JPH08227003A - Rear projection type multi-screen - Google Patents

Abstract

(57) [Abstract] [Purpose] An excellent rear projection type multi-screen that can obtain an excellent image with uniform brightness over the entire screen without the unpleasantness of the image due to grid-shaped frames, joints, or solvent inflow. Provide a screen. [Structure] At least one linear Fresnel lens sheet has two Fresnel lens sheets 2 and 3 each having a plurality of Fresnel centers 5 combined so that both Fresnel lens rows 4 are orthogonal to each other and arranged on the light source side. Rear projection type multi-screen in which the lenticular lens sheet 1 is arranged on the.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen used in a rear projection type multi-screen device composed of a plurality of projector units, and more specifically, it is difficult to see an image due to joints or joints between the projector units. The present invention relates to a rear projection type multi-screen in which the entire screen has uniform brightness.

[0002]

2. Description of the Related Art In recent years, a large multi-screen device constructed by arranging a plurality of projector units of about 40 to 70 inches is capable of displaying different images on a plurality of screens or combining a plurality of screens into one. It has been attracting attention as a large-scale image system because various image patterns such as displaying images can be observed and manufacturing and transportation can be easily performed.

Conventionally, such a rear projection type multi-screen device is constructed by arranging a plurality of projector units so as to be stacked in a predetermined number in a vertical and / or horizontal direction, and a circular Fresnel for each projector unit. A screen consisting of a lens sheet and a lenticular lens sheet was arranged. As the screen, a screen which is fitted in a grid-like frame corresponding to each projector unit or which is joined by using an adhesive or a solvent has been used. For example, in a 9-sided multi-screen device in which three projector units are arranged vertically and horizontally, as shown in FIG.
A screen including a Fresnel lens sheet obtained by arranging three circular Fresnel lens sheets 7 side by side in a row and joining them and a lenticular lens sheet arranged so as to correspond to each circular Fresnel lens sheet has been used.

[0004]

However, a screen in which a circular Fresnel lens sheet and a lenticular lens sheet are combined and fitted into a lattice-shaped frame corresponding to each projector unit, and they are joined together by using an adhesive such as a silicone resin. On the screen, a grid-like frame or joints form a grid-like joint having a width of about 2 to 15 mm and in which no image is captured. In particular, when a plurality of screens are combined to display one image, the joints are conspicuous and very annoying.

Further, in the case of joining using a solvent,
Although the joints due to the joining are eliminated, as shown in FIG. 8, it is necessary to apply a solvent to the joining surface of the circular Fresnel lens sheet 7 which crosses the lens groove, and the solvent is applied along the lens groove to the circular Fresnel lens sheet 7. There is a problem that the solvent flows into the inside and the lens portion near the joint is invaded by the solvent and becomes very dirty. further,
Since the Fresnel lens has a very small pitch, it is extremely difficult to join the adjacent Fresnel lenses at the same lens tilt angle, and the lenses having different lens tilt angles are joined. For this reason, there is also a problem in that when the plurality of screens are combined to display one image, the image is observed unevenly, since the brightness is different at the junction. Therefore, an object of the present invention is to provide a rear projection type multi-screen which has a uniform brightness over the entire screen without causing an unsightly image due to a lattice-shaped frame, joints, or solvent flowing in.

[0006]

The inventors of the present invention have arrived at the present invention as a result of earnest studies on the structure of a Fresnel lens sheet in view of the above problems of the prior art. That is, the rear projection type multi-screen of the present invention comprises a Fresnel lens sheet arranged on the light source side and a lenticular lens sheet arranged on the observation side, and the Fresnel lens sheet includes two linear Fresnel lens sheets. The lens rows are combined so as to be orthogonal to each other, and at least one linear Fresnel lens sheet has a plurality of Fresnel centers.

The rear projection type multi-screen of the present invention is
As shown in FIG. 1, a Fresnel lens sheet obtained by combining two linear Fresnel lens sheets 2 and 3 so that their Fresnel lens rows intersect each other is arranged on the light source side, and the lenticular lens sheet 1 is placed on the observation side. It is configured by placing. The linear Fresnel lens sheets 2 and 3 of the present invention are made of a resin having a high light transmittance such as an acrylic resin, a polycarbonate resin, an olefin resin, a styrene resin, a vinyl chloride resin, or a mixed resin thereof. It is produced by a commonly used method such as a cast molding method, an injection molding method, a hot press molding method, an extrusion molding method, a cutting method or a method using an active energy ray-curable resin. The thickness of the linear Fresnel lens sheet is not particularly limited,
From the viewpoint of reducing multiple images due to flare light due to interface reflection, the thinner one is preferable.

