JPS5919299B2 - Vacuum measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a degree of vacuum measuring device capable of measuring the degree of vacuum of a vacuum system to be measured without contacting the vacuum system to be measured.

Generally, when measuring the degree of vacuum in a vacuum system, a vacuum gauge is connected to the vacuum system.

In processes where vacuum treatment is carried out continuously and at high speed, such as for tubes such as thermal light bulbs and fluorescent lamps, connecting a vacuum gauge to each tube or each work head requires complicated equipment and a large amount of expense. It is not a good idea as it requires Therefore, when measuring the degree of vacuum in the manufacturing process of tubes, etc., it is necessary to apply high frequency waves to the tube bulb to cause a high frequency discharge within the tube, and to measure the luminous intensity caused by this discharge. I try to measure the approximate degree of vacuum. However, even with the conventional non-destructive measurement methods mentioned above, although they are extremely simple, they lack measurement reliability because they are measured based on noise-prone elements such as light bulbs and discharge lamps. It has been difficult to apply this method to systems that require complete automation, such as manufacturing lines.

The present invention was made in view of these circumstances, and its purpose is to provide a vacuum that is less affected by noise, has sufficient reliability, can be measured non-destructively and without contact, and has a simple configuration. An object of the present invention is to provide a degree measuring device.

The details of the present invention will be explained below with reference to the illustrated embodiments.

FIG. 1 shows an example in which the degree of vacuum in a vacuum deposition chamber is measured using the apparatus of the present invention, and 1 in the figure indicates a head for deposition.

The open end 2 of the head 1 is hermetically closed by, for example, a semicircular insulating plate 3 whose inner surface is coated with metal, and in this state is connected to an exhaust system (not shown). A vacuum degree measuring device X according to the present invention is arranged near the head 1.

This device X is roughly composed of a high voltage generator circle that generates a high frequency high voltage, and a potential measuring device Lλ that measures the potential near the head 1.

The high voltage generator u has a generator main body 13 and one end connected to the high potential side output end of the generator main body 13,
The other end side is composed of a lead wire 14 extending to the vicinity of the outer surface of the plate 3.

Note that the low potential side output end of the generator main body 13 is grounded. On the other hand, the potential measuring device 11 has one end connected to the lead wire 1.
4 and the outer surface of the plate 3, and a high input impedance voltmeter 16 connected between the other end of the conductor 15 and the ground end. It is configured.

Note that the deflection of the voltmeter 16 is detected by a detection image 1T using, for example, an optical system, and this detector 17 is configured to perform a notification operation such as an alarm when the deflection is outside a predetermined range. has been done. With such a configuration, when the high voltage generator 11 is activated, the lead wire 14
A high frequency high voltage is applied between the free end and the ground point.

Therefore, the head 1 is placed in a high electric field, and a glow discharge A is generated within the head 1. The so-called intensity of this glow discharge depends on the degree of vacuum within the head 1, and is weak when the degree of vacuum is high and strong when the degree of vacuum is low. Therefore, when the degree of vacuum is high, the potential gradient between the plate 3 and the tip of the lead wire 14 is low, as shown in FIG. 2, and the vacuum inside the head 1 shares most of the potential. Therefore, the potential difference between the conductor 15 and the ground point is large, and the voltmeter 16 swings greatly. Also,
When the degree of vacuum is low, the plate 3 is removed as shown in Figure 3.
The potential gradient in the space between
The potential difference between the ground point and the ground point is small, and the voltmeter 16 swings slightly. Therefore, if each related position is made constant and the relationship between the deflection of the voltmeter 16 and the degree of vacuum is calibrated in advance, the degree of vacuum can be immediately measured from the deflection of the voltmeter 16. In this case, if each relative position is kept constant,
The degree of vacuum can be measured without being affected by environmental conditions, etc.
It has the advantage of high measurement reliability. Furthermore, since the overall configuration is extremely simple, there is an advantage that it can be manufactured at low cost. Furthermore, since the degree of vacuum can be measured without contacting the vacuum system to be measured and without destroying the vacuum system to be measured, the present invention is not limited to the example of use in the embodiment, but can be applied as is to various vacuum systems. FIG. 4 shows an example in which the degree of vacuum is measured in a vacuum container that is intermittently conveyed on a belt conveyor, such as a bulb such as a light bulb or a discharge lamp. ,
A high voltage generator 1j and a potential measuring device L2 are arranged near a belt conveyor 23 that moves intermittently in the direction shown by an arrow 22 in the figure, and the output of the detector 17 attached to the potential measuring device [2] The removal mechanism 24 is operated to remove discharge lamps with poor vacuum to the outside of the conveyance path.

With this arrangement, it can be directly applied to a tube manufacturing line. Note that when measuring the degree of vacuum with the device of the present invention, when the pressure in the vacuum system is close to atmospheric pressure or close to absolute vacuum, the swing of the voltmeter is almost the same, and measurement is impossible in such cases.

Therefore, the device of the present invention has a temperature of 760 mmHg to 1×10 −
Suitable for measurement in the range of 41 nmHg. Furthermore, the means for detecting the deflection of the voltmeter is not limited to optical means, but may also be means using a magnetic contactor, air, or other fluids. Furthermore, this measuring device can be applied not only to tubes but also to other vacuum products and equipment for manufacturing and processing such products. As described in detail above, according to the present invention, it is possible to provide a vacuum degree measuring device that can perform non-contact, non-destructive and highly accurate measurement and has a simple configuration.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, FIGS. 2 and 3 are diagrams for explaining the operation of the same embodiment, and FIG. 4 is a configuration diagram of another embodiment of the present invention. It is an explanatory diagram. 11... High voltage generator, 12... Potential measuring device.

Claims (1)

[Claims] 1. Vacuum degree measurement characterized by comprising means for applying a strong electric field to the vacuum system to be measured, a potential detection conductor provided in the electric field, and an instrument for measuring the potential of the potential detection conductor. Device.