JPH103996A - High pressure discharge lamp lighting device, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high pressure discharge lamp lighting device, and an image display device in which dimming can be smoothly performed in a target range in spite of a relatively simple constitution. SOLUTION: Output of a lamp voltage detection means 3b and/or a lamp current detection means 3a for a high pressure discharge lamp 5 is control- inputted to a control means 6 through a variable voltage dividing means 7, so a lighting main circuit 2 is controlled by the control means 6 to operate the variable voltage dividing means 7 for dimming. The variable voltage dividing means 7 may be operated at a second frequency that is different from a first frequency as an action frequency of the lighting main circuit 2. In the case where PWM control is performed in this case, dimming degrees can be set as desired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dimmable high pressure discharge lamp lighting device and an image display device.

[0002]

2. Description of the Related Art In a device such as a projection television receiver or an overhead projector, a small high-pressure discharge lamp has been used as a light source.

In this case, it is desirable that the high-pressure discharge lamp be controlled at a constant power in order to keep the amount of light constant. In practice, as disclosed in Japanese Patent Publication No. 8-17572, a lamp voltage and a lamp current are detected, and these values are added to control the power supplied to the high-pressure discharge lamp, thereby achieving a constant power control. It is carried out.

[0004]

These devices are required to change the amount of light of the device, that is, to control the light according to the illuminance of the use environment.

In general, dimming of a discharge lamp involves reducing the power supplied to the lamp. However, in the case of a high-pressure discharge lamp, the lamp current is reduced in this method, so that the time required for stable discharge, that is, the luminous flux rise time is long at the time of starting dimming.

As another dimming means, there is a method of reducing the resistance value of the lamp voltage detecting means. In this method, wiring for handling a delicate signal or wiring for handling a reference voltage of the lamp detecting means is routed for dimming, and there is a fear of malfunction due to noise, which is not preferable in some cases.

FIG. 12 is a circuit diagram showing the above prior art.

In the figure, 121 is a power supply, 122 is a lighting main circuit, 123 is a detecting means, 124 is a starting circuit, 125
Is a high-pressure discharge lamp, and 126 is control means.

The detecting means 123 includes a lamp current detecting means 123a inserted in series in the lighting main circuit 122 and a lamp voltage detecting means 12 connected in parallel to the high-pressure discharge lamp 125.
3b. Then, the lamp voltage detecting means 123b
Is configured to be able to short-circuit a part of the resistance on the output side of the switch 127 by the switch 127. When dimming, switch 12
7, the output of the lamp voltage detecting means 123b is increased.

According to this conventional technique, the control means 12 is controlled at the time of dimming.
6 is increased, and accordingly, the lighting main circuit 122 is subjected to PWM control.
5 is dimmed lighting. In practice, the switch 127 is disposed at a position remote from the lighting main circuit, so that the wiring is routed.

Further, it is conceivable to perform dimming using PWM control for controlling the lighting main circuit with constant power.
This control is basically a repetition of ON and OFF, so that the high-pressure discharge lamp tends to extinguish, so that dimming over a required range cannot be performed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high pressure discharge lamp lighting device and an image display device capable of performing dimming over a required range smoothly with a relatively simple structure.

It is another object of the present invention to provide a high pressure discharge lamp lighting device and an image display device which can be crossed over at the time of dimming transition.

[0014]

According to the first aspect of the present invention, there is provided a high pressure discharge lamp lighting device for lighting a high pressure discharge lamp, a starting circuit for the high pressure discharge lamp, and detecting a lamp voltage of the high pressure discharge lamp. Lamp voltage detecting means; lamp current detecting means for detecting a lamp current of a high-pressure discharge lamp; connected so as to be common to both outputs of the lamp voltage detecting means and the lamp current detecting means; , And control means for controlling the lighting main circuit in accordance with the output of the variable voltage dividing means.

In the present invention and each of the following inventions, the terms used in each invention are interpreted as follows unless otherwise defined.

The high-pressure discharge lamp is not particularly limited to a short-arc lamp, but a short-arc high-pressure discharge lamp is used in equipment such as an image display device and an overhead projector.
This is effective because the light utilization is high. As for the enclosure, it is permitted to use a high-pressure discharge lamp such as a metal halide lamp, a high-pressure mercury lamp, and a high-pressure xenon lamp.

The lighting main circuit may light the high-pressure discharge lamp lamp in direct current or in alternating current. In the case of DC lighting, the portion that performs the head flow operation may have any configuration, such as one that operates at a commercial frequency, one that operates at a high frequency, and one that operates at DC. It is preferable that the lighting main circuit be used to control the high-pressure discharge lamp at a constant power. In such a case, the lighting main circuit includes switching means, and the switching means controls both the lamp voltage and the lamp current. , It is possible to perform constant power control. The lighting main circuit including the switching means is constituted by, for example, a chopper circuit, and is controlled at a constant power by controlling the on-duty of chopping of the chopper circuit. It may be made to act also as an active filter for smoothing the smoothed direct current.

