JPH02215095A - Discharge lamp lighting device and illuminating fixture - Google Patents

Abstract

PURPOSE:To allow a restart without impairing the illumination effect and dispense with a troublesome action by keeping the other discharge lamps lighted with the same light output when one lamp is made the non-connection state while multiple hot cathode type discharge lamps are lighted in parallel. CONSTITUTION:When a discharge lamp 2 or a discharge lamp 3 is removed for replacement, the output voltage of an inverter 1 is not changed, thus the remaining discharge lamp is kept lighted with no change of the light output. When a normal discharge lamp is fitted, a load detecting device 6 initiates the oscillation frequency control content of a control device 4. The output voltage of the inverter 1 is changed from the voltage less than the starting voltage to the starting voltage or above, thus the fitted discharge lamp is lighted like at the time of starting. After lighting, the output voltage of the inverter 1 is changed to the voltage less than the starting voltage and the lighting maintaining voltage or above. When one discharge lamp 2 or 3 is replaced among multiple discharge lamps, the illumination effect is not practically impaired.

Description

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

(Prior Art) Conventionally, it is known that a hot cathode discharge lamp (hereinafter simply referred to as a discharge lamp) such as a fluorescent lamp is used for high-frequency lighting. For example, a discharge lamp is lit using an inverter having a resonant circuit, and the output voltage is changed by changing the oscillation frequency of this inverter.
It has been proposed that after a discharge lamp is soft-started, the discharge lamp is turned on and the voltage is lower than the starting voltage of the discharge lamp and higher than the lighting maintenance voltage.

(Problems to be Solved by the Invention) In the conventional device described above, when the discharge lamp reaches the end of its life and is to be replaced, the oscillation frequency of the inverter remains the same as before the discharge lamp was removed. If there is, there is a problem that the discharge lamp will not move. For this reason, the oscillation frequency control content of the inverter has been initialized by cutting off the -temporal power supply.

It is also conceivable to detect the connected state of the discharge lamp and initialize the oscillation frequency control content of the inverter when the discharge lamp becomes disconnected.

However, devices that cut off the power immediately are cumbersome to operate, and devices that light multiple discharge lamps in parallel cause other lit discharge lamps to turn off immediately. During this time, there was a problem of not being able to get any lighting.

In addition, in the case where the discharge lamp is in an unconnected state, that is, when it is removed, the inverter output voltage is reduced (voltage during the soft start period) until the discharge lamp is installed again. Since the other installed discharge lamps are turned off or turned on only in a dimmed state, the desired illumination cannot be obtained.

In this way, with conventional lamps, when multiple discharge lamps are lit in parallel, if even one of the discharge lamps is removed, the other discharge lamps turn off or dim. there were.

The present invention was made in order to solve such conventional problems, and it is a device that lights a plurality of discharge lamps in parallel, and one of the discharge lamps is used for replacement etc. ni-
An object of the present invention is to provide a discharge lamp lighting device that can be started and lit when a normal discharge lamp is installed after it is removed, and that can eliminate or extremely shorten the period during which other discharge lamps are turned off or dimmed. That is.

[Structure of the invention]

(Means for solving the problems) The present invention will be described below with reference to FIG. Reference numeral 1 denotes an inverter, which changes the output voltage by controlling the oscillation frequency. Such an inverter 1 has, for example, a resonant circuit, and changes the output voltage of the resonant circuit by changing the oscillation frequency. 2.3 is a discharge lamp, such as a fluorescent lamp, which is energized by the output of the inverter 1 and whose filament is preheated. Although only two lights are shown in FIG. 1, three or more lights may be used in the present invention.

