JP2751870B2 - Polarizing screen system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen system of a forward projection type, and more particularly to a screen system having a polarizing plate which can be used even in a bright room.

[0002]

2. Description of the Related Art Conventionally, in liquid crystal projectors and overhead projectors, in order to prevent a decrease in image contrast due to the incidence of external light on a screen,
There are a type in which a polarizing sheet is adhered to the screen surface, and a type in which a polarizing plate is disposed in front of the screen (Japanese Patent Application Laid-Open No. Sho 63).
No. 2,670,733, Japanese Utility Model Laid-Open No. 2-83524,
-265094). External light incident on the screen via the polarizing sheet or the polarizing plate is attenuated by only the polarization component in the direction of the polarization plane, while projection from the projector including only the component in the direction of the polarization plane, It will be projected on the screen without attenuation.

[0003]

However, since the projection from the projector also passes through the polarizing sheet or the polarizing plate, the spot opening from the projector projection opening due to the surface reflection is very bright.
The contrast was reduced, and it was difficult to put it to practical use after all.

Further, there is a problem that a large-sized seamless polarizing screen cannot be realized due to restrictions of a polarizing sheet, an adhesive material and the like.

Further, when a polarizing sheet is adhered to a bead screen having an effective reflection characteristic for a large screen to realize a bead polarizing screen, color unevenness or the like is generated, and it cannot be put to practical use.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a polarizing system in which a polarizing plate is arranged in front of a screen and a spot light is not reflected from a projector projection port due to surface reflection of the polarizing plate. To realize a polarizing screen system using a non-polarizing screen.

In order to achieve the above object, the present invention provides a screen, a polarizing plate provided in front of the screen and separated from the screen, an image projection device for projecting onto the screen without passing through the polarizing plate, And a shield that reduces the amount of external light that enters the screen without passing through the polarizing plate. In this case,
Place a non-polarizing screen in the corner of the room,
A large transparent polarizing plate large enough to substantially block the room is arranged a few meters ahead, the direction of the polarizing axis of the polarizing plate is set to match the direction of the polarizing axis of the liquid crystal projector, and the image of the liquid crystal projector is displayed on the polarizing plate. Projected on the screen without going through
Furthermore, the present invention can be configured by blocking the incidence of non-polarized light such as ceiling illumination with a shield such as a curtain as much as possible in the space between the screen and the polarizing plate.

The image projection device can project the image onto the screen from below the polarizing plate, or can project the image through an opening provided in the polarizing plate. Alternatively, a reflecting mirror may be provided on the polarizing plate side so that the image of the image projection device is reflected by the reflecting mirror and projected on a screen.

The image projection device can be a liquid crystal projector or an overhead projector. In particular, the image projection device can be a liquid crystal projector having a regular reflection type reflection surface in which an image light reflection layer of a screen maintains polarization.

Further, the polarizing plate can be configured to be movable with respect to the screen by a caster or the like. When not in use, the polarizing plate can be stored in close contact with the screen.
The room can be widely used.

If the surface reflection of the polarizing plate can be greatly reduced, the distortion of the reflected image of a fluorescent lamp or the like will not be noticeable.
It is also possible to make the polarizing plate into a sheet shape and make it an electric winding type.

Furthermore, the image projection device may be arranged on the screen side, and a reflecting mirror may be provided on the polarizing plate side, so that the image of the image projecting device may be reflected by the reflecting mirror and projected on the screen. The shield may be a light-blocking curtain that hangs from the ceiling of the room and blocks the space above the polarizing plate.

[0013]

With the above arrangement, the projection light of the image projection device directly enters the screen without passing through the polarizing plate, and external light such as ceiling illumination passes through the polarizing plate and is attenuated to reach the screen. The problem that the projection port is seen as a spot due to the reflection of the surface of the polarizing plate is eliminated, and the decrease in image contrast due to the incidence of external light is minimized.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic side view of a polarizing screen system according to the present invention, and FIG. 2 is a front view of the polarizing screen system of the present invention viewed from arrow II in FIG. As shown in the figure, the non-polarizing type screen 1 is disposed close to the wall surface of the room 2 and includes a transparent polarizing plate 201 having a size that divides the room approximately 1 to several meters ahead. A partition 3 is arranged. The polarizing plate 201 has a structure in which a polarizing sheet is attached to one surface of a transparent acrylic plate and a surface antireflection sheet is attached to the other surface. The polarizing plate 201 is supported by the polarizing plate partition 3,
The polarizing plate screen 3 is a leg 20 having casters 203.
2 are provided on both sides. Therefore, when the mode of use is not as shown in FIG. 3, the polarizing plate screen 3 can be accommodated by taking the screen 1 side and taking up almost no space.

