JPH04172401A - Display device - Google Patents

Abstract

PURPOSE:To acquire thin display with relatively low cost but high quality image by arranging innumerable independent long and narrow light transmitting plates, arranging separate emission elements to the respective light transmitting plates and arranging a liquid crystal light shutter which causes a light transmission portion of a strip shape to move successively at a right angle to the light transmitting plate. CONSTITUTION:A data signal 10 is divided into innumerable simultaneous signals by means of a sequence simultaneous conversion circuit in an emission element body drive circuit 9 and inputted into an emission element 7. Emission of the element 7, having each element 7 separated from each other and each light transmission groove 1 also separated from each other, becomes an individual strip shaped emission and irradiates the back of a liquid crystal 12 as a long and narrow emission covering each light transmission groove 1. On the liquid crystal side, a strip shaped opening portion moves successively on the scanning line by means of a scanning circuit inside a liquid crystal drive circuit 15. Thus an image display by line successive driving can be made possible due to the strip shaped emission of the light transmission groove 1 and the strip shaped opening portion of a liquid crystal strip electrode 13 forming an XY matrix.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a thin display device.

[Prior Art] Liquid crystal display devices that utilize the properties of liquid crystal as a light shutter are widely used as display terminals for converters and television image display devices.

This liquid crystal display device displays an image by selectively turning on or off a large number of pixels made up of liquid crystal, which is a light shutter, using light from a lighting device arranged on the back side. The liquid crystal panels used for this generally use an XY matrix system in which pixels are composed of XTt pole groups and yt pole groups that are orthogonal to each other with the liquid crystal in between, but active matrix systems in which each pixel is equipped with elements such as transistors are commonly used. There is also a display device.

There are several methods for rear lighting devices, one of which is a so-called edge-light lighting device that uses a light guide plate made of transparent synthetic resin such as acrylic. This is because the light from a light emitting device, such as a fluorescent lamp, placed on the edge of a single acrylic board is reflected inside the acrylic board and propagates to the entire surface of the board, and then the reflective layer provided on the back of the board and the front The front surface of the plate is irradiated with scattered light by a scattering layer provided on the plate. Since it can be made very thin as a lighting device, it is widely used as a backlight for liquid crystal display devices.

[Problems to be Solved by the Invention] However, conventional liquid crystal display devices have several problems to be solved. First, in the aforementioned XY matrix method, as the number of pixels increases, the contrast decreases and becomes difficult to see. This is due to the optical properties of the liquid crystal itself and its slow response time to electrical signals.
A solution to this problem is an active matrix method in which each pixel is equipped with elements such as transistors.
This method can solve most of the problems of the XY matrix method, but the cost is extremely high. In addition, in both types, if colorization is desired, a fine color filter must be formed on the electrode portion of the liquid crystal, which is also a major factor in increasing costs.

In view of this problem, the present invention proposes a thin display device and its parts that are inexpensive, have high image quality, and can be easily enlarged.

[Means for Solving the Problems] As shown in FIG. 1, the present invention has a large number of elongated light guide plates (hereinafter referred to as light guide grooves (1)) arranged in parallel with each other to form a single plate. The main component is a light guide plate. The light guide plate shown in Figure 1 differs from conventional light guide plates in that the light guide plate has a light entrance (
The light incident from 2) propagates in each light guide groove and is radiated to the front through the scattering and transmitting layer (3).

Since the light guide grooves are independent from each other, the respective incident lights do not interfere with each other.

The configuration diagram of this light guide groove is shown in Fig. 2. Light guide groove (1)
Like a normal light guide plate, it is made of transparent resin such as acrylic, and its side surfaces are treated to scatter and propagate light appropriately to obtain uniform scattered light emission on the front surface. First, on both sides and the bottom surface of the acrylic rod (5), a scattering reflective layer (
6-a) is arranged. This is formed by chemical etching or printing, and the pattern is such that it provides an optimal light scattering and propagation pattern. The surface of the support (4) is painted white as a scattering reflection layer (6-b) that reflects light leaking to the back surface. Like this, the light guide groove (1)
is an acrylic rod (5) and a scattering reflection layer (6-a) and (6-
11>, so that the light from the light entrance (2) is uniformly radiated over the entire lengthwise direction of each groove. The width, length, or number of light guide grooves (1) to be integrated can be freely selected depending on the screen size, resolution, etc.

FIG. 3 shows the configuration of a display device using the new light guide plate illumination device as described above. At one end or both ends of the light guide groove (1), individual light emitting elements that serve as light sources are installed as shown in FIG. 3. (7) is arranged. Third
In the figure, three color light emitting elements of red, blue and green are arranged for one light guide groove, and the light emitting elements for each light guide groove are separated by a shielding plate (8). It is connected to a light emitting element drive circuit (9). A data signal (10) is input to the light emitting element drive circuit (9).

On the other hand, on the front surface of the light guide plate, a liquid crystal light shutter is disposed in which a striped light transmitting part sequentially moves perpendicular to the direction in which the light guide groove (1) extends.

The liquid crystal optical shutter is composed of a liquid crystal layer (12) sandwiched between a common electrode (11) and a stripe electrode (13). Usually, this liquid crystal part is made of two transparent glass substrates (14).

A liquid crystal drive circuit (11) is connected to each stripe electrode (3), and a scanning signal is sequentially applied thereto.

[Operation] The operation of the invention will be explained with reference to FIG. 3 corresponding to the embodiment. This display device operates using the Li sequential driving method, similar to the conventional XY matrix method.
That is, the data signal (10) is transmitted to the light emitting element driving circuit (9).
The signal is sequentially divided into a large number of simultaneous signals by a simultaneous conversion circuit, and is input to each light emitting element (7). Each light emitting element (
Since the light emitted in 7) is separated between each light emitting element and between each light guide groove as described above, it becomes an individual stripe-like light emission and irradiates the back surface of the liquid crystal as a long and narrow light emission over the entirety of each light guide groove. On the other hand, on the liquid crystal side, striped openings are sequentially moved in the form of a scanning line by a scanning circuit in a liquid crystal driving circuit (10).

