JPH09106008A - Projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an impressive screen image which appeals much with the same contrast as that of a cimena even if it is light in a room by providing a polarizing filter having a substantially orthogonal plane of polarization between a screen surface and an illuminating light source in the room. SOLUTION: A projector 1 is a front projection type. Light 2 which is not polarized is applied to a polarizing filter 3 having a vertical plane of polarization, and only the light having a vertical plane of polarization passes through the polarizing filter 3 to be linearly polarized. The linearly polarized light 4 is applied to a front screen 6 where a polarizing filter 5 having a vertical plane of polarization is disposed. A screen image of the front screen 6 is passed through the polarizing filter 5 provided on the front and recognized by an appreciator 7. For the action of external light, a window 8 is provided with a polarizing filter 5 disposed on the screen and a polarizing filter 9 having an orthogonal plane of polarization. Light from the outside of the window is passed through the polarizing filter 9 to be linearly polarized. The linear polarized light 10 is polarized light having a horizontal plane of polarization, so that it can not pass through the polarizing filter 5.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a film projector,
Regarding a projection apparatus having a projector such as a CRT type projector or a liquid crystal projector, projection light emitted from the projector is reflected or passed by a screen, but external light (illumination light in a room or light from a window) is not reflected by the screen. Regarding configuration.

[0002]

2. Description of the Related Art In a projection apparatus including a screen and a projector (a projector using a film, a CRT projector, a liquid crystal projector, etc.), external light (illumination, light from a window) affects the image on the screen. The room is darkened so that it is not given. The cinema is a typical example.

Further, as a technique of using a polarizing filter, Japanese Patent Laid-Open No. 62-266980 discloses a polarizing filter having a polarizing filter 3 in front of a projector 1 as shown in FIG. 5 is provided. In this system, the projection light 2 from the projector is linearly polarized by the polarization filter 3 and becomes the polarization 4, and this polarization passes through the polarization filter 5 having the same plane of polarization, so that the
It is reflected at nearly 0%. Room lighting 11 is 17, 17.
As indicated by reference numeral 8, the light from the window is attenuated by the polarizing screen 5 provided on the front screen 6 and reflected as indicated by reference numerals 15 and 16.

As a result, the viewer 7 can see a relatively clear image without being significantly affected by outside light.

[0005]

However, in Japanese Unexamined Patent Publication No. 62-266980, the reflection amount of external light on the screen is reduced but still exists. Compared to the movie theater method where the room is darkened, the image becomes more hazy (black floating phenomenon) and the contrast is poor. This projection apparatus is required to increase the power of images and appeal with a contrast comparable to that of a movie theater system even in a bright room.

[0006]

In order to solve this problem, the present invention relates to a projection apparatus in the case of a liquid crystal projector that projects polarized light as a projector and in the case of a projector that projects natural light (film projector, CRT type projector). Regarding a projector of the polarized projection type, a polarizing filter having a polarization plane in the same direction as the polarized light of the projector is provided on the front surface (viewer side) of the opposite screen, and in the case of the projector of the natural light projection type, the front surface of the projector. A polarizing filter is provided on the front side (viewer side) of the opposite screen, and a polarizing filter having a polarizing plane in the same direction as the polarizing filter is provided on the opposite side of the screen. Have a polarizing filter with either the illumination light source or the window, or Is that is configured in such a way as to in a square both.

When the vibration direction of light, that is, the direction of the electric field (or magnetic field) of light is limited to the plane including the traveling direction of light, the light wave is called linearly polarized light. Moreover, this plane is called a polarization plane. Light emitted from projectors other than liquid crystal projectors is natural light that is not biased,
Linearly polarized light passes through the polarizing filter. As an example of the polarizing filter, a thin film made of plastic is made to adsorb iodine and arranged in a fixed direction, and only unpolarized natural light (polarized light) oscillating in this fixed direction can pass through. Next, if a polarizing filter having polarization planes substantially orthogonal to each other is arranged at the destination of the transmitted light, this light cannot pass through.

As a result, the light emitted from the projector is projected on the screen opposite to it, and when the screen is a reflection type, the projection light is reflected by the screen, and when the screen is a transmission type, the projection light is reflected on the screen. To Penetrate. The viewer sees the reflected or transmitted light on this screen. On the other hand, on the screen surface, outside light such as room illumination light or window light enters. Since this external light is polarized light having a polarization plane substantially orthogonal to the polarization filter provided on the screen surface, it is not reflected by the screen at almost 100%. In other words, the room is bright, but there is no blackening phenomenon of the image (the image becomes whitish as if it was hazy and the contrast is poor),
Even if the room is bright, it is possible to increase the appealing power and the image with a contrast similar to that of a movie theater method. Therefore, it is possible to see a video with good contrast while taking notes, and the application value is high.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the invention described in claim 1 of the present invention, a polarization filter having the same polarization plane as the polarized light is provided on the screen surface onto which the polarized light is projected, and further, any one of a room illumination light source and a window. A projection device, characterized in that either or both of them are provided with a polarization filter having a polarization plane substantially orthogonal to the above-mentioned polarized light, and the light emitted from the projector is projected on a screen opposite to the screen and reflected by a screen. In the case of the formula, the projected light is reflected by the screen, and in the case of the transmissive type, the projected light is transmitted through the screen. The viewer sees the reflected or transmitted light on this screen. On the other hand, on the screen surface, outside light such as room illumination light or window light enters. Since this external light is polarized light having a polarization plane substantially orthogonal to the polarization filter provided on the screen surface, it has a function of not being reflected by a screen at almost 100%.

The invention according to claim 2 of the present invention is characterized in that the projection device according to claim 1 is any one of a film projector, a CRT type projector, and a liquid crystal projector. External light such as illumination light and light from a window has a function of not being reflected by a screen in almost 100%.

