JPS61240537A - Projection picture tube device - Google Patents

Abstract

PURPOSE:To reduce the influence of heat on a lens, by attaching a frame to the front of a projection picture tube, and fitting the frame with the lens having a circular peripheral surface, and by filling a transparent gel in the space surrounded by the projection picture tube, the frame and the lens, and exposing the gel in the gap between the lens and the frame. CONSTITUTION:The rear of an oblong frame 10 is fixed on the front of the faceplate 8 of a televisional projection picture tube 2 by an adhesive 12. A lens 9 having a circular peripheral surface is secured to the front of the frame 10 by the claws 11a of attaching members 11. A transparent gel 7 of high optical transmission factor is filled in the space surrounded by the faceplate 8, the frame 10 and the lens 9. The surface of the gel 7 is exposed in the gap 14 between the lens 9 and the frame 10. The expansion and contraction of the gel 7 due to the change in temperature are absorbed by the gap 14 to prevent the lens 9 from being deformed. The influence of heat on the lens 9, the adhesive-fixed surface and so forth is thus eliminated to enhance the quality of a projection image.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a projection tube device used in a television image projection tube device, and more particularly to a projection tube device for use in a television image projection tube device, and more particularly to a projection tube device for use in a television image projection tube device. The present invention relates to a projection tube device that emits light while preventing it from emitting light and improves the contrast of the projected image on the screen.

2. Description of the Related Art Conventionally, in order to obtain a large-screen television image, a method is well known in which the television image is projected onto a relatively small projection tube and enlarged and projected onto the screen using a projection lens. In particular, technological advances in projection tubes, screens, and projection devices have been remarkable, with progress toward higher brightness and higher contrast. Among them, there is a method of sealing gel between the face plate of the projection tube and the lens as a relatively inexpensive method that can easily achieve high contrast. As a conventional technique, there is a projection tube gel enclosing technique as disclosed in, for example, Japanese Utility Model Application Publication No. 58-2850.

The conventional projection tube device as described above will be explained below with reference to the drawings. FIG. 3 shows a gel-filled structure of a conventional projection tube device. In Fig. 3, 1 is a lens made of glass or resin, 2 is a projection tube, 3 is an electron gun built into the projection tube 2, 4 is an electron beam emitted from the electron gun 3, 5 is a phosphor, and 6 is resin. A sealing member 7 such as adhesive or rubber packing is a transparent gel with good light transmittance, and this gel 7 is sealed in a space formed by the lens 1, the face plate 8 of the projection tube 2, and the sealing member 6. ing. In the above configuration, first, the electron gun 3 converts an electric signal into an electron beam signal. The electron beam 4 advances as shown in the figure and irradiates the phosphor 5 to emit light.

The emitted light beam further passes through the face plate 8, the gel 7, and the lens 1, but since the refractive index of the face plate 8 and the lens [-] and the refractive index of the gel 7 are almost equal, the interface between the face plate 8 and the gel 7 And the reflectance at the interface between the gel 7 and the lens 1 is much smaller than when the space in which the gel 7 is enclosed is a void, and ``enclosing the gel 7 in the space has an antireflection effect. . Therefore, the phosphor 5 is hardly affected by reflected light, and the image contrast of the face plate 8 is prevented from deteriorating. Further, since the gel 7 has a heat insulating effect, the heat generated in the face plate 8 is not directly transmitted to the lens 1, and has the effect of preventing thermal deformation of the lens 1.

Problems to be Solved by the Invention However, in a structure in which the sealing member 6 such as a rubber gasket is of a closed type as described above, it is difficult to sufficiently absorb or alleviate the expansion of the gel 7 due to a rise in the temperature of the face plate 8. If it is not possible to do so, the lens 1 may be deformed,
Alternatively, there is a problem in that the sealing member 6 is pushed out, creating voids in the gel 7 and reducing light transmittance.

=31 The present invention solves the above problems, and provides a projection tube device that can project a high-contrast image onto a screen by alleviating the expansion and contraction of gel caused by temperature changes on the face plate of the projection tube. The purpose is to provide.

Means for Solving the Problems In order to solve the above problems, the projection tube device of the present invention includes a projection tube, a frame closely fixed to the outer periphery of the face plate of the projection tube, and a frame on the frame. with a lens fixed to
The device includes a gel filled in a space surrounded by the face plate, the frame, and the lens, and the gel is exposed from the gap between the lens and the frame.

Effect According to the above configuration, the gel enclosed in the space surrounded by the face plate, frame, and lens of the projection tube is
When the projection tube is driven, the faceplate expands in volume as the temperature rises. At this time, since there is a gap between the frame and the lens, the gel freely expands in volume, causing the faceplate, frame, and lens to expand. No external force is applied and the lens does not deform. When the driving of the projection tube is stopped, the gel contracts as the temperature decreases, but the gap does not prevent the gel from contracting. Particularly when installing or transporting in a cold region, the gel shrinks greatly and tends to create voids, but such large contraction and expansion can be absorbed by the gaps and no voids are created.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2.

