JPH0275199A - Discharge lamp lighting device and illuminating device using same - Google Patents

Abstract

PURPOSE:To prevent the deterioration of the lamp life by soft-starting a hot cathode type discharge lamp in response to the ambient temperature. CONSTITUTION:When the operation of a high-frequency generating device 1 is started for starting a discharge lamp 2, the output voltage of the device 1 is made lower than the starting voltage of the discharge lamp 2 by a soft-start circuit 3. After it is preheated for a preset time under this condition, the voltage of the starting voltage or above is outputted for lighting. When the temperature of the discharge lamp 2 is higher than its ambient temperature, a temperature sensing device 4 senses the ambient temperature and controls the circuit 3, thereby the voltage lower than that at the ordinary temperature is outputted by the device 1. The discharge lamp 2 is lighted after being preheated for the same time as for the ordinary temperature. When the ambient temperature is higher, preheating is performed with the lower output voltage than that for the ordinary temperature, then the discharge lamp 2 is lighted. A soft-start is performed in response to the ambient temperature, thus a cold-start can be prevented even when the ambient temperature is high and the discharge lamp is easily lighted, and the deterioration of the lamp life is suppressed.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention involves lighting a hot cathode discharge lamp at high frequency, and at the time of starting the lamp, the filament is sufficiently preheated to achieve a so-called soft start. The present invention relates to a discharge lamp lighting device that can provide a discharge lamp lighting device, and a lighting device using such a lighting device.

(Prior Art) When a hot cathode type discharge lamp is lit at high frequency, the no-load voltage of the high frequency generator is generally designed to be high because the starting voltage of the discharge lamp tends to be higher than when lit at low frequency. Because of this, when a discharge lamp is started, it is forcibly turned on without the filament being sufficiently preheated, resulting in a so-called cold start, which can lead to premature deterioration of its lifespan.

In contrast, Japanese Patent Application Laid-Open No. 55-137698 has proposed a method. This device energizes a discharge lamp with a high frequency generator, and includes a switch device installed between both filament I terminals on the non-power side of the discharge lamp, and a switch device that is only used for a certain period of time after the power is turned on. The lamp is equipped with a timer that turns on the discharge lamp, and a temperature sensing device that changes the set time of the timer to a shorter or longer time in response to the level of ambient temperature of the discharge lamp. Therefore, when the discharge lamp is started, the switch device is turned on for the time set by the timer, so that no preheating current is supplied to the filament or high voltage is applied to the discharge lamp during this time.

After that, when the time set by the timer expires, the switch device is turned off and a high voltage is applied to the discharge lamp, turning it on. Furthermore, since this device changes the setting time of the timer depending on the ambient temperature of the discharge lamp, for example, when the ambient temperature is lower than normal, the time for supplying the preheating current to the filament becomes longer. In this way, the conventional lamp can perform a so-called soft start of the discharge lamp, and can change the time required for the soft start depending on the ambient temperature.

(Problems to be Solved by the Invention) However, in the conventional method described above, the time required for soft start changes depending on the ambient temperature, which is unnatural for the user, and the time required for soft start changes depending on the ambient temperature. When the time is long, it is inconvenient to not be able to get light during that time, and furthermore, it gives a sense of anxiety.

The present invention has been made to solve these conventional problems.It is possible to soft start a hot cathode type discharge lamp, prevent it from becoming a hot cathode lamp due to a cold start, and maintain the correctness even when the ambient temperature changes. It is an object of the present invention to provide a discharge lamp lighting device and a lighting device that can preheat a filament without substantially changing the time required for soft start.

[Structure of the Invention] (Means for Solving the Problems) The invention set forth in claim 1 (hereinafter referred to as the first invention) will be explained with reference to FIGS. 3 and 4. 1
is a high frequency generator that energizes the hot cathode type discharge lamp 2. As the high frequency generator 1, a well-known device such as a one-hernge inverter or a sirisk inverter can be used, and the output frequency thereof is, for example, several kHz or more, preferably an audible frequency or more. 3 is a soft start circuit. The soft start circuit 3 reduces the output voltage of the high frequency generator 1 to less than the starting voltage of the discharge lamp 2 for a predetermined period of time when the electric lamp 2 is started;
After the predetermined time has elapsed, the starting voltage is increased.

