26 as described above is made by bonding, for example, a plate-like body having a light-diffusing layer as described above, a plate-like body having a light-diffusing reflection layer as described above, and a transparent plate-like body using a transparent resin. Shall I force you?
Alternatively, it can be produced by polymerizing a transparent resin between a plate-like body having a light-diffusing layer as described above and a plate-like body having a light-scattering reflection layer as described above.

Note that the light reflecting layer 36 is formed by, for example, aluminum vapor deposition.
Alternatively, it is formed by pasting an aluminum vapor-deposited tube. The end face on which the light reflection layer 36 is formed is 5 to
The surface may have a foot slope of about 8 degrees.

It is preferable that the linear light sources 28-1 to 3 and 29-1 to 3 have as high a brightness as possible and have little absorption by the light-transmitting light guide member 24, 25 and the light-transmitting substrate 26. Types of light sources include cold cathode or hot cathode fluorescent lamps, LEDs, etc.
Examples include neon lamps, xenon lamps, and incandescent lamps, and in some cases, a color filter may be attached to obtain a desired color.

The 7 rectors 30, 31 are made of aluminum plates, for example.

The drive element 6 includes a printed wiring board 38.

The printed wiring board 38 is normally connected with circuits for matrix driving and various controls of the liquid crystal display element 2, an interface circuit for receiving image information signals, a power supply circuit for lighting the light source of the surface light source element 4, etc. ing. These circuits are, for example, LSI40, 41, 42, 43, 4
4. ... are fixedly arranged along the printed wiring board 38.

Note that the control circuit and interface circuit in the drive element 6 may be installed in other equipment.

The ends of the printed wiring board 38 corresponding to the two sides E and F along the X direction are bent upward, and the upper end thereof is
- It is bent in the direction of the Y plane and engages with the glass plate 8 of the liquid crystal display element 2 from above. At the bent end of the printed wiring board 38, an end of a wiring 50 that is electrically connected to the driving wiring 20, 21, 22, 23 of the liquid crystal display element is present at a predetermined position. Therefore, in the image display device assembled as shown in FIGS. 2 and 3, the liquid crystal display element 2 and the drive element 6 are properly electrically connected. Further, at an appropriate position on the upper surface of the driving element 6, an end of a power supply circuit for the light source 28, 29 of the surface light source element is provided at a predetermined position (not shown).
In the image display device assembled as shown in FIGS. 2 and 3, the surface light source element 4 and the drive element 6 are electrically connected appropriately.

When assembling this specific example device as described above, the liquid crystal display element 2 and the surface light source element 4 are stacked on the driving element 6 with the bent part of the driving element 6 slightly stretched, and then the bent part of the driving element 6 is stretched. All you have to do is remove the external force. Alternatively, by holding the bent portions in the vertical direction using appropriate means, the positions of the respective elements can be more securely fixed.

The device of this embodiment thus assembled can be housed in an exterior case 60 shown by dotted lines in FIGS. 2 and 3.

FIG. 4 shows a partial view of the display surface of this specific example device as described above, viewed from the liquid crystal display element 2 side in two directions.

In the figure, portions of the mask layers 17 and 19 overlap to form a grid-like mask, and light from the surface light source element 4 is blocked from this portion. A square dot-shaped pixel is formed by the portion excluding the portion shaded by the mask. The amount of light in each pixel changes by adjusting the voltage applied between the transparent electrodes 16 and 18, thereby displaying an image on the entire screen.

In this specific example device, R light sources 28-1, 29-1. G
Light source 28-2.29-2, and B light source 28-3.29-
3 is driven by the driving element 6 for an extremely short time (for example, 10
They are turned on sequentially every millisecond to 100 milliseconds). That is,
R light → G light → B to the light guide member 24° 25 and the substrate 26
Three primary colors of light are made to enter in sequence as follows: light → R light → . . . . Then, the liquid crystal display element 2 has the above-mentioned R
When the light source is turned on, it is driven by eight color drive signals, when the G light source is turned on, it is driven by a G color drive signal, and when the B light source is turned on, it is driven by a B color drive signal. Thus, a viewer of the display can view the color display using a temporal additive method.

In this specific example device, color display is realized by the temporal additive coloring method, so high resolution color display is possible without increasing the size of each display pixel. Furthermore, in this specific example device, since the liquid crystal display element is provided with a mask for controlling the pixel gap tm, the image becomes sharp even when the pixel size is small.

In the above specific example, three light sources, an R light source, a G light source, and a B light source, are arranged on the two side edges of the light-transmitting substrate, but in the device of the present invention, the area of the light-transmitting substrate is small. Sometimes, for example, an R light source may be arranged at one side edge of the substrate, and for example a G light source and a B light source at the other side edge.

In the above specific example, linear light sources arranged in parallel are used as light sources of different colors, but in the device of the present invention, small light sources of each color arranged in a line can also be used. 5(a) is a schematic plan view of a surface light source element 4 showing such a specific example, and FIG. 5(b) is a schematic side view thereof.

