JPH10312888A - Lamp lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To re-light a lamp in the minimum waiting time by providing a temperature detection means detecting the re-lightable temperature of a lamp on the lamp, and informing of a lamp re-lightable state based on a detection result. SOLUTION: A temperature sensor 3 is fitted to the lighting portion of a lamp 2, and outputs a temperature detection signal to a control portion 4 when a cooling down lamp temperature reaches a previously set re-lightable temperature after lighting-off. The control portion 4 generates a signal informing that the lamp 2 is in a re-lightable state, and supply the signal to an informing means 5. The informing means 5 indicates a user that the lamp can be re- lighted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lamp lighting device used for a projection type device such as a liquid crystal projector.

[0002]

2. Description of the Related Art In recent years, with the diversification of video sources, image display devices such as liquid crystal projectors capable of displaying images on a screen larger than a color television receiver have become widespread. Since a video such as a movie can be displayed on a large screen such as a screen, it is possible to enjoy realistic viewing at home.

[0003] Such an image display device is generally called a projection type display. For example, a front projection type liquid crystal projector for projecting an image displayed on a liquid crystal panel and projecting the image on a screen, and a main body including this liquid crystal projector There is a rear-projection type television receiver or the like which is mounted inside and projects an image on a screen using an optical system mirror.

In general, a projection type display uses a high-pressure discharge lamp (hereinafter, referred to as a lamp) as a light source as a light source in order to display a clear image with high luminance. Requires a very large voltage. For this reason, a lamp lighting device for generating such a large lamp starting voltage and lighting the lamp is generally used. In addition, the lamp lighting device has a basic function of maintaining the lighting of the starting lamp and the like, and also has an additional function of improving the power factor and the like, which is indispensable for controlling the lighting of the lamp. .

[0005] The lamp lighting device generates a high lamp lighting voltage at the time of starting the lamp, and applies the generated lamp lighting voltage to both electrodes of the lamp. As a result, the lamp emits glow discharge, for example, by a glow switch provided in the lamp, and then starts to turn on by switching to arc discharge in the arc tube.

As described above, high-pressure discharge lamps such as metal halide lamps are mainly used for lamps used in projection-type devices such as liquid crystal projectors. This main lamp is an improved version of a high-pressure mercury lamp, and emits an optical spectrum peculiar to the metal by mixing various metal vapors in the arc of the discharge in the mercury vapor. For this reason, the luminous efficiency is high, and desired luminous characteristics can be obtained by a combination of metals. In addition, the color temperature is high, and the color is close to natural light and has high color rendering properties. Further, there is an advantage that the square light can be easily extracted using a reflector or the like close to the point light source. Therefore, it is optimal for a liquid crystal projector that requires high image quality and high brightness.

However, such a high-pressure discharge lamp cannot be started immediately because the temperature of the lamp is high immediately after the lamp is turned off and the vapor pressure is high. In other words, the discharge can be started only after a certain amount of time has passed and the vapor pressure has dropped. Therefore, in order to restart the lamp, there is an inconvenience that the user has to wait for a predetermined restart time required for restarting.

In general, a high-pressure discharge lamp emits light when the inner tube of the lamp is heated to a high temperature and the vapor pressure is high when the lamp is turned on. However, when the lamp is started, the lamp starts discharging at a normal temperature and a low vapor pressure. . After the start of discharge, the temperature starts to rise due to the discharge current, and it takes time until light is sufficient. The rise time varies depending on the type of lamp and the type of lamp lighting device, but usually takes several minutes to several tens of minutes.

FIG. 2 is a characteristic diagram showing an example of the characteristic of the temperature of the light emitting tube and the elapsed time relating to the turning on / off of the lamp as described above.

Usually, when the lamp is turned on, it can be seen that the temperature of the arc tube of the lamp rises with time as shown in FIG.

For example, assuming that the time when the lamp is turned on is t0 and the time when the temperature of the lamp reaches the maximum temperature C is t2,
To reach the maximum temperature C, a time of (t2 -t0) is required. Here, when the lamp is turned off, the temperature in the arc tube gradually decreases, and when the temperature at the time when the lamp is turned on (sometimes described as the coldest point) is t7, in this case, the lamp is turned off. Is the time required to reach the coldest point from (t7 -t2). The temperature of the arc tube with respect to the elapsed time after the time t7 is not shown in the figure because it is not so much converted.

