JPH05297450A - Overhead projector device - Google Patents

Abstract

PURPOSE:To illuminate a speaker without making a video projected on a screen difficult to view in the midst of using an overhead projector. CONSTITUTION:An overhead projector device is provided with the overhead projector 1, the screen 11 and an illuminating device 20. The screen 11 is a polarizing screen by which the 1st polarized light component of light projected from the overhead projector 1 is reflected, and the illuminating device 20 is constructed so as to project a 2nd polarized light component which forms 90 deg. with the 1st polarized light component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overhead projector (OHP) device.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional overhead projector (OHP) device. The overhead projector 1 includes an appropriate light source 2, for example, a halogen lamp, a reflecting mirror 3 that reflects and collects light from the light source 2, and a Fresnel lens 4 that collects light from the light source 2 and the reflecting mirror 3.
And a glass plate 5 arranged on the Fresnel lens 4
A projection lens 8 supported by an arm 9 and a plane mirror 10 arranged above the projection lens 8, and the OHP film 6 is arranged on the glass plate 5. There is.

The light from the light source 2 and the light reflected by the reflecting mirror 3 are condensed by the Fresnel lens 4 and OHP.
It is redirected by the plane mirror 10 through the film 6 and the projection lens 8.

The overhead projector (OHP) device further comprises a screen 11, and such screen 11
The image 11A transmitted from the overhead projector 1 is projected on the top.

[0005]

However, in such a conventional overhead projector (OHP) apparatus, the facial expression of the presenter 13 and the sample held by the presenter 13 are viewed in order to dim the room illumination during use. There was a drawback that could not be done.

When the overhead projector (OHP) device is in use, the light in the room is turned on so that the expression of the presenter 13 and the sample held by the presenter 13 can be seen, and the light is reflected on the screen 11. Then video 11
It becomes difficult to see A.

In view of the above point, the present invention allows the expression of the presenter 13 and the sample held by the presenter 13 to be seen during use, and the image 11A on the screen 11 can be clearly seen. Overhead projector (OH
P) The purpose is to provide a device.

[0008]

According to the present invention, for example, as shown in FIG. 1, in an overhead projector device having an overhead projector 1, a screen 11 and a lighting device 20, the screen 11 is projected by the overhead projector 1. It is a polarizing screen that reflects only the first polarization component of the light, and the illumination device 20 is configured to project the light of the second polarization component different from the first polarization component.

In the overhead projector device of the present invention, the first polarization component and the second polarization component are linearly polarized lights having polarization planes orthogonal to each other.

[0010]

The illumination light projected from the illumination device 20 illuminates the presenter 13 because it is polarized, but the polarizing plate screen 1
At 1, it is absorbed and not reflected. Therefore, the light of the lighting device 20 can illuminate only the presenter 13 without obscuring the image 11A on the screen 11.

[0011]

Embodiments of the present invention will be described below with reference to FIG. In FIG. 1, corresponding parts in FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted. Figure 1
Shows an example of an overhead projector device of the present invention, and the overhead projector device includes an overhead projector 1, a screen 11, and a lighting device 20. The overhead projector 1 may be the conventional overhead projector 1 as described with reference to FIG.

Therefore, the overhead projector 1
Is a light source 2 such as a halogen lamp, a reflecting mirror 3, a Fresnel lens 4, a glass plate 5 on which an OHP film 6 is arranged, and a projection lens 8 supported by an arm 9.
And a plane mirror 10.

The illuminating device 20 may have a lamp 14, a reflecting mirror 15 for converging the light of the lamp 14 in one direction, and a condenser lens 16, and further includes a polarizing plate 17. The light projected from the lighting device 20 is polarized plate 17
And becomes a polarized light component in one direction, that is, linearly polarized light.

The screen 11 is a polarizing plate screen which reflects only the polarized component in one direction of the projected light, and is disclosed, for example, in Japanese Patent Application No. 3-207188 filed by the same applicant as the present applicant. It may have been done.

The polarizing plate screen disclosed in Japanese Patent Application No. 3-207188 is a transparent screen plate having a front image projection surface and a rear reflection surface, and is arranged in front of and close to the transparent screen plate. And a polarizing plate, and a Fresnel surface is formed on the rear surface of the screen plate in order to increase the reflective diffusivity in the lateral direction.

The polarization plane of the polarizing plate 17 attached to the illuminating device 20 and the polarization plane of the polarizing plate attached to the polarizing plate screen 11 are arranged in different directions, for example, at an angle of 90 degrees.

Thus, the illumination light of the illumination device 20 illuminates, for example, the presenter 13 or a sample held by the presenter 13 in the same manner as the ordinary illumination light, but since it is polarized, it is applied to the polarizing plate screen 11. Will be absorbed. Therefore,
Even if the illumination light for illuminating the presenter 13 is projected onto the screen 11 at the same time, it is not reflected by the screen 11, and it is the image 11A on the screen 11.
It does not obscure the view.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-mentioned embodiments, and it is apparent to those skilled in the art that various other configurations can be adopted without departing from the gist of the present invention. Easy to understand.

[0019]

According to the present invention, there is an advantage that the presenter can be illuminated by the illumination device while using the overhead projector.

According to the present invention, even when the illumination light for illuminating the presenter is simultaneously projected on the screen by the illumination device while using the overhead projector, the illumination light is absorbed by the screen 11 and thus the screen 11 There is an advantage that the image 11A is not difficult to see.

[Brief description of drawings]

FIG. 1 is a diagram showing a usage example of an overhead projector according to the present invention.

FIG. 2 is a diagram showing a usage example of a conventional overhead projector.

[Explanation of symbols]

 1 Overhead Projector (0HP) 2 Light Source 3 Reflector 4 Fresnel Lens 5 Glass Plate 60 HP Film 8 Projection Lens 9 Arm 10 Plane Mirror 11 Screen 11A Image 13 Presenter 14 Lamp 15 Reflector 16 Lens 17 Polarizing Plate 20 Illuminator

Claims (2)

[Claims] 1. An overhead projector device having an overhead projector, a screen, and a lighting device, wherein the screen is a polarizing screen that reflects only a first polarized component of the light projected from the overhead projector, and the lighting device. Is configured to project light of a second polarization component different from the first polarization component, and the overhead projector device. 2. The overhead projector device according to claim 1, wherein the first polarized component and the second polarized component are linearly polarized lights having polarization planes orthogonal to each other.