JPS62254133A - Projecting device - Google Patents

Abstract

PURPOSE:To input and rewrite an image freely by arranging a convergent Fresnel lens right in front of a panel sheet, providing a light source and an image forming lens in front of the convergent Fresnel lens, and providing a reflecting mirror behind the panel sheet and connecting an external image input device to the panel sheet. CONSTITUTION:A liquid crystal pane 2 as the panel sheet, the reflecting mirror 3 positioned behind it, and the convergent Fresnel lens 4 nearby the front surface of the liquid crystal panel 2 are arranged in a housing body 1 while stood against one another. The light source 5 composed of a halogen lamp, a condenser lens 6, and the image forming lens 7 are arranged in front of the condenser lens 4. Then, a storage device 11, a video camera 13 which photographs a subject such as an original 12, a still image storage device 14, a word processor 15, an image scanner 16, and a mouse 17 are connected to a personal computer 10 to which the liquid crystal panel 2 is connected by a cable 9 through an interface circuit 10a.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a projection device.

2. Description of the Related Art Conventionally, as shown in FIG. 3, a transmissive Fresnel lens 32 on which a transparent sheet 31 with an image is placed, and an illumination lamp 33 located below the lens are mounted on the top of a housing 34. , an imaging lens 35 and a reflection mirror 36 are provided, the light from the illumination lamp 33 is focused by the transmission type Fresnel lens 32 to illuminate the transparent sheet 31, and the light transmitted through the transparent sheet 31 is transmitted through the imaging lens 35. Reflection mirror 3
6 there is an over-rad projector that is reflected towards the screen.

Further, as a device described in Japanese Utility Model Application Publication No. 80-115232, as shown in FIG.
An illumination lamp 40, an imaging lens 41, and a reflecting mirror 42 are placed in the second part of the housing 39, which illuminates the transparent sheet on the Fresnel lens 37 from above, and the reflected light is sent to the imaging lens. 41 and a reflective mirror 42.
There is an over rad projector that reflects towards the screen.

Furthermore, as a device described in Japanese Utility Model Application Publication No. 60-96681, as shown in FIG.
The image of the liquid crystal panel 43 illuminated by the illumination lamp 44 is transmitted through the imaging lens 45 and reflected by the reflection mirror 46.
There is an over rad projector which reflects the light towards the screen 47.

Problems to be Solved by the Invention In the case shown in FIG. 3, the illumination lamp 33 is placed below the transmission type Fresnel lens 32, so the casing 34 becomes large and the distance between the transparent sheet 31 and the transmission type Fresnel lens 32 increases. Since the light transmitted from the back side is imaged, the optical path length becomes long and a large space is required. Moreover, the transparent sheet 31 on which the image is drawn must be prepared in advance, and flexible usage such as changing the projected image on the spot is not possible.

4, the illumination lamp 40 is connected to the imaging lens 4.
1 and the reflective mirror 42 above the housing 39, it is possible to make the housing 39 thinner, but the disadvantage of operability due to the use of a transparent sheet remains.

In the case shown in FIG. 5, the light from the illumination lamp 44 is not focused and is irradiated onto the liquid crystal panel 43, so the screen 47
The projected image above also becomes darker.

This invention was made in view of these points, and provides a projection device that saves space, can provide a bright, large screen, and can freely input and rewrite images on a panel sheet. The purpose is to

Means for Solving the Problems A condensing Fresnel lens is placed just before the panel sheet where the light transmittance and scattering state changes, a light source and an imaging lens are provided in front of the condensing Fresnel lens, and the panel sheet A reflective mirror is provided behind the panel sheet, and an external image input device is connected to the panel sheet via an interface circuit.

Accordingly, the panel sheet is illuminated by a light source, the illumination light is reflected by a reflective mirror at the rear of the panel sheet, and an image of the panel sheet is transmitted through an imaging lens and projected.

A condensing Fresnel lens condenses the light rays from the light source just in front of the panel sheet, illuminates the entire surface of the panel sheet, and condenses the light rays reflected by the reflection mirror so that they illuminate the entire aperture of the imaging lens. This makes it possible to obtain a bright, large screen. Furthermore, by arranging a condensing Fresnel lens just before the panel sheet and arranging the light source and imaging lens in front of it, the optical path length is shortened and space is saved. Furthermore, it becomes possible to input and rewrite display images on the panel sheet on the spot.

