WO2010131538A1

WO2010131538A1 - High-pressure discharge lamp lighting device, light source device, and high-pressure discharge lamp lighting method

Info

Publication number: WO2010131538A1
Application number: PCT/JP2010/056436
Authority: WO
Inventors: 徹永瀬; 信一鈴木; 嘉昭駒津; 祐哉山崎
Original assignee: 岩崎電気株式会社
Priority date: 2009-05-13
Filing date: 2010-04-09
Publication date: 2010-11-18
Also published as: JP2010266607A

Abstract

Provided is a high-pressure discharge lamp lighting device in which it is possible to control the number of inversions of the polarity of a lamp lighting current, i.e., the lighting frequency in an appropriate range even for a light source device which is controlled so that the rotation frequency of a color wheel automatically varies. A high-pressure discharge lamp lighting device which is used in a DLP system using a color wheel comprises an alternating power supply means for supplying an alternating lamp current to a high-pressure discharge lamp, and a means for detecting the number of revolutions of the color wheel, wherein the alternating power supply means controls the timing at which the polarity of the alternating lamp current is inverted, on the basis of the detected number of revolutions.

Description

High pressure discharge lamp lighting device, light source device, and high pressure discharge lamp lighting method

The present invention relates to a high pressure discharge lamp lighting device that supplies an alternating lamp current to light a high pressure discharge lamp, a light source device using the same, and a high pressure discharge lamp lighting method.

A short arc high pressure discharge lamp combined with a reflecting mirror is used as a backlight of a light source device such as a projector or a projection TV. In recent years, these high-pressure discharge lamps are required to improve various characteristics such as further improvement in brightness, downsizing, and longer life.
Among them, in a light source device adopting a so-called DLP (digital lighting processor) system using a reflective mirror device, as described in Patent Document 1, commutation (polarity inversion) of a lamp lighting waveform is described. ) And the rotation of the color wheel mounted on the DLP system are synchronized. This is in order to suppress a decrease in illuminance efficiency by synchronizing the timing of the polarity inversion of the lamp lighting current at which the lamp light output slightly decreases and the timing of the spoke passage between the color segments of the color wheel.

In recent years, as described in Japanese Patent Application Laid-Open No. 2004-228688, as an improvement in the color reproducibility of a projected image, there is a control in which the polarity is inverted in synchronization with each color segment of the color wheel or the current value is increased or decreased for each segment. It is used, and is called variable control or the like (for example, Patent Document 1).

According to Patent Document 1, every time the color wheel makes one rotation, a synchronization signal indicating the reference is transmitted from the light source device to the high pressure discharge lamp lighting device, and the color set in advance by the high pressure discharge lamp lighting device that has received the synchronization signal. Control is performed to increase or decrease the current value supplied to the lamp or to reverse the polarity of the current in accordance with each color segment of the wheel. When one rotation of the color wheel is completed, the synchronization signal is transmitted to the high pressure discharge lamp again, and the high pressure discharge lamp repeats the current supply to the lamp and the polarity inversion again.

JP 2007-242421 A

When the lamp is turned on with the above prior art lighting device, the effect of improving the projected image color reproducibility of the light source device can be expected as described in each document.
However, the polarity inversion of the lamp current is preferably performed at the segment switching point in the color wheel in order to efficiently extract the irradiation light from the lamp as described above. For this reason, the number of polarity inversions (that is, the lighting frequency) and variations in polarity inversion are limited by the number of rotations of the color wheel and the number of segments, and there are problems due to this.

When the lamp is turned on, tungsten of the electrode in the lamp repeatedly evaporates and accumulates at the tip of the electrode due to polarity reversal. However, when the lighting frequency is high, the lamp tends to evaporate as is known, and the lamp voltage rises quickly during the life of the lamp. As a result, the lamp cannot have a long life. For this reason, in order to extend the life of the lamp, it is necessary to light it in an appropriate lighting frequency range according to the lamp.

