JPH05134214A - Video projecting system - Google Patents

Abstract

PURPOSE:To provide a video projecting system in which the contrast of a picture projected on a screen in a bright room is improved without making the room dark. CONSTITUTION:A vertical polarizing film 15 is provided on the silver screen 2 on which a video projector 1 projects video. A horizontal polarizing film 16 is provided on a fluorescent lamp 17 being an illumination instrument except the video projector 1, direct projecting to the screen 2 by means of the illumination instrument is prevented, so that the contrast is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image projection system on a screen by a video projector or the like.

[0002]

2. Description of the Related Art When a video projector 1 is used to project an image on a large screen 2 using a room as shown in FIG. 5, it is necessary to shield the window 3 to darken the room. Even in 5, the emergency light 4 near the door cannot be turned off, so that the light of the emergency light 4 is reflected on the screen 2 and the dark image part also rises brightly, resulting in a non-contrast screen that is difficult to see. There was a problem that

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the contrast of an image projected on a screen in a bright room without darkening the room when projecting an image on the screen.

[0004]

According to the present invention, a horizontal polarizing film or a vertical polarizing film is attached to a screen surface, and the ceiling, wall,
The present invention is characterized in that a vertical polarizing film or a horizontal polarizing film is attached to a lighting device such as a light source such as a window or a fluorescent lamp.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In describing the embodiments of the present invention, the technical idea of the present invention will be described first. According to the present invention, in a room as shown in FIG. 5, a horizontal polarizing film is attached to the surface of the screen 2, and a vertical polarizing film is attached to the ceiling 6 and the wall 7.
Further, a vertical polarizing film is also attached to the window 3 serving as a light source and the lighting fixtures 4 and 5. The polarizing films to be attached may be reverse polarizing films.

A horizontal polarization film or a vertical polarization film is attached to the surface of the screen 2, and the vertical polarization film or the horizontal polarization film is attached to the ceiling 6, wall 7, window 3 serving as a light source, and lighting fixtures 4 and 5 such as a fluorescent lamp. As a result, all the natural light reflected on the screen 2 becomes vertical polarized light or horizontal polarized light from the lighting fixture or the window, and the screen reflection of the direct light can be almost eliminated.

On the other hand, the reflected light is diffusely reflected by the wall 7 and the ceiling 6 and the polarization planes are scattered. This is also changed to vertical polarization or horizontal polarization by attaching a vertical polarization film or a horizontal polarization film to the screen 2. The glare is reduced, and only the video projector 1 that emits light indoors emits light having vertical and horizontal polarization planes, and therefore appears brightly on the screen 2.

The light emitted from the luminaires 4 and 5 illuminates the room in the same manner as in a normal room, so that the person in the room does not feel the darkness, and the wall 7 and the illumination have the same polarization plane. Since the reflected light is transmitted and transmitted, the image projected on the screen 2 can be viewed while keeping the entire room bright.

Based on the above technical idea, specific examples can be realized from the following experimental results for the polarizing film. First
4A, the polarizing film 10 is arranged at a position 30 cm in front of the umbrella end of the 100 W light bulb 8 with the reflector type umbrella 9 serving as a light source, as shown in FIG. 1.
The illuminometer 11 is installed at a position of 5 m. The following experimental results were obtained under such conditions. The brightness was 700 Lux without the polarizing film 10, 280 Lux with one polarizing film, 210 Lux with two in-phase polarizing films, and 5 Lux when the two polarizing films were orthogonal (90 degrees). .. According to this experimental result, the light from the video projector is visually reduced by 210/700 = 0.3 times, but the noise light is reduced by 5/700 = 0.0071 times.

In the second experiment, as shown in FIG. 4B, a silver screen 2 is installed at a predetermined position from the video projector 1 and a polarizing film 12 is provided on the screen surface. Further, a 100 W light bulb 14 with a reflex type umbrella is installed near the video projector 1, and a polarizing film 13 is provided in front of it. With the above layout, the following results were confirmed in the actual shooting experiment from the projector 1. The above 10 from the front with respect to the screen normally projected.
When light is projected by the 0 W light bulb 14 and a real image is taken, when the polarization planes of the two polarizing films 12 and 13 are deviated by 90 degrees, the black level on the screen is significantly lowered, and the contrast is improved. It was confirmed that the image was easy to see.
At this time, the decrease in the brightness of the projector 1 due to the inclusion of the polarizing films 12 and 13 is caused by the decrease in the overall black level.
On the contrary, the test result from the subject that it is easier to see is also obtained.

The following examples can be obtained from the experimental results based on the above technical idea. FIG. 1 shows a first embodiment. In the figure, a vertical polarizing film 15 is provided on the silver-based screen 2. And lighting fixtures 17 such as fluorescent lamps
By sticking a horizontal polarizing film 16 on the front surface of the screen, the polarization plane of which is 90 degrees away from the polarizing film on the screen,
The direct reflection on the screen can be prevented.

FIG. 2 shows a second embodiment. In the figure, a vertical polarizing film 18 is provided on the silver screen 2 in front of the video projector 1, and a horizontal polarizing film 19 is attached to the front surface of the emergency light 20 near the door.

In the case of the first embodiment, the lighting fixture 17
It is possible to prevent direct reflection due to
In the case of the above embodiment, it is necessary to darken the room when projecting onto a large screen, but it is possible to prevent reflection on the screen without turning off the emergency light 20.

FIG. 3 shows a third embodiment. In the case of this embodiment, the screen 2 is installed near the lecture table 21, and the speaker uses the image projected on the screen 2 by the video projector 1 to use the desk lighting device 2
It is suitable when giving a lecture while using 2. In the case of this embodiment, a polarizing film 23 provided on the screen 2 installed near the lecturer in front of the desk lamp 22.
It is possible to prevent the reflection on the screen 2 by attaching the polarizing film 24 whose polarization plane is shifted by 90 degrees. In addition, at this time, when the reflected light of the lecture table 21 has an influence, the polarizing film 2 attached to the lighting fixture 22 is also mounted on the table.
By sticking the polarizing film 25 having the same phase as that of No. 4, it is possible to prevent more complete reflection.

Although each of the above embodiments has been described as applied to video projection, the system of the present invention is
The present invention is not limited to the above embodiment, and similar effects can be obtained in the case of film projection.

[0016]

The present invention has the following effects. (1) A large image with good contrast can be viewed even in a bright room, and the viewer can take notes. (2) It is easy to increase the size of the video projection system. (3) When the video projector system is used in place of the OHP (overhead projector), the illumination of the teaching material presentation device enters the screen to hide the image, but this point is improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of a third embodiment of the present invention.

FIG. 4 is an explanatory diagram of an actual measurement example.

FIG. 5 is an explanatory diagram of a room of the video projection system.

[Explanation of symbols]

1. Video projector 2. Screen 15
..Vertical polarizing film 16..Horizontal polarizing film 17..Light source

Claims (1)

[Claims] 1. A video projection system comprising: a polarization film in one direction provided on a video projection screen; and a light source other than the video projection device provided with a polarization film orthogonal to the one direction.