FIG. 1 is a cross-sectional view of a projection tube device according to an embodiment of the present invention, and FIG. 2 is an external perspective view of the same projection tube device, where the same components as those shown in FIG. The explanation will be omitted. 1 and 2, 9 is a lens, 10 is a metal frame with a black surface treatment, 11 is a lens mounting member, 12 is an adhesive, 13 is a screw, 14 is an open part, 9a is a lens surface, 9b is the outer periphery of the lens 9, 9
a is the inner peripheral part of the frame 10, lla is the lens mounting member, 11
It is the nail of. A frame body 10 is closely fixed onto a face plate 8 of a projection tube 2 with an adhesive 12. The lens 9 is assembled by fitting the lens mounting member 11 having different steps at four locations on the frame 10, attaching the lens 9 to the claw 11a of the lens mounting member 11, and tightening the lens mounting member 11 and the frame 10 with the screws 13. is fixed. The outer peripheral part 9b of the lens 9 is circular, the inner peripheral part 10a of the frame 10 is rectangular, and an open part 14 is formed between the lens 9 and the frame 10. With the open portion 14 facing upward, the space between the face plate 8 and the lens 9 is filled with an uncured liquid of the transparent gel 7. Gel 7 hardens over time or overheating. A lens surface 9a of the lens 9 that contacts the gel 7 is a convex surface.

The operation of the above configuration will be explained below. A television image is projected on the surface of the phosphor 5 by scanning the surface of the phosphor 5 with an electron beam 4 emitted from the electron gun 3 of the projection tube 2 . While the projection tube 2 is being driven, the face plate 8 reaches a high temperature of about 80 to 150 degrees Celsius.
The temperature of the gel 7, which is in close contact with the gel 7, also rises, and the gel 7 expands in volume.

The volumetric expansion is calculated by the opening 1 between the frame 10 and the lens 9.
Absorbed at 9. Also, when using or transporting in cold regions,
Conversely, although the gel 7 contracts in volume, it is also absorbed in the open portion 19 at this time.

As described above, according to this embodiment, the lens mounting member 11 is provided on the frame body 10, and the periphery of the lens 9 fixed to the lens mounting member 11 is formed into an open structure. The strain caused by expansion of the gel 7 or contraction in cold regions can be absorbed by the open part 14, and the stress applied to the lens 9, the face plate 1-8, the frame 10, etc. can be eliminated, and the gel 7 has no voids. Therefore, it is possible to provide a projection tube device that does not cause such problems. Further, as the unique effects of this embodiment, the claws of the lens mounting member 11], 1. By adding a step to a, it is possible to create an angle between the surface of the face plate 8 and the lens surface 9a, and it is possible to create a tilt angle for optical adjustment. Furthermore, since the lens mounting member 11 can be tightened with the screws 13, the lens 9 can be easily fixed. Moreover, the lens surface 9 in contact with the gel 7
By making b a convex surface, it is possible to obtain the effect that no air bubbles remain even though the lens surface 9b is directed upward when filling the gel 7. Also, the metal frame 10
By using this, the cooling effect of the gel 7 can be increased, and the brightness of the projection tube 2 can be improved.

In the above embodiment, the frame 10 is made of metal with a black surface treatment, but the frame 10 may also be a resin molded product containing glass fiber.

In addition, by using a liquid-cooled projection tube as the projection tube 2 of the above embodiment, it is possible to obtain effects of higher brightness and higher contrast.

Effects of the Invention As described above, according to the present invention, there is a gap between the mounting surface of the frame and the lens, and the gel is exposed through this gap, so that the stress caused by volumetric expansion and contraction of the gel is reduced. It is possible to prevent deformation of the lens and generation of voids at the interface between the face plate surface and the gel, the interface between the lens surface and the gel, and even inside the gel.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a projection tube device according to an embodiment of the present invention, FIG. 2 is an external perspective view of the projection tube device, and FIG. 3 is a sectional view of a conventional projection tube device. 2... Projection tube, 7... Gel, 8... Face plate, 9... Lens, 10... Frame, 11... Lens mounting member, 13... Screw agent Morimoto YoshihiroFigure 2Figure 3

Claims (1)

[Claims] 1. A projection tube, a frame closely fixed to the outer periphery of a face plate of the projection tube, a lens fixed on the frame, and the face plate, the frame, and the lens. a gel filled in a space surrounded by the lens, and the gel is exposed from a gap between the lens and the frame. 2. The projection tube device according to claim 1, wherein the lens has a circular outer circumference, and the frame has a rectangular inner and outer circumference. 3. The projection tube device according to claim 1, wherein the frame body has a plurality of lens attachment members. 4. The projection tube device according to claim 3, wherein the lens mounting member is removable from the frame. 5. The projection tube device according to claim 3, wherein the frame body has means for movably adjusting the lens mounting member. 6. The projection tube device according to claim 1, wherein the frame is made of a metal material, and air cooling fins are provided on the outer periphery. 7. The projection tube device according to claim 1, wherein the lens has a convex surface that contacts the gel.