As shown in FIG. 3, the linear Fresnel lens formed on the linear Fresnel lens sheet is formed by arranging a large number of linear Fresnel lens rows 4 in parallel, and is used in a rear projection type multi-screen apparatus. The Fresnel center 5 is formed according to the number of units.
The formation of the Fresnel center 5 differs depending on the configuration of the rear projection type multi-screen device, but it is necessary to form a plurality of Fresnel centers 5 on at least one linear Fresnel lens sheet. For example, in a nine-sided multi-screen device in which three projector units are arranged vertically and horizontally, three Fresnel centers 5 are formed on both linear Fresnel lens sheets 2 and 3.
Further, in a three-sided multi-screen device in which three projector units are arranged in parallel, one Fresnel center 5 is formed on one linear Fresnel lens sheet, and one Fresnel center 5 is formed on the other linear Fresnel lens sheet. To form.

In the present invention, a plurality of Fresnel centers 5
The linear Fresnel lens sheet on which the above is formed can be formed by shifting the center position of each Fresnel as shown in FIG. Generally, in a rear projection type multi-screen device, an image is made incident vertically from a corresponding projector unit onto a corresponding screen, and each image is independently formed, so that the light amount is small around each screen. The image tends to be dark and the brightness tends to be uneven over the entire screen. Further, when observing an image at a relatively short distance, the amount of light from the surrounding screen tends to be insufficient and the image tends to be difficult to see. In such a case, the unevenness of the brightness of the entire screen can be solved by arranging the Fresnel center position of the linear Fresnel lens sheet so that the image from each projector unit is refracted at a specific position. You can Incidentally, in the conventional circular Fresnel lens sheet, it was very difficult to position the Fresnel center of the Fresnel lens sheet between the upper and lower sides and the left and right at the time of cutting or joining, assembling, but the linear Fresnel lens sheet of the present invention. In the above, the desired Fresnel center position can be easily shifted by forming the Fresnel center at a preset position.

In addition, the linear Fresnel lens sheet of the present invention is formed by joining or adhering a plurality of linear Fresnel lens sheets as shown in FIG. May be In this case, joining the same direction as the Fresnel lens row direction as the joining surface can minimize the width of the joining portion,
It is preferable that the solvent or the like does not flow along the lens groove to contaminate the lens portion near the joint. When it is necessary to join the Fresnel lens in the direction orthogonal to the column direction as the joining surface, join with a solvent in a state where a sealing agent such as a silicone resin has been sealed in the vicinity of the joint in advance, and then the solvent etc. It is necessary to prevent the contamination of the lens portion near the joint portion due to the inflow into the lens groove. Also in this case, the alignment of the lenses of the linear Fresnel lens sheets to be joined can be performed more easily than when the circular Fresnel lens sheets are joined together.

Lenticular lens sheet 1 of the present invention
Is composed of a synthetic resin having a high light transmittance such as an acrylic resin, a polycarbonate resin, an olefin resin, a styrene resin, a vinyl chloride resin or a mixed resin thereof, and an extrusion molding method, a casting molding method, It is manufactured by a commonly used method such as an injection molding method, a hot press molding method, a cutting method or an active energy ray curing method. The lens shape of the lenticular lens formed on the lenticular lens sheet 1 is not particularly limited, and a generally used lenticular lens having a semicircular cross section, a semielliptical cross section, or the like can be used. Also, as the lenticular lens sheet 1,
A single-sided lenticular lens sheet with a lenticular lens formed on either the exit surface or the entrance surface,
A double-sided lenticular lens sheet having lenticular lenses formed on both the exit surface and the entrance surface can be used. Further, on the observation side surface of the lenticular lens sheet 1, a black stripe may be formed on the light opaque portion of the lenticular lens for the purpose of improving the contrast of an image.

In the present invention, the lenticular lens sheet 1 or the linear Fresnel lens sheets 2 and 3 are used for the purpose of widening the viewing angle in the vertical direction and suppressing the occurrence of the moire phenomenon and the reflection of the Fresnel lens and the lenticular lens. A small amount of the light diffusing agent may be mixed in at least one of them in the range of about 0.1 to 3% by weight. The light diffusing agent is not particularly limited, and known diffusing agents can be used, for example, silica, calcium carbonate, barium sulfate, titanium oxide, alumina, zinc oxide, inorganic fine particles such as crows, crosslinked polymers and the like. Examples include organic fine particles. Further, instead of or in combination with the light diffusing agent, a light diffusing agent layer containing the light diffusing agent may be formed, or a horizontal micro-lenticular lens surface or fine uneven surface may be formed. You may. Further, in addition to the light diffusing agent, additives such as a tinting agent, a wavelength-specific absorber, a flame retardant, a light stabilizer, and a heat deterioration preventing agent can be added as required.

