JPH04149587A - Large-screen display device - Google Patents

Abstract

PURPOSE:To obtain the large-screen display device whose joints are unnoticeable by arranging a parallel light beam projection part on the reverse surface of transmission type display devices and inputting the parallel light beam output projected from the parallel light beam projection part to the transmission type display devices, enlarging display images equally to desired magnifications by 1st optical path change parts provided on the respective display images, and removing no-display areas present between transparent type display devices from a visual field. CONSTITUTION:The parallel light beam projection part 1 emits the parallel light beam 7 and N transmission type display devices 3 constitute one large-screen display device. The parallel light beam 7 is modulated with a display image 11, deflected by a 1st optical path change part 4, and enlarged by a 2nd optical path change part 5 to at least the width of a frame 12. The 2nd optical path change part 5 makes the enlarged image, which is inputted at various angles with places, uniform in a constant direction (e.g. parallel light) and the image is scattered by a scattering plate part 6 to improve visibility. Consequently, the influence of slight linear gaps between 2nd adjacent optical path change parts 5 is reduced to obtain a uniform display on a final image plane 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a large screen display device realized by two-dimensionally arranging a plurality of display panels.

[Conventional technology]

The conventional technique described in JP-A-61-138288 "Liquid Crystal Display Device" is shown in FIGS. 5 and 6. FIG. 5 is a schematic cross-sectional view of the liquid crystal display device, and FIG. 6 is a plan view of the liquid crystal display device. A transmission scattering plate 21 is placed at the top, a large display panel 22 is placed below it at an appropriate distance d1, and an enlarged point light source 23 is placed below it at an appropriate distance d2. The above large display panel 22
is constructed in the form of a plurality of transmissive TN liquid crystal display units 30 joined together. Each display unit 30 consists of a transparent liquid crystal portion 31 and an opaque frame portion 32.

Therefore, the frame portion 32 of the display unit 30 and the joint portion between each display unit 30 are opaque and do not transmit light. A drive section (not shown) in the liquid crystal display unit 30 is arranged in the frame portion 32. An enlarged point light source 23 is provided for such connected large display panels 22 in order to eliminate the opaque portion during actual display. This enlarged point light source 23
are provided below the center of the liquid crystal portion 31 which is the display surface of each display unit 30. By providing the enlarged point light source in this way, the enlarged point light source 2
The light from 3 passes through the liquid crystal part 31, and the light from the liquid crystal part 31
is enlarged and projected onto the transmission scattering plate 21. Display unit 3
The dark areas caused by the frame portion 32 and the joint portion of 0 are eliminated by the scattering effect of the transmission scattering plate 21. That is, the sixth
By creating the scattering portion shown by the shaded area 42 in the figure,
The overall amount of light transmitted is averaged out to be approximately uniform. Transmissive scattering plate 21 and enlarged point light source 23 for large display panel 22
The distances d1 and d2 were determined so that the liquid crystal portions 31, which are the display surface portions of each display unit 30, are adjacent to each other on the transmission diffuser plate 21 onto which the images are projected.

[Problem to be solved by the invention]

The configuration of the prior art as described above has the following problems. [No.] When realizing a large display screen using a plurality of display units, each display unit has its own light source in the five-bokuto type, so a large number of light sources are required as a whole. As a result, in addition to being expensive as a large screen display device, there are also problems such as increased power consumption, generation of heat associated with it, and equivalent reliability deterioration due to the life of the light source.

Second, although it is related to the method of realizing an expanded point light source and the dl and d2 values, the depth dimension of the entire device (d1 + d2 + transmission scattering plate 1
There is a problem in that the thickness (thickness of the display unit 30) cannot be made smaller. Third, since the light from the enlarged point light source enters each part of the display unit at a certain angle, the transmittance varies due to the characteristics of the liquid crystal (viewing angle dependence), which causes problems such as uneven display brightness. was there.

The present invention solves the above problems and makes it difficult to see the seams (
The aim is to obtain a large screen display device (seamless).