51 Embodiment An embodiment of the present invention will be explained based on FIGS. 1 and 2. Inside the housing 1, a liquid crystal panel 2 which is a panel sheet, a reflective mirror 3 located on the back side of the liquid crystal panel 2, and a condensing Fresnel lens 4 close to the front of the liquid crystal panel 2 are arranged in a leaning state. In front of Fresnel lens 4,
A light source 5 using a halogen lamp, a condenser lens 6, and an imaging lens 7 are arranged. Furthermore, legs 8 are attached to both sides of the casing 1 so as to be rotatable and fixable at any position for changing the elevation angle of the casing 1.

A personal computer 10 to which the liquid crystal panel 2 is connected via an interface circuit 10a via a cable 9 is provided with a storage device 11, a video camera 13 for photographing a subject such as a document 12, and a still image storage device 14.
A word processor 15, an image scanner 16, and a mouse 17 are connected. These 6 personal computers 10 serve as external image input devices. Video camera] 3, still image storage device 14, word processor 15, image scanner 16, etc. may be connected to the liquid crystal panel 2 independently.

In addition, the panel sheet can be used instead of the liquid crystal panel 2, such as a TN liquid crystal panel, a smectic liquid crystal panel, an ECD panel, or a T
A phase changeable panel sheet such as eOx may also be used.

In such a configuration, images are selectively input to the liquid crystal panel 2 from any of the external image input devices, and images can be freely changed and new images created on the spot. for example,
A photographic screen of a subject such as the original 12 taken with a video camera 13, a screen on the original 12 optically read by an image scanner 16, a text or image created on a personal computer 10 using a mouse 17, etc., a word processor 15 The sentences etc. created by the above are input to the liquid crystal panel 2. In addition, an image signal from any external image input device is inputted to the still image storage device 14, and the image is inputted as it is to the liquid crystal panel 2, or a part of the image is added to or deleted from the image by the personal computer 10, etc. After processing, inputting to the liquid crystal panel 2 can be performed freely.

Furthermore, when a smectic liquid crystal panel is used in place of the liquid crystal panel 2, an image once input can be stored semi-permanently unless it is rewritten, and there is an advantage in that light loss is reduced.

The image thus formed on the liquid crystal panel 2 is projected onto the screen 18. That is, the light rays from the light source 5 are diffused by the condenser lens 6 into an area corresponding to the size of the liquid crystal panel 2, and further condensed by the condensing Fresnel lens 4 to avoid waste, and irradiated onto the liquid crystal panel 2 all at once. be done. This illumination light is reflected by a reflection mirror 3, and further condensed by a condensing Fresnel lens 4 so as to illuminate the entire aperture of an imaging lens 7, and projected onto a screen 18.

In this way, an image is projected. The condensing Fresnel lens 4 condenses the light rays from the light source 5 just in front of the liquid crystal panel 2 and illuminates the entire surface of the liquid crystal panel 2, and the light beams reflected by the reflection mirror 3 It becomes possible to condense the light so that it illuminates the entire aperture of the imaging lens 7, and a bright large screen can be obtained.

Further, by arranging the condensing Fresnel lens 4 immediately before the liquid crystal panel 2 and arranging the light source 5 and the imaging lens 7 in front of it, the optical path length can be shortened and space can be saved.

Effects of the Invention Since the present invention is configured as described above, the panel sheet is illuminated by a light source, the illumination light is reflected by the reflective mirror at the rear of the panel sheet, and the image of the panel sheet is transmitted through the imaging lens and projected. However, a condensing Fresnel lens condenses the light rays from the light source just in front of the panel sheet, illuminates the entire surface of the panel sheet, and also irradiates the light rays reflected by the reflection mirror onto the entire aperture of the imaging lens. It is possible to condense light, and therefore a bright large screen can be obtained.Also, by placing a condensing Fresnel lens just in front of the panel sheet and placing the light source and imaging lens in front of it, the optical path length can be reduced. It is possible to shorten the time and save space, and furthermore, it has effects such as being able to manually and rewrite the display image on the panel sheet on the spot.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 show an embodiment of this invention.
FIG. 1 is a vertical sectional side view, FIG. 2 is a side view showing a connection state of an external image input device in a reduced scale, and FIGS. 3 to 5 are side views showing a conventional example.

Claims (1)

[Claims] A condensing Fresnel lens is arranged immediately before the panel sheet whose light transmittance and scattering state changes, a light source and an imaging lens are provided in front of the condensing Fresnel lens, and a reflecting mirror is provided behind the panel sheet, A projection device characterized in that an external image input device is connected to the panel sheet via an interface circuit.