JPH0698479A - Discharge lamp lighting circuit - Google Patents

Abstract

(57) [Summary] [Object] The discharge lighting circuit according to the present invention backs up a power failure of a power source with a simple configuration. [Structure] A discharge lighting circuit according to the present invention performs discharge lighting on a discharge path L. Discharge lighting circuit of the present invention, a first power supply E _B, which is connected to the discharge path L of the first voltage higher than the voltage of the power source E _B for outputting a voltage for connected to said discharge path L discharge lighting a second power source E _a for outputting said first-acid unit C _B of the first charging voltage is charged by the power source E _B is applied to the discharge path L when instantaneous interruption of the first power source E _{B A} second power storage means C _A that is charged by the second power source E _A and applies a charging voltage to the discharge path L when the second power source E _A is interrupted; Current limiting means R _A and R _B that are provided in the application path and limit the current are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting circuit for a direct current lighting discharge tube (hereinafter, simply referred to as a discharge tube) used in a large-sized image display device installed in, for example, a baseball field, a racetrack, etc. Is.

[0002]

2. Description of the Related Art As shown in FIG. 2, a large image display device has a frame 1 on which a plurality of display units 2 are arranged in a matrix to form a display screen.

Details of the display unit are shown in FIG. The surface plate 3 is formed with holes in a matrix shape, and the head of the discharge tube 4 is provided so as to project from the holes. Discharge tube 4
The base portion of the above is engaged with the holder 5, and a circuit is provided in the case 6 behind the holder 5 for controlling the lighting of the discharge tube 4. On the back surface of the case 6, connectors and the like connected to the lines leading to the respective circuits are provided.

A circuit for controlling lighting is constructed, for example, as shown in FIG. That is, the video signal is the terminal 21
The signal arrives at the A / D converter 22 via the, is converted into a digital signal, and is sent to the signal processing unit 23. On the other hand, a synchronization signal synchronized with the video signal is applied to the timing pulse generation circuit via the terminal 24, and a pulse having a predetermined frequency synchronized with the video signal is created. This pulse is given to the signal processing unit 23, where the digital signal is converted into data and sent at a speed according to the pulse, for example, to a blinking display circuit 26 provided corresponding to each display unit 2. . The blinking control circuit 26 performs blinking control for each discharge tube by pulse width control based on the above digital data, and gradation control is performed for each discharge tube.

The signal relating to the gradation control is given to the terminal 10 of the conventional discharge lighting circuit shown in FIG. A voltage from a power source Ef for filament heating is applied to the cathode of the discharge tube L to heat the cathode. The transistor Q, which is a switch, is turned on / off by the signal given to the terminal 10, and the voltage of the main power source E _B1 (E _B2 ) is applied to the discharge tube L via the resistor R _B. In addition, an auxiliary power supply E _A1 (E _A2 ) that outputs a voltage higher than the voltage of the main power supply E _B1 (E _{B 2} ) is provided, and the voltage of this auxiliary power supply E _A1 (E _A2 ) passes through the resistor R _A. It is applied to the discharge tube L. The diode D connected to the emitter of the transistor Q has a structure for preventing a reverse current flow due to the auxiliary power supply E _A1 (E _{A 2} ).

In the above discharge lighting circuit, the main power source E
The voltage of _B1 (E _B2 ) is, for example, several tens of volts,
The voltage of the auxiliary power supply E _A1 (E _A2 ) is several hundreds of volts, and the voltage of the auxiliary power supply E _A1 (E _A2 ) is constantly applied to the discharge tube L to cause a slight discharge, and the lighting voltage is lowered to start. The characteristics are improved.

Also, two main power sources, E _B1 and E _B2, and two auxiliary power sources, E _A1 and E _A2 , are provided in order to prepare a dual power source and prepare for a momentary power interruption. is there. Therefore, the switch SW _A provided in the switching unit 12,
SW _B is switched by the power source switching control unit 11 so that the standby power source is used when the current power source is interrupted.

[0008]

However, according to the discharge lighting circuit having the above-mentioned configuration, although there is an advantage that a stable display or the like can be provided by duplicating and switching the power supply system as a power failure countermeasure, There is a problem that the configuration becomes large and complicated, and the cost becomes very high.

The present invention has been made to solve the problems of the conventional discharge lighting circuit as described above, and its purpose is to reduce the size and simplification of the structure, reduce the cost, and reduce the cost of a normal power supply. An object of the present invention is to provide a discharge lighting device that can sufficiently cope with a defect.

[0010]

Therefore, in the present invention, a first power supply which is connected to the discharge path and outputs a voltage for discharge lighting to a discharge lighting circuit for performing discharge lighting on the discharge path,
A second power source that is connected to the discharge path and outputs a voltage higher than the voltage of the first power source; and a first power storage unit that is charged by the first power source and applies a charging voltage to the discharge path. A discharge lighting circuit is configured by including a second power storage unit that is charged by the second power source and applies a charging voltage to the discharge path.

Furthermore, according to the present invention, a first power source connected to the discharge path and outputting a voltage for discharge lighting to a discharge lighting circuit for lighting the discharge path by discharge, and the discharge power circuit connected to the discharge path. A second output that outputs a voltage higher than the voltage of the first power supply
Power source, a first power storage unit that is charged by the first power source and applies a charging voltage to the discharge path when the first power source is interrupted, and a charging voltage that is charged by the second power source A discharge lighting circuit is configured by including a second power storage unit that is applied to the discharge path when the second power source is momentarily cut off, and a current limiting unit that is provided in a voltage application path for the discharge path and that limits a current. did.