The rear projection type multi-screen of the present invention is
The linear Fresnel lens sheet and the lenticular lens sheet as described above are arranged on the light source side by combining the two linear Fresnel lens sheets 2 and 3 so that the Fresnel lens rows intersect each other as shown in FIG. , The lenticular lens sheet 1 is arranged on the observation side. Two linear Fresnel lens sheets 2, 3
Are arranged in combination so that the Fresnel lens rows intersect each other, but in general, a Fresnel lens row and a vertical linear Fresnel lens sheet in which the Fresnel lens rows are parallel to the lenticular lens rows of the lenticular lens sheet 1, Is combined with a lateral linear Fresnel lens sheet orthogonal to the lenticular lens rows of the lenticular lens sheet 1 and arranged so that the Fresnel lens rows are orthogonal to each other. The arrangement of the vertical linear Fresnel lens sheet and the horizontal linear Fresnel lens sheet is not particularly limited, but the vertical linear Fresnel lens sheet is arranged on the light source side and the horizontal linear Fresnel lens is arranged on the lenticular lens sheet 1 side. Arranging the sheet is preferable from the viewpoint of suppressing the moire phenomenon due to the Fresnel lens and the lenticular lens.

Further, in the rear projection type screen of the present invention, since the inclination angle, shape, pitch, etc. of each Fresnel lens of the two linear Fresnel lens sheets can be independently set, the horizontal and vertical directions can be set. It is possible to give anisotropy to the focal length in the direction, and various optical designs can be easily performed. For example, as to the phenomenon such as hot band and see-through which occurs when the projection distance of the light source is shortened, as shown in FIG. 5, only the vertical linear Fresnel lens sheet is used without changing the vertical focal length. By making the inclination angle of the Fresnel lens gentle, the total reflection at the peripheral portion can be prevented without making phenomena such as hot band and see-through remarkable.
Also, not only when the projection distance of the light source is short, but when a phenomenon such as a hot band or see-through is remarkable, the tilt angle of the Fresnel lens of the lateral linear Fresnel lens sheet is adjusted to adjust the focal length only in the vertical direction. By shortening, it is possible to reduce phenomena such as hot bands and see-through without impairing the image characteristics in the horizontal direction.

[0015]

EXAMPLES The present invention will be specifically described below with reference to examples. Example 1 A linear Fresnel lens having three Fresnel centers with a focal length of 1000 mm and a pitch of 0.5 mm was formed 3.
Two 048 mm × 2286 mm polycarbonate resin linear Fresnel lens sheets were prepared. On the other hand, a lenticular lens with a pitch of 0.7 mm was formed 304
A double-sided lenticular lens sheet made of 8 mm × 2286 mm polycarbonate resin was prepared.

The two linear Fresnel lens sheets and the lenticular lens sheet thus obtained are arranged in this order from the light source side to the vertical linear Fresnel lens sheet, the horizontal linear Fresnel lens sheet, and the lenticular lens sheet, and rear projection is performed. A type multi-screen was created.
This rear projection type multi-screen was installed in a nine-sided multi-projector in which three 50-inch projector units were arranged vertically and horizontally, and a 150-inch rear-projection type multi-screen device was assembled.

When an image is projected using this rear projection type multi-screen device, whether a different image is projected on each surface or a combined single image is projected,
There was no uncomfortable feeling due to the joint part of the screen, and an image with excellent brightness was obtained over the entire screen.

Example 2 One 1016 mm × 2286 mm acrylic resin linear Fresnel lens sheet having a focal length of 1000 mm and a pitch of 0.3 mm and a linear Fresnel lens having a Fresnel center 5 in the center, and a focal length of 1000 mm and a pitch of 0. Forming a linear Fresnel lens with a Fresnel center 5 of 70 mm offset by 0.3 mm, 1016 mm x 2286
Two mm linear acrylic Fresnel lens sheets were prepared. The three linear Fresnel lens sheets obtained were joined by solvent bonding as shown in FIG.
A vertical linear Fresnel lens sheet of 3048 mm × 2286 mm was prepared.

