JPS6216494B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing a cathode ray tube, and more particularly to an exhaust sealing method and an exhaust sealing apparatus. Conventional cathode ray tube before evacuation, for example, color picture tube 1
has a shape as shown in Figure 1. That is, a face portion 2 having a fluorescent surface (not shown) adhered to the inner surface;
A shadow mask 3 having a large number of electron beam passing holes arranged at predetermined intervals on the fluorescent surface, a mask frame 4 supporting the shadow mask 3, and a large diameter portion in the face portion 2. A funnel part 6 which is connected and has a neck part 5 connected to the small diameter part, an internal conductive film 7 formed from the funnel part 6 and deposited on the inner surface of a part of the neck part 5, and an open end surface of the neck part. A glass exhaust pipe 9 is provided in the center of the stem 8 and extends in the tube axis direction, and a plurality of stem pins 10 are implanted in the peripheral edge of the stem 8. A voltage other than the high voltage is applied from the stem pin 10 to the electron gun 11 attached to the electron gun 11, and the high voltage is applied via the spacer 12 and the internal conductive film 7 from an anode terminal provided in the funnel (not shown). It's summery. The color picture tube having such a structure is evacuated before evacuation by connecting the exhaust pipe 9 to an exhaust device such as an exhaust pump, and when a predetermined degree of vacuum is reached, the exhaust pipe 9 is automatically melt-sealed. The exhaust sealing work will be completed. During this time, the entire color picture tube, particularly the conductive film inside the mask frame 4, the shadow mask 3, and the electron gun 11 are heated to generate gas and the cathode of the electron gun 11 is activated, but these operations are not relevant to the present invention. is omitted as it is not particularly relevant. However, although the above-described evacuation method has been used in the past and is almost an established technology, it has various drawbacks depending on the design of the cathode ray tube. That is, for example, a shadow mask type color picture tube has a shadow mask 3 and a mask frame 4 inside as shown in FIG. A black oxide film (Fe ₃ O ₄ ) is formed and serves as a large gas occlusion body, and the internal conductive film 7 also serves as a large gas occlusion body. Therefore, in a cathode ray tube, such as a shadow mask type color picture tube, which incorporates parts having many gas sources, it is necessary to provide sufficient gas output and a sufficiently high exhaust speed. However, on the other hand, in order to reduce the power consumption of color television receivers equipped with color picture tubes, designs have been made to reduce the diameter of the neck of the color picture tube to reduce the power consumption of the deflection circuit. The tube 9 must also be made thinner in proportion to the neck diameter. In this case, as is well known, the exhaust speed is proportional to the cross-sectional area determined by the inner diameter of the exhaust pipe, so for example, if a glass exhaust pipe neck with an inner diameter of 5 mm is used in a color picture tube with an outer diameter of 29 mm. Comparing the exhaust speed with an exhaust pipe with an inner diameter of 3 mm (used in color picture tubes with an outer diameter of 20 to 22 mm), just reducing the diameter of the exhaust pipe to the extent mentioned above reduces the exhaust speed by approximately 1. /3.
In addition, since color picture tubes generally have a large face part 2, funnel part 6, mask frame 4, etc., the thinner the exhaust pipe is, the more likely it is to break due to mechanical impact during the manufacturing process, resulting in a decrease in productivity. In order to eliminate the above-mentioned drawbacks, attempts have been made to design the diameter of the exhaust pipe 9 to be as large as possible; Moreover, it is impossible to design it to a desired thickness. Another method is to exhaust the air from other than the stem part 8, for example, by providing an exhaust pipe in a part of the funnel part 6 or the neck part 5, but this method is not practical from the viewpoint of structure and cost. Not the point. This invention was made in view of the various drawbacks of the conventional art described above, and it is a cathode ray tube that can obtain a sufficient pumping speed even in a cathode ray tube having a narrow neck diameter and relatively large face and funnel parts. The object of the present invention is to provide a method for manufacturing a tube and an apparatus therefor. Next, one embodiment of the present invention will be explained with reference to FIG. That is, if we take a color picture tube as an example of a cathode ray tube, the color picture tube before exhaust sealing, that is, the envelope 21 , includes a face portion 22 having a fluorescent surface (not shown) adhered to the inner surface, and a face portion 22 with a fluorescent surface (not shown) adhered to the inner surface. A shadow mask 23 having a large number of electron beam passage holes arranged at intervals, a mask frame 24 supporting the shadow mask 23, and the face portion 22.
It consists of a funnel part 26 having a large diameter part connected to the neck part 25 and a neck part 25 connected to a small diameter part, and an internal conductive film 27 formed from the funnel part 26 to the inner surface of the neck part 25 . The envelope 21 is the base 3 of the exhaust device 33 .
By placing the funnel portion 26 on a support frame 35 implanted in the tube 4, the funnel portion 26 is supported so that the tube axis is in a predetermined position. Next, a plurality of stem pins 30 are implanted in the stem 28 , and an electron gun 31 consisting of a plurality of electrodes is attached to one of the stem pins 30 . The stem 28 is designed to apply a desired voltage to the electrodes except for the stem pin 3 in an opening provided on the upper surface of the mounting table 36.
The mounting table 36 is made movable in the tube axis direction via a sliding ring 38 and fixed at a predetermined position by a screw 39. On the upper surface of the peripheral edge of the stem 28, that is, on the upper surface of the portion that loosely fits into the inner surface of the neck 25 near the open end ₂₅₁ , a solder glass 40 is coated in an annular shape or placed as a member.
The gap 29 between the inner surface and the vicinity of the open end ₂₅ is approximately 1
It is designed to be held at about mm. Further, around the neck portion 25, a heating coil 42 ₁ of the electron gun and a heating coil 42 ₂ for melting the solder glass and sealing the gap 29 are provided.
are provided, and the envelope 21 , a support frame 35,
A bell gear 43 is airtightly mounted on the base 34 of the exhaust device 33 with screws 44 so as to surround the mounting base 36, and an exhaust hole 45 is provided in the center of the base 34. A protrusion ₃₄₁ formed around the periphery is connected via a pipe 46 to a large-capacity exhaust pump (not shown) that exhausts the air in the direction of an arrow 47. In the figure, 32 indicates a spacer. Now, after the envelope 21 , stem 28, etc. are arranged as described above, exhaust is performed as follows. That is, the evacuation procedure is performed using a heating device (not shown) provided outside the bell gear 43 made of metal.
3 and heat the shadow mask 23 in the envelope 21 ,
At the same time, exhaust is performed by an exhaust pump (not shown) while releasing the gas contained in the pipe internal parts such as the internal conductive film 27 of the mask frame 24. After a predetermined period of time, the heating coil 42 ₁
As in the conventional case, the electron gun 31 is heated by the electron gun 31 to degas the electron gun 31, and then the thermionic emission surface of the cathode built into the electron gun 31 is activated. . Next, when the above-mentioned series of so-called exhaust steps are completed, the heating coil ₄₂₂ is activated to remove the solder glass 40.
When heated and melted, the solder glass fills the gap 39 between the stem side wall and the inner wall ₂₅₁ near the open end of the neck 25. Of course, the amount of filling of the solder glass 40 into the gap 39 at this time is determined by the heating temperature and time.
In this way, the sealing process is completed. The embodiments of the present invention described above have the following various advantages. First of all, the exhaust gas is connected to the side wall of the stem 28 and the neck part 2.
This is done by a gap 39 between the open end portion 251 and the inner wall of the open end ₂₅₁ , and the effective cross-sectional area of this gap 39 can also be secured to be approximately 50 to ⁶⁰ mm. This is about three times the exhaust pipe (inner diameter 5 mm) of a color picture tube with a 29 mm neck that is commonly used in the past, and if the neck diameter becomes thinner, the ratio will become even larger. As a result, efficient evacuation can be performed and a color picture tube having an extremely high degree of vacuum can be obtained. Next, in this embodiment, an exhaust pipe for the stem is not required, and therefore, not only can the cost of the stem be reduced, but also there is no problem of exhaust pipe bending, which was the most common problem in conventional exhaust systems. Furthermore, the most important thing is that conventionally sealing was performed by welding the envelope and the stem fitted with the electron gun before evacuation, but according to this embodiment, the sealing work can be performed in the same process as the evacuation work. This has the advantage that the conventional sealing process can be omitted. In addition, since no exhaust pipe is required, there is more room for the lead-in wires, accidents caused by distortion of the glass stem are reduced, and the reliability of the color picture tube is improved. In the above-mentioned embodiment, a method of sealing the gap by placing solder glass on the side edge of the stem and melting it was explained, but the method is not limited to this, and it is also possible to use a method instead of a bell gear. A vacuum gasket that can withstand high temperatures is used in contact with the outer wall of the funnel or neck to exhaust only the area below the funnel or neck, and the heating is applied directly to the envelope via the bell gear. Of course, the device can be simplified and the exhaust device can be made smaller. As mentioned above, the cathode ray tube manufacturing method and apparatus of the present invention can be applied not only to color picture tubes but also to black and white picture tubes and all other cathode ray tubes that conventionally use exhaust pipes, so that they can be applied to various industries. The value is extremely high.

