JPH03265832A - Overhead projector - Google Patents

Abstract

PURPOSE:To protect viewer's eyes from being harmed by arranging plural stages near to each other or continuously arranging them and also disposing each stage capable of moving in a horizontal direction so that each stage can be selectively arranged on an illumination position. CONSTITUTION:Two stages 16 and 17 made of transparent glass for placing a film original F on it are freely attachably and detachably disposed on the upper surface of an original placing table 21 in a copying machine 2. And the placing table 21 is moved in the horizontal direction in a state that a new original F for replacing is placed on the stage 17, and then, the original F is arranged on an original illuminating position A. At this time, since each stage 16 and 17 is near to each other, the net original F on the stage 17 is gradually transferred to the illuminating position A in accordance with retreating the projected original F on the stage 16 from the illuminating position A. Then, either of the originals F on each stage 16 and 17 is always positioned at the illuminating position A, so that a screen can be prevented from rapidly becoming dazzling. Thus, the viewer's eyes can be protected from being harmed.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an overhead projector (OHP).

<Prior Art> Conventionally, an overhead projector has been provided as one of the projection devices for projecting an original image onto a screen. This overhead projector condenses light that illuminates a film original on a stage using a condenser lens, and then projects the light onto a screen via a projection lens and a projection mirror.

<Problem to be Solved by the Invention> In the overhead projector described above, in order to project a new original image onto the screen, it is necessary to replace the film original placed on the stage with a new film original. When replacing this film original, the film original on the stage is removed from the stage and a new film original is placed on the stage, so there is no original placed on the stage temporarily. occurs. Naturally, when no original is placed on the stage, no image is projected on the screen. Furthermore, very strong illumination light is projected onto the screen so that the original image can be projected even in a bright room. Therefore, when no image is projected on the screen, the screen becomes very dazzling. Here, since the removal of the film original on the stage is done almost instantaneously, there is a problem in that the brightness changes rapidly, which has an undesirable effect on the viewer's eyes.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an overhead projector that can protect the eyes of viewers.

<Means for Solving the Problems> In order to achieve the above object, the overhead projector of the present invention has a plurality of stages arranged close to each other or in a continuous state, and each stage has the following features:
It is movable in the horizontal direction so that it can be selectively placed at the illumination position.

<Operation> According to the overhead projector having the above configuration, by moving the stages in the horizontal direction with the film originals placed on each stage, the film originals to be projected can be replaced. At this time, since the stages are close to each other or are continuous, as the film original in the projection flow moves from the illuminated position to the non-illuminated position, the film original to be projected is gradually transferred to the illuminated position. Become. Therefore, since the film original is always present at the illumination position, it is possible to prevent the screen from becoming dazzling.

<Example> Hereinafter, embodiments will be described in detail with reference to the accompanying drawings showing examples.

FIG. 1 is a perspective view showing an overhead projector 1 of the present invention. To the above RAD projector 1
is constructed integrally with the original moving type copying machine 2, and includes a support 11 erected from behind the copying machine main body 20.
A casing 10 extending horizontally is provided on the top of the casing 10, and a light source 12 and a reflector 13 for illuminating the film original F are provided in the casing 10. A projection lens 14 and a projection mirror]-5 are provided for projecting the image of the film original F onto a screen (not shown). Further, two stages 16 and 17 made of transparent glass for placing a film original F are removably provided on two sides of the original placing table 2 of the copying machine 2. Furthermore, a projection lens 14 is provided directly below each of the stages [6] and 7 for condensing the light illuminated on the film original F.
A Fresnel lens 8 serving as a condensing lens for reflecting light is integrally provided with respect to the stages 1.6 and 1.7. The Fresnel lens 18 is of a reflective type in which reflective mirrors are laminated.

The light source 1-2 is a halogen lamp, a metal halide discharge lamp, or the like, and its light is irradiated toward the film document F placed at the document illumination position A in cooperation with the reflector 13. Each stage 16.1
7 are provided close to each other, and can be selectively placed at the original illumination position A by moving the original placing table 21. Stage 16.1 above
7 is fixed to the original table 21 by a frame (not shown).

2. The document mounting table 21 is made of transparent glass and a cover covering the upper surface thereof, and is supported so as to be movable in the horizontal direction by a slider rail 23 provided on the upper surface of the copying machine main body 20. The document table 21 is automatically moved back and forth to expose and scan the document when the copying machine 2 is used. Further, when using the overhead projector, it can be moved by operating the keyboard 24 of the copying machine 2, that is, by manual operation. Note that the movement stroke of the document table 21 is regulated by stoppers 22 that protrude from both the copying machine main body 20 and the document table 21 and are engageable with each other.
(See especially Figure 2).

With the above configuration, in the case of the figure, stage 17
By moving the document mounting table 21 in the horizontal direction with a new film document F for replacement placed on the
The film original F can be placed at the original illumination position A. At this time, since the stages 16 and 17 are close to each other, as the film original F in the projection style of stage 6''2 is evacuated from the illumination position A, a new film original F on the stage 17 is moved. It will be gradually transferred to illumination position A. Therefore, one of the film originals F on each stage 1, 6, and 17 is always present at the illumination position A, so that it is possible to prevent the screen from becoming suddenly dazzling.

Further, the film original F to be placed at the original illumination position A can be easily switched. In addition, the movement of the document stage], 6.1.7 from the original platen 21 of the copying machine 2 to
Since this is done using a mechanism for moving, the cost burden is also low.

In addition, each stage 16. ], 7 may be provided in a continuous manner. This continuous state includes not only a state in which opposing sides are butted against each other, but also a state in which both stages 16 and cores are integrally formed in advance.

Further, in the above embodiment, the stage 16° core and
Although the structure was such that the Fresnel lens 18 provided directly below it was moved integrally, it is also possible to fix the Fresnel lens 8 only at the document illumination position A and move only the stage 1.6.17. good.

Furthermore, the present invention can of course be applied to a stand-alone overhead projector that is not integrated with the copying machine 2, and in this case, a reflective type that reflects illumination light, a reflective type that reflects illumination light, and a transmission type that transmits illumination light. It may be of any transmission type.

In addition, the present invention can be modified in various ways, such as configuring three or more stages.

<Effects of the Invention> As described above, according to the overhead projector of the present invention, the film original to be projected is replaced by moving the plurality of stages in the horizontal direction, so that the film original is always placed at the original illumination position. As a result, it is possible to prevent the screen from suddenly becoming dazzling or becoming dark.

Therefore, the unique effect of protecting the viewer's eyes is achieved.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an overhead projector of the present invention, and FIG. 2 is a sectional view of essential parts. ]... Overhead projector, 14... Projection lens, 16, 1. ．． 7... Stage, 18... Fresnel lens (condensing lens).

Claims (1)

[Claims] 1. In an overhead projector where light that illuminates a film original placed on a stage is focused by a condensing lens and then projected onto a screen through a projection lens, multiple stages are arranged close to each other or in a continuous state. An overhead projector characterized in that each stage is movable in the horizontal direction so that each stage can be selectively placed at an illumination position.