JPS6231923A - Heating method for cathode-ray tube - Google Patents

Abstract

PURPOSE:To prevent the breakdown of a cathode-ray tube by blowing heated air alternately from the panel side and the funnel side when the cathode-ray tube is heated to remove the volatile component included in the fluorescent coating on the inside surface of the panel. CONSTITUTION:An air blower 3 provided with a fan 3A rotatable to both direction of normal and inverse is provided at the center of the upper wall of an oven room 2 of a heating furnace 1, and on both sides of the fan the radiant tubes 4, 5 and the guide plates 6, 7 are arranged. A cathode-ray tube 10 is inserted between the guide plates so as the panel side is upward and heated by blowing the heated air alternately from the panel side while the normal rotation of the air blower fan and from the funnel side while the inverse rotation of the said fan to remove the volatile component included in the fluorescent coating applied on the inside surface of the panel. Therefore the whole cathode ray tube can be heated uniformly to prevent surely the breakdown of the cathode-ray tube due to the thermal strain.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for heating a cathode ray tube, which is applied when creating a vacuum inside the cathode ray tube.

[Background of the invention]

A cathode ray tube consists of a panel and a funnel, and the inner surface of the panel is coated with fluorescent paint. Therefore, when vacuuming the inside of the cathode ray tube, the pressure is usually 350~
[Prior art] Conventionally, as shown in Fig. 5, a blower (3 ) hanging down from both sides of the radiant tube (4) which is a heating source.

(5) is suspended, and the radiant tube (4), (
A configuration in which a force is attached to the guide plate f6) inside the heating furnace (1) is applied, and a trolley (8) is installed inside the furnace chamber (2) of the heating furnace (1).
The cathode ray tube (101) supported on the support part (9) is blown into the tube and the hot air is circulated as shown by the arrow by the blower (3) to heat the cathode ray tube (10). No. 59-33727).

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional technology, the temperature of the hot air blown onto the cathode ray tube (1) decreases as it goes from the panel side to the funnel side. If it is attached, the temperature on the funnel side will be approximately 265℃, which will lower the overall heat transfer coefficient, causing uneven heating between the panel side and the funnel side of the CRT A, which may easily cause damage to the CRT A. Means for Solving] The present invention provides a method for solving the above-mentioned problems of the prior art by improving panel θ [A side and funnel 00) B of a cathode ray tube α0).
Hot air is blown alternately from the sides.

[Effect]

The operation of the present invention is as follows.0 The temperature of the hot air blown from the panel side of the cathode ray tube decreases as it goes to the funnel 111j, and the overall heat transfer coefficient to the funnel side decreases. Next, the hot air blown from the funnel side of the cathode ray tube decreases in temperature as it goes toward the panel side, and the overall heat transfer coefficient toward the panel side decreases.

〔Effect of the invention〕

Therefore, in the present invention, as a result of blowing hot air alternately from the panel side and the funnel side of the cathode ray tube, the cathode ray tube is heated uniformly, and damage to the cathode ray tube due to thermal distortion can be reliably prevented. . In addition, since both the panel side and the funnel side are heated uniformly, the temperature drop of the hot air blown from the panel side or the funnel side is small, and therefore the overall heat transfer coefficient is also small. Thus, according to the present invention, the required amount of hot air is reduced to about 60 inches compared to the conventional method.

In Figures 1 and 2, a fan (3) A that can rotate forward and backward is installed from the center of the clay wall of the furnace chamber (2) formed in the heating furnace (1) in Figure 0 showing the first embodiment. Blower with (3)
is suspended from both sides of the blower (3), and radiant tubes (4) and (5), which are heating sources, are suspended from both sides of the blower (3), and a guide plate (
6).

(7) is installed. The heating furnace (1) has a furnace chamber (2).
) are arranged in parallel as shown in Fig. 2 to form the furnace chamber (2).
Inside, a trolley (8) mounted on a rail 0υ is conveyed at a predetermined speed, and a cathode ray tube a0 is supported on the support portion (9) of the trolley (8) with the panel side facing upward. There is. When the fan (3) A of the blower (3) rotates forward, the hot air circulates as shown by the solid arrow, heating the cathode ray tube OQ from the panel side, and the hot air itself is cooled by the radiant tube +4) and (5). It will be heated again. Also, when fan (3) A rotates in the opposite direction, the hot air flows as shown by the dotted arrow.
The hot air circulates to the radiant tube (4) and heats the cathode ray tube OI from the funnel side, and the hot air itself is cooled.
.

(5)) is heated again. At the same time, the inside of the cathode ray tube 0 is evacuated via the support part (9).
The volatile components of the fluorescent paint applied to the inner surface of the panel are removed.

As shown in Figure 3, the cathode ray tube 00) is connected to the panel (10A
For example, panel (10)
The thickness tl of A is 12.5 uoa, 7 annel (the upper thickness tl of 10B is 9.4 rsttr, the lower thickness t3
is 2.5 peng, and in this case the weight of the panel QOIA is about 1
0kg, n-annel (IOIB weighs about 5~

Therefore, the heat capacity ratio of panel:funnel is approximately 2:1. Therefore, in order to uniformly heat the cathode ray tube α■, it is desirable that the forward rotation time:reverse rotation time of the fan (3)A of the feeder (3) be approximately 2:1.

FIG. 4 shows a second embodiment. In this embodiment, a plurality of furnace chambers (2)A in which the fan (3)A of the blower (3) rotates in the forward direction and a plurality of furnace chambers (2)B in which the fan (3)A of the blower (3) rotates in the reverse direction are arranged in parallel.

Furnace chamber (2) A and furnace chamber (2) B are cathode ray tube (1)
0) are arranged at a ratio equal to the heat capacity ratio of the panel QOA and the funnel QGB. Braun tube aO shown in Figure 3
) In the case of (2) A: F chamber (2) B = 2:1, the furnace chamber (2) 8-furnace chamber (2) A-furnace chamber (2) B-furnace chamber (2)
)A-...They are arranged like a mountain. The cathode ray tube α0) is blown with heated air alternately from the panel side and the funnel side, but the amount of hot air blown is equal to the heat capacity ratio of the panel and the funnel, so the cathode ray tube θ0)
is heated evenly.

In addition to the embodiments described above, the blower may also be attached to the side of the furnace chamber to blow hot air from the side. In addition to the radiant heat source, a well-known heating source such as a burner or an electric heater may be used. The heating temperature of a cathode ray tube is usually 350 to 400.
It is about ℃. Further, in the present invention, it is desirable that the amount of air blown from the panel side and the funnel side of the cathode ray tube match the heat capacity ratio of the panel and the funnel, but this does not limit the present invention.

[Brief explanation of the drawing]

1 and 2 relate to a first embodiment of the present invention, in which FIG. 1 is a cross-sectional view, FIG. 2 is a plan view, FIG. 3 is a sectional view of a cathode ray tube, and FIG. FIG. 5 is a schematic partial vertical cross-sectional view of the second embodiment, and FIG. 5 is a cross-sectional view of the conventional example. In the figure (1)...Heating furnace, (2)...Furnace chamber, (3)
...Blower, (3)A...Fan, 00)...Cathode ray tube, (10)A...Panel, (In)B...
Funnel patent applicant: Daido Steel Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] A method for heating a cathode ray tube characterized by blowing hot air alternately from the panel side and the funnel side of the cathode ray tube.