JPS5937639A - Projection cathode-ray tube - Google Patents

Abstract

PURPOSE:To keep heat transfer efficiency and obtain high luminance in a simple construction than that using refrigerant by installing a side wall peripheral metal body which contacts in a side wall periphery of a phosphor screen panel through a grease-like heat radiation material, and a heat radiation fin thereon. CONSTITUTION:A glass plate 12, which is arranged through colorless, transparent silicon resin to prevent spreading out of a grease-like heat radiation material to an image surface, is installed on the outer surface of an image surface of a phosphor screen panel 11 of a cathode-ray tube 10 to increase heat transfer. A cooling metal plate 14 having a heat radiation fin 14a which is installed through the greasep-like heat radiation material which is placed between periphery of the image surface of the panel 11 is arranged. A supporting plate 15 which is arranged to increase heat transfer through the grease-like heat radiation material in the side periphery, the metal plate 14, and a heat radiation sheet 16 for improving contact of the supporting plate 15 with a panel side wall are installed. This design is effective for heat transfer, and high luminance is obtained by simple construction.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a projection cathode ray tube, and in particular, a method for reducing thermal stress on the cathode ray tube envelope in response to an increase in input cover force due to high brightness. The present invention relates to a projection type cathode ray tube that is equipped with a heat dissipation body that takes into consideration the limits of thermal stress of the envelope and has an extremely simple structure.

[Technical background of the invention]

Among television reception systems, systems using projection cathode ray tubes have been around for a long time.A bright image is drawn on the image surface of the fluorescent panel of a small projection cathode ray tube, and this image is transferred to an optical system consisting of lens threads and mirrors. The image can be enlarged and projected onto a large screen.

In order to draw a bright image on the image surface of a fluorescent panel, 1. For example, the final anode voltage of a projection cathode ray tube used in a video projector must be operated at a high positive pressure of 25 KV to 30 KV. 1. In order to scan the image plane with an electron beam with a DC density several tens of times higher than that of a cathode ray tube for cameras, the fluorescent surface and the panel on which the fluorescent surface is adhered are heated rapidly, and the outer area of the cathode ray tube is heated. Since this is the limit for cracking the vessel, the current practice has been to use forced air cooling with a blower for a long time.

However, this structure that uses forced air cooling to cool projection cathode ray tubes has problems such as increased power consumption and noise.
Structures that use projection cathode ray tubes at low brightness and structures that use thermal conduction cooling using liquid, which would result in complicated devices, have been considered, but these are not yet sufficient.

[Problems with background technology]

Cathode ray luminescence, in which high-speed playback beams, i.e., cathode rays, collide with a phosphor to emit light, is highly energy efficient, with a conversion efficiency of about 20 cm, and when used in projection cathode ray tubes. , energy efficiency decreases due to temperature, etc., and efficiency further decreases. As can be seen from this value, most of the electron beam becomes heat. This heat heats the fluorescent surface and is further convectively transferred from the outer surface of the panel and the outer surface of the funnel into the atmosphere. Therefore, how to carry out efficient thermal design regarding this heat transfer becomes a problem in the design of the projection type helmet tube.

On the other hand, for projection cathode ray tubes, industrially usable materials such as phosphors and glass for envelopes are limited, and as a result, the amount of heat generated and the thermal conductivity of the glass are also limited. Furthermore, since the image surface of a cathode ray tube must be able to function as a path for light, it is necessary to transfer heat without blocking the light. This structure is currently considered to be efficient.

In this case, the liquid used has a thermal conductivity comparable to that of glass, which is two orders of magnitude lower than that of metal. Therefore, the limit of heat transfer is determined by the thermal conductivity of the liquid used, and since it is a liquid, if the temperature change during heat generation is large, the flow of the liquid will be large, and the image projected on the screen will be distorted. There is a problem that causes Lucky 1.

This kind of liquid conduction cooling (liquid cooling) usually has a face panel with a coolant passing through it on the outside of the fluorescent face panel, and metal brackets are placed around this coolant.

The face panel and metal bracket are bonded to the fluorescent surface panel with adhesive, but in this structure, refrigerant leaks and contact is required, which results in a complete seal. However, when the volume of the refrigerant expands due to the heat generated by the fluorescent surface, the internal pressure increases. Therefore, a means of relieving this pressure is necessary, but it is also required to be highly reliable so that the refrigerant does not leak even when the pressure increases due to sealing, and if the refrigerant leaks, the projection set will be damaged. There are problems that can cause damage.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a projection cathode ray tube having a cooling mechanism that is simpler than the liquid cooling described above and has a heat transfer efficiency equivalent to that of liquid cooling.