The starting circuit may have any configuration as long as it can start the high-pressure discharge lamp, and various known starting circuits can be employed.

The lamp voltage detecting means and the lamp current detecting means need only be able to directly or indirectly detect the lamp voltage and the lamp current, respectively, and are not limited to specific circuits. Then, the lamp voltage detecting means and / or the lamp current detecting means can be used for constant power control of the lighting main circuit.

In the present invention, the variable voltage dividing means is connected so as to function in common with the output of the lamp voltage detecting means and the output of the lamp current detecting means. In addition, it is sufficient that the voltage dividing ratio can be changed by an operation, and the invention is not limited to using a specific circuit component or a specific circuit. Operation may be direct or indirect, or may be remotely controlled. Further, acting in common means that a partial pressure action acts on the output of both means.

In the present invention, the control means may have any configuration as long as it controls the lighting main circuit in accordance with the output of the variable voltage dividing means.

Next, the operation of the high pressure discharge lamp lighting device of the present invention will be described.

For ease of understanding, it is assumed that the control means controls the main lighting circuit so that the high pressure discharge lamp emits all light when the variable voltage dividing means is not operated.

Then, when the variable voltage dividing means is operated to increase the voltage dividing ratio, the control voltage is supplied to the control means via the variable voltage dividing means of the respective detection outputs of the lamp voltage detecting means and the lamp current detecting means. The rate of control input increases. By increasing the control input to the control means not only for the lamp voltage detection signal but also for the lamp current detection signal as in the conventional case, the load characteristics at the time of dimming are different from the conventional case, and the reduction in the lamp current can be reduced. it can. Therefore, even during dimming, a lamp current close to that at full light can be supplied to speed up the rise of the luminous flux.

In the above description, the time when the variable voltage dividing means is not operated is the full light time, but this case can be the light control time. In other words, the amount of feedback is large when not operating,
What is necessary is just to comprise so that the feedback amount may decrease when it operates. It is also allowed to change the control characteristic so that the light is adjusted when the feedback amount decreases. The dimming may be stepwise or continuous.

A high-pressure discharge lamp lighting device according to a second aspect of the present invention is a lighting main circuit that operates at a high frequency and lights the high-pressure discharge lamp; a starting circuit for the high-pressure discharge lamp; and a lamp that detects a lamp voltage of the high-pressure discharge lamp. Voltage detecting means; variable voltage dividing means connected in parallel to the output of the lamp voltage detecting means and changing the voltage dividing ratio at the time of dimming operation; variable voltage dividing means at a second frequency lower than the high frequency first frequency And a control means for controlling the lighting main circuit in accordance with the output of the variable voltage dividing means.

In the present invention and the following invention, the first frequency means a frequency of about 10 KHz or more,
Preferably, it is about 40 KHz or more. On the other hand, the second frequency is a degree invisible to the naked eye, ie, about 1
The frequency may be about 00 Hz or more, preferably about 500 Hz or more, and about 1/10 or less of the frequency of the lighting main circuit.

According to the present invention, the output of the variable voltage dividing means is switched between high and low at a second frequency by the dimming operation means, and the power supply to the high pressure discharge lamp is controlled by the control of the lighting main circuit by the control means. By alternately setting the frequency to two levels of high and low, the average value of the supplied power is reduced to perform light control. The dimming degree can be arbitrarily set by changing the high / low time ratio, that is, the on-duty. In addition, it is possible to continuously change the dimming degree, that is, to perform a crossover, by changing the proportion of time of the height with time. By setting the second frequency in the above range, the dimming can be performed without a sense of incongruity with the naked eye.

A high pressure discharge lamp lighting device according to a third aspect of the present invention is a lighting main circuit which operates at a high frequency and lights the high pressure discharge lamp; a starting circuit for the high pressure discharge lamp; and a lamp which detects the lamp voltage of the high pressure discharge lamp. Voltage detection means; lamp current detection means for detecting the lamp current of the high-pressure discharge lamp; parallelly connected to both outputs of the lamp voltage detection means and the lamp current detection means, and the voltage division ratio changes during the dimming operation Variable voltage dividing means; dimming operation means for changing the voltage dividing ratio of the variable voltage dividing means at a second frequency lower than the high frequency first frequency; and controlling the lighting main circuit according to the output of the variable voltage dividing means. And control means.

In the present invention, the variable voltage dividing means functions in common with the lamp voltage detecting means and the lamp current detecting means as compared with the above-mentioned invention, so that the light flux rises faster as in the first aspect.