When the time when the lamp temperature reaches the temperature B at which the temperature does not reach the maximum temperature C is denoted by t1, the time required to reach the temperature B from the lamp lighting time t0 is (t)
1−t0). Here, assuming that the lamp is turned off at time t1 when the temperature reaches temperature B, the lamp temperature gradually decreases as shown in the figure, and the time when the temperature at which the lamp is lit (the coldest point) is reached. Assuming that t4, the time required to reach the coldest point is (t4-t1).

In this case, the temperature B and the time t are supposed to have the same characteristics as the temperature decrease from the maximum temperature C described above (the temperature decreases according to the elapsed time, the inclined state indicated by the broken line in the figure).
Assuming that the temperature gradually decreases from the intersection with 1 (at the time of turning off the light) and considering the influence of the ambient temperature, the time to reach the coldest point is the time of t5. In other words, there is a tendency that when the temperature decreases from the middle temperature B rather than the highest temperature C, the temperature decreases more steeply with respect to the elapsed time.

As described above, depending on the length of the lighting time,
Since the height of the lamp temperature is different and the time required for decreasing the temperature after the lamp is turned off is also different, a maximum (t7-t1) time is required as the waiting time required for relighting the lamp. That is, since the lamp cannot be re-lit while the temperature of the arc tube of the lamp is high, it is necessary to wait until the lamp can be re-lit.

If it is possible to detect the temperature at which the lamp can be turned on again after the lamp is turned off and the temperature of the arc tube drops due to air cooling of the tube wall, the sealing portion, the reflector, etc. Can be turned on again. However, in the conventional lamp lighting device, such a temperature cannot be detected, and the falling state of the temperature decrease differs depending on the length of the lamp lighting time. As a result, the cold spot is obtained as described above. There was a problem of having to wait until time.

[0016]

As described above, the conventional lamp lighting device cannot detect the temperature at which the lamp can be relighted, and depends on the lighting time of the lamp and the temperature of the lamp and the lamp after the lamp is turned off. Since the temperature drop characteristics are different, as a result, there is a problem that the light cannot be turned on again unless a predetermined time from the time when the light is turned off to the time when the coldest point becomes the same temperature when the light is turned on.

In view of the above, the present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a lamp with a temperature detecting means for detecting a re-lightable temperature of the lamp and to enable the lamp re-lighting control based on the detection result. Accordingly, it is an object of the present invention to provide a lamp lighting device capable of lighting a lamp again with a minimum waiting time.

[0018]

A lamp lighting device according to the present invention comprises: a lamp body having a lamp as a light source;
A temperature sensor that is provided in a lamp lighting portion of the lamp body to detect a temperature change of the lamp, detects that a preset temperature has been reached, and outputs a detection result, and monitors a temperature detected by the temperature sensor. A control unit for recognizing that the lamp has a relightable temperature based on the detection result, and generating information for informing the relightable state, and supplying the information from the control unit to restart the lamp. Notifying means for notifying that lighting is possible.

According to the present invention, a change in the temperature of the lamp is constantly detected by the temperature sensor provided in the lamp lighting portion of the lamp body, and when the temperature reaches a preset temperature, a detection result is output. When the detection result is supplied to the control unit, the control unit recognizes that the temperature is such that the lamp can be re-lit based on the supplied detection result,
Generates information to notify that relighting is possible. The notification unit notifies that the lamp can be re-lit when the information is supplied from the control unit. That is, the user is notified that re-lighting is possible. This allows the user to be notified when the lamp is ready to be re-lit even if the lamp temperature does not reach the coldest point when the lamp is re-lit after the lamp is turned off. Can be shortened.

[0020]

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

FIG. 1 is a block diagram showing an embodiment of a lamp lighting device according to the present invention. The lamp lighting device according to the present invention is incorporated in a projection-type device such as a liquid crystal projector.

As shown in FIG. 1, the lamp lighting device 1 comprises:
A lamp body 2, a temperature sensor 3 attached to the lamp body 2, and control as control means capable of controlling lighting (re-lighting) of the lamp body 2 based on temperature information obtained by the temperature sensor 3. 4.

