JPS60213935A - Overhead projector - Google Patents

Abstract

PURPOSE:To project an output picture from an information processor on a screen as it is by forming an original platen of a prescribed transparent liquid crystal display panel. CONSTITUTION:An overhead projector 1 consists of a case body 2, light source 3, original platen 4, original 5, reflectors 6, 7, a screen 8, and an electronic computer 9. The platen 4 consists of a transparent liquid crystal panel 10 and a Fresnel lens 11. Transparent electrodes 12 are arranged like a guide matrix on the liquid crystal panel 10 and a required character or a required pattern in displayed by applying voltage to a required electrode and turning the part to an opaque state. When voltage is applied to a prescribed electrode on the liquid crystal panel using a dynamic dispersion effect in accordance with the picture output from the electronic computer 9, a divided area 14 having different molecular orientation is generated, light is dispersed and light from the light source 3 is made difficult of transmission, so that the output information from the computer 9 is projected on the screen 8.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an overhead projector.

・Technical background Overhead projectors project images written on a document onto a screen, and there are two types: transmissive and reflective types.0 Normal overhead projectors project the transmitted light from the document onto a screen. Therefore, a transparent film is used as the manuscript paper. In addition, a Fresnel lens with a film wipe is often used as a projection lens, and the Fresnel lens is attached to a document table when purchased.

There are many demands for projecting information output from an electronic subtraction machine or the like onto a screen, and conventionally, video projectors have been used for this purpose.

・Prior art and problems As described above, in the past, overhead projectors and video projectors were used depending on the purpose of use, but with the development of various information processing devices, paper has traditionally been the main medium used for manuscripts. Image information that was previously stored is now often stored on magnetic recording media, which requires frequent exchange of image information between different media. Small areas are increasingly occurring where the image information recorded in each case must be projected onto a screen. In such cases, conventionally, both an overhead projector and a video projector had to be prepared, and since the video projector uses a CRT (cathode ray tube), it is very large, expensive, and difficult to handle. There was also the problem that it was troublesome. Furthermore, when an overhead projector and a video projector are used together, it is also impossible to synthesize and display an image on a document and an output image from an electronic subtraction machine or the like.

・Purpose of the Invention This invention was made to solve the problems of the conventional device described above, and provides an overhead projector that can directly project the output image from an electronic subtractor or other information processing device onto a screen. The purpose of this invention is to provide a device that can project both an output image from a computer, etc. and an image of a document, and can also combine and project these images. It is something.

- Structure of the Invention The overhead projector of the present invention is characterized in that the document table, which was conventionally formed of a glass plate or the like, is formed of a transparent display panel. As transparent display panels, liquid crystal panels, panels that utilize the polarization phenomenon of transparent ceramics, and the like have been put to practical use, and by using these display panels, the overhead projector of the present invention can be configured. In particular, liquid crystal panels that utilize dynamic scattering (dynamic scattering) effects have been technologically perfected, have good light transmittance, and can be made into very thin plate shapes. It is suitable as a transparent display panel used in an overhead projector. Also,
Generally, the image output of an electronic divider etc. is displayed in a dot matrix pattern, so if a display panel with a dot matrix display compatible with this is used, the present invention can be achieved by simply providing a simple interface circuit. overhead projector as normal electronic t
It becomes possible to connect to +z'> machine.

・Embodiment of the Invention The drawings show one embodiment of the present invention. FIG. 1 is a cross-sectional side view showing the configuration of an overhead projector, FIG. 2 is a view showing the document table, and FIG. 3 is a view showing the liquid crystal panel. It is a figure shown typically.

In the figure, 1 shown as a whole is an overhead projector,
Reference numeral 2 denotes its housing, 3 a light source, 4 a document table, 5 a document placed on the document table 4, 6 and 7 reflectors, 8 a screen, and 9 an electronic subtraction mode.

As shown in FIG. 2, the document table 4 is made up of a transparent liquid crystal panel 10 and a Fresnel lens 11 attached thereto, and the Fresnel lens 11 is used as a projection lens for the overhead projector 1. As shown in FIG. 3, transparent electrodes 12...12 are arranged in a dot matrix on the liquid crystal panel 10, and a voltage is applied to a desired electrode to make the voltage applied area opaque. As a result, desired characters or figures can be displayed. In a liquid crystal panel that utilizes the dynamic scattering effect, by applying a voltage to the electrode 12, domains 14 with different molecular orientations are generated within the liquid crystal 13, and light is scattered at the boundaries of these domains 14. Since the light from the light source 3 is no longer transmitted, by applying a voltage to a predetermined electrode using the image output of the electronic subtractor 9, the output information of the electronic computer 9 is projected as a shadow on the screen 8. It will be. When no voltage is applied to the electrode 12, the transparent liquid crystal panel 10 is just a single transparent plate, so the transparent original 5 is placed on the original platen 4.
, the image of the document 5 will be projected on the screen 8 in the same way as with a conventional overhead projector.

Furthermore, as shown in FIG. 4, the electronic IF calculation 8!9 outputs information jA BJ to the transparent liquid crystal panel 10,
If you place transparent raw stones 1 and 5 with the information ``CD EJ'' written on them, screen 9 will display a composite image of these stones.
The information A B CD EJ will be projected,
If necessary, the output information from the computer and the information on the transparent original created in advance can be arbitrarily combined and displayed on the screen.

Note that the illustrated embodiment has a transmission type overhead panel 1.
A reflecting mirror will be attached below 0.

・Effects of the Invention The overhead projector of the present invention described above has the same function as a conventional overhead projector as well as the same functions as a conventional video projector. To provide a device that can project both original information and output information from a computer, etc. onto a screen with one device, and is far more compact and easy to handle than conventional video projectors. I can do it.

In addition, since the output information from a computer, etc. is displayed on the document table of the overhead projector, the optical system for projecting this output information may be the same as that of the overhead projector. It is also possible to combine the displayed image and the image written in the manuscript and project it onto a screen, making it possible to display graphed data on the same screen, for example, at meetings, lectures, etc. An extremely useful device can be provided.

[Brief explanation of the drawing]

The figure shows one embodiment of the present invention, and FIG. 1 is a cross-sectional side view schematically showing the structure of an overhead projector;
Figure 2 is a cross-sectional side view showing the depiction of the document table, Figure 3 is a partially enlarged perspective view of the liquid crystal panel, and Figure 4 is a composite image! FIG. 7 is an explanatory diagram showing a method of projecting the i1 plane. In the figure, 1 is an overhead projector, 3 is a light filter, 4 is a manuscript table, 5 is a manuscript, 8 is a screen, 9 is a computer,
10 is a transparent liquid crystal panel, 11 is a Fresnel lens, 12 is a transparent electrode, and 13 is a liquid crystal. Agent Patent Attorney Takao Nishi

Claims (3)

[Claims] (1) An overhead projector with a document table formed from a transparent display panel. (2) The overhead projector according to claim 1, wherein the transparent display panel is a dot matrix display panel. (3) The overhead projector according to claim 1 or 2, wherein the transparent display panel is a liquid crystal panel that utilizes a dynamic scattering effect.