According to a fourth aspect of the present invention, in the high pressure discharge lamp lighting device according to the second or third aspect, the lighting main circuit includes switching means; the control means performs PWM control of the lighting main circuit. To do;

In the present invention, the switching means of the lighting main circuit is PWM-controlled by the control means at the first frequency to control the power supply to the high-pressure discharge lamp in a predetermined manner to maintain the lighting.

According to a fifth aspect of the present invention, there is provided a high pressure discharge lamp lighting device according to any one of the first to fourth aspects, wherein the variable voltage dividing means comprises a voltage dividing means and a voltage dividing means. It is characterized by comprising switch means connected in parallel.

In the present invention, the divided voltage output can be changed in two steps of high and low levels by opening and closing the switch means. The opening and closing of the switch means may be continuously closed at the time of dimming, or may be opened and closed at a predetermined frequency and at a time interval which is invisible to the naked eye. In the latter case, dimming or all-light and all-light or dimming are switched between during opening and closing and during non-opening and closing.

A high pressure discharge lamp lighting device according to a sixth aspect of the present invention is the high pressure discharge lamp lighting device according to the fifth aspect,
The switching means includes a photocoupler.

In the present invention, since the output of the variable voltage dividing means is switched directly or indirectly by using a photocoupler as a switching means, it is easy to remotely control the dimming operation. Also, electrical insulation on the secondary side of the lighting main circuit is easy. Further, it is easy to perform high-speed switching that cannot be recognized by the naked eye.

According to a seventh aspect of the present invention, there is provided the high pressure discharge lamp lighting device according to the fifth or sixth aspect, wherein the switch means is switched at a predetermined frequency and the PWM control is performed to control the dimming degree. It is characterized by changing.

[0038] In the present invention, the predetermined frequency is defined by claim 2.
And may be, but not limited to, the second frequency defined in If the PWM control is set to a constant on-duty, a constant dimming degree is obtained. If the on-duty is changed with time, continuous dimming, that is, crossover, is performed from one lighting state to another different lighting state. be able to. According to an eighth aspect of the present invention, in the high pressure discharge lamp lighting device according to the seventh aspect, the crossover is performed by continuously changing the PWM control of the switch means at the time of dimming transition. And

In the present invention, the term “crossover” refers to continuously changing the brightness when changing from a certain lighting state (for example, all light) to another lighting state (for example, dimming). The first lighting state is not limited to all light,
The transition from one dimming state to another different dimming state may be performed. Further, the dimming is not limited to dimming from a bright direction to a dark direction, but may be reversed.

In the present invention, since the crossover is performed by the PWM control, the high pressure discharge lamp does not become unstable. Therefore, the change in the color temperature is reduced, so that the viewer of the device implementing the present invention does not feel uncomfortable.

According to a ninth aspect of the present invention, there is provided a high pressure discharge lamp lighting device comprising:
The high-pressure discharge lamp lighting device according to any one of claims 1 to 8, wherein the lighting main circuit includes a chopper device.

In the present invention, the chopper device can be subjected to PWM control to supply predetermined power to the high-pressure discharge lamp, act as an active filter of a rectified DC power supply, and further act as dimming. .

According to a tenth aspect of the present invention, in the high pressure discharge lamp lighting device according to any one of the first to ninth aspects, the high pressure discharge lamp is a short arc high pressure discharge lamp. And

In the present invention, since the high-pressure discharge lamp has a short arc, the light utilization is high. In the case of DC lighting, the life is further extended.

The high pressure discharge lamp lighting device according to the eleventh aspect of the present invention is characterized in that, in the high pressure discharge lamp lighting device according to any one of the first to tenth aspects, the high pressure discharge lamp is a metal halide lamp.

The metal halide lamp according to the present invention comprises:
Although the luminous metal and other inclusions are not limited to specific ones, as a high-pressure discharge lamp for a projection television receiver, the following configuration is used.
Preferred results are obtained in terms of required luminescence characteristics such as luminous efficiency, correlated color temperature, chromaticity, and color rendering. That is, dysprosium Dy, cesium Cs and neodymium Nd are the main components, and thallium Tl and / or tin S
n is added as a sub-component as required, and an appropriate amount of iodine I and / or bromine Br is sealed with mercury and a rare gas for these components.

A high pressure discharge lamp lighting device according to a twelfth aspect of the present invention is the high pressure discharge lamp lighting device according to any one of the first to eleventh aspects, wherein the high pressure discharge lamp is integrally provided with a reflector. I have.

In the present invention, since the reflector is integrated with the high-pressure discharge lamp so that the optical performance is easily exhibited, it is suitable for a projection color television receiver, an overhead projector, and the like.

According to a thirteenth aspect of the present invention, there is provided the high pressure discharge lamp lighting device according to any one of the first to twelfth aspects, further comprising a high pressure discharge lamp.

That is, the present invention also includes a high-pressure discharge lamp as a component. The high-pressure discharge lamp and a circuit part such as a main lighting circuit may be a common assembly or may be separated.

