JPS63313143A - Back projection type screen - Google Patents

Abstract

PURPOSE:To hold high fineness and to attain maximization by forming a screen by adjacently arranging many lenticular lenses, which are thinly and lightly formed, in parallel and burying or fixing a wire having high-tensile strength in the border parts of the respective adjacent lenticular lenses. CONSTITUTION:The high-tensile strength wire 5 is buried or fixed in the parts adjacent to the lenticular lens 3a, which is thinly and lightly formed. And both ends of the wire 5 are fixed to a strong screen frame 6 whose rigidity is high so that the screen is supported in a plane by given tension. The lenticular lens 4a having the same constitution as the lens 3a is fixed to the back surface of the screen. Thus, the thickness of the material of screen can be reduced and the fineness of a video can be improved by decreasing a sag and scattered light caused by the change of the temperature of environment, etc., so that the maximization can be enhanced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for forming a large-sized IJ with easy maintenance of flatness, and suppressing scattering of image light inside the screen. The present invention relates to a rear projection screen that provides high definition and is suitable for, for example, a projection high definition television receiver.

[Conventional technology]

FIG. 2 is a perspective view showing an example of a conventional rear projection screen for a projection television receiver.

In the figure, 1 is a screen material (i.e. a lenticular material described later).
2 is a black stripe to prevent light from the front (indoor light) from reflecting back to the viewer and reducing the contrast of the image, and 3 is a black stripe between these black stripes. In the gap, there is a lenticular lens that efficiently condenses the image light projected from the back and expands the visible range in the front left and right directions, and 4 is a lenticular lens that also expands the visible angle in the vertical direction. It's a lens.

With rear-projection television receivers, the reduction in the amount of light displayed on the image is smaller than the reduction in the amount of reflected light on the screen, and compared to front-projection televisions, images with better contrast can be obtained even in bright rooms. It has the advantage of

However, in the conventional rear projection screen structure shown in Figure 2, in order to increase the screen size, the thickness of the screen IJ must be increased to increase the strength of the screen. There must be.

However, simply increasing the screen thickness will
There is also an increase in dead weight, so it is unreasonable to make it too large. In addition, acrylic resin is a plastic material that has good translucency and is durable, but as the thickness of the screen increases, the amount of light absorbed inevitably increases.
Moreover, the increased material thickness makes it easier for scattered light to diffuse into adjacent lenticular lens regions within the screen, creating the even more undesirable problem of reduced definition.

This type of related technology includes U, S, P, and 4.
, 432ρ10.

[Problem that the invention seeks to solve]

It is an object of the present invention to solve the above-mentioned problems of the conventional rear projection screen, and to provide a rear projection screen that can easily increase the size of the image screen and maintain high definition even when the screen is increased in size. shall be.

[Means for solving problems]

In order to solve the above problems, in the present invention, in order to avoid suffering from an increase in the thickness of the screen itself and an accompanying increase in its own weight when increasing the size of the screen,
A large number of lenticular lenses made of a translucent material and formed as thin and light as possible within the range that allows the desired lens action are arranged adjacently and in parallel to form a screen, and at the boundary between each adjacent lenticular lens, The screen was held in a flat shape by embedding or fixing wires having high tensile strength and applying tension by pulling these wires. As in the case of the conventional example shown in FIG. 2, another screen (or Fresnel lens) whose lenticular lens arrangement direction is orthogonal to the lenticular lens arrangement direction of the screen is installed behind it. However, this screen is also made thin and light, and is fixed to the screen at multiple points to hold it in a flat shape.

In addition, as a countermeasure for increasing the size of the screen, which causes a decrease in definition as described above, in the present invention, a large number of lenticular lenses made of a translucent material are arranged adjacently and in parallel. At the border of each adjacent lenticular lens of the formed screen, in addition to the conventional black stripes for absorbing front-incident light, there is also a black non-reflective surface with high tensile strength. wire rods (preferably those with a long cross-sectional shape in the thickness direction of the screen) are embedded and fixed as deep as possible, and the screen is held in a flat shape by pulling these wire rods and applying tension. . As a result, at the boundary between each adjacent lenticular lens, a high tensile strength wire with a black surface for maintaining a flat state is applied in the thickness direction of the screen.
penetrates deeply, making it possible to suppress image light from scattering and mutually diffusing into areas of adjacent lenticular lenses.