The length of the legs 202 of the polarizing plate screen 3 is set so that the lower end 11 thereof is slightly higher than the heights of the table 12 and the chair 13, and the large table as shown in FIG. Even if 12 is installed indoors,
It is possible to dispose the table 12 in the lower space 15 of the polarizing plate screen 3 and to install the polarizing plate 201 at an appropriate position.

Reference numeral 4 denotes an image projection device which can directly project an image on the screen 1 below the polarizing plate screen 3 via a space (lower space 15) formed by the legs 202 of the polarizing plate screen 3. is set up. In this case, if the image can be directly projected on the screen 1, the position of the image projection device 4 may be set further 1 to 2 m ahead of the polarizing plate screen 3. When a liquid crystal projector is used as the image projection device 4, the polarization axis direction of the polarizing plate 201 is made to coincide with the polarization axis direction of the liquid crystal projector to be used. The image projection light 14 from the image projection device 4 onto the screen 1 does not pass through the polarizing plate 201 using the lower space 15 of the polarizing plate screen 3 as an optical path, and therefore does not generate surface reflected light from the polarizing plate 201. 1 is projected. 1 in the figure
Reference numeral 6 denotes a line of sight of an observer who observes an image on the screen 1 from the table 12 side, and the image reflected light from the screen 1 passes through the polarizing plate screen 3 and is visually recognized by the observer.

The light-shielding curtain 7 is hung from the ceiling above the polarizing plate screen 3 to block the space between the polarizing plate screen 3 and the ceiling surface, so that non-polarized light such as ceiling lighting fixtures 6 and the like are not transmitted to the screen 1. The incidence on the space 5 between the polarizer screens 3 is blocked as much as possible. As a result, most of the external light such as the illumination light 8 and the wall reflection light 9 is incident on the screen 1 via the polarizing plate 201. When these external lights pass through the polarizing plate 201,
Of the P-polarized wave and the S-polarized wave whose light polarization axes are orthogonal to each other,
The polarized light orthogonal to the polarizing axis of the polarizing plate is cut off, and the polarized light 10 whose amount of light is reduced by half is incident on the screen 1.

FIG. 4 is a schematic side view showing another embodiment of the present invention using a reflection system. In this embodiment, the image projection device 4 is installed below the screen 1, and a reflection mirror 301 is installed below the polarizing plate partition 3.
In this state, the image light of the image projection device 4 is reflected by the reflection mirror 30.
1 is reflected on the screen 1.

FIGS. 5 and 6 are schematic side and front views of another embodiment of the present invention using an overhead projector (OHP). In the figure, reference numeral 501 denotes an OHP having no head arm, which is used by placing it on the table 12. As shown in FIG. 6, a cut 602 is formed at the center of the lower end 11 of the polarizing plate screen 3 so as to avoid the OHP 501, so that the projection light from the OHP 501 is directly incident on the screen. By providing the cuts 602 in this manner, the lower end 11 of the polarizing plate partition 3 is kept as low as possible, and the incidence of external light on the screen 1 side is suppressed as much as possible.

FIG. 7 shows an O type having a head arm.
It is a schematic front view of other Example of this invention using HP701. In the figure, 701 is an OHP with a head arm
Then, an image is projected on the screen 1 via the reflection mirror 703 provided at the tip of the head arm 702. Therefore, an opening 704 is formed in the central portion of the polarizing plate 201 corresponding to the position of the reflection mirror 703, and the reflection mirror 70
The image light reflected by 3 is projected on the screen 1 without transmitting through the polarizing plate 201. This is provided because the OHP image light is non-polarized light, so that when transmitted through a polarizing plate, the amount of light is reduced by half.