According to a fourteenth aspect of the present invention, there is provided an image display apparatus comprising: a high-pressure discharge lamp having a reflector;
A high-pressure discharge lamp lighting device according to any one of the above; an image display means for irradiating from behind a light emitted from the high-pressure discharge lamp and reflected by the reflector; an image control means for controlling the image display means; It is characterized by comprising an optical system for condensing light transmitted through the means and projecting the light on a screen; and a main body case for accommodating each of the above-mentioned components.

The present invention is an image display device capable of smoothly adjusting the light of a high-pressure discharge lamp.

According to a fifteenth aspect of the present invention, in the image display device according to the fourteenth aspect, a fan for cooling the high pressure discharge lamp; and a fan control for controlling the fan in synchronization with the dimming operation of the high pressure discharge lamp. Means are provided.

According to the present invention, when the high-pressure discharge lamp is changed from the all-light state to the dimming state, for example, the cooling demand of the high-pressure discharge lamp also changes. Stable light control can be performed.

[0055]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing a first embodiment of the high pressure discharge lamp lighting device of the present invention.

In the figure, 1 is a power supply, 2 is a lighting main circuit,
3 is a detecting means, 4 is a starting circuit, 5 is a high pressure discharge lamp,
Reference numeral 6 denotes a control unit, and 7 denotes a variable pressure dividing unit.

The lighting main circuit 2 is a step-down chopper device having a current limiting function for stably lighting a high-pressure discharge lamp and a function for constant power control.

The detecting means 3 comprises a lamp current detecting means 3a inserted in series with the lighting main circuit, and a lamp voltage detecting means 3b connected in parallel with the high-pressure discharge lamp 5. Each of the detecting means 3a and 3b is composed of a resistor.

The starting circuit 4 is used to start the high-pressure discharge lamp 5, and is normally used to generate a high voltage at the time of starting.

The high-pressure discharge lamp 5 is a short arc 250 W metal halide lamp having a distance between the electrodes of 3 mm, which is integrally provided with a reflector (not shown).

The control means 6 performs PWM control on the lighting main circuit 2 in accordance with the sum of the detected outputs of the lamp voltage and the lamp current to supply power to the high-pressure discharge lamp 5 at constant power during non-dimming. To do.

The variable voltage dividing means 7 includes the lamp current detecting means 3
a and a variable resistor connected in parallel to the sum of the outputs of the lamp voltage detecting means 3b.

Next, the operation will be described.

When the power supply 1 is turned on, a high voltage is applied to the high-pressure discharge lamp 5 by the starting circuit 4 to start the high-pressure discharge lamp 5. Then, electric power necessary for lighting is supplied from the lighting main circuit 2, and the high-pressure discharge lamp 5 is turned on. When the lamp is turned on, the detection output from the lamp current detection unit 3a and the detection output from the lamp voltage detection unit are added, and the control output is input to the control unit 6 via the variable voltage dividing unit 7. The control means 6 controls the power supplied to the high-pressure discharge lamp 5 in a constant power manner according to the control input.

When dimming the high-pressure discharge lamp 5, the variable voltage dividing means 7 is operated to increase the divided voltage output. Then, since the respective outputs of the lamp current detecting means 3a and the lamp voltage detecting means 3b are controlled and input to the control means 6 via the variable voltage dividing means 7, they are increased in accordance with the increase of the divided voltage output and are sent to the control means 6. Control input. Therefore, the lamp current detecting means 3
a and the detection output of the lamp voltage detecting means 3b does not change, the operation level of the control means 6 changes, and the power supplied from the lighting main circuit 2 to the step-down discharge lamp 5 is reduced, so that the step-down discharge lamp is dimmed. It shifts to lighting.

FIG. 2 is a graph showing a load characteristic curve of the first embodiment of the high pressure discharge lamp lighting device of the present invention.

In the figure, the horizontal axis represents the lamp voltage, and the vertical axis represents the lamp current. Curve A is a load characteristic curve in an all-light state,
A curve B is a load characteristic curve in a dimming state, and a curve C is a load characteristic curve in a dimming state in the case of the related art shown in FIG.

As can be understood from FIG. 2, in the case of the present invention, the slope of the load characteristic curve B at the time of dimming is larger than that of the conventional curve C. That is, even if the lamp voltage decreases during dimming, the decrease in the lamp current is small.

FIG. 3 is a graph showing a luminous flux rising characteristic at the time of starting the first embodiment of the high pressure discharge lamp lighting device of the present invention.

In the figure, the horizontal axis indicates the lighting time (second) from the start of the start, and the vertical axis indicates the luminous flux ratio (%). A curve A shows a light beam rising curve at the time of starting all light, a curve B shows a light beam rising curve at the time of light control start, and C shows a light beam rise curve at the time of light control start in the case of the prior art shown in FIG.