As a means for controlling the output voltage of the quick start circuit 3 or the high frequency generator 1, for example, the input to the high frequency generator 1 may be controlled, the output may be controlled, or the high frequency generator 1 may be a transistor inverter, In the case of a silice inverter or the like, it will be easily understood that it is sufficient to change its switching frequency, on-duty, etc. It will also be readily understood that the predetermined time period can be set by a well-known mechanical or electrical circuit timer. Reference numeral 4 denotes a temperature sensing device, which is provided in the soft start circuit 3 so as to be able to control this soft start 4H3. In response to the ambient temperature of the discharge lamp 2, the temperature sensing device 4 controls the output voltage of the high frequency generator W1 within a predetermined time period of the soft start circuit 3 to within a range below the starting voltage of the discharge lamp 2. It is something that can be changed. That is, at least when the ambient temperature is high, the output voltage of the high-frequency generator 1 is made lower than at normal temperature, and further, if necessary, when the ambient temperature is low, it is made higher. In order to change the output voltage of the high frequency generator 1 within the predetermined time of the soft start circuit 3, the temperature sensing device 4 is provided in conjunction with the output voltage control means of the rough 1 to start circuits 3 described above. This can be achieved by controlling the output control means. Note that, in the present invention, being sensitive to the ambient temperature of the discharge lamp 2 does not necessarily mean that the temperature sensing device 4 is disposed around the discharge lamp 2; It is permissible to install them separately as long as the temperature can be obtained. 5 is a current limiting impedance device for the discharge lamp 2.

The invention set forth in claim 2 (hereinafter referred to as the second invention) is one in which the first invention is attached to a lighting fixture (not shown). It will be easily understood that the lighting equipment may be of any type, such as a table lamp, a ceiling hanging light, or a direct-mounted light.

(Function) Hereinafter, the first invention will be explained in detail. First, when the ambient temperature of the discharge lamp 2 is normal temperature (for example, 25°C), when the high-frequency generator 1 starts operating when the discharge lamp 2 is started, the output voltage of the high-frequency generator 1 changes from the soft star 1 to the circuit 3.
Therefore, as shown in FIG. 4(a), the starting voltage (Vs) of the discharge lamp 2 is lowered. When the predetermined time (1) set in the soft start circuit 3 has elapsed, the output voltage of the high frequency generator] becomes a voltage (0) higher than the starting voltage (Vs) of the discharge lamp 2; In step 1), the filament of the discharge lamp 2 is preheated, so there is no possibility of a cold start.

Next, the ambient temperature of the discharge lamp 2 is high (for example, 35°C).
), by controlling the temperature sensing device 4 or the soft start circuit 3 in response to this ambient temperature, the output voltage of the high frequency generator 1 becomes as shown in FIG. 4 (c), which is lower than that at room temperature. However, the predetermined time (1) of the soft start circuit 3
is constant, and after the elapse of this predetermined time (1), the output voltage of the high frequency generator 1 becomes as shown in FIG. 4 (b) as described above. Therefore, the discharge lamp 2 has its filament preheated during a predetermined time (1) and is then turned on.

When the ambient temperature of the discharge lamp 2 is high, starting performance is improved,
Since the light is turned on at a low voltage, unless the present invention is applied, the light will turn on immediately upon startup even at the output voltage (a) at normal temperature, resulting in a cold start. By lowering the output voltage to (c), it is possible to prevent the discharge lamp 2 from lighting up immediately after starting, that is, a cold start. Note that the extent to which the output voltage of the high-frequency generator 1 is reduced when the ambient temperature is high is determined by considering the type of discharge lamp, the minimum required filament preheating voltage, etc.

Therefore, in some cases, the discharge lamp 2 may turn on within the predetermined soft start time (1), but it is easy to understand that it is okay as long as the cold start does not significantly deteriorate the lamp life. will be done.

= 9- Furthermore, the ambient temperature of discharge lamp 2 is low (for example, 5°C)
However, in the present invention, the output voltage of the high frequency generator 1 does not necessarily have to be changed from that at room temperature. That is, the output voltage (b) may be set to a voltage higher than the voltage at which the discharge lamp 2 can be started even at low temperatures predicted from the location of use.

However, considering that the discharge lamp 2 has poor starting performance when the ambient temperature is low, the output voltage of the high-frequency generator 1 is increased and the filament preheating power is increased, thereby reducing the temperature inside the discharge lamp 2. It is desirable to increase it to some extent, and the present invention also includes such a thing6.
Whether or not to change the output voltage of the high frequency generator 1 when the ambient temperature is low can be arbitrarily configured by setting the temperature sensing level of the temperature sensing device 4, etc. In the following, a case will be described in which the output voltage of the medium and high frequency generator 1 is changed to the starting voltage of the discharge lamp 2 (■S
) and is higher than the voltage (a) at normal temperature (d) after 6 predetermined time <1) has elapsed, the voltage (b) is set to be equal to or higher than the starting voltage (Vs) as described above. In this case as well, the predetermined time (1) remains unchanged. I wanted to,
The discharge lamp 2 has a filament preheated during a predetermined time (1),
Then it lights up.

