JPH02215096A - Discharge lamp lighting device and illuminating fixture - Google Patents

Abstract

PURPOSE:To allow a restart when a discharge lamp is again connected and dispense with a troublesome action by initiating the control content when one discharge lamp is made the non-connection state while multiple hot cathode type discharge lamps are lighted in parallel. CONSTITUTION:When one discharge lamp 2 is removed while discharge lamps 2 and 3 are lighted, the signal from (f) is made high, the output of an OR circuit 601 of a load detecting device 6 is made high, the output of a reversing circuit 602 is made low, an oscillation frequency control unit 406 is controlled, a control device 4 is initiated, and this state is maintained. When a normal discharge lamp is fitted as the discharge lamp 2, outputs of detecting devices 51 and 52 are both made low, the output of the OR circuit 601 is made low, the output of the reversing circuit 602 is made high, and the control device again repeats sequences at the time of starting. No troubles and uncomfortableness are given until dim lighting is started.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a discharge lamp lighting device for lighting a plurality of hot cathode discharge lamps connected in parallel using an inverter; The present invention relates to a lighting device using the same device.

[Structure of the invention]

(Example) The inverter 1 in this example includes a pair of switching elements 101. 102, a half-bridge type inverter having a resonant circuit 103. 104 for each discharge lamp 2.3
It has been set up in response to The control device 4 includes an oscillation device 401 having a well-known voltage-frequency conversion function. As such an oscillation device 401, a commercially available IC or the like can be used. Further, the oscillator 4 has a timer section 402, and the timer section 402 is used to set a predetermined period when the discharge lamp 2.3 is started. Further, the timer section 402 is configured to charge a time constant circuit according to the voltage across the discharge lamp 2.3. That is, the transistor 403 provided on the input side of the timer section 402 functions as a current amplifier. The output of this timer section 402 controls on/off of a transistor 404, and the collector side of this transistor 404 is connected to an oscillation frequency control section 406 via a diode 405.

The detection devices 51, 62 are both configured to pick up a signal via one filament of the discharge lamp 2.3.

That is, when the discharge lamp 2.3 is connected, it is a low signal, and when it is not connected, it outputs a no signal. In addition,
Although this embodiment can directly detect the connection state of only one filament, in a case where a pair of electrodes are concentrated in one place, such as in an annular fluorescent lamp, this embodiment can detect the connection state of only one filament. There is virtually no problem, and it is possible to detect the connection state of both filaments if necessary.

That is, the signal may be extracted through both filaments. The load detection 6 includes the detection device 51.5.
2, and an inverting circuit 602 provided on the output side of this OR circuit 601. The output side of this inverting circuit 602 is connected to the diode 40.
7 to the oscillation frequency control section 406.

Note that this embodiment further includes a NAND circuit 603, and the operation of the oscillation device 401 can be controlled by the output of this NAND circuit 803.

Furthermore, this embodiment has a dimming control section 7. This dimming control section 7 controls the oscillation frequency control section 406 in accordance with the operation of the changeover switch 8. 9 is a night light.

Next, the operation of this embodiment will be explained. When the power is turned on by the changeover switch 8 (the state shown in FIG. 2), the inverter 1 is activated and outputs a high frequency voltage.

However, in the initial stage, the voltage detection signal across the discharge lamps 2 and 3 (signal from h) does not rise sufficiently, and the oscillation device 401 outputs a signal at a relatively high frequency (for example, 80 kHz). After several m5ec to 1ossec have passed, the signal from above rises and the transistor 40
3 increases, the collector side potential of transistor 404 is applied to oscillation frequency control section 40B, and oscillation device 401 outputs a signal with a frequency of, for example, 75 kHz. At the conventional oscillation frequency, the resonant circuit 103 of the inverter 1. 104 is set so that it does not output a voltage higher than the starting voltage. The discharge lamp 2.3 therefore only has its filament preheated. Next, the timer section 40
2 outputs a signal after about 1 second, the transistor 40
4 turns on. Therefore, since the collector side potential of transistor 404 changes, oscillation device 401 outputs a signal with a lower frequency, for example, 70 kHz. At this time, the resonant circuit 103. 104 is set to output a voltage higher than the starting voltage. Therefore, discharge lamp 2
, 3 are lit. When the discharge lamp is turned on, the lamp voltage decreases, so the signal from h becomes smaller, and accordingly, the oscillation device 401 outputs a frequency signal of, for example, 40 kHz. At this time, the resonant circuit 103. Although a resistance component of the discharge lamp 2.3 is added to 104, even if this resistance component were not present, the resonant circuit 103. 104 It is set so that the starting voltage cannot be output at the above 40kllz. In addition, in this example, the above-mentioned 80k
Hz to 70kHz is the resonance circuit 103. 104 is located in the slow phase region, and the 40 kHz is located in the fast phase region.

Next, when one of the discharge lamps 2 is removed while the discharge lamps 2 and 3 are lit, the signal from f becomes ``1''. Therefore, the output of the OR circuit 801 in the load detection device 6 is high, and therefore the output of the inverting circuit 802 is low.
Oscillation frequency control section 406 is controlled. That is, the control device 4 is initialized and maintains this state. When the Shokeisei electric lamp is installed as the discharge lamp 2, each detection device 51
．． The outputs of the circuits 52 and 52 both become low, and the output of the OR circuit 801 and the output of the low inversion circuit 602 become high. The control device therefore repeats the start-up sequence again.

Note that when the dimming control section 7 is supplied with a signal via the changeover switch 8, it controls the transistor 70L, thereby controlling the oscillation frequency control 40B. At this time, the output of the oscillation device 401 is set to about 71 kHz, for example. Furthermore, in this embodiment, a NAND circuit 702 is provided to enable full light starting when setting the dimming state. That is,
Until the discharge lamps 2 and 3 are lit and the voltage across them drops, the transistor 408 is turned on to prevent the oscillation frequency from shifting to the dimming mode, and at the same time as the discharge lamps 2 and 3 are lit, I am trying to switch to dimmer lighting.

For this reason, the user will not feel uncomfortable or distrustful due to the change in brightness after the discharge lamp 2.3 is turned on suddenly brightly until it shifts to dimmed lighting.

〔Effect of the invention〕

As described above, the present invention is for lighting a plurality of hot cathode discharge lamps in parallel, and when one lamp becomes disconnected, the control contents of the control device are initialized and the lamp is turned off. When the light is connected again, it can be restarted, so there is no need for unusual operations.

[Brief explanation of the drawing]

FIG. 1 shows a circuit showing one embodiment of the present invention.

Claims (2)

[Claims] (1) An inverter whose oscillation frequency is controlled to change the output voltage; and a plurality of hot cathode discharge lamps connected in parallel with each other and energized by the output of the inverter and whose filaments are preheated. ; By controlling the oscillation frequency of the above inverter,
The output voltage of the inverter is set to be less than the starting voltage of each of the discharge lamps for a predetermined period when starting the hot cathode discharge lamp, and after the predetermined period, the output voltage of the inverter is set to be equal to or higher than the starting voltage, and after lighting, the lamp is turned on at a voltage lower than the starting voltage. a control device for increasing the voltage to the maintenance voltage or higher; a detection device for detecting the connection state of each hot cathode discharge lamp; and one hot cathode of each hot cathode discharge lamp in response to a detection signal from the detection device; and a load detection device that initializes the oscillation frequency control content of the control device so that the output voltage of the inverter changes in the same way as when starting the discharge lamp when the discharge lamp is disconnected. discharge lamp lighting device. (2) A lighting device comprising: a lighting device body; and a discharge lamp lighting device according to claim (1) attached to the device body.