JPS59228235A - Transmission type screen - Google Patents

Abstract

PURPOSE:To obtain a transmission type screen with good color balance by combining sheets which have mutually parallel lenticular lenses on top and reverse surfaces so that the lenses cross each other at right angles, and providing a light shield layer to the nonconvergence part of a projection surface. CONSTITUTION:The two lens sheets 3 and 6 which have the mutually parallel lenticular lenses 1 and 2, and 4 and 5 on the top and reverse surfaces at 0.5-5mm. pitch (p) are combined so that the lenticular lenses of the sheets 3 and 6 cross each other at right angles, and light shield layers 7 are provided to the projection parts of nonconvergence parts of the lenticular lens 4 on the surface of the sheet 6 at the side of the lenticular lens 4, so that light beams 8-10 incident to the same position in different directions are refracted and projected as nearly parallel light beams 8'-10'. Consequently, moire due to the use of a circular lens is eliminated and a large-sized transmission type screen is manufactured easily.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a transmission screen suitable for projecting an image using a projection device such as a television and observing it from the side opposite to the projection direction.

(Prior art) As a transmission screen, a circular Fresnel lens sheet is arranged on the incident side of the projection light, a lenticular lens sheet is arranged on the exit side, and a non-light condensing part of the non-lens surface of the lenticular lens sheet is arranged. It is already known that a light shielding layer is provided. In this conventional transmission screen, first, the incident light is focused in the observation direction using a circular Fresnel lens, and then the incident light is refracted using a lenticular lens. A light shielding layer is provided on the non-lens surface of the lenticular lens sheet in order to expand the observable range and block unnecessary light and reflection of external light from the viewing side.

However, it is difficult to obtain large-sized circular Fresnel lens sheets for use in the above-mentioned conventional transmission type screens. Circular Fresnel lenses are made up of many concentric grooves, so when making large-scale copies of circular Fresnel lenses, a large metal plate must be rotated while cutting, and this type of cutting process is possible. The cutting machine itself must be specially manufactured.

(Objects of the Invention) Therefore, one object of the present invention is to provide a transmission screen that does not have the manufacturing difficulties of the above-mentioned prior art and has performance comparable to that of the prior art.

(Structure) The transmission screen of the present invention is made by combining two lens sheets, each of which has lenticular lens shapes in parallel directions on its front and back surfaces, so that each lenticular lens is orthogonal to each other. It is characterized in that a light shielding layer is provided on the non-light condensing portion of the exit surface of the side lens sheet.

The transmission screen of the present invention will be described below with reference to the drawings. As shown in FIG. A lens sheet 6 provided with lenticular lenses 4 and 5 is combined with the lenticular lenses of each lens sheet being perpendicular to each other. , a light shielding layer 7 is provided on the convex portion of the non-concentrating portion of the lenticular lens 4.

In the above, it is preferable that the thickness t of each lens sheet and the focal length of the front and back lenses be equal to each other. If this is done, as shown in FIG. and 10 are refracted and emitted as parallel lights 8/, 8', and 10', so color unevenness is eliminated even when different colored lights are incident from different positions as in a color television. Since the emitted light becomes parallel light in this way, a circular Fresnel lens, which is essential in conventional transmission screens, is completely unnecessary.

Also, the pitch p of the lenses of each lens sheet is usually 0.5~
It may be about 5x.

The transmission screen of the present invention basically has the above configuration, but the following modifications may be made.

Modification 1 If a light shielding layer 11 is also provided on the exit side of the lens sheet disposed on the light source side as shown in FIG. 3, the contrast of the image can be further improved.

Modification 2 Glare can be prevented by adding a small amount of light diffusing agent to each lens sheet or by matting the surface of the lens sheet.

Modification 3 The light shielding layer is provided at a location other than the area where the incident light is focused by the lens on the opposite side, so for example, it is placed around the boundary line of each lens. (b) Since the emitted light may be blocked, it is recommended to appropriately shift the position of the light shielding layer so that the emitted light efficiently reaches the observation position.

In addition, as shown in FIGS. 1 and 3, the light-shielding layer is provided on the convex portion by manufacturing a sheet having the convex portion and the lens portion in advance, and then applying roll coating, printing, transfer, etc. This makes it suitable for applying light-shielding compositions. However, the light-shielding layer may be formed without particularly providing a convex portion in advance, or the position where the light-shielding layer is provided may be made flat or concave in advance.

(Effects) According to the present invention, a large transmission screen can be easily obtained by using two lenticular lens sheets, and a transmission screen with good color balance can be obtained without using a circular Fresnel lens. A mold screen is obtained.

There is also the advantage that moiré, which is caused by using a circular Fresnel lens, does not occur.

[Brief explanation of drawings]

1 and 3 are perspective views showing embodiments of the present invention, and FIG. 2 is an explanatory view for explaining the function of the lens sheet. 1.2, 4.5 ・・・・・・・・・Lenticular lens 3.6 ・・・・・・・・・・・・ River lens sheet 7.11 ・・・・・・・・・・・・・・・・Light shielding layer 8.9, 10・・・・・・・・・・Photograph 1 Figure 6 Figure 2 - $8t! 1

Claims (1)

[Scope of Claims] (11) Two lens sheets each having a lenticular lens shape provided in parallel directions on the front and back surfaces are combined so that each lenticular lens is orthogonal to each other, and a lens on the output side is assembled. A transmissive screen that has a light shielding layer on the non-light condensing part of the sheet's exit surface.