As is apparent from FIG. 3, in the case of the present invention, the rise of the light beam at the time of starting the dimming is slightly slower than at the time of starting all the light, but is considerably earlier than the prior art.

FIG. 4 is a circuit diagram showing a second embodiment of the high pressure discharge lamp lighting device according to the present invention.

In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, the power supply 1 'includes a rectified DC power supply, the lighting main circuit 2' includes a step-down chopper, the variable voltage dividing means 7 'includes a photocoupler, and corresponds only to the lamp voltage detecting means 3b. I have.

More specifically, the rectified DC power supply 1 ′
Rectifies the AC from the AC power supply 8 and supplies the non-smooth DC to the step-down chopper. The DC power supply 1 'does not include a smoothing capacitor. Therefore, the lighting main circuit 2 'including the step-down chopper also functions as an active filter. The step-down chopper has a switching means 2'a and a step-down inductor 2'b inserted in series with a lighting circuit, and a switching means 2'a and a step-down inductor 2'b and a negative electrode of the rectified DC power supply 1 '. And a step-down inductor 2'b.
And the capacitor 2 ′ in parallel with the diode 2′c
d is connected to the illustrated polarity. Step-down inductor 2 '
b, the diode 2'c and the capacitor 2'd constitute a smoothing means to supply a DC which is considerably flat to the load and stepped down.

The lamp current detecting means 3a comprises a resistor inserted in series with the lighting circuit between the diode 2'c and the capacitor 2'd.

The variable voltage dividing means 7 'is configured such that the light receiving side of the photocoupler is connected to the resistor 3b on the output side of the lamp voltage detecting means 3b.
One part of the resistor 3b2 is electrically connected in parallel.

Next, the circuit operation will be described.

The lighting main circuit 2 'composed of the step-down chopper is 4
Operating at a high frequency of 0 KHz, a step-down and flat DC voltage is applied to the step-down discharge lamp 5. The high-pressure discharge lamp 5 is started by the starting circuit 4, and is supplied with required DC power from the lighting main circuit 2 'to perform DC lighting. When the all light is turned on, the variable voltage dividing means 7 'composed of a photocoupler is not operated, so that the partial voltage level is not increased.

During light control, the photocoupler was turned on and off at 1 KHz by an external operation. When the photocoupler is turned on, the resistor 3b on the output side of the lamp voltage detecting means 3b
2 is inserted, the output level of the lamp voltage detection rises. Since the photocoupler is subsequently turned on, the output level drops again and returns to the original level. As a result of this off and on being repeated at the second frequency, the detection output of the lamp voltage has increased on average, and the lighting means main circuit 2 ′ has the control means 6 to average the DC power supplied to the high-pressure discharge lamp 5. Because of the reduction in value, the high-pressure discharge lamp 5 appears to be dimmed.

From the above circuit operation, it can be understood that the dimming degree can be arbitrarily set by changing the off duty of the photocoupler. Further, for example, when shifting from all-light lighting to dimming lighting, the off-duty is set to 10
From 0%, the value at the time of dimming is set to 0%.
If it is changed continuously, crossover can be achieved. In summary, when changing from a certain lighting state to another certain lighting state, crossover can be performed over an arbitrary time. In a high-pressure discharge lamp, the change in lighting power rapidly changes to the emission color and thus to the color temperature.Thus, by crossover, the change in color temperature is extremely reduced, and the sudden change in brightness is avoided. For example, in an application such as a television receiver, it is possible to avoid psychological discomfort given to a viewer.

It is also possible to control a cooling fan (not shown) for the high-pressure discharge lamp in synchronization with the dimming, if necessary. That is, switching from the all-light state to the dimming state reduces the power consumption of the lamp and the temperature of the lamp. Therefore, it is desirable to reduce the number of rotations of the fan or change the rotation direction. This is because the supercooling makes the high-pressure discharge lamp easily extinguish and causes a change in color temperature.

FIG. 5 is a circuit diagram showing details of a photocoupler driving circuit in a second embodiment of the high pressure discharge lamp lighting device of the present invention.

In the figure, reference numerals 3b1 and 3b2 denote resistors on the output side of the lamp voltage detecting means 3b. A transistor 51 is connected in parallel with the resistor 3b2, and the emitter of the phototransistor 52a of the photocoupler 52 is connected to the base of the transistor 51. Connected. The emitter of the phototransistor 52a is also connected to the connection point between the lamp current detecting means and the lamp voltage detecting means via the resistor 53, and the collector is connected to the collector power supply via the resistor 54, and the light receiving side of the photocoupler is connected. Is composed.

On the other hand, the light emitting diode 52b of the photocoupler 52 is connected to a dimming operation power supply (not shown) through a resistor 55 and an inverter 56,
A capacitor 57 is connected in parallel with 2b to form the light emitting side of the photocoupler 52. The dimming operation power supply is externally operated to turn on and off the power supply.

