JP2001188304A - Back projection type projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the parting between first and second screen members even in the case of the environment having high humidity. SOLUTION: This back projection type projector 1 is mounted with the screen 10 constituted by superposing the first and second screen 13 and 14 on each other in an aperture of a cabinet 21 and is constituted to project the video light from a projector body 11 to the back side of the screen 10. The projector has an atmosphere pressure dropping means which has an exhaust fan 24 for releasing the air in the cabinet to the outside and maintains the air pressure in the cabinet lower that the atmosphere pressure outside the cabinet by the exhaust fan.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear projection type projector for projecting image light on a screen to display an image.

[0002]

2. Description of the Related Art Conventionally, as a rear projection type projector, image light from a projector main body is projected from the back of a screen, and a displayed image is viewed from the front side. The screen is configured by overlapping a Fresnel screen and a lenticular screen, and the lenticular screen is arranged on the front side. By providing both the Fresnel screen and the lenticular screen in this manner, the peripheral light amount on the screen is prevented from lowering, and the image quality when the viewer views the screen from an inclined direction is prevented.

However, in such a rear projection type projector, in a high humidity environment, the front side (viewer side) of the lenticular screen and the rear side (projector main body side) of the Fresnel screen are higher than the opposite sides. Since a lot of moisture is absorbed first, the lenticular screen is warped to the viewer side, the Fresnel screen is warped to the projector side, and the two screens are separated from each other, causing the screen to float.

FIG. 3 is an explanatory view showing such warpage of the Fresnel screen and the lenticular screen.

As shown in FIG. 3, when the Fresnel screen 91 and the lenticular screen 92 are warped due to a high humidity environment, the gap between the Fresnel screen 91 and the lenticular screen 92 becomes wider as approaching the center of the screen. Become.

If the gap between the Fresnel screen 91 and the lenticular screen 92 is wide open,
The focus of the image light from the projector body deteriorates,
The image displayed on the lenticular screen was blurred.

[0007]

In the above-mentioned conventional rear projection type projector, in a high humidity environment, the front side of the lenticular screen and the rear side of the Fresnel screen have more moisture than the opposite side. Therefore, the lenticular screen and the Fresnel screen are warped in opposite directions, and the two screens are separated from each other, so that the focus of the image light from the projector main body is deteriorated and the image displayed on the lenticular screen is blurred.

Accordingly, an object of the present invention is to provide a rear projection type projector which can prevent separation between a lenticular screen and a Fresnel screen even in an environment with high humidity.

[0009]

A rear projection type projector according to the present invention has a screen in which first and second screen members are overlapped, and image light from the projector body is provided on the back side of the screen. In a rear projection type projector adapted to project, a cabinet having an opening for accommodating the projector main body therein and having the screen attached thereto, and an exhaust attached to the cabinet for discharging air in the cabinet to the outside. The air conditioner includes a fan, and pressure reducing means for lowering the air pressure inside the cabinet than the air pressure outside the cabinet.

[0010]

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

FIG. 1 is a sectional view showing a first embodiment of a rear projection type projector according to the present invention, in which an exhaust fan is operated.

In FIG. 1, a rear projection type projector 1
Is configured such that image light from a projector body 11 composed of, for example, a liquid crystal projector is reflected by a mirror 12 and projected on the back side of the screen 10. The screen 10 is composed of first and second screen members (Fresnel screen 13 and lenticular screen 14), and the lenticular screen 14 is usually arranged on the viewer side.

The rear projection type projector 1 is a cabinet 2 in which the projector main body 11 is housed and the screen 10 is attached to an opening 28 in the front.
And an exhaust fan 15 attached to the cabinet 21 and blowing out the air in the cabinet 21 to the outside.
And

Hereinafter, the rear projection type projector 1 will be described in more detail.

The cabinet 21 is formed in a box shape, and the projector main body 11 is disposed on the upper surface of the bottom panel 22 of the cabinet 21 at a predetermined angle.

An opening 24 is provided below the back panel 23 of the cabinet 21, and an exhaust fan 15 is provided behind the opening 24. The exhaust fan 15 emits warm air in the cabinet 21 heated by the projector main body 11 to the outside and has an exhaust amount enough to lower the atmospheric pressure inside the cabinet 21. It is formed so that the atmospheric pressure decreases.

An inclined panel 26 is provided between the rear panel 23 and the upper panel 25 of the cabinet 21, and the mirror 12 is mounted on the inner surface of the inclined panel.

