JPH01204001A - Display device - Google Patents

Abstract

PURPOSE:To reduce the space for the device and to make a display in a light place by arranging an optical deflecting means where many prisms which have ridges in the inward direction of a display surface crossing the directivity of display picture elements at right angles contiguously to the display picture elements are arrayed at right angles to the ridges. CONSTITUTION:A display means 2 has an optical fiber bundle 10 as an image transmission body. The original image input end surface 10a of the optical fiber bundle 10 is arranged opposite an active display device such as a CRT and the display end surface 10b slants at an angle alpha to the lengthwise direction of the optical fibers, so projection light has sharp directivity in the length direction of the optical fibers. For the optical deflecting means providing contiguously to the display means 2, the face 16 of the observing side is a plane. On the side of the display means 2, the prisms having their ridges in a (y) direction are arranged in a (z) direction. Therefore, the light which is incident from the display means 2 is transmitted through a 1st surface 18 and reflected by a 2nd surface 20 to travel in the normal direction of the display surface 18.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a display device, and particularly relates to a display device in which light emitted from a display surface is directional.
is suitably used for large screen display.

[Prior art and problems to be solved by the invention] Conventionally,
2. Description of the Related Art Devices are used in conference halls, lecture halls, classrooms, etc. that allow a large number of people to view dynamic image displays on large screens.

Furthermore, in recent years, displaying dynamic images on large screens to an unspecified number of people has become popular even outdoors.

Conventional typical large-screen dynamic image displays include those that project images onto the screen using a reflective or transmissive method, but these require darkening of the surrounding area or insufficient directivity. Due to the lack of transparency, the efficiency of the light used for observation is not good, and the projector needs to be placed in a position that is quite visible from the screen, which requires a considerable amount of space for the display device. There are problems like this.

Furthermore, in recent years, images on active display devices such as cathode ray tube (CRT) display devices and liquid crystal display devices have been immediately enlarged and displayed on a large screen. A display device using an optical fiber bundle in one image transmission body has been proposed as suitable for such uses (see Japanese Patent Application Laid-Open No. 181706/1983).

This device has one end face of an optical fiber bundle as the original image input side and the other end face as the display side. On the image input side end face, the optical fibers are arranged densely and the end face of the optical fibers is directed in the longitudinal direction. On the other hand, on the display side end face, the end face of the optical fiber is a face oblique to the length direction to form an elliptical display pixel, and an appropriate interval is provided in the short axis direction of the ellipse. The optical fibers are arranged as follows.

According to this, even if the original image input means is included, it is possible to make the display sufficiently thin, the space required for the apparatus is relatively small, display can be performed in a bright place, and the original image can be enlarged and displayed.

However, in this device, since the end face of the optical fiber is oblique to the length direction of the optical fiber on the display surface,
The light emitted from the display pixels has relatively sharp directivity in the length direction of the optical fiber. Therefore, when observing from this direction, the utilization efficiency of the light provided for observation is good, but this reduces the effect of enlarged display. The effect of enlarged display is most effective when observing from the normal direction of the screen, but the amount of light emitted in this direction is small and the utilization efficiency of the light provided for observation is reduced. Generally, observation is often performed at an angle close to the normal direction of the screen, so this device suffers from reduced light utilization efficiency.

Therefore, in view of the above-mentioned prior art, the present invention provides a display device that requires less device space, can display in a bright place, and has directivity in a direction close to the normal direction of the screen. The purpose is to

[Means for Solving the Problems] According to the present invention, the present invention achieves one or more of the following objects: A display means having display pixels capable of emitting light with directionality in a direction inclined with respect to the normal direction of the display surface. and a light deflection means having a plurality of prisms arranged adjacent to the display pixels of the means and having ridge lines in the display plane direction orthogonal to the ridge lines. A display device is provided, characterized in that:

In the present invention, the display means has an optical fiber bundle as an image transmission body, and one end surface of each optical fiber constituting the optical fiber bundle is a surface oblique to the longitudinal direction of the optical fiber. It is possible to use a device whose end face is used as a display pixel.

[Example] Hereinafter, specific examples of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing an embodiment of a display device according to the present invention.

In the figure, 2 is a display means, and 4 is a light deflection means. Note that the X direction is the normal direction of the display surface.

FIG. 2 is a partial view showing the display-side (ie, light-emitting side) end of the display means 2, as seen from the X direction. Also, the third
The figure is a partial view showing the original image input side (ie, light incident side) end of the display means 2. As shown in FIG.

Note that FIG. 1 corresponds to a cross-sectional view taken along line II in FIG. 2.

The display means 2 has an optical fiber 1O as an image transmission body. loa indicates the original image input end face of the optical fiber bundle,
Reference numeral 10b indicates a display end face. The optical fiber bundle 2 is composed of a large number of optical fibers 12, and 12a and 12b are a light input end face and a light output end face thereof, respectively.

The light incident end surface 12a of each optical fiber is a circular surface perpendicular to the length direction of the optical fiber, and as shown in FIG. The arrangement is fixed at (a=b) to form the original image input surface of the optical fiber bundle lO. The light emitting end surface 12b of each optical fiber is an oblique elliptical surface forming an angle α with respect to the length direction of the optical fiber, and these end surfaces are elliptical in two directions as shown in FIG. Pitches A and B in the y direction and two directions, respectively, in the long axis direction.
The above optical fiber bundle l is arranged and fixed at (=b/sin α)
A display end surface 10b of O is formed.

The optical fiber bundle IO is positioned and fixed by a fixture 14 on the display side. That is, as shown in FIG. 2, a large number of fixtures 14 are stacked, and the light emitting ends of the optical fibers are arranged in a row in two directions in the gaps formed between them, and fixed with adhesive. By doing so, the display end face fo
b is formed.