[Summary of the invention]

Namely, the present invention includes a frame-shaped metal plate that is brought into close contact with the outer periphery of the outer surface of the image plane of the fluorescent panel via heat dissipation grease, and a grease-like metal plate that is attached to the outer periphery of the side wall of the fluorescent panel that is connected to the outer periphery. It is characterized by comprising a side wall outer peripheral metal body which is finally integrated with the frame-shaped metal plate when brought into close contact with each other through a heat dissipating material, and a radiation fin provided at a desired part of this side wall outer peripheral metal body. A predetermined adhesive layer, such as silicone, is applied to the window part of the frame-shaped metal plate on the outer surface through a resin so that the image surface has the same area as the image surface, and the outer surface is used for projection. A glass plate is provided with an electrically conductive member that does not cause any practical problems, and this electrically conductive member is brought into close contact with a frame-shaped metal plate, and this drowsy electrically conductive member removes dust and sludge that adheres to the glass plate. It is designed to prevent

[Embodiments of the invention]

The inventors conducted stress analysis on the crank of the cathode envelope and found that compressive stress was generated in the center of the fluorescent panel, and tensile stress was generated in the peripheral side walls of the fluorescent panel. .

This occurs when the peripheral side wall restricts the rise in temperature of the fluorescent panel, and the difference in temperature between the peripheral side wall and the fluorescent panel causes stress. Therefore, a design is required to reduce this temperature difference.

Next, we conducted a design experiment in which the design stress of the envelope, which is a design requirement, was satisfied with an input power of 30 W using tempered glass and a 7-inch projection cathode ray tube with an input power of 3000 psib using raster manual power.

This experiment used a frame-shaped metal plate closely surrounding the rascou, and a side wall outer peripheral body that was closely connected to the peripheral side wall, which connected the heating of this metal plate to a fluorescent surface panel. When heat was transferred to the outer metal body of the side wall that was in close contact with the surrounding side wall, results were obtained that fully satisfied the design requirements mentioned above.

This structure places a frame-shaped metal plate in close contact with the periphery of the raster, but this close contact is achieved by using heat dissipating grease with good thermal conductivity, which allows heat to be transferred best from the outer periphery of the image plane on the outer surface of the fluorescent panel. can be done. This is because when metal is brought into contact with ordinary high-temperature glass, tensile stress is generated on the metal-contact side of the glass, and glass is strong against compressive stress but very weak against tensile stress, which is not common sense when dealing with heated glass. However, in the case of this polarized tube envelope, the expansion of the phosphor panel is restrained by the side walls. This is because the stress caused by heat movement around the raster may be reduced due to the 1llill constraint.

Therefore, by actively transferring heat to the rod-shaped metal plates placed around the raster and reducing the restraining force by transferring heat to the side walls, an extremely efficient thermal stress design can be achieved. A bright projection type shaded heald tube is realized.

Heat conduction between solid bodies as a means of efficient heat transfer is poor even when glass and gold are brought into direct contact due to the fine protrusions on the surface.1 The purpose of the present invention is to conduct efficient heat conduction. Therefore, in order to ensure that the glass and metal are in perfect contact with each other, a grease-like heat dissipating material having a thermal conductivity comparable to that of the glass is used.

The side walls and the periphery of the fluorescent panel image plane have curves and angles, and metal plates are processed to align them. A grease-like heat dissipating material that intervenes on the outer periphery or outer surface of the image plane has a problem in that it oozes out onto the outer surface of the image plane due to volumetric expansion when the temperature rises. For this purpose, a glass plate having the same area as the image plane and the crosspiece is arranged on the outer surface, and a silicone resin that does not pose an optical obstacle is interposed between the glass plate and the outer surface of the image plane.

The addition of a glass plate increases the thermal design thermal resistance, but even without this glass plate, the thermal resistance against air is large, so if we consider only the heat transfer within the glass of the fluorescent panel. good.

