JPS61116338A - Producing device of screen for video projector - Google Patents

Abstract

PURPOSE:To separate a mold easily and to produce the titled screen for a short period without generating distortion by using the bottom frame of a screen mold, the frame of the screen mold, a means for injecting ultravioret-cured resin, and an ultraviolet ray source. CONSTITUTION:The screen mold bottom frame 4 is flexible and has a surface corresponding to the unevenness of the screen. A screen mold roof plate 6 is abutted upon the edge of the screen mold bottom frame 4. The roof plate 6 transmits ultraviolet rays. Ultraviolet-cured resin is injected from an injection port 8 into the screen mold frame and air is exhaust from an exhaust port 11. The injected resin is cured by ultraviolet rays radiated from the ultraviolet ray source 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to the arrangement of screens used in video projectors, and particularly to improvements in the manufacturing apparatus thereof.

[Conventional technology]

In this specification, a Fresnel lens will be explained as an example of a screen for a video projector.

As a general thermoplastic acrylic express screen,
Figure 2 shows a Fresnel lens. Figure (a) is a front view;
(b) is an A0 sectional view of (a). In the figure, (
11 is a Fresnel lens, +21 is a lens surface, and +31 is a non-lens surface.

Conventionally, such Fresnel lenses have been manufactured by hot pressing resin ft. In these methods, heated acrylic resin is molded using a mold, cooled, and then released from the mold. By cooling the acrylic resin, for example,
In the case of a cular Fresnel lens, the non-lens surface +31, which causes contraction of about 7 mm, strongly clamped the mold for the shape. However, slow cooling is required to prevent distortion during cooling, and one process takes more than 60 minutes.

As a result, it becomes very difficult to release the mold, and the time required for exclusive use of the mold is long, resulting in poor productivity.

The present invention was made to solve these problems, and provides a device for producing video projector screens with good mold releasability and with high productivity! The purpose is to provide all f.

[Means for solving problems]

The video projector screen manufacturing apparatus of the present invention includes a screen mold made of a flexible screen mold bottom frame having an uneven screen surface, and an ultraviolet-transparent screen mold top plate that is in contact with the edge of the screen mold bottom frame. form,
A means for injecting an ultraviolet curable resin into the screen mold, and an ultraviolet ray for curing the injected resin.

[Effect]

In this invention, since the bottom frame of the screen mold is flexible, the mold can be easily released. However, since it is cured using ultraviolet light without heat, there is no need for slow cooling and no distortion occurs, so it can be manufactured using a short process.

``Example'' An apparatus for manufacturing a Fresnel lens using an ultraviolet curable resin according to the present invention will be described with reference to FIG.

FIG. 1 (IL) is a perspective view showing an embodiment of a screen form which is the main part of the present invention, and FIG. 1(b) is a sectional view schematically showing a Fresnel lens manufacturing apparatus according to an embodiment of the present invention.

In the figure, [41] is a mold that replaces the conventional mold, and is a screen made of a highly flexible material such as silicone rubber, which has irregularities on the screen surface (in this case, the lens surface of a 7-lens lens). The mold bottom frame, (6) is a rigid support member that supports the flexible screen mold bottom frame (41 from below and maintains its flatness), (6) is an ultraviolet-transparent screen that comes into contact with the edge of the screen mold bottom frame. The mold top plate is a flat plate made of quartz glass that forms a non-lens surface.

(71 is a guide that fully fixes the screen type top plate (6),
The flexible screen mold bottom frame (4) and the top plate (6) are in contact with each other at their four edges, and by clamping the guide 17+ and the rigid support part R (51), the screen mold bottom frame (4) and the top plate are in contact with each other. Plate (6) is fully pressurized and the inside of the screen formwork (one person) is sealed. +81 is the ultraviolet curable resin injection port, (91 is the exhaust port, both are pipes and 9 flexible screen Openings are formed in at least two places in the mold bottom frame (4) by inserting them into holes smaller than the outside diameter of the polypropylene inlet (8) and the exhaust port (91). direction, Q
]) indicates the direction of air exhaust, and (gong) is the ultraviolet source that cures the ultraviolet curable resin.

Next, a manufacturing method using the manufacturing apparatus shown in FIG. 1 will be described.