As for the specific frequency, the optimum value differs depending on the design of each lamp, but when considering the lower limit value, it is approximately 60 Hz or more. This is because the flickering of illuminance due to the polarity inversion of the lamp is visually recognized by humans up to about 50 Hz.
Moreover, although it is necessary to actually confirm the upper limit value by a life test in each lamp, it is known that the upper limit is about 150 Hz when a general lamp is turned on under general lighting conditions. .
In other words, by setting the lighting frequency in the range of about 60 Hz to about 150 Hz, the lamp voltage does not drop abnormally when the lamp is lit, and the lamp voltage rises slowly during the life, and the desired life is achieved. Can do.

Here, in a light source device employing the above-described DLP system (hereinafter referred to as a DLP light source device), in many cases, the rotation speed of the color wheel, that is, the rotation frequency is 50 Hz or 60 Hz which is a power supply frequency, Alternatively, the frequency is double the speed, that is, 100 Hz or 120 Hz, or the triple speed, that is, 150 Hz or 180 Hz. This is because the frequency corresponds to the frequency of the video signal of the electronic device connected to the light source device, and control is performed so that this frequency and the video output signal from the light source device are synchronized. The color wheel is often divided into 3 to 6 color segments.

Some recent DLP light source devices detect the type of electronic equipment connected to the light source device and automatically change the rotation frequency of the color wheel.
When the lamp is lit while synchronizing the rotation of the color wheel and the polarity reversal of the lamp lighting current waveform in the high pressure discharge lamp lighting device mounted on such a light source device, the lighting supplied to the lamp from the high pressure discharge lamp lighting device The number of inversions of the polarity of the current, that is, the lighting frequency varies depending on the rotation frequency of the color wheel (hereinafter referred to as “fcw”).

As described above, it is assumed that the polarity inversion timing of the lamp lighting current is controlled to be synchronized with the color wheel, and for example, a current waveform is set as shown in FIG. 6A for one rotation of the color wheel. At this time, the number of polarity reversals per one rotation of the color wheel of the lamp lighting waveform is three, which is 1.5 cycles. Therefore, when fcw = 50 Hz, the lamp lighting frequency is 75 Hz which is 1.5 times 50 Hz.
Similarly, at fcw = 60 Hz, the lamp lighting frequency is 90 Hz, which is 1.5 times 60 Hz.

However, similarly to the above, when the current waveform is set as shown in FIG. 6A, when fcw is 100 Hz or 120 Hz, or 150 Hz or 180 Hz, the lamp lighting frequency is considerably high, 150 Hz or 180 Hz, or 225 Hz or 270 Hz, respectively. It becomes a frequency.

A first aspect of the present invention is a high-pressure discharge lamp lighting device used in a DLP system using a color wheel, an AC power supply means for supplying an AC lamp current to the high-pressure discharge lamp, and rotation of the color wheel The high-pressure discharge lamp lighting device includes means for detecting the number, and the AC power supply means adjusts the polarity inversion timing of the AC lamp current based on the detected rotational speed.

The second aspect of the present invention is a light source device including a DLP system including the high pressure discharge lamp lighting device, the high pressure discharge lamp, and the color wheel according to the first aspect.

According to a third aspect of the present invention, there is provided a lighting method for a high pressure discharge lamp used in a DLP system using a color wheel, wherein the AC power supply means supplies an AC lamp current to the high pressure discharge lamp, and the detection means is a color. The lighting method includes a step of detecting the rotation speed of the wheel and a step of adjusting the polarity inversion timing of the AC lamp current by the AC power supply means based on the detected rotation speed.

In each of the above aspects, when the detected rotational speed is greater than a predetermined value preset in the AC power supply means, the polarity reversal number of the AC lamp current is reduced, and the detected rotational speed is lower than the predetermined value preset in the AC power supply means. When the number is small, the polarity inversion number of the AC lamp current is increased.
Here, the polarity inversion timing is adjusted so that the frequency of the AC lamp current is 60 Hz or more and 150 Hz or less.