[0012]

According to the discharge lighting circuit having the above structure,
Due to the electric charge charged in the second electricity storage means, a voltage can be applied to the discharge path at the time of power failure, and backup is performed.

Further, according to the discharge lighting circuit having the above-mentioned structure, the electric charge charged in the first and second power storage means causes a voltage to be applied to the discharge path through the current limiting element at the time of a momentary interruption. It can handle possible power interruptions.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a configuration example of a discharge lighting circuit according to an embodiment of the present invention. The signal related to the gradation control shown in FIG. 4 is given to the terminal 10 of the discharge lighting circuit of the embodiment. A voltage from a power source Ef for filament heating is applied to the cathode of the discharge tube L to heat the cathode. A transistor Q, which is a switch, is turned on / off by a signal given to the terminal 10 to control gradation (light control).

The voltage of the main power source E _B is applied to the discharge tube L via the resistor R _B. Further, an auxiliary power supply E _A that outputs a voltage higher than the voltage of the main power supply E _B is provided, and the voltage of this auxiliary power supply E _A is applied to the discharge tube L via the resistor _RA . Diode D connected to the emitter of the transistor Q is a structure for preventing a reverse flow of current due to the auxiliary power supply E _A. Transistor Q that comes with the discharge tube L, a diode D, resistors R _A, R _B is added according to the number of discharge tubes L.

[0016] In a discharge lighting circuit described above, the voltage of the main power source E _B is, for example, a few tens of volts, the voltage of the auxiliary power supply E _A is a several hundred volts, the voltage of the auxiliary power supply E _A constantly discharge tube It is applied to L to cause a slight discharge to lower the lighting voltage and improve the starting characteristics.

In this embodiment, the capacitor C _B is connected in parallel to the main power source E _B and the capacitor C _A is connected in parallel to the auxiliary power source E _A. These capacitors C _B and C _A are connected to the main power source E _B and the auxiliary power source E _{A in case} of power failure, in particular, instantaneous interruption (100 m
A power failure of about sec. ) In order to prepare for the time, the electric charge is accumulated so as to become a backup power source. Resistance R _B
Is a current limiting means for flowing an electric current by the voltage of the main power source E _B by an appropriate value, and the resistor _RA is a current limiting means for limiting the current by the voltage of the auxiliary power source E _A (limited to about several microamperes). Make up.

In normal operation, the voltage of the auxiliary power source E _A is constantly applied to the discharge tube L via the resistor R _A to cause a slight discharge, and the lighting voltage is lowered to improve the starting characteristic.
At the time of lighting by the gradation control signal given through the terminal 10, the main power source E _B supplies power to the discharge tube L. At this normal time, the capacitors C _A and C _B are both charged.

In contrast to the above, when the main power supply E _B is cut off instantaneously,
The electric charge charged in the capacitor C _B flows through the resistor R _B, and the instantaneous power interruption of the main power source E _B is backed up. On the other hand, when the auxiliary power supply E _A is momentarily disconnected, the electric charge charged in the capacitor C _A flows through the resistor R _A, and the instantaneous power interruption of the auxiliary power supply E _A is backed up.

[0020]

As described above, according to the present invention, a voltage can be applied to the discharge path at the time of a power failure due to the charges charged in the first and second power storage means, and backup is performed. It That is, since backup is provided in the event of a power failure simply by providing the electricity storage means, the configuration can be simplified, the size can be reduced, and the system can be made inexpensive.

Further, according to the present invention, due to the charges charged in the first and second power storage means, a voltage is applied to the discharge path through the current limiting element at the time of momentary interruption, and the momentary occurrence of the power supply that can normally occur. It is possible to deal with disconnection, the configuration is simple, the size can be reduced, and the system can be inexpensive.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a perspective view of a large image display device.

FIG. 3 is a perspective view of a main part configuration of a large-sized image display device.

FIG. 4 is a block diagram of a lighting control circuit of a discharge tube used in a large-sized image display device.

FIG. 5 is a configuration diagram of a conventional discharge lighting circuit.

[Explanation of symbols]

E _B Main power supply E _A Auxiliary power supply C _B , C _A Capacitor R _A , R _B
Resistance L Discharge tube D Diode Q transistor 10 terminal

Claims (2)

[Claims] 1. A discharge lighting circuit for performing discharge lighting on a discharge path, comprising: a first power supply connected to the discharge path and outputting a voltage for discharge lighting; and a first power supply connected to the discharge path A second power source that outputs a voltage higher than the voltage of the power source; a first power storage unit that is charged by the first power source and applies a charging voltage to the discharge path; and a second power source that charges the battery. And a second power storage unit that applies a charging voltage to the discharge path. 2. A discharge lighting circuit for performing discharge lighting on a discharge path, comprising: a first power source connected to the discharge path and outputting a voltage for discharge lighting; and a first power source connected to the discharge path. A second power source that outputs a voltage higher than the voltage of the power source, and a first power storage unit that is charged by the first power source and applies a charging voltage to the discharge path when the first power source is momentarily cut off. A second power storage unit that is charged by the second power source and applies a charging voltage to the discharge path when the second power source is momentarily cut off; A discharge lighting circuit comprising: a current limiting means for limiting.