JPS59201032A - Overhead projector - Google Patents

Abstract

PURPOSE:To project sharply the picture of an original on a screen even if the original is curled or contracted due to the irradiation heat of an illuminating lamp, by providing a transparent original holding member placed on a stage. CONSTITUTION:A square-shaped transparent or translucent stage 3 for placing a transparent original 2, and a transparent or translucent original holding member 5 attached so as to be freely openable and closeable by a pair of clip rings 4 provided along the side edge of one end of this stage 3 are provided on the upper face of a machine body 1. When the member 5 is closed and made to adhere tightly onto the surface of the stage 3, a curl generated on the original 2, and a partial contraction due to the radiation heat of an illuminating lamp 6 are eliminated, and an irradiating light of the lamp 6 transmits through a Fresnel lens 7 and the transparent original 2, also reaches a screen 10 through a projection lens 8 and a reflecting mirror 9, and is projected to the picture of the transparent original 2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an overherad projector,
In particular, the present invention relates to an over-the-radar projector that can sharply project an image of a transparent original onto a screen.

[Prior art]

In a conventional over-the-radar projector, a transparent original is placed on the stage, and the image of the transparent original is projected onto a screen through a projection lens and a reflective mirror placed above the top surface of the projector. The transparent original may be curled, or the transparent original placed on the stage may shrink and curl due to the heat irradiated by the illumination lamp, causing the transparent original to be partially lifted from the stage surface. (Above) (The two projected images had defects such as blurring and double images.

[Purpose of the invention]

The present invention eliminates and improves these drawbacks of the prior art, and provides an over-the-top projector that can sharply project an image of a transparent original onto a screen.

[Structure of the invention]

In the over-the-air projector of the present invention, a transparent or semi-transparent document holding member is provided on the upper surface of the main body of the main body so as to be able to open and close the transparent original placed on the stage of the main body of the main body. Therefore, even if the transparent original placed on the stage (second device) is curled, or even if the transparent original partially shrinks due to the heat irradiated by the illumination lamp, the transparent original can be held by the action of the original pressing member. Since it is pressed tightly onto the stage surface, the image of the transparent original can be projected sharply onto the screen.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 shows a perspective view of an over-the-top projector with the head section equipped with a projection lens and a reflection mirror omitted.The top surface of the main body (1) has a rectangular shape on which a transparent original (2) is placed. A transparent or translucent stage (8) and a transparent or translucent original holding member (5) attached to the stage (3) so as to be openable and closable by a pair of clip rings (4) provided along one edge of the stage (3). ), and is characterized in that by closing the original document pressing member (5), the transparent document (2) is pressed and brought into close contact with the surface of the stage (3).

Then, to use this over-the-air projector, place the transparent original (2) at a predetermined position on the surface of the stage (3) as shown in Figure 2, close the original holding member (5), and then (8) After coming into close contact with the surface, the stage (3)
), and illuminates the transparent original (2), the irradiated light illuminates the frame mounted on the back of the stage (3).
a projection lens (8) that transmits through the transparent original (2) and the transparent original (2), and is further placed on the blade on the surface of the stage (3);
It passes through a reflective mirror (9) and onto a screen (10) to project the image of the transparent original (2).

In this embodiment, the illumination lamp for illuminating the transparent original is provided at a position below the stage surface, but the system is not limited to this method. It has the effect of However, if the illumination lamp is installed above the stage surface, it is necessary to further provide a reflective member on the lower surface of the Fresnel lens (7) shown in FIG.

〔Effect of the invention〕

The present invention has the above-described configuration, and the document holding member presses the transparent document placed on the stage to bring it into close contact with the stage surface, so that even if the transparent document is curled,
Alternatively, even if the transparent document partially shrinks due to the illumination lamp, its image can be sharply projected onto the screen.

Moreover, since the transparent original does not move on the stage surface due to the pressure of the original pressing member, the transparent original does not move on the stage surface (
The practical effects of the present invention are great, such as being able to project bistable images.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view of the OVERRAD projector of the present invention with the head portion omitted, and FIG. 2 is an explanatory diagram thereof. Code explanation

Claims (1)

[Claims] In an overdrive projector that projects a transparent original placed on a stage of the main body of the machine onto a screen, a transparent or semi-transparent original is placed on the top surface of the main body of the main body, and the transparent original is pressed against the transparent original and is brought into close contact with the stage. An over-head projector characterized by having a presser member that can be opened and closed.