It is a circuit block diagram which shows the discharge lamp lighting device of this invention. It is a figure which shows a color wheel. It is a figure which shows a color wheel. It is a figure which shows a color wheel and a synchronizing signal. It is a figure which shows a color wheel and a synchronizing signal. It is a figure which shows the lamp current synchronized with the color wheel. It is a figure which shows the lamp current synchronized with the color wheel. It is a figure which shows the lamp current synchronized with the color wheel. It is a figure which shows the lamp current synchronized with the color wheel. It is a figure which shows the lamp current synchronized with the color wheel. It is a figure which shows the lamp current synchronized with the color wheel. It is a figure which shows the lamp current synchronized with the color wheel. It is a figure which shows the lamp current synchronized with the color wheel. It is a figure which shows the lamp current synchronized with the color wheel. It is a figure which shows the lamp current synchronized with the color wheel. It is a figure which shows the lamp current synchronized with the color wheel. It is a figure which shows the lamp voltage fluctuation | variation by the conventional lighting method and the lighting method of this invention. It is a figure explaining the light source device of this invention. It is a flowchart of the lighting method of this invention.

<Basic configuration and operation>
FIG. 1 is a circuit configuration diagram of the present invention. In the high pressure discharge lamp lighting device of the present invention, the step-down chopper circuit 20, the full bridge circuit 30, and the control unit 60 constitute an alternating current supply means. More specifically, the DC power supply 10, the step-down chopper circuit 20 that controls the DC voltage of the DC power supply 10 to a predetermined lamp power or lamp current by a PWM (pulse width modulation) control circuit, and the DC output voltage of the step-down chopper circuit 20 are AC. In order to control the full bridge circuit 30 for converting to a rectangular wave current and applying it to the lamp 50, the igniter circuit 40 for applying a high voltage pulse voltage to the lamp when starting the lamp, and the step-down chopper circuit 20 and the full bridge circuit 30. The control part 60 is comprised. The power source of the high pressure discharge lamp lighting device is shown as a DC power source 10 for easy viewing of the drawing. However, if necessary, a commercial AC power source is rectified by a full-wave rectification by a capacitor input type circuit, It also includes circuits (power factor correction circuits).

The step-down chopper circuit 20 includes a transistor 21, a diode 22, a choke coil 23, and a smoothing capacitor 24 that are PWM-controlled by a PWM control circuit 28. The DC voltage supplied from the DC power supply 10 is converted into predetermined lamp power or lamp current. Controlled to convert. The full bridge circuit 30 is controlled by the bridge control circuit 35 so that the pair of

transistors

31 and 34 and the pair of

transistors

32 and 33 are alternately turned on / off at a predetermined timing. As a result, an alternating current (basically a rectangular wave) is applied to the lamp 50, but the value of the predetermined lamp power or lamp current and the timing of the polarity inversion of the lamp current by the full bridge circuit 30 are controlled. Determined by the unit 60. The lamp 50 is assumed to have a rated power of about 50 to 400 W. The above-described control is for a general high-pressure discharge lamp lighting device, but the control in the case of variable control will be described below.

In the variable control, as shown in FIG. 3B, every time the color wheel makes one rotation, a synchronization signal indicating the reference is transmitted from the light source device to the high pressure discharge lamp lighting device. In the high pressure discharge lamp lighting device, the synchronization signal receiving unit 61 detects the synchronization signal, the microcomputer of the synchronization signal receiving unit 61 or the control unit 60 recognizes the detected synchronization signal as the reference point of the color wheel, and the control unit 60 detects the reference point. The period of one rotation of the color wheel is controlled from the starting point. In the microcomputer, the angle of each color segment of the color wheel, the current value in each color segment, and the polarity inversion timing of the lamp current are programmed in advance, and the control unit 60 controls the PWM control circuit 28 and the bridge control circuit 35 according to this program. . When the rotation of the color wheel is completed, the synchronization signal of the next cycle is transmitted at the same time, and the high pressure discharge lamp lighting device receives this synchronization signal, and again controls the period of the next rotation of the color wheel from this as a starting point. Do. In this way, a slight deviation between the actual rotation speed of the color wheel and the operation programmed in the microcomputer is corrected every rotation of the color wheel, and the operation of the color wheel and the output control of the high pressure discharge lamp lighting device are always performed. And are trying to synchronize.

Example 1.
The specifications of the first embodiment of the present invention are as follows.
A color wheel 81 is shown in FIG. 2A. The color wheel 81 includes two sets of (red (R), green (G), and blue (B)), and the angle of each color segment is 60 °.
FIG. 3A shows a synchronization signal generated by the light source device. One synchronization pulse is generated for every half rotation of the color wheel. This synchronization pulse is detected by the synchronization signal receiver 61.

