JPS6282699A - Microwave discharge light source - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] This invention relates to a microwave discharge light source device for lighting an electrodeless lamp using microwaves generated by a microwave oscillator such as a magnetron. Something.

In particular, it relates to the $(Ja) method of power supply for driving a microwave oscillator.

[Conventional technology]

For example, FIG. 7 is a circuit diagram showing an example of a microwave discharge light source device which is controlled based on the conventional optical signal number disclosed in Japanese Patent Laid-Open No. 59-103271.

In the figure, (111! microwave oscillator, (2) is (1
) is a power source for driving a microwave oscillator, (3) is an electrodeless lamp that emits light when excited by a microwave flea, (4)
) is a light receiving element that detects the light from this electrodeless lamp.

The operation is as follows. That is, the light intensity of the electrodeless lamp (3) emitted by the microwave from the microwave oscillator is detected by the light receiving element (4), and the signal from the light receiving element (4) of C and the predetermined control logic G are detected. Based on this, open and close the contact (Sl, change the capacitor valley shortness,
This controls the drive input to the microwave oscillator.

However, in this conventional method, only the light output at the time of light emission is detected by the light receiving element (4), so the lamp tube wall changes due to the duration of continuous lighting and the microwave input to the lamp. There was a drawback that the thermal load could not be detected and the thermal lamp would be damaged.

[Means for solving problems]

The present invention has been made to solve the above-mentioned drawbacks of conventional microwave discharge light source devices.

It detects the radiant heat from the tube wall of the lamp, and if the intensity of this radiant heat exceeds a set value, it reduces or stops the microwave output to prevent the lamp from being damaged. The purpose is to

[For production]

For this reason, the present invention uses a light-receiving element that is sensitive to infrared radiation or its vicinity, provides an extremely short microwave pause period, and during this period, the radiation energy from the lamp tube wall is detected. , is characterized by controlling.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit block diagram of a microwave discharge light source device showing an embodiment of the present invention. In FIG. 2, the same reference numerals as in FIG. 7 represent the same or corresponding parts.

Below, the operation in this circuit block diagram is explained by the power supply (
2) boosts and rectifies the commercial power supply to generate the power supply voltage shown in Figure 2, which is necessary to operate the microwave oscillator (1). Based on this power supply, a microwave oscillator (1
) does not generate microwaves below a certain voltage as its own characteristic, so it generates the microwave output shown in Figure 4. Namely.

For the power supply voltage in Figure 2, the microwave output is T in Figure 3.
It will have a suspension period as shown below. This microwave output is applied to an electrodeless lamp (3) using a microwave resonator (not shown) for three days, and the electrodeless lamp (3) is excited to emit light. The signal detected by the light receiving element (4) is the fifth
As shown in the figure. As the electrodeless lamp (3) continues to be lit and the temperature of the tube wall of the lamp (3) rises, the signal level of the signal in Figure 4 increases during the rest period as shown in Figure 5, and this is determined by a certain standard. By comparing the voltages, a signal indicating an abnormal temperature rise on the wall of the lamp (3) as shown in Fig. 6 can be obtained, and based on this signal, the power supply device (2) controls the subsequent microwave oscillator ( 1) The drive is controlled and 9, for example, the drive is stopped. Alternatively, damage to the electrodeless lamp (3) can be prevented by control such as reducing the power supply voltage output as shown in FIG.

〔effect〕

In this way, according to the present invention, the amount of infrared radiation from the tube wall of the lamp is measured while the plasma is not emitting light. This can be done in an extremely cheap and easy way, and has high practical value.

[Brief explanation of drawings]

Fig. 1 is a circuit block diagram of a microwave discharge light source device showing an embodiment of the present invention, Fig. 2 shows a voltage wave of the power supply supplied from the power supply device shown in Fig. 2 to the microwave oscillator, and Fig. 3 shows the voltage wave of the power supply supplied from the power supply device shown in Fig. , Figure 1 shows the microwave output diagram from the microwave oscillator φ driven based on the power source, Figure 3 shows the light emitting output of the electrodeless lamp l which is excited to emit light from the microwave energy ρ in Figure 7, and the light receiving element Figure 5 shows the signal output diagram of the light detected by the light-receiving element when the temperature of the tube wall of the electrodeless lamp rises. A signal diagram when the signal output is calculated using a certain set reference voltage, and FIG. 7 is a circuit diagram showing an outline of a conventional device. In the figure, (1) is a microwave oscillator, and (2) is a power supply device. (3) is an electrodeless lamp, and (4) is a light receiving element. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] At least a microwave oscillator, a power source for driving the microwave oscillator, a forced air-cooled electrodeless lamp lit by the microwave, and a light-receiving sensitivity at or near infrared rays for detecting light from the electrodeless lamp. A light receiving element is provided, and the microwave generation is paused for a very short period of time, and the drive of the microwave oscillator after this pause period is controlled based on the signal level from the light receiving element during this pause period. Microwave discharge light source device.