JPH04116842U - video projector screen equipment - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent deterioration of image quality in a transmission type video projector by preventing the screen on which images are formed by the projection tube from loosening due to heat, moisture, etc. [Configuration] Housing 8 with opening 9 on the front and front lens
13 and a screen 12 having a film-like rear lens 16 constitute a screen device of a video projector,
The front lens 13 is formed into a cylindrical curved surface with an intermediate portion protruding rearward, and is fixed to the opening 9, and one end of the rear lens 16 is tightly coupled to one straight end of the front lens 13, The other end was pulled outward and forward along the curved surface of the front lens 13 to bring it into close contact with the front lens 13.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a screen device for a video projector.

0002

[Conventional technology]

Figure 3 shows a conventional transparent video projector, in which 1 has an opening 2 on the front. The video projector housing 3 is equipped with three colors of red, green, and blue from the bottom inside the housing 1. 4 is a projection tube that projects the corresponding image toward the back, and 4 is the image from projection tube 3. A reflector 5 for folding back forward reflects the image projected by the projection tube 3 via the reflector 4. It is a screen that forms and transmits images. The screen 5 is made of synthetic resin such as acrylic. As shown in FIG. A front lens 6 with a stripe 6b on its outer surface and a Fresnel lens 7a on one surface. The lenses 6 and 7 are joined together at the peripheral edge. , is attached to the opening 2.

0003 By the way, the screen 5 had the following drawbacks. The first drawback is Due to changes in temperature and humidity, one or both of the lenses 6 and 7 may be bent, causing the lens to bend. This reduces the parallelism between lenses, which negatively affects focus and color reproduction. There were cases where it caused The second drawback is that the screen 5 has thick lenses stacked on top of each other. Since the screen has a large configuration, the thickness of the screen becomes large, and therefore The transmission loss of these rays increases, and double images occur, reducing image quality. Ta.

0004

[Problem that the idea aims to solve]

This invention solves the above drawbacks, prevents the lens from bending, and improves the light transmittance. To provide a screen device for a video projector that is high and does not cause noticeable double images. It is an object.

[0005]

[Means to solve the problem]

In order to solve the above problems, the present invention has developed a video projector that forms an image using a projection tube. A screen device for a projector, the screen device having an opening on the front. a screen having a front lens and a rear lens; is formed into a cylindrical curved surface with a middle part protruding rearward and fixed to the opening. and one end of the rear lens is tightly coupled to one straight end of the front lens. At the same time, the other end was pulled outward and forward along the curved surface of the front lens. So The rear lens was formed into a film shape.

[0006]

[Effect]

According to the above configuration, the screen that forms the image from the projection tube is the front lens and the rear lens. The front lens has a cylindrical curved surface with the middle part protruding backwards. The rear lens is formed into a film shape and fixed to the opening of the housing, and one end is formed into a film shape. The part is closely connected to one straight end of the front lens, and the other end is connected to the front lens. By applying pressure outward and forward along the curved surface of the It absorbs and brings the middle part into close contact with the front lens.

[0007]

【Example】

An embodiment of the present invention will be described below with reference to the drawings. Figures 1 and 2 8 is a casing with an opening 9 on the front, 10 is a red part located at the bottom inside the casing 8. , 11 is a projection tube that projects images corresponding to the three colors of blue and green toward the back. a reflector plate 12 for returning the image from the projection tube 10 to the front; 12 is the opening 9; is attached to the reflector plate 11 to form and transmit the image projected by the projection tube 10. It is a screen made of synthetic resin.

[0008] The screen 12 has a black stripe 14 on the front and a lenticule on the back. - With the lens 15, the middle part is slightly (5 to 10 mm) rearward with respect to both ends. The front lens 13 is formed into a protruding uniform thick cylindrical curved surface, and and a film-shaped rear lens 16 equipped with a Fresnel lens 17 at the front lens. The lens 13 has a peripheral edge formed into the opening 9 with a curve corresponding to the front lens 13. The rear lens 16 is fixed with one end (fixed end) 18 to the front lens. It is fixed by adhesive to one straight end (upper end) of the lens 13, and the other end (movable end) 19 is biased by a spring 21.

[0009] In addition, 22 is a set screw of the metal fitting 20, and 23 is the other end (movable end) 1 of the rear lens 16. 9 to the front and outward along the curved surface of the front lens 13. -, 24 is a support fitting that supports both ends of the roll bar 23, and 25 is a rear lens 16 and other parts. It is provided integrally with the end (movable end) 19 and is locked to one end of the spring 21. A horizontal bar 26 is formed to protrude rearward from the front surface of the housing 8, and other than the spring 21, This is a locking knob for locking the end.

0010 Although not shown, the screen 12 is located at both straight ends of the front lens 13. In addition to those arranged so that they face each other vertically as mentioned above, they are also arranged so that they face each other horizontally. It is also possible to arrange it in

[0011]

[Effect of the idea]

As described above, according to the present invention, the rear lens is always pulled forward and outward. Since it is in close contact with the lens, there is no drop in parallelism due to lens flexure, and the image is improved. It is possible to prevent quality deterioration. In addition, the rear lens is formed into a film shape. As a result, the transmission loss of light rays is small and a bright screen can be obtained. image can be reduced.

[Brief explanation of drawings]

FIG. 1 is a side sectional view schematically showing a screen device for a video projector according to the present invention.

FIG. 2 is a partially omitted plan cross-sectional view of a screen related to a screen device for a video projector according to the present invention.

FIG. 3 is a side sectional view showing an outline of a conventional transmissive video projector.

FIG. 4 is a partially omitted plan cross-sectional view of a screen related to a conventional transmissive video projector.

[Explanation of symbols]

8 Housing 9 Opening 12 Screen 13 Front lens 16 Rear lens

Claims (2)

[Scope of utility model registration request] [Claim 1] A screen device for a video projector that forms an image using a projection tube, the screen device comprising a casing with an opening in the front, and a screen with a front lens and a rear lens. , the front lens is formed into a cylindrical curved surface with an intermediate portion protruding rearward and is fixed in the opening, one end of the rear lens is closely coupled to one straight end of the front lens; , the other end of the front lens is pulled outward and forward along the curved surface of the front lens. 2. The screen device for a video projector according to claim 1, wherein the rear lens is formed in a film shape.