Fig. 4A shows one unit of lamp current. In one unit, a half-cycle low-frequency part is followed by one cycle of a high-frequency part, followed by a positive and negative inversion followed by one unit. The peak value of the first half cycle of the low frequency part and one cycle of the high frequency part is IL, the second half cycle of the high frequency part 1 cycle is IH, and IL <IH. It is known that this lamp current waveform (apart from the color wheel problem) can solve the so-called flicker problem and is suitable for lighting a high-pressure discharge lamp (for example, Japanese Patent Laid-Open No. 2000-052718). Is referenced).

FIG. 5A shows the initial setting of the lamp current in the high pressure discharge lamp lighting device. As shown in the figure, the initial setting corresponds to double speed (fcw = 100 Hz or 120 Hz). The lamp current is set so that the lamp current becomes one unit for one rotation of the color wheel (two synchronization pulses). As a result, the frequency of the lamp current is 100 Hz or 120 Hz (the frequency is calculated assuming that there is no high frequency part). In this case, it may be controlled to start one unit of lamp current by skipping one synchronizing pulse, or may be controlled to start a half unit of lamp current for each synchronizing pulse.

Here, it is assumed that the rotation of the color wheel 81 is tripled by the light source device, that is, fcw = 150 Hz or 180 Hz. FIG. 5B shows the correspondence to the triple speed. The lamp current is configured so that the lamp current becomes a half unit for one rotation of the color wheel (two synchronization pulses). As a result, the lamp current is 75 Hz or 90 Hz.

Here, it is assumed that the rotation of the color wheel 81 is set to 1 × speed by the light source device, that is, fcw = 50 Hz or 60 Hz. FIG. 5C shows the correspondence to the 1 × speed. The single speed can be identified by the fact that the synchronization pulse is not detected for a certain period. The lamp current is configured so that the lamp current is 2 units for one rotation of the color wheel (two synchronization pulses). As a result, the lamp current is 100 Hz or 120 Hz.

According to the above, even if the rotation speed of the color wheel 81 is changed, the frequency of the lamp current is 75 Hz to 120 Hz, which falls within the preferred range of 60 Hz to 150 Hz.
FIG. 8 shows the relationship between the lighting time at each lighting frequency and the lamp voltage fluctuation (ie, life). In the sample of “200 Hz lighting” outside the above 60 Hz to 150 Hz range, it can be seen that the lamp voltage increases by about 20 V from the beginning of lighting after 500 hours, and the electrodes are consumed and the distance between the electrodes is increased. . On the other hand, in the samples of “75 Hz lighting” and “100 Hz lighting” within the range of 60 Hz to 150 Hz, the lamp voltage remains within the range of about ± 5 V of the initial lamp voltage after 500 hours, and the electrode is consumed. I understand that there is no. Therefore, it can be seen that the lamp life is secured by this embodiment.

Example 2
The specifications of the second embodiment of the present invention are as follows.
A color wheel 82 is shown in FIG. 2B. The color wheel 82 is divided into five segments of red (R), green (G), blue (B), white (W), and yellow (Y), and the angle of each segment is red (R) = 100 deg. , Green (G) = 100 deg, blue (B) = 100 deg, white (W) = 30 deg, yellow (Y) = 30 deg. This is incorporated in a light source apparatus that employs a so-called DLP system using a reflective mirror device.

FIG. 3B shows a synchronization signal generated by the light source device. One synchronization pulse is generated for each rotation of the color wheel. This synchronization pulse is detected by the synchronization signal receiver 61.

Fig. 4B shows the peak value and period length of the lamp current for each segment. The period length is proportional to the angle of each segment, the crest value is set to a different value for each segment, and the polarity inversion timing varies depending on the number of rotations of the color wheel 82. The current value of each segment is I (Y) = I1 (rated current ratio 150%), I (G) = I2 (rated current ratio 110%), I (R) = I (B) = I (W) = It is I3 (rated current ratio 90%). The lamp rated power is 200W.

