JP2907829B2 - Gas discharge tube lighting method - Google Patents

Description

The present invention relates to a gas-filled discharge tube, and more particularly to a discharge lighting method suitable for a discharge lamp using Townsend discharge. [Prior Art] Conventionally, a lighting circuit system for a gas-filled discharge tube has been discussed in "Lighting Handbook, (1978), pp. 160-203 (published by Ohmsha)". In this document, the lighting method of the fluorescent lamp is discussed. [Problems to be Solved by the Invention] The above-mentioned prior art does not discuss the lighting of the townsend discharge with a small current, and the technology of automatically starting the townsend discharge has not been established. An object of the present invention is to automatically start Townsend discharge. Another object is to control the amount of ultraviolet light after lighting. [Means for Solving the Problems] The above object is achieved by applying a composite waveform of a DC voltage and a pulse voltage between an anode and a cathode of a gas discharge tube. Further, the control of the amount of ultraviolet rays is achieved by controlling the applied voltage of the amount of ultraviolet rays after lighting up via an ultraviolet ray detector. [Operation] The gas sealed in the discharge tube is ionized by a DC voltage applied between the anode and the cathode. Therefore, the value of the DC voltage is set to the minimum voltage required for remaining charged particles generated by ionization.
After the application of the DC voltage, the charged particles remaining in the tube are continuously excited by a pulsed voltage. This excitation causes a breakdown when the pulse voltage rises, and a current flows through the discharge tube. As a result, the energy level of the charged particles changes, and the charged particles emit ultraviolet light to cause the phosphor on the tube wall to emit light. In this way, the discharge can be automatically started by combining the application time of the DC voltage and the pulse voltage. Further, in the present invention, the ultraviolet ray generated by the discharge is detected, and the current flowing through the discharge tube is controlled. Therefore, the peak value of the applied pulse voltage and the cycle of the pulse are varied to control the amount of ultraviolet light. Embodiment One embodiment of the present invention will be described below with reference to FIG.
FIG. 1 is a block diagram for explaining the present invention. When a switch 100 is turned on, a DC voltage application timing circuit 101 operates and outputs a timing signal of V _DC shown in FIG. 2 for a predetermined T _DC period. At the end of the _TDC period, the signal line 110
, The pulse timing generation circuit 102 is activated. A pulse timing generation circuit generates a pulse signal consisting V _P shown in Figure 2. According pulse signal V _P is the passage of time, issues a waveform period of the pulse is changed, the supply to the connexion driver circuit 104 preparative logical sum of V _DC signal and V _p signal of the DC voltage application timing circuit 101 by an OR circuit 103 I do. In response to the above timing, the driver circuit 104 applies a high voltage to the discharge tube unit 106. FIG. 3 shows a circuit example of the driver circuit 104. The signal of the logical sum is applied to the gate G of the FET (field effect transistor). A resistor 30 is connected in series with the discharge tube 302 on the drain D side of the FET.
3, and a resistor 301 is connected in parallel with the connection. The resistor 301 is provided for determining the potential of the cathode K of the discharge tube 302, and the resistor 303 is provided for the purpose of stabilizing the discharge. By applying the gate voltage, the voltage between the drain D and the source S decreases, and the FET is completely turned on.
Goes to ground level. As a result, a high voltage is applied to the anode A and the cathode K of the discharge tube 106, and charged particles are discharged from the discharge tube 30.
Generate within 2. Here, the DC voltage application period T _DC varies depending on the gas pressure and gas type in the discharge tube, but is set to a range in which glow discharge is not generated and a time for generating charged particles. Then a pulse high voltage従Tsuta timing through the driver circuit 104 to the V _P of FIG. 2 is applied to the discharge tube section 106. The Townsend discharge occurs seed the T _DC generated charged particles to a high voltage pulse T _ON period into the discharge tube 302. For example, a mercury (6 ×
10 ^-3 Torr) and argon (3 Torr) are sealed and the rise is 50 × 1
0 ^-9 seconds Townsend discharge when a pulse voltage is applied to it is confirmed that has occurred. As a result, ultraviolet rays are generated inside the tube by the discharge and radiate outside the tube. The generated ultraviolet light is detected by the detector circuit 107 shown in FIG. A voltage V _SET in proportion to a target amount of emitted ultraviolet light is set in the discriminating circuit 111 in advance. In order to temporally average the pulsed ultraviolet light, the ultraviolet light is detected by an ultraviolet light detection circuit 107 inserted with an integration circuit. The V _B of the signal a second view of the ultraviolet detector 107 via the signal line 108 placed on the discrimination circuit 111, setting value V
_{Make a} comparison with _SET . As a result, when it is below the set value,
A voltage is applied to the pulse timing circuit 102 via the signal line 109 to reduce the pulse cycle (increase the frequency). As the frequency increases, the amount of ultraviolet light due to discharge increases, and the signal of the ultraviolet light detection circuit 107 increases. Therefore always compares the signal V _B from the setting value and an ultraviolet detector circuit 107, and stops the voltage signal for varying the period of the pulse when has decreased to less than the set value, holds. As a result, radiation of a predetermined amount of ultraviolet light can be obtained. Further, in the present invention, no coil is required for the automatic discharge lighting circuit and the ultraviolet ray amount control circuit. Therefore, the circuit can be easily integrated into an IC. [Effects of the Invention] As described above, according to the lighting method of the present invention, a townsend discharge is automatically generated and the amount of ultraviolet rays can be controlled. It is effective.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a timing chart and waveform diagram of signals used in FIG. 1, and FIG. FIG. 2 is a circuit diagram illustrating an example of a driver circuit 104. 100: switch, 101: DC voltage application timing circuit, 10
2… Pulse timing generation circuit, 103… OR circuit, 104…
Driver circuit, 105: high voltage application circuit, 106: discharge tube section,
107 ... ultraviolet ray detection circuit, 111 ... discrimination circuit.

Continuation of the front page (56) References JP-A-50-113068 (JP, A) JP-A-53-100676 (JP, A) JP-A-61-71596 (JP, A) JP-A-59-60881 (JP, A) , A) (58) Field surveyed (Int.Cl. ⁶ , DB name) H05B 41/14-41/234 H05B 41/26-41/30

Claims (1)

(57) [Claims] A gas discharge tube in which a phosphor is applied to a tube wall and gas is sealed, and a glow discharge is not generated in a driving circuit of the discharge tube, and a DC voltage and a Tausen discharge which are output during generation of charged particles are generated and maintained. Means for obtaining a pulse voltage;
A gas discharge driving device comprising: a detecting unit for detecting ultraviolet rays from the discharge tube; and a unit for controlling an interval between the pulse voltages based on a signal from the detecting unit. 2. 2. The gas discharge driving device according to claim 1, wherein the driving circuit is a field effect transistor. 3. 2. The gas discharge driving device according to claim 1, wherein the rise time of the pulse voltage is about 50 nanoseconds.