An active display device such as a CRT is disposed opposite to the original image input side of the display means 2, and an image is input thereto.

The magnification ratio of the image output from the display end face of the display means 2 with respect to the original image is A/a in the y direction and B/b in the two directions.
(= l/s i n α) There is. The magnification in both directions can be the same if desired.

In order to obtain a sufficient magnification, the angle α is set to, for example, 5 to
Therefore, the light emitted from the display side has high directivity in the direction of about +80 degrees with respect to the direction normal to the display surface, according to the definition of positive and negative angles shown in the yS1 diagram.

This display means 2 is similar to the display device disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 181706/1983.

On the other hand, the viewing side surface 16 of the light deflection means 4 is flat, and the display means 2 side has a shape in which a large number of prisms having ridge lines in the y direction are arranged in two directions. FIG. 4 is an enlarged view showing the junction between the light deflection means 4 and the display means 2. As shown in the figure, each prism has a surface on one side (in the figure The left surface) [first surface 118 is tilted by the above angle α, and the other side surface (right surface in the figure) [second surface] 20 is tilted at the angle β (=45 degrees − α/2
) is only tilted.

Therefore, as shown in FIG.
The light reflected by the screen will travel in the direction normal to the display surface.

In reality, the light emitted from the optical fiber end face 12b is not unidirectional but has a certain degree of angular spread, so the traveling direction of the light emitted from the optical deflection means 4 also has a distribution.

The above-mentioned example device was actually created and the light amount distribution in the light output direction from the display surface (ie, the aw side surface 16 of the light deflecting means 4) was measured. Here, the angle α is about 10 degrees, the angle β is about 40 degrees, and the size of one display surface is 6 inches x 6 inches.
Inches. Moreover, as the optical fiber 12, the diameter is 0.
A 5 mm one was used. The shape of the light emitting end face of the optical fiber 12 was an ellipse with a major axis of 3 mm and a minor axis of 0.5 mm. Further, the arrangement pitch of the prisms constituting the light deflecting means 4 was 0.5 mm. This light deflection means 4 is made by creating a prism-shaped mold, and inserting the mold into a transparent acrylic resin plate [
"Acrylite" (trademark) manufactured by Mitsubishi Rayon Co., Ltd.; thickness 2 mm] was pressed against the - side by hot press.

In the measurement, convergent light from a commercially available projector was made incident on the light incident end face of the display means 2, and the angular distribution of the amount of emitted light within the X-2 plane in FIG. 1 was measured. A brightness measuring machine BM-3 (measurement circle: 6 mm) manufactured by Tokyo Kogaku Kikai Co., Ltd. was used for the measurement.

The measurement results are shown in Table 1, and the relative brightness is also shown when the brightness at the angle where the amount of emitted light is maximum is taken as 100%, and the relative brightness distribution is also shown in FIG.

Table 1 The angle range where the brightness value is 80% or more of the maximum brightness is 30 to 32
It is about degree.

For comparison, the angular distribution of the amount of emitted light was similarly calculated for the device of this embodiment with the light deflection means 4 removed (that is, corresponding to the display device described in the above-mentioned Japanese Patent Application Laid-Open No. 181706/1983). was measured. The results are shown in Table 2.
The relative brightness distribution is shown in FIG.

Table 2 Table 11a The angle range where the 1 degree value is 80% or more of the maximum brightness is 17
It is about 18 degrees.

From the above results, according to the embodiment of the present invention, it is possible to obtain directivity at an angle close to the normal line of the display surface, and also to obtain a relatively wide W.
A good viewing angle range can be obtained over the A area.

By varying the angle β in the above embodiment, the directivity can be changed.

Further, in the above embodiment, the angle that the light output end face 12b of the optical fiber of the display means 2 makes with respect to the longitudinal direction of the optical fiber and the angle that the first surface 18 of the prism of the light deflection means makes with the display surface normal line are both the same. Although it is assumed that they are equal at α, they may be different.

It is also possible to form a desired large screen by using a large number of display devices of the above embodiments.

[Effects of the Invention] As described above, according to the present invention, there is provided a display surface that is adjacent to a display pixel that can emit light with directionality in a direction tilted with respect to the normal direction of the display surface and that is orthogonal to the direction of the display surface. Since the light deflection means is arranged in which a large number of prisms having ridge lines inward are arranged in the display plane direction perpendicular to the ridge lines, the space required for the device is small, display can be performed in a bright place, and the screen Display with directivity in a desired direction close to the linear direction is possible.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a display device according to the present invention. FIG. 2 is a partial view showing the display side end of the display means. FIG. 3 is a partial view showing the original image input side end of the display means. FIG. 4 is an enlarged view showing the joint between the light deflection means and the display means. FIGS. 5 and 6 are diagrams showing relative luminance distribution. 2: Display means, 4: Optical deflection means, 10: Optical fiber bundle. 10a: original image input end face, 10b: display end face, 12 optical fibers, 12a: light incidence end face. 12b: light emitting end surface, 14: fixture, 16: display surface. Agent Patent Attorney Seki Yamashita Box 1, Figure 4, Figure 2, Figure 3←bA, Figure 5, Figure 6

Claims (2)

[Claims] (1) A display means having a display pixel capable of emitting light with directionality in a direction inclined with respect to the normal direction of the display surface, and a display surface disposed adjacent to the display pixel of the means and perpendicular to the direction of the directivity. 1. A display device comprising: a light deflecting means in which a large number of prisms each having an inward ridgeline are arranged in a direction within a display surface perpendicular to the ridgeline. (2) The display means has an optical fiber bundle as an image transmission body, and one end surface of each optical fiber constituting the optical fiber bundle is a surface oblique to the longitudinal direction of the optical fiber, and the end surface is The display device according to claim 1, wherein the display device is a display pixel.