First, a release agent is applied to the upper surface of the rigid support member (61), and the flexible screen mold bottom frame (4) is set on the upper surface of the support part Oi51 with the screen surface facing up.Next, the injection port (8) and Insert the exhaust port (91) into the hole made in the rubber-like lens mold, and apply mold release treatment by spraying on one side of the ultraviolet-transparent screen-type top plate (61). Use a silicone-based spray mold release agent.After the mold release treatment, place the screen mold top plate i61'k d on top of the screen mold bottom frame with the treated ifli' facing down.
and set it on the guide (7) and the la screen top plate (6) as shown in the diagram. First, by a method not shown, the guide (7) and the screen type top plate (61° screen type bottom frame f41 and support part F) r+51 are clamped by a pressure bonding means not shown to complete the assembly. Next, the pressure inside the screen formwork (iA) is reduced from the exhaust port (9) by means of an evacuation means (not shown), in this case a vacuum pump, through a pipe (also not shown). The inlet (8) leads by a pipe (not shown) to a hopper, also not shown.

A defoamed ultraviolet curable resin 110i is contained in the hopper, and the inside of the lens mold (IA) and the hole are shielded with pulp. In this case, the means for injecting the jujube fat is made of pulp, etc. When the desired reduced pressure is reached, the pulp is opened inside the ultraviolet curable resin whole lens mold (one person). After that, ultraviolet light is irradiated from above the screen mold top plate (6) using ultraviolet light source 4 to harden the ultraviolet curing resin in the screen mold (one person). After confirmation, remove the clamp, remove the guide [7+ and the screen mold top plate (6), and release the cured ultraviolet-like hardening resin in the screen mold frame (1A), that is, the 7 Renel lens (II't-). Fresnel lens. (To release the mold in step 11, remove the support part (5), wipe the inlet (81 and exhaust port, and air port (9)).
At this time, bend the inlet (8) and exhaust port (the resin inside 91 is not cured because it is not exposed to ultraviolet rays) and the bottom frame (4) of the flammable screen mold to the opposite side of the Fresnel lens il+. Then, the flexible screen mold bottom frame (4) and the Fresnel lens (1) are released from the mold, and the manufacturing is completed.

In addition, as a screen for a video projector, a lenticular lens, aluminum or 7-lens lenses and a lenticular surface are provided on both sides, and a UV-curable l! 1: It goes without saying that by using the resin and the device according to the present invention, effects similar to those of the above-mentioned Fresnel lens (b) can be obtained.

〔Effect of the invention〕

As explained above, the present invention includes a removable screen mold bottom frame with an uneven screen surface.

A screen form formed from the bottom frame edge of the screen form and an ultraviolet-transparent screen top plate, a means for injecting an ultraviolet-like curable resin into the screen form, and an injector 7 for injecting the resin. By equipping it with UV curing #vl, it can be easily released from the mold, and since it is cured by irradiation with 7ft of UV light that does not involve heat, there is no need for slow cooling, etc., and no distortion occurs. This has the effect of providing an apparatus that can manufacture a video projector screen in a short time.

[Brief explanation of the drawing]

FIG. 81(a) is a perspective view showing an embodiment of the screen formwork of the main part of the present invention, and FIG. 81(b) is a cross-sectional configuration diagram showing an outline of a Fresnel lens manufacturing apparatus as an example of the present invention.
2L9(a) is a front view of a general Fresnel lens, and FIG. 2(bl is a sectional view taken along line A0 in FIG. 2(a). frame, +
51 is a rigid support member, (6) is an ultraviolet-transparent screen-type top plate, (8+ is an ultraviolet-transparent resin head, (91 is an exhaust port, and 4 is an ultraviolet source. In addition, the same reference numerals in the figures are the same) , Mano shows a considerable part.

Claims (2)

[Claims] (1) A flexible screen mold bottom frame that is placed on a rigid support member, has an ultraviolet ray curable resin injection port and an exhaust port, and has an uneven screen surface, and ultraviolet rays that come into contact with the edge of the screen mold bottom frame. A transparent screen-type top plate, a crimping means for crimping the screen-type bottom frame and the top plate, and exhausting the air in the screen-form frame formed by the screen-type bottom frame and the mold top plate through the exhaust port. Exhaust means to reduce the pressure, resin press-fitting means to inject and fill the ultraviolet curable resin into the reduced pressure screen formwork from the injection port, and ultraviolet rays to cure the ultraviolet curable resin filled in the screen formwork. Video projector screen manufacturing equipment with a power source. (2) The video projector screen manufacturing apparatus according to claim 1, wherein the flexible screen mold bottom frame is made of silicone rubber.