[Effect]

If the above measures are taken, the screen itself becomes a collection of thin (light (and therefore not very strong)) lenticular lenses, and relies on high tensile strength wires that are embedded or fixed at the boundaries of each lens and are given tension. Therefore, as long as it does not interfere with the function as a lenticular lens, it is possible to make the screen larger and thinner. By making the screen thinner, the diffusion of harmful and useless scattered light that occurs inside the screen is suppressed.In addition, the outer surface of the high tensile strength wire used to hold the screen in a flat shape is made black and non-reflective. In addition to the black stripes provided to absorb incident light from the front, these (preferably long cross-sectional shapes in the direction of the thickness of the clean)
By embedding the wire deeply into the boundary between each adjacent lenticular lens forming the screen, it is possible to suppress the scattered light inside the screen material from diffusing into the area of the adjacent lenticular lens (adjacent pixel). . Also,
In the conventional example shown in Figure 2, another screen with lenticular lenses adjacent and parallel in the direction orthogonal to the black stripes is installed behind it, but this screen also has the effect of the lenticular lenses. If you make the screen as thin and light as possible without causing any problems, and fix it at multiple points to a screen held in a flat shape using high-tensile strength wire, and similarly hold it in a flat shape, you can avoid increasing the size of the screen. It's easy. Also in this screen, since the material is thin, unnecessary scattering of light inside the screen is suppressed, contributing to improved definition. It is better to use a Fresnel lens for the screen behind this if the diagonal diameter is up to about 50 inches, but if the screen is larger than that, a lightweight Fresnel lens made of plastic should be used.
The lens becomes difficult to manufacture and must be a parallel assembly of lenticular lenses.

Furthermore, as the screen becomes thinner, it goes without saying that the amount of lost light absorbed by the screen decreases.

As wire rods with high tensile strength, it is possible to use various metal materials with a long track record as well as various non-metallic composite materials that have been developed in relatively recent years. Since it is black in color, it can directly absorb scattered light without any special black coating on the surface.

When using so-called piano wire, it is better to apply a black coating to the surface, but since the material itself is cheap, there is no problem in terms of cost even if it is colored.

〔Example〕

FIG. 1(a) is a perspective view of essential parts of an embodiment of the present invention; FIG.
b) is a sectional view taken along a plane orthogonal to the high tensile strength wire of the same example. In the figure, l is a screen material (acrylic resin material), 3 m, 4 a is a lenticular range formed thin and light according to the present invention, 5 is a high tensile strength wire according to the present invention, and 6 is a rigid and strong screen frame. It is. Both ends of the high tensile strength wire 3a are fixed to a highly rigid and durable screen frame 6 by sufficiently pulling and applying tension so that the screen is supported in a plane. In this example, the lenticular lenses that form the screen are made as thin and light as possible, and the screen is made of carbon fiber with a black surface and low reflection, as shown in the figure, as a high tensile strength wire material that expands and holds the screen in a flat shape. A composite wire material having a nearly rectangular cross section that is elongated in the thickness direction is deeply embedded in the boundary between adjacent lenticular lenses.

By carrying out the present invention, the flatness of the screen, which was conventionally maintained by the strength of the screen material itself, is replaced and maintained by thin wires with high tensile strength, so the thickness of the screen material can be significantly reduced. (usually up to 20-50% of the thickness of conventional screen materials), and it is also possible to keep screen sagging due to larger screens, changes in environmental humidity, etc. to within the required range. It has become possible. Furthermore, as shown in Figure 1(b), some of the image light projected from the back is scattered inside the screen material, but the embedded black wire acts as a barrier, preventing the scattered light from occurring. It is scattered to adjacent pixel areas and cannot be used. This prevents image blurring, and when evaluating the image definition of rear projection television receivers by dividing them into five ranks, it was definitely improved by half the ranks.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to obtain the effect that the definition of the image is improved and the screen size can be easily increased.

[Brief explanation of the drawing]

FIG. 1(a) is a perspective view of essential parts of an embodiment of the present invention; FIG.
b) is a sectional view taken along a plane perpendicular to the high tensile strength wire of the same embodiment, and FIG. 2 is a perspective view showing an example of the screen of a conventional rear projection television receiver. 1...Screen material 2...Black wire at3a+
4s4a... Lens 5... Black high tensile strength wire material according to the present invention 6... Screen frame agent Patent attorney Masaru Ogawa Otokohaku 1 Figure a No. ? figure

Claims (1)

[Claims] 1. A screen is formed by forming a screen by arranging a large number of lenticular lenses made of a translucent material and formed as thin as possible within a range capable of achieving a desired lens action, adjacent to each other in parallel. A rear projection screen characterized in that the screen is held in a flat shape by embedding or fixing wire rods having high tensile strength in the boundary parts of the screen and applying tension by pulling these wire rods. 2. Behind the above screen, in a direction perpendicular to the lenticular lens arrangement direction of the above screen, a screen of approximately the same size as the above screen, which is made up of a large number of thin lenticular lenses adjacent to each other and arranged in parallel, is installed at multiple locations. The rear projection screen according to claim 1, wherein the rear projection screen is fixed to the screen and held in a flat shape. 3. A large number of lenticular lenses made of translucent material are arranged adjacently and in parallel to form a screen, and black lenses are placed at the boundaries of each adjacent lenticular lens to absorb front incident light. In addition to the stripes, this rear projection screen features a black non-reflective wire embedded behind the stripes. 4. The rear projection screen according to claim 3, wherein the wire is a black composite wire whose main material is carbon fiber.