The high-pressure discharge lamp 5 used is a short arc metal halide lamp having a rated power of 350 W and a distance between the electrodes of 3 mm.

Next, the circuit operation will be described.

Before the dimming power is turned on, the inverter 5
6, the light emitting diode 52b is energized and emits light. Then, since the phototransistor 52a receives the light emission and turns on, the base potential of the transistor 51 increases, and the transistor 51 turns on. Thereby, the resistor 3b2 is short-circuited. Therefore, the output level of the lamp voltage detecting means has decreased. In this state, the high-pressure discharge lamp is lit in an all-light state.

Next, when the dimming operation power is turned on, the power supply to the light emitting diode 52b is stopped by the inverter 56. Then, the circuit operates reversely to the above and the resistor 3b
2, the detection level of the lamp voltage detecting means is increased. In this state, the high pressure discharge lamp is dimmed.

The above explanation is based on whether the dimming operation power supply is turned on,
Although it has been described that the dimming operation signal is turned off, the dimming operation signal at the second frequency can be dimmed at any desired level by transmitting a PWM-controlled dimming operation signal as a dimming operation power supply.

FIG. 6 is a waveform diagram of a dimming operation signal, a lamp current, and an illuminance at the time of 100% lighting in the second embodiment of the high pressure discharge lamp lighting device of the present invention.

The lamp power in this case was 350 W.

FIG. 7 is a waveform chart at the time of 50% lighting.

The lamp power in this case was 250 W.

FIG. 8 is a waveform chart at the time of 17% lighting.

The lamp power in this case was 250 W.

FIG. 9 is a circuit diagram showing a third embodiment of the high pressure discharge lamp lighting device according to the present invention.

In the figure, the same parts as those in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted. This embodiment is different from the second embodiment in the part of the variable voltage dividing means 7 ". That is, the variable voltage dividing means 7" is common to each output of the lamp current detecting means 3a and the lamp voltage detecting means 3b. Arranged to function.

More specifically, of the pair of resistors 91 and 92 connected in series between the output terminals of the detection means 3a and 3b, a transistor 93 is connected in parallel with the resistor 92, and the base of the transistor 93 is connected. It is connected to the collector of the phototransistor 94, which is the light receiving side of the photocoupler. The collector of the phototransistor 94 is further connected to a collector power supply via a resistor 95. The emitter is connected to the negative electrode of the rectified DC power supply 1 '. Note that a resistor 96 is connected between the emitter and the base of the transistor 94.

The other end of the resistor 91 is connected to the output terminal of the lamp voltage detecting means 3b and to the control input terminal of the control means 6.

The variable voltage dividing means 7 "is constituted by circuit portions 91 to 96 in the above description.
Although the light-emitting side of the photocoupler is not shown, the circuit configuration shown in FIG. 5 is allowed.

Next, the circuit operation will be described.

The outputs of the lamp current detecting means 3a and the lamp voltage detecting means 3b are added and applied to the variable voltage dividing means 7 ". The output of the variable voltage dividing means 7" is controlled and input to the control means 6. .

In the case of the present embodiment, the inverter 56 as shown in FIG. 5 is unnecessary. Therefore, at the time of dimming, the photocoupler operates and the phototransistor 94 is turned on. In this state, the base potential of the transistor 93 is low, so that the transistor 93 is off. In this state, the output of variable voltage divider 7 "is high,
For this reason, the control means 6 controls the lighting main circuit 2 ′ to supply lighting power in a dimming state to the high-pressure discharge lamp 5.

On the other hand, when the dimming operation power supply is opened, the phototransistor 94 is turned off, so that the base potential of the transistor 93 is increased and the transistor 93 is turned on. As a result, the resistor 92 is short-circuited and the output level of the variable voltage dividing means 7 "is reduced.
Controls the lighting main circuit 2 ′ to supply lighting power in the all-light state to the high-pressure discharge lamp 5.

FIG. 10 is a partial sectional front view showing an embodiment of the high-pressure discharge lamp in the high-pressure discharge lamp lighting device of the present invention.

In the figure, a high-pressure discharge lamp 5 has an anode 5b and a cathode 5c disposed in an elliptical quartz bulb 5a with the tips of the anode 5b and the cathode 5c facing each other, and a pair of sealing portions 5d provided at both ends of the bulb 5a. To support the base ends of the anode 5b and the cathode 5c, respectively. Reference numeral 5e denotes a sealing metal hermetically embedded in the sealing portion 5d, and reference numeral 5g denotes an outer conductor connected to the sealing metal on the cathode side. 5f is an insulator supported by the sealing portion 5d on the anode 5b side. The reflector 9 integrated with the high-pressure discharge lamp 5 is provided with a light interference film 9a of an infrared transmission visible light reflection type on its inner surface, and by fixing an insulator 5f with a base cement 10 in the neck 9b. , Supporting the high-pressure discharge lamp 5 and being integrated with each other. Reference numeral 9c denotes a through hole formed in a part of the reflection surface of the reflector 9 and leads the outer conductor 5g toward the back of the reflector 9. Reference numeral 11 denotes a high-pressure discharge lamp lighting device, to which the above-described embodiments of the present invention are applied.

