JPS5988723A - Lenticular screen - Google Patents

Abstract

PURPOSE:To obtain a screen having a sufficient thickness without changing the angle of diffusion of light by providing a two-layered structure to a screen and by using an optical material with a lower refractive index as the material of one of the layers having the surface of a lenticular lens and an optical material with a higher refractive index as the material of the substrate layer at the rear side. CONSTITUTION:A substrate 4 made of a material having a higher refractive index than the material of a lenticular lens 2B is laminated on the rear side of the lens 2B, and black stripes 3 are formed on the substrate 4 to obtain a lenticular screen 1B. When the light enters the substrate 4 through the lens 2B, it is refracted and passes through the screen 1B as shown by the arrows. Accordingly, the thickness Tb of the screen 1B is increased without changing the angle of diffusion of light.

Description

[Detailed description of the invention] Concerning improvements to the cular screen.

For example, the transmissive screen of a PROJE TV is often a screen that uses a lenticular lens and has a so-called black stripe, a strip that absorbs external light, on the back side of the screen that does not transmit image light.

Transparent synthetic resins, particularly polymethyl methacrylate-1 and polystyrene, are preferably used as materials for this type of screen, taking advantage of their ease of molding and light weight.

In order to improve the quality of the image seen through the screen, it is preferable to use a lenticular lens with a fine lens pitch, that is, a lenticular lens in which lenses with a small radius of curvature are closely arranged. On the other hand, in the black stripe type 0 screen, due to its structure, if the lens pitch is made smaller, the plate thickness must be made thinner.
This not only makes molding difficult, but also reduces the strength of the screen.

The first objective of the present invention is to solve these problems and provide a lenticular screen with sufficient thickness at a low cost without changing the diffusion angle of light passing through the screen. A certain 3° lenticular screen of the present invention has at least 2 screens in a lenticular screen with 0 black strife and 0 tiff.
It is characterized by the use of an optical material with a low refractive index for the layer on the surface of the lenticular lens, and an optical material with a high refractive index for the base layer on the back surface.

This will be explained below with reference to the drawings. As shown in Fig. 1, the conventional blackstrive type lenticular screen IA has a lenticular lens 2A molded in one piece from a transparent synthetic resin material, and a blackstripe 03
Since the light beam in the direction of the arrow (/(passes between the black stripes with an appropriate diffusion angle), the thickness is determined by the lens pitch and the monthly refractive index. , Ta is the limit.

According to the present invention, as shown in FIG. 2, a lenticular screen], B C, a profit 4 made of 4'A$'l having a higher refractive index is laminated on the back surface of the lenticular lens 2B, On top of that is Plax Strife 03. 901 When the light enters the base material 4 from the lenticular lens 2B, it is refracted and transmitted through the screen along the path indicated by the arrow.

Therefore, even though the diffusion angle is the same, the screen thickness is TI)
``It can be increased by t.

This principle can be easily understood by referring to FIG.

In Figure 3, among the parallel lights incident perpendicularly on the lenticular lens, the one at the arrow position travels at an angle of θl, and if the screen is made of a single material with a refractive index of 111, it will be transmitted through the lenticular lens. There is a relationship between nl5inθI=sinθ3 between the diffusion angle θ and θl. If there is a base material with a refractive index n2 (n2>nl), the slope θ2 at the time of profiteering is n1
sinθ+ = r+2 S I11θ2, and the slope θ4 when exiting from the base material is n2sin θ2 = s
Since in θi, sin θ4−=sin θ3.

The lumber 1 of the lenticular screen of the present invention is suitably a transparent thermoplastic resin, and various materials can be used, but the typical material is the one shown below, with a refractive index as shown below. All you have to do is consider the value, select and combine them.

Cellulose acetate butyrate 1- 1.47
Small polyethylene terephthalate 1.65
Matters related to the design of the dog screen, especially the thickness of the lenticular lens layer and the thickness of the base material, should be adjusted according to the above-mentioned values so that the desired diffusion angle can be changed depending on the lens pitch, the refractive index of the lens material used, and their combination. J: Yes, if you decide based on the relationship.

A specific example is as follows.

(Conventional product) Only lenticular lens layer...I) MMA
Thickness l 890 t* (Product of the present invention) Lenticure "S/F?"
・・・・・・PMMA thickness 20μ Base material layer・・・・・・・・・PS thickness 2010
μ Thickness: 2030 μ The two-layer laminate may be laminated by heat fusion, or an appropriate adhesive may be used. Techniques for providing black stripes are known.

The screen of the present invention, as in the above example, can be increased in thickness by 7.4% compared to the conventional screen. As a result, the screen can have sufficient strength; the optical performance is virtually unaffected by the two-layer construction.
In the example of Juyaku, the combination is thin PMMA and thick I)S, and since the inexpensive PS is the main material, the cost of materials can be reduced3.In molding, it is also possible to use commercially available materials. At the same time, a PMMA film with a thickness of 20/l and a culm density of 20/l can be made into a Nyori lenticular lens using the roll embossing method, and at the same time, it can be integrated with the base material 1) S1 by heat fusion, so the processing cost can be kept low. In this way, the above-mentioned object of the present invention can be achieved.

[Brief explanation of the drawing]

1 is an enlarged sectional view showing the structure and function of a conventional black stripe type lenticular screen. 3. FIG. 3. FIG. 3 is a diagram illustrating one side of the screen that can be made thicker without changing the diffusion angle of transmitted light according to the present invention. 1A - Conventional lenticular screen 1B - Lenticular screen of the present invention 2A, 2B - Lenticular lens 3 - Black stripe 4 - Base material Patent applicant Dainippon Printing Co., Ltd. Agent Patent attorney Sou Suga 1 Figure 8 years old

Claims (1)

[Claims] (1) In a black stripe type lenticular screen, the screen is composed of at least two layers, the layer on the lenticular lens surface has an optical 4:A layer with a low refractive index, and the base material layer on the back side has a high refractive index. A screen characterized by the use of different optical materials. +21 Cellulose triacetate-1 as an optical material
・. Cellulose triacetate-1, cellulose acetate butyrate, polymethyl methacrylate. Nitrocellulose, polyvinyl chloride, carbonate, polystyrene, and polyethylene terephthalate
1. The screen according to claim 1, which uses a combination of two types of synthetic resins selected based on their refractive indexes.