Note that FIG. 4 shows the level of the output voltage of the high frequency generator 1, and is simplified by omitting details such as when the voltage changes.

It will be easily understood from the above description that in the present invention, the power source for preheating the filament of the discharge lamp 2 does not necessarily have to be shared by the high frequency generator 1, and may be provided separately. . In this case, it is optional whether or not the filament preheating voltage is changed depending on the ambient temperature.

In addition, when starting the discharge lamp, in addition to turning on the power to the high-frequency generator 1 to which the discharge lamp 2 is connected, when necessary,
This may include a case where the discharge lamp 2 is replaced with a new one while the high-frequency generator 1 is in operation. In this case, the timer of the soft start circuit 3 may be configured to be reset in accordance with the removal or attachment of the discharge lamp 2.

Next, the second invention is based on the first invention described above. Since this invention is attached to a lighting equipment, it is clear that it has the same effect as the first invention.

(Example) Hereinafter, an example of the first invention will be described with reference to FIG. The high frequency generator 10 of this embodiment is a so-called -5 type transistor inverter, with transistors 11.
A first inductor 12 . connected in series to this transistor 11 . It mainly consists of a first capacitor 13 and a DC power supply section 14 connected in parallel to this inductor 12. The discharge lamp 20 includes the first inductor 1
A second inductor 50 as a current limiting device between both terminals of
A second capacitor 60 is connected between each filament terminal on the non-power supply side of the discharge lamp 20. The second inductor 50 has a feedback winding 1.
5, one end of this feedback winding 15 is connected to the base of the transistor 11 via a third inductor 16 and a third capacitor 17, and the other end is connected to the emitter of the transistor 11 via a diode 18. has been done. The soft start circuit 30 has a time constant circuit 31, a collector connected to the other end of the feedback winding, an emitter connected to the base of the transistor 11 via a second diode 32 and a resistor 33, and a time constant circuit 31. A transistor 34 whose conduction is controlled by the output of the circuit 31
It is composed of.

The temperature sensing device 40 is, for example, a temperature sensing resistor with a positive characteristic, and is connected in parallel with the transistor 34. 70 is a commercial AC power source, and 71 is a power switch.6 Below, the operation of this embodiment will be explained. First, when the ambient temperature is normal temperature, when the power switch 71 is turned on, the high frequency generator 10
The transistor 11 is turned on, and approximately the output voltage of the DC power supply section 14 appears across the parallel circuit of the first inductor 12 and the first capacitor 13. This voltage is supplied to the second capacitor 60 and the second inductor 50.
resonates and supplies a filament preheating current to the discharge lamp 20, and this resonant output is applied between the base and emitter of the transistor 11 through the feedback winding 15. Then,
When the transistor 11 is turned off due to saturation of the transistor 11 or reversal of the resonant voltage, the first inductor and the first capacitor 13 resonate, and the second capacitor 60 and the second inductor 50 are turned off as described above.
supply to. After that, the above operation is repeated and the high frequency generator 1
0 continues oscillation. Note that the first inductor 12
．． First capacitor 13. It has been confirmed through experiments that the resonance operation between the second capacitor 60 and the second inductor 50 is not necessarily clear, and that as a result, the high frequency generator 10 continues to oscillate and outputs a high frequency voltage.

Here, the transistor 34 remains off until the predetermined time of the soft start circuit 30, that is, the time constant circuit 31 reaches its set time, for example, 0.5 to 1.5 seconds. Therefore, during the off-period of the transistor 11, the charge in the third capacitor 17 is discharged through the third inductor 16, the feedback winding 15, the temperature sensing device 40, the diode 32, and the resistor 33, and the transistor 34 is The amount of discharge is less than when it is on.

As a result, the charging current of the capacitor 17 when the transistor 11 is turned on next time, that is, the transistor 11
The base current of the transistor 11 decreases, the on period of the transistor 11 becomes shorter, and the switching frequency becomes higher. In this way, by shortening the on period of the transistor 11, the output voltage of the high frequency generator 10 is reduced as shown in FIG. 4(A), for example. Therefore, the discharge lamp 20 is not lit during this predetermined time, and its filament is preheated. When the time constant circuit 31 of the soft start circuit 30 reaches its set value and the transistor 34 is turned on, the charge in the capacitor 17 is discharged via the transistor 34. Therefore, the amount of discharge of the capacitor 17 increases, and therefore the base current of the transistor 11 increases next time, and the output voltage of the high frequency generator 10 increases as shown in FIG. 4 (b). The discharge lamp 20 is turned on by applying this voltage.

Next, when the ambient temperature of the discharge lamp 20 is high, the temperature sensing device 40 increases its resistance value, so that the amount of discharge of the capacitor 17 during the predetermined time of the soft start circuit 30 becomes even smaller. Therefore, the output voltage of the high frequency generator 10 in this case is lower than that at room temperature, for example as shown in FIG. 4(c). Other conditions are the same as those at room temperature.