4 is a control device for controlling the oscillation frequency of the inverter 1, and the oscillation frequency is set such that the output voltage of the inverter 1 is less than the starting voltage of the discharge lamp 2.3 for a predetermined time when the discharge lamps 2 and 3 are started; After a predetermined period of time has elapsed, the oscillation frequency is set to be equal to or higher than the starting voltage, and furthermore, after the discharge lamp 2.3 is lit, the oscillation frequency is set to a lighting maintenance voltage that is lower than the starting voltage of the discharge lamp 2.3. Such a control device 4 may include an oscillation device and change the output frequency of this oscillation device in accordance with a timer, a lighting detection output of the discharge lamp 2.3, and the like. Reference numerals 51 and 52 are detection devices for detecting the connection state of the discharge lamps 2 and 3. 6 is this detection device 51.52
This is a load detection device that controls the control device 4 according to a detection signal from the load detection device. That is, when the discharge lamps 2 and 3 are turned on and one of the discharge lamps becomes disconnected due to, for example, being removed, the output of the inverter 1 is not changed, that is, the oscillation frequency is changed by the control device 4. I have nothing to do. On the other hand, when the disconnected discharge lamp 2 is replaced with a normal discharge lamp and connected, the oscillation frequency control contents of the control device 4 are initialized.

(Operation) Next, the operation will be explained. When starting the discharge lamp 2.3, when the DC type [E is turned on, the inverter 1 is activated.
The output voltage is controlled to be less than the starting voltage of the discharge lamps 2 and 3. Therefore, the discharge lamps 2, 3 cannot be started and the filament is preheated. Then, after a predetermined period of time has elapsed, the control device 4 controls the oscillation frequency of the inverter to be equal to or higher than the starting voltage. Therefore, the discharge lamp 2.3 lights up once at the start. In this case, since the filament is sufficiently preheated, there is no deterioration in life due to a so-called cold start. After the discharge lamp 2.3 is lit, the control device 4 controls the oscillation frequency so that the output of the inverter 1 is less than the starting voltage of the discharge lamp 2.3 and more than the discharge sustaining voltage. Therefore, the discharge lamps 2 and 3 continue to be lit. Even if the discharge lamp 2 or 3 is removed for replacement, the output voltage of the inverter 1 does not change, so the remaining discharge lamps continue to be lit without changing their light output. Further, when a normal discharge lamp is installed, the load detection device 6 initializes the oscillation frequency control contents of the control device 4.

Therefore, the output voltage of the inverter 1 changes from less than the starting voltage to more than the starting voltage, so the attached discharge lamp lights up in the same way as when starting. After lighting, the output voltage of the inverter 1 changes from less than the starting voltage to more than the lighting maintenance voltage.

Of course, it is possible to keep the remaining discharge lamps lit when a voltage lower than the starting voltage after initialization is output, and in this case, the light may be slightly dimmed, but this period will last for 1 to 2 seconds at most. (usually the soft start period is around 1 second), and the lighting effect is not substantially impaired.

(Example) Hereinafter, an example of the present invention will be described in Section 2! This will be explained with reference to J. Note that parts that are the same as or correspond to those in FIG. 1 are given the same reference numerals.

The inverter 1 in this embodiment includes a pair of switching elements 101. A half-bridge type inverter having a resonant circuit toa, 104 connected to each discharge lamp 2.
It is provided in accordance with 3. The control device 4 has a known voltage -
It includes an oscillation device 401 having a frequency conversion function.

As such an oscillation device 401, a commercially available IC or the like can be used. Further, the oscillation device 4 has a timer section 402,
This timer section 402 is used to set a predetermined period of time 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 a diode 405.
It is connected to the oscillation frequency control section 406 via.

The detection devices 51, 52 are both configured to pick up a signal via the filament of one of the discharge lamps 2, 3.

That is, when the discharge lamp 2.3 is connected, it outputs a low signal, and when it is disconnected, it outputs a high signal. Note that in this example, only the connection state of one filament can be directly detected, but in a case where a pair of electrodes are concentrated in one place, such as in a ring-shaped fluorescent lamp, this example can be used to detect the connection state of only one filament. There is virtually no problem with this, 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, an inverting circuit 602 is provided on the output side of this NOR circuit 601, and the output side of this inverting circuit 802 is connected to a diode 4.
07 to the oscillation frequency control section 406. Note that this embodiment further includes a NAND circuit 603, and the output of this NAND circuit 603 causes the oscillation device 401 to
The operation of the system can be controlled.