An opening 28 is provided above the front panel 27 of the cabinet 21, and a screen 10 composed of a Fresnel screen 13 and a lenticular screen 14 is provided behind the opening 28. Fresnel screen 13 and lenticular screen 14
Are provided in the upper and lower gaps between them.
Is inserted. The purpose of providing the rod-shaped members 31 and 32 is to provide an appropriate gap between the Fresnel screen 13 and the lenticular screen 14 to form an air flow passage.
Fresnel screen 13 and lenticular screen 1
4 is provided so as to be in close contact.

The lenticular screen 14
Is formed thinner than the Fresnel screen 13 so that the flexibility of the lenticular screen 14 is set higher than that of the Fresnel screen 13.
Thus, when the exhaust fan 15 lowers the air pressure inside the cabinet 21 to be lower than the air pressure outside the cabinet 21, the lenticular screen 14 curves toward the Fresnel screen 13 and comes into close contact with the lenticular screen 13.

The image light of the projector main body 11 is reflected by a mirror and projected on a Fresnel screen 13 and a lenticular screen 14.

According to the embodiment of the present invention, the exhaust fan 15 lowers the air pressure in the cabinet 21 and the Fresnel screen 13 and the lenticular screen 14 are bent inside the cabinet 21 so as to be in close contact with each other. Even in an environment, it is possible to prevent the Fresnel screen 13 and the lenticular screen 14 from separating from each other, thereby preventing the focus of the image light from the projector body from deteriorating, and blurring the image displayed in front of the lenticular screen. Image quality can be prevented from deteriorating.

FIG. 2 is a sectional view showing a rear projection type projector according to a second embodiment of the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.

In FIG. 2, a rear projection type projector 5
The opening 6 is formed on the front panel 67 of the cabinet 61.
8, and the cabinet 61 is located at the back of the opening 68.
An intake fan 70 for blowing outside air into the cabinet 61 is provided, and the exhaust amount of the exhaust fan 15 is set to be larger than the intake amount of the intake fan 70.

According to the embodiment of the present invention, as in the embodiment of the present invention shown in FIG. 1, the first and second screen members have an effect of closely contacting each other, and external air is supplied from the intake fan 70 to the projector. Since the air is blown into the main body 11, the cooling efficiency of the projector main body 11 can be improved.

Although the Fresnel screen 13 and the lenticular screen 14 are used as the first and second screen members in the embodiment of the invention shown in FIGS. 1 and 2, other combinations of screens may be used. Further, in the embodiment of the invention shown in FIGS. 1 and 2, the projection light of the projector main body is reflected by the mirror and is projected on the Fresnel screen 13 and the lenticular screen 14, but the projection light of the projector main body is not passed through the mirror but is transmitted through the mirror. You may comprise so that it may project on a 1st and 2nd screen member.

[0026]

As described above, according to the present invention, the first
And a rear projection type projector configured to project image light from the projector main body onto a screen having a second screen member from the rear side. In a rear projection type projector, even if the environment is high in humidity, between the first and second screen members. Can be prevented from being separated from each other, so that the focus of the image light from the projector body can be prevented from deteriorating, and the image quality of the image displayed on the screen can be prevented from deteriorating.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a rear projection type projector according to the present invention.

FIG. 2 is a sectional view showing a rear projection type projector according to a second embodiment of the invention.

FIG. 3 is an explanatory view showing warpage of a conventional Fresnel screen and lenticular screen.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rear projection projector 10 Screen 11 Projector main body 13 Fresnel screen 14 Lenticular screen 15 Exhaust fan 21 Cabinet 28 Opening

Claims (3)

[Claims] 1. A rear projection type projector having a screen configured by superimposing first and second screen members and projecting image light from a projector main body on a back side of the screen, wherein the projector A cabinet having an opening in which the main body is housed and the screen is attached; and an exhaust fan attached to the cabinet for discharging air in the cabinet to the outside, wherein the air pressure in the cabinet is adjusted outside the cabinet. A rear projection type projector comprising: a pressure lowering means for lowering the pressure to a value lower than the pressure. 2. The air pressure reducing means has an exhaust fan for discharging air in the cabinet to the outside, and an intake fan for taking in outside air in the cabinet. 2. The rear projection type projector according to claim 1, wherein the intake amount is set to be larger than an intake amount of the intake fan. 3. The rear projection type projector according to claim 1, wherein the screen has a screen member provided on the front surface side of the cabinet having a higher flexibility than a screen member on the rear side.