JP2919185B2 - High frequency heating device for fluorescent display tubes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency heating device for a fluorescent display tube, and more particularly to a high-frequency heating device for a fluorescent display tube for heating gettering.

[0002]

2. Description of the Related Art A conventional high-frequency heating apparatus for a fluorescent display tube is:
As shown in FIG. 4, a high frequency generator 5 for generating a high frequency, a heating coil 1 for inducing a high frequency, a concentrator 3 for concentrating the high frequency and heating the gettering 6 and a heating state of the gettering 6 for receiving light generated at the time of heating. And a light receiving sensor 4 for outputting a signal. Note that gettering 6
The purpose of heating is to further increase the degree of vacuum inside the evacuated fluorescent display tube 8.

Next, a method of heating a getter by the present apparatus will be described.

As shown in FIG. 5, first, a getter ring 6 attached to a support 7 inside a fluorescent display tube 8 is brought close to the tip of the heating coil 1 for inducing high frequency.
Next, the concentrator 3 is passed through the hole of the plate portion at the tip of the heating coil 1 to approach the gettering 6, so that high frequency is concentrated on the gettering 6 and heated. The heating coil 1 and the concentrator 3 maintain an arbitrary gap, and the light receiving sensor 4 is attached to a position where the heating state is obliquely checked from this gap. When the heating is continued, the gettering 6 forms an opaque getter film 9 on the inner glass surface of the fluorescent display tube 8. When the getter film 9 becomes thicker, the amount of light entering the light receiving sensor 4 decreases, and the light receiving sensor 4 operates. After that, the concentrator 3 receives a signal from the light receiving sensor 4.
Then, the fluorescent display tube 8 returns to the home position, and the heating of the gettering 6 is completed.

[0005]

The above-mentioned conventional high-frequency heating apparatus for a fluorescent display tube monitors the heating state of gettering from a gap between a heating coil and a concentrator.
At the time of gettering heating, there is a problem in that partial heating of other components is monitored and erroneous detection is performed, or when the getter film is small, a decrease in the amount of received light cannot be detected, resulting in overheating failure of gettering.

Further, since the light receiving sensor is mounted obliquely with respect to the concentrator, there has been a problem that it is difficult to adjust the position for reliable detection.

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-frequency heating device for a fluorescent display tube in which the positions of the light receiving sensor and the concentrator are easily adjusted and no overheating is caused by erroneous detection.

[0008]

According to the present invention, there is provided a high-frequency oscillator for generating a high frequency, a heating coil for inducing the high frequency, and the inside of the fluorescent display tube exhausted by concentrating the high circumference induced by the heating coil. In a high-frequency heating apparatus for a fluorescent display tube having a concentrator for heating the gettering disposed in the apparatus and a light receiving sensor for confirming a heating state of the gettering, an optical path is provided by making the concentrator tubular, and the gettering and the optical path are provided. And the light receiving sensor are arranged on the same straight line.

[0009]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a partial cross-sectional side view showing the structure of a first embodiment of the present invention, and FIG. 2 is a partial cross-sectional side view for explaining a gettering heating method according to the embodiment of FIG.

In the first embodiment, as shown in FIG. 1, a heating coil 1 is brazed to a copper plate and a copper tube, and cooling water 2 flows through the copper tube. A hole larger than the diameter of the end of the concentrator 3 is formed in the plate at the end of the heating coil 1 so as not to come into contact with the concentrator 3, and the other end is screwed or brazed to the high-frequency generator 5. Fixed. The concentrator 3 has a tube-shaped optical path, is insulated and fixed to the heating coil 1, and has a structure capable of moving to the heating coil 1 side. Where
Centrifuges are generally made of magnetic ferrite.
By bringing the concentrator closer to the heating coil,
The magnetic flux around the heating coil is collected near the tip of the concentrator.
The bundle near the tip of the concentrator
High frequency can be concentrated on tarling. The light-receiving sensor 4 is attached while being insulated and fixed to the concentrator 3 so that the light-receiving sensor 4 can always be moved at equal intervals to prevent heating. The gettering 6, the optical path of the concentrator 3, and the light receiving sensor 4 are arranged on the same straight line. Receiver
The gettering 6 heated by high frequency induction
The heat generated by the temperature rise is detected.

As shown in FIG. 2, the gettering 6 is heated by bringing the fluorescent display tube 8 close to the heating coil 1 and the concentrator 3 approaching the gettering 6 through a hole in the plate at the tip of the heating coil 1. And heat it.

The light receiving sensor 4 monitors the amount of light passing through the optical path of the concentrator 3 to obtain gettering 6.
Can be easily checked. When the heating is continued and the opaque getter film 9 is formed, the amount of incident light decreases, and the light receiving sensor 4
, The concentrator 3 and the fluorescent display tube 8 return to their home positions, and the heating of the gettering 6 is completed.

FIG. 3 is a partial cross-sectional side view for explaining a gettering heating method according to a second embodiment of the present invention.

In the second embodiment, as shown in FIG. 3, the heating coil 1 has the same structure as that of the first embodiment, but a tube-shaped concentrator 3 is resin-bonded to the hole of the plate at the tip. The light receiving sensor 4 is insulated from the heating coil 1 and insulated from the heating coil 1 by being insulated and fixed by the agent 10.
The heating state of the gettering 6 can be easily confirmed through the optical path.

[0016]

As described above, according to the present invention, the concentrator of the high-frequency heating apparatus for a fluorescent display tube is provided with a tube-shaped optical path, and the gettering, the optical path of the concentrator and the light receiving sensor are arranged in the same straight line. When heating gettering, partial heating of other components is not detected, and even if the getter film is small, it is easy to detect a decrease in the amount of received light. It has the effect of being prevented.

Further, since the light receiving sensor is mounted on the same straight line with respect to the optical path of the concentrator, there is an effect that the position can be easily adjusted.

In the second embodiment, since the concentrator is always cooled by the cooling water, there is also an effect that the overheating efficiency of the concentrator can be prevented from lowering.

[Brief description of the drawings]

FIG. 1 is a partial sectional side view showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a partial cross-sectional side view for explaining a gettering heating method according to the embodiment of FIG. 1;

FIG. 3 is a partial cross-sectional side view illustrating a gettering heating method according to a second embodiment of the present invention.

FIG. 4 is a partial cross-sectional side view showing an example of the configuration of a conventional high frequency heating device for a fluorescent display tube.

5 is a partial cross-sectional side view illustrating a method of heating gettering by the high-frequency heating device for a fluorescent display tube of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating coil 2 Cooling water 3 Concentrator 4 Light-receiving sensor 5 High frequency generator 6 Gettering 7 Support body 8 Fluorescent display tube 9 Getter film 10 Resin adhesive

Claims (1)

(57) [Claims] 1. A high-frequency oscillator for generating a high-frequency wave, a heating coil for inducing the high-frequency wave, and a gettering disposed inside a fluorescent display tube which is concentrated and evacuated by the high-period induced by the heating coil. In a high-frequency heating apparatus for a fluorescent display tube having a concentrator for heating and a light receiving sensor for checking a heating state of the gettering, an optical path is provided by making the concentrator tubular, and the gettering, the optical path and the light receiving sensor are arranged on the same straight line. A high-frequency heating device for a fluorescent display tube, wherein the high-frequency heating device is arranged in a device.