FIGS. 8A and 8B are schematic plan views showing another form of the polarizing plate screen, wherein FIG. 8A shows a curved type and FIG. 8B shows a bent type. These are modifications of the flat polarizing plate screen 3 described above, and screens of various shapes can be used according to the arrangement of the table and the like. Relatively, the non-flat polarizing plate screen can construct a more compact polarizing screen system than the flat polarizing plate screen 3. Also in the present embodiment, the image of the image projection device 4 is directly projected on the screen 1 without passing through the polarizing plate.

[0022]

According to the present invention as described above, the following effects can be obtained. (1) The projection light of the image projection device directly enters the screen without passing through the polarizing plate, and external light such as ceiling illumination passes through the polarizing plate and is attenuated to reach the screen. In addition to eliminating the problem of spot-like appearance due to the surface reflection of the polarizing plate, a decrease in image contrast due to the incidence of external light can be minimized.

(2) Since a polarizing sheet is not adhered to a screen as in the prior art, a large-sized seamless polarizing screen can be realized.

(3) According to the present invention, even if a bead screen is used, no color shift occurs, and a screen brighter than a polarizing bead type in which a polarizing sheet is adhered can be obtained.

(4) Currently, the brightest spherical aluminum reflective screen is available, and the brightest polarizing screen system can be constructed.

(5) Just by moving and setting the polarizing plate stand with casters, it is possible to easily construct a polarizing screen system using a screen currently used for OHP or a screen conventionally used. is there.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a polarizing screen system according to the present invention.

FIG. 2 is a front view of the polarizing screen system of the present invention as viewed from arrow II in FIG.

FIG. 3 is a schematic side view of the polarizing plate screen in a housed state.

FIG. 4 is a schematic side view showing another embodiment of the present invention using a reflection method.

FIG. 5 is a schematic side view of another embodiment of the present invention using an OHP.

FIG. 6 is a schematic front view of another embodiment of the present invention using an OHP.

FIG. 7 is a schematic front view of another embodiment of the present invention using an OHP of a type having a head arm.

FIGS. 8A and 8B are schematic plan views showing another form of the polarizing plate screen, in which FIG. 8A shows a curved type and FIG. 8B shows a bent type.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Screen 2 Room 3 Polarizer screen 4 Image projection apparatus 5 Space 6 Ceiling lighting fixture 7 Curtain 8 Illumination light 9 Wall reflected light 10 Polarized light 11 Lower end 12 Table 13 Chair 14 Image projected light 15 Lower space 16 Viewing direction 201 Polarizer 202 Leg 203 Caster 301 Reflecting mirror 302 Image projection light 501 OHP 601 Projection opening 602 Cut 701 OHP 702 Head arm 703 Reflecting mirror 704 Opening 801 Curved polarizing plate screen 802 Bending polarizing screen screen

Claims (5)

(57) [Claims] 1. A screen, a polarizing plate provided in front of the screen and separated from the screen, an image projection device for projecting onto the screen without passing through the polarizing plate, and the image projecting device without passing through the polarizing plate. A shielding member for reducing the amount of external light incident on the screen, wherein the image projection device is a liquid crystal projector,
Specular reflection type where the image light reflection layer of the screen keeps polarized light
A polarizing screen system, characterized by having a reflective surface . 2. The polarizing screen system according to claim 1, wherein the image projecting device projects the image on the screen from below the polarizing plate. 3. The polarizing screen system according to claim 1, wherein the image projection device projects the light onto the screen from an opening provided in the polarizing plate. 4. The apparatus according to claim 1, wherein the image projection device is provided before the polarizing plate.
It is arranged on the screen side and
Provide a reflecting mirror on the polarizing plate side from the position, The image of this image projecting device is reflected by the reflecting mirror and
2. The polarization switch according to claim 1, wherein the light is projected on a screen.
Clean system. 5. The polarizing screen system according to claim 1, wherein the polarizing plate is a polarizing screen system.
The room that uses the system
Tables and chairs used in the room at the lower end
Have a space high enough to accommodate such equipment, and
Claims: A leg having a caster capable of moving a light plate.
The polarizing screen system according to 1, 2, 3, or 4.