FIG. 6A shows the initial setting of the lamp current in the high pressure discharge lamp lighting device. The initial setting corresponds to 1 × speed (fcw = 50 Hz or 60 Hz). The lamp current is inverted between R and Y, and between G and W, and this is inverted in polarity every sync pulse (ie, between B and R).
As a result, 1.5 cycles of lamp current are included in one rotation of the color wheel (50 Hz or 60 Hz), and the lamp current is 75 Hz or 90 Hz.

FIG. 6B shows correspondence to double speed (fcw = 100 Hz or 120 Hz). The polarity inversion timing as shown in the figure is programmed in the control unit 60, and by executing this, the lamp current is included in 1.5 cycles within two rotations of the color wheel (equivalent to 50 Hz or 60 Hz), and the lamp current is 75 Hz or 90 Hz. It becomes.

FIG. 6C shows the correspondence to the triple speed (fcw = 150 Hz or 180 Hz). The polarity inversion timing as shown in the figure is programmed in the control unit 60, and by executing this, 0.5 cycle of lamp current is included in one rotation of the color wheel (150 Hz or 180 Hz), and the lamp current is 75 Hz or 90 Hz. Become.

Example 3 FIG.
The specifications of the third embodiment of the present invention are as follows.
The color wheel, the synchronizing signal, and the lamp current configuration used are the same as those in Example 2, and are shown in FIGS. 2B, 3B, and 4B, respectively.

FIG. 7A shows an initial setting of the lamp current in the high pressure discharge lamp lighting device. The initial setting corresponds to double speed (fcw = 100 Hz or 120 Hz).
With the inversion timing as shown in the drawing, 1.5 cycles of the lamp current are included in two rotations of the color wheel (equivalent to 50 Hz or 60 Hz), and the lamp current becomes 75 Hz or 90 Hz.

FIG. 7B shows the correspondence to 1 × speed (fcw = 50 Hz or 60 Hz). The polarity inversion timing as shown in the figure is programmed in the control unit 60, and by executing this, the lamp current is included in 3.5 cycles within 2 rotations of the color wheel (equivalent to 25Hz or 30Hz), and the lamp current is 87.5Hz. Or 105 Hz.

FIG. 7C shows the correspondence to the triple speed (fcw = 150 Hz or 180 Hz). The polarity inversion timing as shown in the figure is programmed in the control unit 60, and by executing this, the lamp current is included in 1.5 cycles within two rotations of the color wheel (equivalent to 75 Hz or 90 Hz), and the lamp current is 112.5 Hz. Or it becomes 135 Hz.

In Examples 2 and 3, the lamp current frequency falls within the range of 60 Hz to 150 Hz, and the same effect as in Example 1 can be obtained.

Example 4
In the above-described embodiment, a high pressure discharge lamp lighting device capable of extending the life of the lamp is shown, but a light source device as an application using the high pressure discharge lamp lighting device is shown in FIG.
In FIG. 9, 71 is the high pressure discharge lamp lighting device of FIG. 1 described above, 72 is a reflecting mirror to which the lamp is attached, 73 is a high pressure discharge lamp lighting device, and a housing containing the lamp. In addition, the figure is a schematic illustration of the embodiment, and the dimensions, arrangement, and the like are not as illustrated. Then, in addition to a color wheel (not shown), a video system member and the like are appropriately arranged in the housing to constitute a projector.

As a result, in a light source device that employs a DLP system, it is possible to extend the life of the lamp even in the case of a light source device that performs control in which the rotation frequency of the built-in color wheel automatically changes, and is highly reliable. A projector can be obtained and versatility of the high-pressure discharge lamp lighting device can be enhanced.

Embodiment 5 FIG.
In FIG. 10, the flowchart of the lighting method for implementing Example 1-3 is shown.
When the lighting is started, first, in step S100, the AC lamp current by the initial setting is supplied to the high pressure discharge lamp.
In step S110, the synchronization signal receiving unit 61 detects the rotation speed (fcw) of the color wheel. Here, if the detected number of rotations is the same as that of the initial setting, the process returns to step S100, and if different, the process proceeds to step S120.
In step S120, the polarity inversion timing of the AC lamp current is adjusted based on the detected rotational speed. That is, as shown in each embodiment, the polarity inversion timing is adjusted so that the frequency of the lamp current falls within the range of 60 Hz to 150 Hz.