An embodiment of the projection apparatus of the present invention will be described below with reference to FIGS. 1 and 2. 1 and 2, parts corresponding to those in FIG. 3 of the conventional example are denoted by the same reference numerals, and detailed description thereof will be omitted.

(First Embodiment) FIG. 1 is a block diagram for explaining the concept of a projection apparatus according to an embodiment of the present invention. The configuration of FIG. 1 includes a projector 1, a polarizing filter 3 that polarizes light 2 emitted from the projector, a front screen 6, a polarizing screen 5 provided in front of the front screen, a front surface of a window, a polarizing screen 9 provided inside a room, and illumination. It consists of a polarizing screen 12 provided in front of the light source.

In FIG. 1, when the projector 1 is on the viewer side, a so-called front projection type is shown in which unpolarized light 2 is applied to a polarizing filter 3 having a vertical polarization plane and has a vertical polarization plane. Light only this filter 3
The linearly polarized light 4 that has passed through is incident on a front screen 6 provided with a polarizing filter 5 having a vertical polarization plane.

Light emitted from the projector 1 shown in FIG. 1 forms an image on the front screen 6. This image passes through the polarizing filter 5 provided on the front surface of the front screen 6 and is recognized by the viewer 7. Next, the effect of external light will be described. The window 8 is provided with a polarization filter 9 (in this case, a horizontal polarization filter) whose polarization plane is orthogonal to that of the polarization filter provided on the screen. Light from outside the window passes through the polarization filter 9 and is linearly polarized. Since the linearly polarized light 10 is polarized light having a horizontal polarization plane, it cannot pass through the polarization filter 5 having a vertical polarization plane, so that it is not reflected by the front screen 6 and is not recognized by the viewer 7.

Further, the indoor illumination light source 11 is provided with a polarization filter 12 (horizontal polarization filter in this case) whose polarization plane is orthogonal to that of the polarization filter provided on the screen. The light from the indoor illumination light source 11 passes through the polarization filter 12 and is linearly polarized. Since the linearly polarized light 13 is polarized light having a horizontal polarization plane, it cannot pass through the polarization filter 5 having a vertical polarization plane.
The reflection is not generated and the viewer 7 does not recognize it.

(Second Embodiment) FIG. 2 is a block diagram for explaining the concept of a projection device according to another embodiment of the present invention.
The configuration of FIG. 2 includes a projector 1, a polarizing filter 3 that polarizes light emitted from the projector, and a rear screen 1.
4, a polarization screen 5 provided in front of the rear screen, a front surface of the window, a polarization screen 9 provided inside the room, and a polarization screen 12 provided in front of the illumination light source.

FIG. 2 shows a so-called rear projection type in which the projector 1 is on the opposite side of the screen from the viewer, and the unpolarized light 2 is applied to the polarizing filter 3 having a vertical polarization plane, Only light having a vertical polarization plane passes through this filter 3 and is linearly polarized. The linearly polarized light 4 is applied to a rear screen 14 provided with a polarization filter 5 having a vertical polarization plane.

Light emitted from the projector shown in FIG. 2 forms an image on the rear screen 14. This image passes through the polarizing filter 5 provided on the front surface of the rear screen 14 and is recognized by the viewer 7. Next, the influence of external light will be described. The window 8 is provided with a polarization filter 9 (in this case, a horizontal polarization filter) whose polarization plane is orthogonal to that of the polarization filter provided on the screen. Light from outside the window passes through the polarization filter 9 and is linearly polarized. Linearly polarized light 10
Is a polarized light having a horizontal plane of polarization and cannot pass through the polarizing filter 5 having a vertical plane of polarization, so that it does not affect the image formed on the rear screen 13.

Further, the indoor illumination light source 11 is provided with a polarization filter 12 (horizontal polarization filter in this case) whose polarization plane is orthogonal to that of the polarization filter provided on the screen. The light from the indoor illumination light source 11 passes through the polarization filter 11 and is linearly polarized. Since the linearly polarized light 13 has a horizontal polarization plane and cannot pass through the polarization filter 5 having a vertical polarization plane, it does not affect the image formed on the rear screen 14.

The projectors shown in FIGS. 1 and 2 are projectors (film projectors, CRTs) that project natural light.
Type projector), the liquid crystal projector can be implemented in the same manner. However, since the light emitted from the liquid crystal projector is already polarized, the polarization filter 3 is removed.

[0021]

As described above, according to the projection apparatus of the present invention, the light emitted from the projector is projected on the screen oppositely arranged, and in the case of the front type, the projected light is reflected by the screen and is of the rear type. In the case the projected light passes through the screen,
Outside light (room lighting or windows) is not reflected by the screen. As a result, the room is bright, but there is no blackening phenomenon of the image (the image becomes whitish as if it was hazy and the contrast is poor), and even if the room is bright, it is appealing with a contrast similar to that of a movie theater system. Increased power is possible. Therefore, it is possible to view an image with good contrast while taking notes.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a concept of a projection device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating the concept of a projection device according to another embodiment of the present invention.

FIG. 3 is a configuration diagram illustrating a concept of a projection device in a conventional example.

[Explanation of symbols]

 1 Projector 4 Polarization 3, 5, 9, 12 Polarization filter 6 Front screen 8 Window 11 Light source 14 Rear screen

Claims (2)

[Claims] 1. A polarization filter having the same polarization plane as the polarized light is provided on a screen surface onto which polarized light is projected, and further, either or both of a room illumination light source and a window have a polarization plane substantially orthogonal to the polarized light. A projection device having a polarizing filter having the same. 2. The projection device is a film projector, a CRT
The projection device according to claim 1, wherein the projection device is a projector or a liquid crystal projector.