FIG. 11 is a conceptual diagram showing an embodiment of the image display device of the present invention.

In the figure, the high-pressure discharge lamp 5 includes a reflector 9 and is integrated to form a light source 12. 1
Reference numeral 3 denotes an image display means, which is composed of, for example, a liquid crystal display, and is irradiated with light emitted from the high-pressure discharge lamp 5 from its back surface and condensed by the reflector 9. Reference numeral 14 denotes an image control unit which drives and controls the image display unit 13, and can have a television receiving function if necessary. 1
An AC power supply 5 supplies necessary power to the high pressure discharge lamp lighting device 11 and the image control means 14. Reference numeral 16 denotes an optical system which collects light transmitted through the image display means 13 and projects it on a screen 17. Reference numeral 18 denotes a main body case that houses the above-described components.

[0110]

According to the first to thirteenth aspects of the present invention, it is possible to provide a high-pressure discharge lamp lighting device capable of performing dimming over a required range smoothly with a relatively simple structure. it can.

According to the first aspect of the present invention, it is possible to provide a high pressure discharge lamp lighting device in which the light flux rises quickly at the start of dimming.

According to the second aspect of the present invention, it is possible to provide a high-pressure discharge lamp lighting device in which the discharge at the time of dimming is stable and the degree of dimming can be arbitrarily set.

According to the third aspect of the present invention, it is possible to provide a high-pressure discharge lamp lighting device in which the luminous flux rises quickly at the start of dimming.

According to the fourth aspect of the present invention, there is provided an apparatus for lighting a high-pressure discharge lamp in which the switching means of the lighting main circuit controls the high-pressure discharge lamp as desired, such as constant power control, and the dimming control is easy. Can be.

According to the fifth aspect of the present invention, since the variable voltage dividing means includes a switching means, the dimming can be easily switched by opening and closing the switching means, and the switching can be performed at a frequency which is invisible to the naked eye. Accordingly, it is possible to provide a high-pressure discharge lamp lighting device capable of performing more stable dimming.

According to the sixth aspect of the present invention, in addition, by providing the switch means including a photocoupler, it is possible to provide a high-pressure discharge lamp lighting device in which remote operation, wiring routing and secondary side insulation are easy. be able to.

According to the seventh aspect of the present invention, since the switch means is additionally PWM-controlled, it is possible to provide a high-pressure discharge lamp lighting device in which a desired dimming degree can be easily set.

According to the eighth aspect of the present invention, it is possible to provide a high-pressure discharge lamp lighting device which crosses over at the time of shifting to dimming.

According to the ninth aspect of the present invention, since the lighting main circuit is formed of a chopper, power control and dimming of the high-pressure discharge lamp can be easily performed, and at the same time, the high-pressure discharge lamp also functions as an active filter against power supply ripple. And a high-pressure discharge lamp lighting device that can be provided.

According to the tenth aspect, since the high pressure discharge lamp has a short arc, it is possible to provide a high pressure discharge lamp lighting device having a high light utilization rate.

According to the eleventh aspect of the present invention, there is provided a high-pressure discharge lamp lighting device capable of desirably selecting luminous characteristics such as luminous efficiency, correlated color temperature, chromaticity and color rendering by using a metal halide lamp. Can be.

According to the twelfth aspect of the present invention, in addition, since the high-pressure discharge lamp is integrally provided with the reflector, it is possible to provide a high-pressure discharge lamp lighting device that easily exhibits optical characteristics.

According to the thirteenth aspect of the present invention, there is provided a high pressure discharge lamp lighting device including a high pressure discharge lamp.

According to the fourteenth aspect, it is possible to provide an image display device having the effects of the first to twelfth aspects.

According to the fifteenth aspect, by controlling the cooling fan of the high-pressure discharge lamp in synchronization with the dimming operation, it is possible to provide an image display device capable of more smoothly dimming. .

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a high pressure discharge lamp lighting device of the present invention.

FIG. 2 is a graph showing load characteristics of the first embodiment of the high pressure discharge lamp lighting device of the present invention.

FIG. 3 is a graph showing a luminous flux rising characteristic at the time of startup of the first embodiment of the high pressure discharge lamp lighting device of the present invention.

FIG. 4 is a circuit diagram showing a high-pressure discharge lamp lighting device according to a second embodiment of the present invention.