More specifically, in step S120, when the detected rotational speed is larger than the initial value, the polarity inversion number of the AC lamp current is decreased, and when the detected rotational speed is smaller than the initial value, the polarity inversion number of the AC lamp current is increased. To do.
In the above example, one adjustment is performed for one lighting, but a plurality of adjustments may be performed during one lighting.

According to the present invention, even in the case of a light source device that performs control in which the rotation frequency of the color wheel automatically changes according to the electronic device connected to the light source device, the number of inversions of the lamp lighting current, that is, the lighting frequency is appropriately set. Since it can be controlled within the range, the lamp can have a long life.

In addition, although the said Example was shown as the most suitable example of this invention, the following is noted in connection with it.
(1) The rotation frequency of the color wheel is not limited to 50, 60, 100, 120, 150, and 180 Hz. In other words, the polarity inversion timing may be controlled so that the frequency of the lamp current falls within the range of 60 Hz to 150 Hz regardless of the frequency of rotation of the color wheel.

(2) Immediately after the rotation frequency of the color wheel changes, it takes time for the lighting device to detect it, and during that time, the rotation of the color wheel and the lamp current reversal operation are not synchronized. Become. However, this only has a change that can be seen in the color and brightness of the screen for a moment in the light source device, so it is not a significant effect.

(3) In the embodiment, the AC power supply circuit is configured by a rectifier circuit, a step-down chopper circuit, and a full bridge circuit, but other configurations may be used as long as an AC rectangular wave can be supplied to the lamp. For example, if the input power source is a direct current power source, the preceding stage of the full bridge circuit may be only a DC / DC converter. In addition, a circuit of another system such as a push-pull inverter may be used instead of the full bridge circuit as long as it can convert direct current into alternating current.

(4) If the control unit 60 can perform the inversion control of the transistors 31 to 34 of the full bridge circuit 30 and the PWM control of the transistor 21 of the step-down chopper circuit 20, the configuration in the control circuit is limited to that shown in the figure. Not.

10. DC power supply 20. Step-down chopper circuit 30. Full bridge circuit 40. Igniter circuit 50. High pressure discharge lamp
60. Control unit 61. Sync signal receivers 81, 82. Color wheel

Claims

A high pressure discharge lamp lighting device used in a DLP system using a color wheel,
AC power supply means for supplying an AC lamp current to the high-pressure discharge lamp, and means for detecting the rotational speed of the color wheel, wherein the AC power supply means reverses the polarity of the AC lamp current based on the detected rotational speed A high pressure discharge lamp lighting device configured to adjust timing.
2. The high pressure discharge lamp lighting device according to claim 1, wherein the polarity reversal number of the AC lamp current is reduced when the detected rotational speed is larger than a predetermined value preset in the AC power supply means. High pressure discharge lamp lighting device.
2. The high pressure discharge lamp lighting device according to claim 1, wherein the polarity reversal number of the AC lamp current is increased when the detected rotational speed is smaller than a predetermined value preset in the AC power supply means. High pressure discharge lamp lighting device.
2. The high pressure discharge lamp lighting device according to claim 1, wherein the polarity inversion timing is adjusted so that the frequency of the AC lamp current is 60 Hz or more and 150 Hz or less.
A light source device comprising a DLP system comprising the high pressure discharge lamp lighting device according to claim 1, the high pressure discharge lamp, and the color wheel.
A method for lighting a high pressure discharge lamp used in a DLP system using a color wheel,
An AC power supply means energizes the AC lamp current to the high-pressure discharge lamp;
A lighting method comprising the steps of: detecting means for detecting the rotation speed of the color wheel; and adjusting the polarity reversal timing of the AC lamp current based on the detected rotation speed.
7. The lighting method according to claim 6, wherein the adjusting step includes a step of decreasing the polarity reversal number of the AC lamp current when the detected rotation speed is larger than a predetermined value preset in the AC power supply means. Lighting method.
7. The lighting method according to claim 6, wherein the adjusting step includes a step of increasing the polarity reversal number of the AC lamp current when the detected rotational speed is smaller than a predetermined value preset in the AC power supply means. Lighting method.
7. The lighting method according to claim 6, wherein the polarity inversion timing is adjusted so that the frequency of the AC lamp current is 60 Hz or more and 150 Hz or less.