JPS60209728A - Screen - Google Patents

Abstract

PURPOSE:To obtain a projection image optionally settable in size with good quality which has no break by integrating numbers of small screen pieces in a plane and thus forming a reverse surface projection type screen. CONSTITUTION:The projection image from a projector 1 is converted by a Fresnel lens 6 into parallel projection light 2b, which is incident on a convex lens 4. This incident beam is made into convergent light 2c divided along optical axes of numbers of convex lenses 4 fitted to a fitting frame 3 in contact and in a plane while respective grating squares are covered with grating crosspieces and the light 2c reaches a concave lens 4. The light is made by this concave lens 4a into a diffused light beam 2d, which reaches screen components 5a. The screen components 5a are fitted to the fitting frame 3 in contact and in a plane while the grating squares are covered with grating crosspieces, and an image formation layer 5b is formed on its front surface; and the diffused light beam 2d arriving there is diffused by this layer to form the projection image.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a projection screen IJ-phone used in a back projection method.

[Prior art]

A conventional device of this type is shown in FIG. In the figure, (11 is a projector, (21 is a projection lens, and (separate) is the approximate optical path of an enlarged projection light beam.

(51 is a (single plate) screen made of transparent plastic material, (61 is a (single plate) Fresnel lens placed close to the back of the screen + 51, (5b) is a screen (single plate) This is an imaging layer formed on the front (front side).

Next, the operation will be explained.

The enlarged projection light (2a) of the image enlarged and projected from the projector (11) through the projection lens (2) reaches a Fresnel lens (plate lens) made of a transparent plastic material such as methacrylic resin material. The projection light beams are aligned in parallel optical paths and are incident perpendicularly on the back surface of the screen (3).The incident projection light beams reach the imaging layer (5b) formed on the front side of the screen (31).

The imaging layer (5b) is a milky-white translucent film or has been subjected to a light scattering treatment in the form of ground glass, and the projection light forms a clear image here. The viewer will see this statue from the front.

Since conventional screens have a structure made of a single plate as described above, it is difficult to change the size once manufactured, and there are restrictions on the size due to the dimensional standards of the material. Sometimes, the use of larger materials increased weight due to the need for thicker plates to maintain strength. On the other hand, by forming a conventional screen into a small unit and adding this unit into a flat shape,
Although it is possible to configure a larger screen,
This method requires a mounting frame to fix the screen to the device, and has the disadvantage that there is a portion where the projected image does not appear at the joint between the screens.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above.The screen is divided into small screen pieces of the same shape and structure, and these are placed in a strongly made lattice-like mounting frame. By storing them individually and stacking them together, you can obtain a screen of any size with a light and strong structure, and the lattice-shaped mounting frame crosspieces (grids) interposed at the joints between the screen pieces reflect the projected light. Intercept and form. In order to eliminate portions where images are not reflected, a screen is provided in which a convex and a concave lens are combined to change the optical path of projection light.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, fi+ is an image projector, (2) is a projection lens, and (2a) is an enlarged projection light from the projection lens (2). (3) is the mounting frame for attaching the screen parts, (
4) is a convex lens attached to the projector (11 side) which is the back side of the mounting frame (3), (51 is a screen component attached to the viewer side which is the front side of the mounting frame (3), and (6) is a convex lens ( 4) is a Fresnel lens placed close to.

Figure 3 is a partial cross-sectional view showing the details around the screen component (5). The concave lens (5b) attached between the screen component (51) is an imaging layer thinly formed on the surface of the screen component (51).

Next, the operation of the screen according to this invention will be explained.

The projected image from the projector +11 becomes (radially) enlarged projection light (>) from the projection lens (2) and reaches the Fresnel lens (6), and the transmitted light is parallel projected due to the lens (refraction) action of this lens. The convex lens (
4) is incident perpendicularly to This incident light beam is divided along the optical axis of each lens by the mounting frame (41), which is attached to a large number of convex lenses (41) that are closely attached to each other in a planar manner by covering each of the 31 lattice holes with a lattice crosspiece. The convergent light (2c) is focused and reaches the concave lens (4a).Concave lens (4a)
The convergent light (next) that has passed through the lens is diffused (
radiation) rays ('1Ii) and screen parts (5)
reach. The screen component (51) is attached in a planar manner by covering each of the lattice holes of the mounting frame with a lattice crosspiece, and in front of this, a thin film-like light scattering layer is formed as an imaging layer (5b). ), and the diffused light beam (2d) that reaches this layer is scattered by this layer and forms a projected image.

Note that in the above embodiment, the convex lens (4) and the concave lens (4a
), screen part (51), and Fresnel lens (6) are each separate parts, but among these, the convex lens (4
), the Fresnel lens (61), the concave lens (4a), and the screen component (5) may be integrated into one component, an example of which is shown in FIG.

In FIG. 4, (71 is the above Fresnel lens (6)
and a convex lens (4) integrated into a deformed convex lens (part),
(8) is the concave lens (4a) and the screen part (5).
) is a deformed screen part that integrates.

〔Effect of the invention〕

As described above, according to this invention (-), a back projection screen is constructed by stacking many small screen pieces in a flat shape, so the size can be set arbitrarily. is easy.

In addition, gaps between adjacent screen pieces create areas where the displayed image cannot be seen, but this can be avoided by changing the optical path using the built-in concave-convex lens system, so you can enjoy high-quality, seamless images. This has the effect of providing a projected image.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional back projection screen, FIG. 2 is a perspective view showing a back projection screen according to an embodiment of the present invention, and FIG. 3 is a perspective view of a screen according to an embodiment of the present invention. FIG. 4 is a partially enlarged sectional side view (at the center) of a screen according to another embodiment of the invention.
A partially enlarged cross-sectional side view (at the central portion) is shown. Symbol (1) is the projector, (21 is the projection lens, (2a) is the enlarged projection light, (2b) is the parallel projection light, (f) is the convergent projection light, (2d) is the diffused projection light, and (3) is the Mounting frame, (4) is a convex lens, (4a) is a concave lens, (5) is a screen,
(5a) is a screen component, (5b) is an imaging layer, (6)
(7) is a modified convex lens; (8) is a modified screen component. In the figures, the same reference numerals indicate the same or equivalent parts. Agent Masuo Oiwa Figure 1 Figure 2 Figure 3 Continued from page 1 0 Inventor Yoshi Oka Mitsubishi Electric Corporation Control Works 1-1-2 Wadazaki-cho, Hyogo-ku, Kobe t'i'1 FFIi Director 1 role 18sfr'l display T4410rlji 59-
No. 67910 No. 2, Title of the invention, Screen 13, Representative piece II + Part 8 of the specification, Claims section and Detailed description of the invention section. 6. Contents of the amendment (υ The scope of claims in the specification is corrected as shown in the attached sheet. C) The specification is corrected as shown in . Claims: An image is projected from the back, formed through a front panel lens, and is viewed from the front on a screen that combines a convex lens and a concave lens, and uses a transparent material to transmit the light that has passed through these lenses. and an imaging layer closely attached to the front side of the transparent material, and a plurality of these units are assembled closely together to form a flat plate shape.

Claims (1)

[Claims] An image is projected from the back and formed through a Fresnel lens, and on the screen where this image is viewed from the front, a convex lens and a concave lens are combined, and the light passing through these lenses is passed through a transparent material and this 1. A screen characterized in that a unit is formed of a transparent material and an image forming layer closely adhered to the front side thereof, and a plurality of these units are assembled closely together to form a flat plate shape.