Furthermore, this embodiment has a dimming control section 7. This dimming control section 7 controls the oscillation frequency control section 40B 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 (state a in Fig. 2), the inverter 1 operates and outputs a high-frequency voltage. The oscillation device 401 outputs a signal at a relatively high frequency (for example, 80 kHz).

After approximately a few @BeC-10m5ec have passed, the signal from above rises, the current flowing through the transistor 403 increases, the collector side potential of the transistor 404 is applied to the oscillation frequency control section 406, and the oscillation device 401 is activated at a frequency of, for example, 75kHz. Outputs a frequency signal. 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. Then, when the timer section 402 outputs a signal after about one second, the transistor 404 is turned on.

Therefore, since the collector side potential of the transistor 404 changes, the oscillation device 401 becomes lower, for example, 70
Outputs a signal with a frequency of kHz. At this time, the resonant circuit 103. 104 is set to output a voltage higher than the starting voltage. Therefore, the discharge lamp 2.3 is lit. When a discharge lamp is lit, the lamp voltage drops, so h
The signal from the oscillator 4 becomes smaller, and accordingly, the oscillator 4
01 outputs a frequency signal of 40k) I2, for example.

At this time, the discharge lamps 2 and 3 are connected to the resonance circuits 103 and 104.
However, even if there were no resistance component, the resonant circuit 103. 104 above 40kHz
The setting is such that the starting voltage cannot be output. In addition, in this example, the above-mentioned 80kHz to 70kHz
z is the resonant 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 2.3 are lit, the signal from f becomes high. However, the output of the NOR circuit 601 in the load detection device 6 is low, and therefore the output of the inversion circuit 602 is high, and does not affect the oscillation frequency control section 406. Therefore, the output of inverter 1 does not change. When a normal discharge lamp is installed as the discharge lamp 2, the outputs of each detection device 51 and 52 are both high, the output of the NOR circuit 601 is high, and the output of the inverting circuit 6 is high.
The output of 02 becomes low. Therefore, the oscillation frequency control section 406 is controlled, and the timer section 402 is also controlled.

discharged through j'. Therefore, the control device 4 is initialized and repeats the start-up sequence described above.

Note that when the dimming control section 7 is supplied with a signal via the changeover switch 8, it controls the transistor 701, thereby controlling the oscillation frequency control section 40B.

At this time, the output of the oscillation device 401 is set to 71kHz, for example.
degree. Furthermore, in this embodiment, the NAND circuit 702
is provided to enable full-light starting when setting the dimming state. That is, by turning on the transistor 408, until the discharge lamps 2 and 3 are lit and the voltage across them drops, the transition to the oscillation frequency during dimming is prevented, and the discharge lamps 2 and 3 are lit. At the same time, the lighting is switched to dimming mode. 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 other discharge lamps are kept lit with the same light output. Therefore, the lighting effect is not impaired, and since it is possible to restart the device when it is connected again, there is no need for unusual operations.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the present invention, and FIG. 2 is a circuit showing an 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 that increases the voltage to or above the maintenance voltage; A detection device that detects the connection status of each of the hot cathode discharge lamps; In response to a detection signal from this detection device, all of the hot cathode discharge lamps are lit. When one hot cathode discharge lamp becomes disconnected from a certain point, the output voltage of the inverter is not changed, and when the hot cathode discharge lamp that is disconnected is connected, the output voltage of the inverter changes. A discharge lamp lighting device comprising: a load detection device that initializes the oscillation frequency control content of the control device so that it changes in the same manner as at the time of starting. (2) A lighting device comprising: a lighting device body; and a discharge lamp lighting device according to claim (1) attached to the device body.