Similarly, one sheet of 762 mm × 3048 mm acrylic resin linear Fresnel lens on which a linear Fresnel lens having a Fresnel center 5 at the center is formed with a focal length of 700 mm and a pitch of 0.3 mm, and a focal length of 700 mm and a pitch. 0.3 mm, Fresnel center 5
A linear Fresnel lens with a deviation of 50 mm was formed 76
Two 2 mm × 3048 mm acrylic resin linear Fresnel lens sheets were prepared. The three obtained linear Fresnel lens sheets were joined by solvent adhesion, and 304
An 8 mm × 2286 mm lateral linear Fresnel lens sheet was prepared. On the other hand, three double-sided lenticular lens sheets of 1016 mm × 2286 mm made of a polycarbonate resin on which lenticular lenses having a pitch of 0.42 mm were formed were prepared. 3048 m of the obtained three double-sided lenticular lens sheets are joined by solvent adhesion.
A double-sided lenticular lens sheet of m × 2286 mm was prepared.

The two linear Fresnel lens sheets and the lenticular lens sheet thus obtained are arranged in this order from the light source side to the vertical linear Fresnel lens sheet, the horizontal linear Fresnel lens sheet, and the lenticular lens sheet. As shown in FIG. 7, a rear projection type multi-screen in which the Fresnel center 5 was eccentric was prepared. This rear projection type multi-screen was installed in a nine-sided multi-projector in which three 50-inch projector units were arranged vertically and horizontally, and a 150-inch rear-projection type multi-screen device was assembled. When an image is projected using this rear projection type multi-screen device, no matter whether the different images are projected on each surface or the combined single image is projected, there is no uncomfortable feeling due to the joint part of the screen, The whole image was uniform and very bright, and an excellent image without a hot band phenomenon was obtained.

Comparative Example 1 Using a methacrylic resin plate, a circular Fresnel lens having a pitch of 0.5 mm was formed on one surface of the methacrylic resin plate by a hot press method to prepare 9 Fresnel lens sheets of 1016 mm × 762 mm. The resulting 9 Fresnel lens sheets were joined by solvent adhesion, and 3048 m
A Fresnel lens sheet of m × 2286 mm was prepared.
In the obtained Fresnel lens sheet, contamination due to the inflow of the solvent was observed in the vicinity of the joint, and the Fresnel lens inclination angle was also displaced at the joint. On the other hand, pitch 0.7
3048mm × with a mm lenticular lens formed
A 2286 mm double-sided lenticular lens sheet made of polycarbonate resin was prepared.

The Fresnel lens sheet and the lenticular lens sheet thus obtained, the Fresnel lens sheet on the light source side, and the lenticular lens sheet on the observation side were arranged to form a rear projection type multi-screen. This rear projection type multi-screen was installed in a nine-sided multi-projector in which three 50-inch projector units were arranged vertically and horizontally, and a 150-inch rear-projection type multi-screen device was assembled. When an image is projected using this rear projection type multi-screen device, whether a different image is projected on each surface or a combined single image is projected, the stains on the joint portion of the screen are conspicuous due to the solvent. The brightness was different at the junction and the screen was uneven.

[0023]

In the rear projection type multi-screen of the present invention, two linear Fresnel lens sheets are used in combination so that both Fresnel lens rows are orthogonal to each other. It is possible to obtain an excellent image having uniform brightness over the entire screen without causing the image to be unsightly due to the flow of light, and to enable various optical designs.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of a configuration of a rear projection type multi-screen of the present invention.

FIG. 2 is a sectional view showing an outline of a linear Fresnel lens sheet of the present invention.

FIG. 3 is a sectional view showing an outline of a decentered linear Fresnel lens sheet of the present invention.

FIG. 4 is a sectional view showing an outline of a cemented linear Fresnel lens sheet of the present invention.

FIG. 5 is a schematic diagram showing optical characteristics of a rear projection type multi-screen of the present invention.

FIG. 6 is a cross-sectional view schematically showing a linear Fresnel lens sheet according to an embodiment of the present invention.

FIG. 7 is a schematic view showing an embodiment of a rear projection type multi-screen of the present invention.

FIG. 8 is a schematic view showing a Fresnel lens sheet of a conventional rear projection type multi-screen.

[Explanation of symbols]

 1 Lenticular lens sheet 2 Horizontal linear Fresnel lens sheet 3 Vertical linear Fresnel lens sheet 4 Fresnel lens row 5 Fresnel center 6 Splice 7 Circular Fresnel lens

Claims (2)

[Claims] 1. A Fresnel lens sheet arranged on the light source side and a lenticular lens sheet arranged on the observation side, wherein the Fresnel lens sheet comprises two linear Fresnel lens sheets such that both Fresnel lens rows intersect each other. A rear projection type multi-screen, characterized in that at least one linear Fresnel lens sheet has a plurality of Fresnel centers in combination. 2. The rear projection type multi-screen according to claim 1, wherein the Fresnel center of at least one of the linear Fresnel lens sheets is decentered.