[Means to solve the problem]

The above object is to provide a large screen display device in which a plurality of transmissive display devices are connected in the direction of the display surface, which includes a transmissive display device, a parallel light projection section disposed on the back surface of the transmissive display device, and a a first optical path changing unit disposed on the display surface;
a second optical path changing section for converting the light deflected by the first optical path changing section back into parallel light; and a scattering plate section for scattering the output light of the second optical path changing section; This is achieved by enlarging the display section of the transmissive display device using the first optical path changing section to form an enlarged image, and by excluding the non-display area existing between the transmissive display devices from the field of view.

[Effect]

In the present invention, a parallel ray projection section is disposed on the back surface of a transmissive display, and the parallel ray output emitted from the parallel ray projection section is input to the transmissive display, and a first The optical path changing unit uniformly enlarges the displayed image to a desired magnification.

Here, the above-mentioned enlargement is performed in the display image device at least to a width greater than the width of each frame-shaped non-display area, but the above-mentioned deflected light.

The second optical path changing section is provided with a predetermined distance from the first optical path changing section.
The light beam enters the optical path changing section, is converted into parallel light beams again, and then passes through the scattering plate section, thereby making the slight gap between the adjacent second optical path changing sections inconspicuous.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a transmission type display device which is an embodiment of the large screen display device according to the present invention, FIG. 2 is a sectional view of a large screen display device in which three of the above transmission type display devices are connected, and FIG. 3 4 is a diagram showing an embodiment of the parallel ray projection section according to the present invention, and FIG. 4 is a diagram showing another embodiment of the parallel ray projection section.

1 and 2, reference numeral 1 denotes a parallel ray projection unit that generates parallel rays, and N transmission type display devices 3
It consists of two large screen display devices. 4 is a first optical path changing unit for deflecting parallel light in a desired direction. Reference numeral 5 denotes a second optical path changing section for converting the light deflected by the first optical path changing section into parallel light again. The first optical path changing section 4 and the second optical path changing section 5 are spaced apart by a distance necessary to obtain a desired magnification. Reference numeral 6 denotes a scattering plate section provided to receive parallel light and improve visibility.

Reference numeral 7 indicates the parallel light output of the parallel light projection unit 1, and reference numeral 8 indicates the output light of the first optical path changing unit 4, which is deflected around the center so as to uniformly enlarge the display image 11 to a desired magnification. The angle changes continuously. With such a configuration, the parallel light 1!7 is modulated by the display image 11, then deflected by the first optical path changing unit 4, and then deflected by the second optical path changing unit 5 to at least the width of the frame 12. will be enlarged by an amount corresponding to The second optical path changing unit 5 aligns the enlarged images input at various angles depending on the location in a certain direction (for example, parallel light),
The scattering plate portion 6 scatters the light to improve visibility.

Therefore, the influence of a small linear gap between adjacent second optical path changing sections 5 can be reduced, and a uniform display can be obtained on the final image plane 6.

The first optical path changing unit 4 is constructed using a microlens system in which lenses with different refractive indexes are installed for each pixel of a transmissive display device. For example, a method in which a prism is arranged, or a method in which a Fresnel lens having an appropriate resolution is installed.

The configuration method of the second optical path changing section 5 is also basically the same as the configuration of the first optical path changing section 4 described above. The difference is that the configuration of the first optical path changing section targets pixels of a transmissive display device, whereas in the second optical path changing section 5, only the portion corresponding to the pixel corresponds to the frame section 12 as a whole. It has been enlarged, and everything else is the same.

Possible configuration methods for the scattering plate section 6 include a method in which a kamaboko lens (lenticular plate) is arranged for each pixel array, and a method in which a fly's eye lens is arranged corresponding to each pixel (which can be constructed with a flat microlens, etc.). .

FIG. 3 shows an embodiment of the parallel ray projector 1. In FIG. When supplying parallel light beams to N transmissive display devices, the parallel light generation section 51 and the light distribution section 54 are combined, and the light distribution section 54 consists of N-1 semitransparent tIAs 55 and one total reflection mirror. 56. The size of the semi-transparent #I55 and the total reflection mirror 56 are the same, and they are arranged so that the center of each image and the center of the optical axis of the parallel rays coincide. In addition, in each semi-transparent mirror, in the order of arrangement from the light source side,
We assign numbers from 55□ to 55 to distinguish each one,
The lower number is placed in the first stage, and each picture is arranged so that the reflected light from the full-stage mirror does not overlap with the reflected light from the mirror in the immediately following stage, and so that there are no gaps (the final stage is the total reflection mirror 56). , In order to keep the intensity of each reflected light constant, the reflectance R and transmittance T of each semi-transparent mirror are set as follows (Here, loss at the chain part is ignored to simplify the explanation) .