Further, when the ambient temperature of the discharge lamp 20 is low, the temperature sensing device 40 or its resistance value is decreased. Therefore, the output voltage of the high frequency generator 10 during the predetermined time period of the soft start circuit 30 is lower than the starting voltage of the discharge lamp 20 or higher than that at room temperature, as shown in FIG. 4(d), for example. Other conditions are the same as those at room temperature.

Another embodiment of the first invention will be described with reference to FIG. The soft start circuit 80 of this embodiment controls the input voltage of a high frequency generator 90 made of a well-known transistor inverter, etc., and includes a time constant circuit 81 and a switch device whose conduction is controlled by the time constant circuit 81. 82 and an impedance element 83 connected in parallel to this switch device 82. The temperature sensing device 100 is, for example, a temperature sensing resistor with a positive characteristic, and the impedance element 8
3 are connected in series. 110 is a discharge lamp, and 120 is a current limiting device.

The operation of this embodiment will be explained. When the discharge lamp 100 is started, the switch device 82 is turned off for a predetermined period of time of the soft start circuit 80, so the input voltage of the high frequency generator 90 is reduced by the voltage drop caused by the impedance element 83 and the temperature sensing device 100. and the output voltage will be reduced accordingly. Since the resistance value of the temperature sensing device 100 changes depending on the ambient temperature of the discharge lamp 110, the output voltage of the high frequency generator 90 also changes. After the predetermined time of the soft start circuit 80 has elapsed, the switch device 82 is turned on, so that the impedance element 83 and the temperature sensing device 100 are short-circuited. Therefore, the high frequency generator 9
0 outputs a voltage higher than the starting voltage of the discharge lamp 110 to light the discharge lamp 110, and thereafter lights it at a high frequency via the current limiting device 120.

"Effects of the Invention" As detailed above, the first invention energizes a hot cathode discharge lamp with the output of a high frequency generator, and uses a soft start circuit to start the discharge lamp for a predetermined period of time. A temperature sensing device is provided to reduce the output of the high frequency generator to less than the starting voltage of the discharge lamp, and to control the soft star 1 to the circuit in response to the ambient temperature of the discharge lamp, and when the ambient temperature is high, the predetermined Since the output voltage of the high-frequency generator is further reduced than at room temperature during the operation time, even if the discharge lamp is likely to light up due to high ambient temperature, it will not turn on immediately after starting, resulting in a so-called cold start. Therefore, it is possible to provide a discharge lamp lighting device that can prevent deterioration of lamp life.

In the second invention, since the discharge lamp lighting device of the first invention is attached to a lighting fixture, it is possible to provide a lighting device that has the same effects as the first invention.

[Brief explanation of the drawing]

1 and 2 are circuit diagrams showing different embodiments of the first invention, FIG. 3 is a block diagram showing the first invention, and FIG. 4 is a voltage level used to explain the operation of FIG. 3. FIG. = 18- 1.10.90...High frequency generator. 2,20. 110...Discharge lamp. 3, 30.80...Soft start circuit 14.40
．． 100...Temperature sensitive device.

Claims (2)

[Claims] (1) A hot cathode discharge lamp; A high frequency generator that energizes the discharge lamp; For a predetermined time when starting the discharge lamp, the output voltage of the high frequency generator is reduced to below the starting voltage of the discharge lamp. , a soft start circuit that increases the starting voltage or higher after the elapse of the predetermined time; and a soft start circuit that is provided in conjunction with the soft start circuit and controls the soft start circuit in response to the ambient temperature of the discharge lamp. A discharge lamp lighting device comprising: a temperature sensing device that lowers the output voltage of the high frequency generator within a predetermined time period when the ambient temperature of the discharge lamp is high compared to when the ambient temperature is normal temperature. (2) A lighting fixture; A hot cathode discharge lamp attached to the lighting fixture; A lighting device for the discharge lamp provided in the lighting fixture; The lighting device includes the discharge lamp. a high-frequency generator for controlling the discharge lamp; a soft-start circuit that reduces the output voltage of the high-frequency generator to less than the starting voltage of the discharge lamp for a predetermined time when starting the discharge lamp; and a soft start circuit that reduces the output voltage of the high-frequency generator to less than the starting voltage of the discharge lamp after the elapse of the predetermined time; is provided in connection with the soft start circuit, and controls the soft start circuit in response to the ambient temperature of the discharge lamp to control the output voltage of the high frequency generator within the predetermined time period of the discharge lamp; A lighting device comprising: a temperature sensing device that lowers the ambient temperature when the ambient temperature is high compared to normal temperature;