JPH04116840U - lenticular lens sheet - Google Patents

Abstract

(57) [Summary] [Purpose] The present invention provides a lenticular lens sheet that does not cause uneven brightness or screen stains. [Structure] A layer containing substantially no light diffusing agent is formed on the entrance surface of a lenticular lens sheet in which a light diffusing agent is mixed into the base.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is suitable for lenticular lens sheets used in rear projection screens. related.

0002

[Conventional technology]

Traditionally, the front screen of a rear projection television is It has a parallel convex lens to widen the field of view, and a light amplifying lens to widen the vertical viewing angle. Combining a lenticular lens sheet mixed with scattered materials and a Fresnel lens I am using it.

0003 For lenticular lens sheets, transparent plastics such as methacrylic resin are used. As shown in Figure 2, the light diffusing agent mixed into the base of the glass is partially exposed to the lens surface on the incident side. It becomes a prominent state.

0004 The lenticular lens sheet and Fresnel lens that make up the screen are in close contact. Although it is fixed, the protrusion and Fresnel lens may rub against each other during transportation, etc. This results in uneven brightness in that area. In addition, the lens caused by the above protrusion Due to the zoom effect, fine unevenness in brightness occurs, making the entire screen look dirty. .

[0005]

[Problem that the idea aims to solve]

The present invention is a lens screen that eliminates the uneven brightness and screen stains that occur as described above. The purpose is to provide a regular lens sheet.

[0006]

[Means to solve the problem]

The above purpose is to provide a lenticular lens sheet of the present invention, that is, a light source in the base 1. In the lenticular lens sheet mixed with the diffusing agent 2, on the light incident surface 3 , by forming a layer 4 in which substantially no light diffusing agent is mixed; Generally, the thickness of the layer 4 in which the light diffusing agent is not mixed is 1/2 or more of the average particle size of the light diffusing agent 2. This is achieved by

[0007]

[Effect]

The above-mentioned problems are caused by the light diffusing agent 2 mixed into the base 1 forming a lenticular lens system. This is due to the fact that the light protrudes from the lens surface 3 on the incident side of the light beam. Its harmful effects In order to eliminate the A layer 4 (hereinafter simply abbreviated as layer 4) that does not exist is formed. Layer 4 is identical to substrate 1 It may be a resin or something else, but a transparent resin is preferable.

[0008] The light incident surface of the lenticular lens is lens surface 3 in Figures 1 and 2. , may be flat. A lenticular lens is used to form the layer 4 on the lens surface 3. Form the sheet and layer 4 separately and laminate them, or coextrude base resin 1 and layer 4. , to form a layer 4 on the entrance side lens surface 3 by pressing between a pair of rolls (Fig. 1) . In this case, it is desirable that the thickness of the layer 4 is 1/2 or more of the average particle size of the light diffusing agent 2. Yes. Note that the layer 4 may be a single layer or may have two or more layers.

[0009]

【Example】

The present invention will be explained in more detail with reference to Examples below. Example 1 100 parts by weight of polymethyl methacrylate resin with a refractive index of 1.49 and a particle size of 5 to 4 A mixture of 4 parts by weight of glass beads 2 of 0 μm (center particle size 20 μm) and polymer Chill methacrylate resin alone is coextruded and pressed between a pair of rolls to form an incident lens. A wrench with a 150 μm transparent resin layer 4 on the lens surface and a distance between lenses of 1000 μm. A cular lens sheet (Figure 1) was obtained. The incidence of this lenticular lens sheet Lens surface 4' has no protruding glass beads and can be combined with a normal Fresnel lens. When visually evaluated on a white screen, there were very few stain-like defects. or , combining a regular Fresnel lens sheet and a lenticular lens sheet, They rubbed against each other, but no scratches occurred. Comparative example Add 100 parts by weight of polymethyl methacrylate resin 1 with a refractive index of 1.49 to a particle size of 5 to 100 parts by weight. 3.8 parts by weight of glass beads 2 of 40 μm (center particle size 20 μm) were mixed. , pressed between the same pair of rolls as in Example 1, and a wrench with a distance between lenses of 1000 μm. A cular lens sheet (Figure 2) was obtained. The incidence of this lenticular lens sheet The lens surface has protruding glass beads, and can be combined with a regular Fresnel lens sheet. At the same time, when a visual evaluation was performed on a white screen, stain-like defects were observed. Also, normal When combined with a Fresnel lens sheet and rubbed against each other, scratches may occur. It was done.

0010

[Effect of the idea]

The lenticular lens sheet of this invention eliminates uneven screen brightness and images. No surface stains occur.

[Brief explanation of drawings]

FIG. 1 is an enlarged partial cross-sectional view of a lenticular lens sheet of the present invention.

FIG. 2 is an enlarged partial cross-sectional view of a conventional lenticular lens sheet.

[Explanation of symbols]

1 Lenticular lens sheet base 2 Light diffusing agent 3 Entrance side lens surface 4 Layer that does not substantially contain light diffusing agent

Claims (3)

[Scope of utility model registration request] 1. A lenticular lens sheet having a base material mixed with a light diffusing agent, wherein a layer substantially free of the light diffusing agent is formed on a light incident surface. 2. The lenticular lens sheet according to claim 1, wherein the thickness of the layer substantially free of the light diffusing agent is 1/2 or more of the average particle size of the light diffusing agent. 3. The lenticular lens sheet according to claim 1, wherein the light incident surface is a lens surface.