[Brief explanation of the drawing]

FIG. 1 is a simplified sectional view showing the structure of a conventional cathode ray tube before evacuation, FIG. 2 is a simplified sectional view of an embodiment of the present invention, and FIG. 3 is an enlarged sectional view of section A in FIG. 21 ... Envelope, 2, 22... Face part,
3, 23... Shadow mask, 11, 31... Electron gun, 5, 25... Network part, 8, 28... Stem, 9... Exhaust pipe, 29... Gap part, 40... Solder glass.

Claims (1)

[Scope of Claims] 1. An outer enclosure consisting of a face portion having a fluorescent surface adhered thereto, and a funnel portion having a large diameter portion connected to the face portion and a neck portion connected to the small diameter portion. A step of mounting an electron gun through a mounting table so as to have a gap between the inner wall near the open end of the neck portion and loosely fitting the stem on which the solder glass is placed inside the device; A method for manufacturing a cathode ray tube, comprising the steps of: evacuating the inside of the envelope; and after evacuating, melting the solder glass and sealing the gap. 2. At least the neck portion of the envelope consists of a face portion on which a fluorescent surface is adhered and formed on the inner surface, and a funnel portion having a large diameter portion connected to the face portion and a neck portion connected to the small diameter portion. a container that airtightly holds the vicinity of the open end; a mounting table into which the stem, on which the electron gun is mounted and the solder glass is mounted, is loosely fitted so as to have a gap between the inner wall and the inner wall of the neck portion in the vicinity of the open end; and an exhaust device that heats and exhausts the inside of the envelope and the electron gun through the gap, and a heating coil that melts the solder glass after exhausting and seals the gap. Cathode ray tube manufacturing equipment.