In the present invention, a glass plate is provided on the outer surface of the image plane via a silicone resin, and a frame-shaped metal plate is arranged on the outer periphery of the outer surface of the image plane, which reduces the distance for heat transfer in the glass. Since the heat transfer area between glass and metal increases, stacking glass plates creates a condition where heat transfer increases.

Next, one embodiment of the projection type cathode helmet tube of the present invention will be explained with reference to the drawings.

That is, although not shown on the outer surface of the image plane of the fluorescent surface panel αυ of the cathode mwan, a grease-like heat dissipating material is placed on the image plane.
A glass plate az is disposed through a colorless and transparent silicone resin so as not to ooze out, and an opening (13a) having a recess (13b) into which the vicinity of the edge of the glass plate α enters and is approximately equal to the outer surface of the image. ) is perforated therein, and the frame-shaped metal plate 0311 is made of aluminum or the like and has approximately the same size as the panel, and the recess (13b) in this frame-shaped metal plate Q3.
), and a grease-like heat dissipating material interposed between the outside and the outer periphery of the image plane of the panel aυ, and a grease-like heat dissipating material interposed between the outer periphery of the side wall that is finally integrated with the frame-shaped metal plate. A heat dissipation fin (14a) that improves the provided heat dissipation effect
A cooling metal plate (141) made of aluminum or the like as a part of the side wall outer periphery metal body having A support plate (151 and this cooling gold electric plate Q4) made of aluminum, etc., and a support plate (
15) and a heat dissipating seam provided on the panel side wall to make good contact with the panel side wall. +
Up to the periphery of 21, the frame metal plate (I3) and the heat dissipation plate (14)
, support plate (Is) is in close contact with the cathode ray tube (10) via a grease-like heat dissipation material. However, in the figure, only one support plate Q51 (heat dissipation plate OJ) and support plate Q51 are shown. Of course, they are provided facing each other with the tube in between. Also, the heat dissipation sea) Q[J is the grease-like heat dissipation material is the cooling plate 04) support plate 0! ] L and the outer periphery of the side wall are made uniform to ensure heat transfer and retention.

In the above embodiment, a glass plate (121) is provided on the side wall of the panel through silicone (VJ resin). The adhesion of dust, lint, etc. may occur and interfere with the image projection.In order to dissipate this static electricity, a transparent conductive film is applied to the outer surface of the glass plate. A guiding kick member may be formed, and the transparent conductive film or electrically conductive member may be allowed to escape to the cooling base. Especially, it is easy to implement the force formed on a separate glass plate 021 as in the present invention.

〔Effect of the invention〕

In the projection type cathode ray tube of the present invention as described above, the stress in the side wall restraint portion was 3000 psi or less at an input power of 30 W, and characteristics sufficiently satisfying the design Φ requirements were obtained. That is, since high brightness can be obtained with a much simpler structure than the conventional structure using a refrigerant, its industrial value is extremely large.

[Brief explanation of drawings]

The figure is a partially omitted exploded view of one embodiment of the projection type cathode ray tube of the present invention. 10...Cathode ray tube 11...Panel 12...
Glass plate 13... Frame-shaped metal decoy plate 14... Cooling plate 15... Support plate agent Patent attorney Inoue - Male

Claims (2)

[Claims] (1) A frame-shaped metal plate closely attached to the outer periphery of the outer surface of the image plane of the fluorescent panel via a grease-like heat dissipating material, and the fluorescent panel connected to the outer periphery of the outer surface. in close contact with the outer periphery of the side wall via the grease-like heat dissipating material, and
1Iltl that is finally integrated with the frame-shaped metal plate.
1. A projection type pole ray tube comprising a wall outer metal body and a radiation fin provided at a desired portion of the wall outer metal body. (2) Disposed on the outer surface of the image plane of the fluorescent panel through a predetermined adhesive layer, the shape is approximately the same as that of the image plane, and the outer surface has no practical hindrance to image projection. a glass plate provided with a drowsy guide member, and a frame-shaped metal plate in which the periphery of the glass plate is brought into close contact with the outer periphery of the outer surface via a grease-like heat dissipating material so as to be in contact with the electrically conductive member. and a side wall outer periphery metal that is in close contact with the side wall outer periphery of the fluorescent panel connected to the outer periphery of the outer surface via the grease-like heat dissipation material and is finally integrated with the frame-shaped metal plate. 1. A projection type cathode ray tube, comprising: a body; and a radiation fin provided at a desired portion of the side wall outer peripheral metal body.