As a result, the striped light emission of the light guide 111 ('1) and the striped openings of the liquid crystal stripe electrode (13) form an XY matrix, making it possible to display images by line sequential driving.

[Examples] Some examples for carrying out the present invention are shown below.
As described above, the first aspect of the present invention is a light guide plate in which a large number of light guide grooves are integrated, and the second aspect of the present invention is a display device using the above light guide plate. 1st
The figure shows a light guide plate corresponding to the embodiment of the first invention;
The figure shows the configuration of a basic display device for implementing the second invention.

First, the light guide plate, which is the first aspect of the present invention, is formed by integrating narrow light guide grooves (1) as shown in FIG. The operating principle of the light guide groove is the same as that of a normal light guide plate. The scattering-reflection layer (6) and the scattering-transmission layer (3) are for appropriately distributing the propagation of light and the radiation due to scattering, and they also play the same role as a normal light guide plate. Emit light uniformly In order to make the scattering reflection layer <6-a) directly
) by printing or etching in a barcode or dot-like optimal distribution pattern, and the scattering reflection layer (6-b) reflects light emitted from the side of the acrylic rod (5). This is for returning the material to the original state, and is formed by applying white coating to the support (4). In Fig. 4, instead of forming a scattering reflection layer on the acrylic rod, the cross-sectional shape of the acrylic rod is shaped so that the farther it is from the light source, the easier it is to emit light to the front, so that a uniform radiation distribution can be obtained. Further, depending on the position of the light emitting element, that is, the position and number of the entrance ports, several shapes of the light guide groove can be considered, as shown in FIG. For example, Fig. 5(a) shows the case where the light emitting elements (7) are placed on the back of the screen, and Fig. 5(b) shows the case where the screen is divided to increase the number of light emitting elements (7) and increase the brightness. FIG. 3 is a cross-sectional view parallel to the length direction of the groove.

Next, an embodiment of a display device using the above-mentioned light guide plate, which is the second aspect of the present invention, will be described with reference to FIG. As shown in the figure, this display device is a light guide plate that forms a striped light emitting light guide plate with the signal side as described above. 1! (1
), a light emitting element group (7) that emits light in response to a signal, and a liquid crystal part (12) (13) (
14) are the main components. Embodiments can be considered separately for each of these components.

First, the light emitting element group (7) is a CRT, a fluorescent display tube, a light emitting diode, a plasma display, etc., but in any case, the light emitting surface, for example, in the case of a fluorescent display tube, from the fluorescent screen to the entrance of the light guide groove. Each pixel must be partitioned to avoid color mixing, or light crosstalk, between adjacent pixels. For example, in the case of a CRT, it is best to use a front glass such as a fiber optics tube. FIG. 3 shows a case in which a light-emitting device such as a light emitting diode is used, and is partitioned by a shielding plate (8). In the case of a color panel, it is also possible to arrange three color light emitting elements of red, blue and green in one light guide groove so that a mixture of the three colors can enter, but it is also possible to have one color in each light guide groove. It is also possible to use a white light emitting element and arrange a color filter at the entrance or emission surface of each light guide groove.

In addition, the liquid crystal layer (12) on the scanning side is made of any of the TN type, STN type, or ferroelectric type used in normal display devices.
May be used. Furthermore, since the structure is simpler than the normal XY matrix type, a plastic sheet can be used instead of the glass substrate (14). Common electrode (
11) and the stripe electrode (13) both use transparent conductive films such as indium tin oxide.

[Effects of the Invention] As described above, according to the light guide plate of the present invention and the display device to which the light guide plate is applied, a light emitting body that responds quickly to a signal can be freely selected. Among the disadvantages of , low image quality due to slow response can be improved. Furthermore, a large, high-resolution screen can be formed much more easily and inexpensively than conventional methods in which light-emitting elements such as plasma displays, electroluminescence, or light-emitting diodes are uniformly formed over a wide area. Of course, it can be made much larger and cheaper than an active matrix liquid crystal display device.

[Brief explanation of the drawing]

No. 1121 is a light guide plate having a light guide groove according to the present invention. (1) is a light guide groove, (2) is an entrance that introduces light into (1), and (3) is a scattering transmission layer. Figure 2 is a more detailed configuration diagram of the light guide groove (1). (5) is a transparent acrylic rod through which light propagates. (4) is a support for fixing the acrylic rod. (6-a) is a transparent acrylic rod through which light propagates. (6-a) is a support that fixes the acrylic rod. The provided barcode-shaped scattering/reflection layer (6-b) is the scattering/reflection layer on the surface of (4). The third (21) is a configuration diagram of the display device according to the present invention. In the element, (8) is a shielding plate that separates the light of (7) from the neighboring light. (9) is a light emitting element drive circuit for driving (7). (10) is a data signal. (12) is a liquid crystal layer, (11) and (13) are its electrodes. <14> are two glass substrates on which (11) and (13) are respectively attached. (15) is a liquid crystal drive circuit Fig. 4 shows an example of the shape of the light guide groove. Fig. 5 shows an example of the shape of the light guide groove depending on the position of the entrance, and shows a cross section parallel to the length direction.

Claims (1)

[Claims] 1. A display light guide plate in which a large number of independent elongated light guide plates are integrated in parallel to form a single plate. 2. A display device in which a large number of striped liquid crystal light shutters are arranged in front of the light guide plate, and an XY matrix is formed by combining them.