That is, in this specific example, the R light source 28-1°29-1
, -G light source 28-2.29-2 and B light source 28-3.2
9-3 are repeatedly arranged in this order.

In the above specific example, the mask in the liquid crystal display element consists of the mask layer 17 formed on the glass plate 8 and the glass plate 10.
It is composed of a mask layer 19 formed on top,
The mask used in the apparatus of the present invention is not limited to this.

6 to 8 are partial sectional views showing the liquid crystal display element portion of the device of the present invention having a mask different from the above-mentioned specific example.

In the embodiment of FIG. 6, a planar grid-like mask 70 having a noreen as shown in FIG. 4 is located in the liquid crystal layer 14 between two glass plates 8,10. The mask 7
Of course, the transparent electrodes 16 and 18 are arranged in such a way that the openings are located in the overlapping portions. mask 7
0 can be manufactured, for example, by machining, machining, chiming, etc.

In the embodiment of FIG. 7, a mask 70 similar to that in FIG. 6 is positioned in contact with the transparent electrode 18.

In the specific example shown in FIG. 8, a planar grid-like mask 70 having a pattern as shown in FIG. 4 is bonded to the opposite side of the glass plate 10 to the liquid crystal layer 14 side. In this specific example as well, the transparent electrodes 16 and 18 are similar to the specific example in FIG.
The openings are arranged in such a way that the openings are located in the overlapping parts. In addition, in the case of such a mask position, the mask 70 does not necessarily have an opening, and a transparent body may exist in place of the opening. Therefore, as a mask, it is possible to use, for example, a mask formed by forming an opaque portion in a grid pattern on a /IJ ester film having a thickness varying from 10 to 20 μm.

In the above specific examples, the display pixels are square, but the display pixels in the device of the present invention may have other shapes. That is, by using a pattern mask as shown in FIG. 9, the pixel can be made circular, and the dimensions of the transparent electrodes 16 and 18 and the dimensions and shape of the mask can be changed as appropriate. Accordingly, a desired pixel shape can be obtained.

In the above specific example, the printed wiring board 38 is case-shaped with a predetermined shape, but in the device of the present invention, the printed wiring board may be a flexible printed wiring board, and this In such a case, it is sufficient to use a clamping means that ensures electrical connection with the liquid crystal display element at least at the bent portion.

〔Effect of the invention〕

In the image display device of the present invention as described above, since the electrical connection between the liquid crystal display element and the driving element is made across the surface light source element, the liquid crystal display element, the surface light source element, and the driving element are integrally configured. In addition, it is possible to make the screen sufficiently thin, so even if the display screen size is large, the weight will not increase that much, and since the surface light source element can be made thinner, even if the screen size is large. The uniformity of the light intensity distribution is also good, and even when the pixel size is small and the number of connections between the liquid crystal display element and the drive element is large, assembly work is relatively easy, and inspection and inspection are easy.
Maintenance is also convenient.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of the unexploded 94i & position, and FIGS. 2 and 3 are a partial cross-sectional view along ■-■ and ■-■ in the undisassembled state. 4 and 9 are partial plan views showing the mask pattern, w, 5 (,) and (b) are respectively a plan view and a side view of the surface light source element, and is a partial cross-sectional view of a liquid crystal display element. 2: Liquid crystal display element, 4: Surface light source element, 6 dual drive element, s
, io:, Glass plate, 12 Ni spacer-114: Liquid crystal layer, 16.18: Transparent electrode, 17° 19: Mask layer, 20
, 21, 22, 23: driving wiring, 24, 25: translucent light guiding member, 26: translucent substrate, 28-1 to 3.29
-1 to 3: light source, 30.31: reflector, 32: light diffusion layer, 34: light scattering reflection layer, 36: party reflection layer, 38: printed wiring board, 40 to 44: LSI, 50: wiring, 60: Exterior, 70: Mask. Figure 1 Figure 4 Figure 5 (O)/Hill Figure 6 'M7 Figure 8 Figure 9

Claims (4)

[Claims] (1) A flat image display device formed by sequentially stacking a liquid crystal display element, a surface light source element, and a driving element, in which the ends of the driving wiring of the liquid crystal display element are arranged laterally in three directions or less. The surface light source element is placed on at least one of the light-transmitting substrates.
The driving element includes a printed wiring board, and the driving element includes a printed wiring board, and the driving element has a plurality of types of light sources of different emission colors arranged opposite to one side edge of the liquid crystal display element. An image display device, characterized in that the portion is connected to the printed wiring of the driving element across the surface light source element. (2) The image display device according to claim 1, wherein the liquid crystal display element is provided with a mask for blocking light between pixels. (3) At least one side end of the printed wiring board of the driving element is bent, and the liquid crystal display element and the driving element are electrically connected at the bent part. The image display device described in Section 1. (4) The image display according to claim 1, wherein a plurality of types of light sources such as a liquid crystal display element and a surface light source element are synchronously driven and blinked by a driving element to perform color display by a temporal additive coloring method. Device.