FIG. 5 is a circuit diagram showing details of a photocoupler driving circuit in a second embodiment of the high pressure discharge lamp lighting device of the present invention.

FIG. 6 is a waveform diagram of a dimming operation signal, a lamp current, and an illuminance at the time of 100% lighting in a second embodiment of the high pressure discharge lamp lighting device of the present invention.

FIG. 7 is a waveform diagram when 50% lighting is performed.

FIG. 8 is a waveform chart when the lamp is turned on at 17%.

FIG. 9 is a circuit diagram showing a third embodiment of the high pressure discharge lamp lighting device of the present invention.

FIG. 10 is a partially sectional front view showing one embodiment of a high pressure discharge lamp in the high pressure discharge lamp lighting device of the present invention.

FIG. 11 is a conceptual diagram showing an embodiment of the image display device of the present invention.

FIG. 12 is a circuit diagram showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Power supply 2 ... Lighting main circuit 3a ... Lamp current detecting means 3b ... Lamp voltage detecting means 4 ... Starting circuit 5 ... High pressure discharge lamp 6 ... Control means 7 ... Variable voltage dividing means

Claims (15)

[Claims] A lighting main circuit for lighting a high-pressure discharge lamp;
Starting circuit for the high pressure discharge lamp; lamp voltage detecting means for detecting the lamp voltage of the high pressure discharge lamp; lamp current detecting means for detecting the lamp current of the high pressure discharge lamp; both outputs of the lamp voltage detecting means and the lamp current detecting means And a control means for controlling a lighting main circuit according to the output of the variable voltage dividing means. A high pressure discharge lamp lighting device characterized by the above-mentioned. 2. A lighting main circuit which operates at a high frequency and illuminates a high pressure discharge lamp with direct current; a starting circuit of the high pressure discharge lamp; a lamp voltage detecting means for detecting a lamp voltage of the high pressure discharge lamp; A variable voltage dividing means connected in parallel to the output and having a variable voltage dividing ratio during a light controlling operation; a light modulating means for varying the voltage dividing ratio of the variable voltage dividing means at a second frequency lower than the high frequency first frequency A high pressure discharge lamp lighting device, comprising: operating means; and control means for controlling a lighting main circuit in accordance with an output of the variable voltage dividing means. 3. A main circuit for operating at a high frequency and lighting a high pressure discharge lamp in a direct current manner; a starting circuit for the high pressure discharge lamp; a lamp voltage detecting means for detecting a lamp voltage of the high pressure discharge lamp; Lamp current detecting means for detecting current; variable voltage dividing means which is connected in parallel to both outputs of the lamp voltage detecting means and the lamp current detecting means and changes the voltage dividing ratio at the time of dimming operation; Dimming operation means for changing the voltage division ratio of the variable voltage dividing means at a second frequency lower than the frequency of: and control means for controlling the lighting main circuit according to the output of the variable voltage dividing means. High pressure discharge lamp lighting device characterized by the above-mentioned. 4. The lighting main circuit includes switching means;
4. The high pressure discharge lamp lighting device according to claim 2, wherein the control means performs PWM control on the lighting main circuit. 5. The high-voltage dividing device according to claim 1, wherein said variable voltage dividing means comprises a voltage dividing means and a switch connected in parallel to said voltage dividing means. Discharge lamp lighting device. 6. The high pressure discharge lamp lighting device according to claim 5, wherein the switch means includes a photocoupler. 7. The high pressure discharge lamp lighting device according to claim 5, wherein the degree of dimming is changed by switching the switching means at a predetermined frequency and performing PWM control. 8. The high pressure discharge lamp lighting device according to claim 7, wherein the PWM control of the switch means is changed continuously during the dimming transition so as to perform crossover. 9. The high pressure discharge lamp lighting device according to claim 1, wherein the lighting main circuit includes a chopper device. 10. The high pressure discharge lamp lighting device according to claim 1, wherein the high pressure discharge lamp is a short arc high pressure discharge lamp. 11. The high pressure discharge lamp lighting device according to claim 1, wherein the high pressure discharge lamp is a metal halide lamp. 12. The high pressure discharge lamp lighting device according to claim 1, wherein the high pressure discharge lamp is provided with an integral reflector. 13. The high pressure discharge lamp lighting device according to claim 1, further comprising a high pressure discharge lamp. 14. A high pressure discharge lamp with a reflector;
A high pressure discharge lamp lighting device according to any one of claims 1 to 12, image display means for irradiating light emitted from the high pressure discharge lamp and reflected by a reflector from behind, and image control for controlling image control means. Means; an optical system for condensing light transmitted through the image display means and projecting the light on a screen;
An image display device, comprising: a main body case accommodating each of the above components. 15. The image according to claim 14, comprising: a fan for cooling the high-pressure discharge lamp; and fan control means for controlling the fan in synchronization with a dimming operation of the high-pressure discharge lamp. Display device.