R, = 1/(N-i+1) ・・・・・・・・・
Enclosure... (1) T, = (N-i) / (
N-i+1) (2) where i indicates the i-th semi-transparent mirror from the light source side.

For example, as shown in FIG. 4, in a light distribution section consisting of three semi-transparent mirrors and one total reflection mirror (N=4).

When each reflected light is made equal, the reflectance and transmittance of each semi-transparent mirror are as follows.

1st semi-transparent M: (R, = 1/4 = 0.Z5, T1
= 3/4 = 0.75) 2nd semi-transparent II: (R, = 1
/3=0.33. T, = 2/3 = 0.67) Third sheet semi-transparent II: (R, = 1/2 = 0.50. T, = 1/
2=0.50) 4th total reflection mirror: (R4=1.OO,
T, = 0.00) As a result of the above, if the incident light is 1, each reflected light is 0.25 (in Fig. 4, the relative light intensity of each part is expressed numerically). When distributing light to a larger number of transmissive display devices, the light distributing section can be arranged in layers without increasing the number of laminated semi-transparent mirrors in the light distributing section 54 and in order to make the light distributing section 54 have a repeating structure. It is also conceivable to have a configuration.

〔Effect of the invention〕

As described above, the large screen display device according to the present invention includes a large screen display device in which a plurality of transmissive display devices are connected in the direction of the display surface. a projection section, a first optical path changing section disposed on the display surface of the transmissive display device, and a second optical path changing section for converting the light deflected by the first optical path changing section back into parallel light.
an optical path changing section and a scattering plate section that scatters the output light of the second optical path changing section, and the display section of the transmissive display device is enlarged by the first optical path changing section to form an enlarged image. In addition, by excluding the non-display area between the transmissive display devices from the field of view and making the area of the non-display area between adjacent transmissive display devices inconspicuous, the light source of a display device composed of a large number of display units can be reduced. Since it is possible to share the same information, it is possible to reduce the number of light source lamps, thereby reducing costs, reducing heat generation, and improving reliability. Furthermore, the stacked reflecting mirror structure of the light distribution section allows the light source section to be made thinner, contributing to the miniaturization (thinnerness) of large screen display devices. Furthermore, since parallel light rays are perpendicularly projected onto the display portion of the transmissive display device, it is possible to obtain uniform transmitted light regardless of the location of the display area. In the case of a transmissive liquid crystal display device, etc., this has the advantage that the influence of viewing angle dependence can be avoided and improvement in image quality can be expected.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a transmission type display device which is an embodiment of the large screen display device according to the present invention, FIG. 2 is a sectional view of a large screen display device in which three of the above transmission type display devices are connected, and FIG. 3 FIG. 4 is a diagram showing another embodiment of the parallel ray projection section in the present invention, FIG. 5 is a diagram illustrating an example of the configuration of a conventional large screen display device, FIG. 6 is a plan view of the conventional display device. 1... Parallel light projection unit 3... Transmissive display device 4
...First optical path changing section 5...Second optical path changing section 6
... Scattering plate section Patent applicant Junnosuke Nakamura, Patent attorney representing Nippon Telegraph and Telephone Corporation Fig. 3-11 Transparent type display training 1 Optical path changing section 4-41 6 --- Curling plate section 3 Figure T=0.75 T=0.67 T=0.5
R=0.25 R=0.33 R=0.5
■=00 R=1.0 Figure 4

Claims (1)

[Claims] 1. In a large-screen display device in which a plurality of transmissive display devices are connected in the direction of the display surface, the transmissive display device, a parallel light projection section disposed on the back surface of the transmissive display device, and a display of the transmissive display device. a first optical path changing section disposed on the surface;
A second optical path changing section for converting the light deflected by the optical path changing section into parallel light again, and a scattering plate section for scattering the output light of the second optical path changing section, A large screen display device, characterized in that a display section of the transmissive display device is enlarged by an optical path changing section to form an enlarged image, and a non-display area existing between the transmissive display devices is excluded from the field of view.