Specifically, the lamp body 2 uses a high-pressure discharge lamp (for example, a metal halide lamp or the like) which is optimal as a light source of a projection type device such as a liquid crystal projector. This type of high-pressure discharge lamp has a high color temperature and color rendering properties, and also has a high luminous efficiency. Therefore, it is most suitable for a liquid crystal projector that requires high image quality and high luminance.

In this embodiment, the lamp body 2 is provided with a temperature sensor 3 for detecting the temperature of the lamp body 2 (the arc tube). This temperature sensor 3
Is installed, and outputs a detection result indicating a relightable time by detecting a temperature set in advance.

In this embodiment, a plurality of temperature sensors 3 can be provided. In this case, by attaching a plurality of the temperature sensors 3 so that the respective temperature settings are different, it is possible to output the respective detection results when the respective different set temperatures are reached. In other words, by providing a plurality of temperature sensors 3 having different set temperatures, it is possible to detect the time during which the lamp can be re-lit regardless of the length of the lighting time.

The temperature sensor 3 may be of a variable type so that, for example, the temperature to be detected can be set arbitrarily. It may be constituted by a simple one. Thus, even if the lamp model is different, it is possible to easily recognize the relightable information by using the temperature sensor for setting the relighting temperature according to the model.

The result of detection by the temperature sensor 3, that is, a temperature detection signal is given to the control unit 4 via the input terminal 4b.

The control section 4 is constituted by, for example, a microcomputer (hereinafter, referred to as a microcomputer). The microcomputer 4 outputs a power on / off signal (also referred to as a drive control signal) to a lamp via an output terminal 4a. By supplying the lamp to the main body 2, the turning on / off or re-lighting of the lamp is controlled.

For example, when starting the lamp, the microcomputer 4 starts the lamp 2 by supplying a power-on signal to the lamp body 2 by a user operation. That is, the microcomputer 4 generates a high-voltage lamp lighting voltage necessary for lighting the lamp, and applies the generated lamp lighting voltage to both electrodes (not shown) of the lamp body 2 so that the lamp is, for example, in the lamp. A glow discharge is generated by the glow switch provided in the light emitting device, and then the lighting is started by shifting to arc discharge in the arc tube.

On the other hand, when turning off the lamp, the microcomputer 4 stops the lighting state of the lamp by giving a power-off signal to the lamp body 2 by a user operation. That is, by stopping the output of the lamp drive voltage supplied to both electrodes (not shown) of the lamp, the lighting state of the lamp is stopped.

When the microcomputer 4 receives the temperature detection signal from the temperature sensor 3 after the lamp is turned off, the temperature of the lamp body 2 (the arc tube) reaches a temperature at which the lamp 4 can be turned on again from the temperature detection signal. Recognizing that the re-lighting is possible, a signal is generated to notify the re-lightable state, and the signal is supplied to the notifying means 5. Thereby, the notification means 5 displays to the user that re-lighting is possible, and the user can immediately perform the operation of re-lighting when this display is made. Therefore, re-lighting can be performed without waiting for the lamp to reach the coldest point as in the related art.

Therefore, since the lamp can be turned on again at the time when the temperature detection signal is supplied after the lamp is turned off, the restart time is set to be shorter than the predetermined time required for the temperature after turning off to reach the coldest point. It is possible to greatly shorten the time.

Next, the operation of the apparatus shown in FIG. 1 will be described in detail with reference to FIG.

FIG. 2 is a characteristic diagram showing an example of the characteristics of the temperature of the arc tube and the elapsed time related to the lighting / extinguishing of the lamp.

In general, a high-pressure discharge lamp emits light when the inner tube of the lamp 2 becomes high in temperature and the vapor pressure is high when the lamp is turned on. However, at the time of starting, the lamp 2 discharges at a normal temperature and a low vapor pressure. Start. Thereafter, as shown in FIG. 2, after the start of the discharge, the temperature of the arc tube of the lamp 2 starts to rise with the passage of time due to the discharge current, and eventually reaches the highest temperature C.

For example, suppose that the time when the lamp is turned on is t0 and the time when the temperature of the lamp reaches the maximum temperature C is t2.
To reach the maximum temperature C, a time of (t2 -t0) is required. Here, when the lamp is turned off, the temperature in the arc tube gradually decreases, and when the temperature at the time when the lamp is turned on (the coldest point) is set to t7, in this case, the lamp reaches the coldest point from the lamp turned off. (T7-t2)
) Time. The temperature of the arc tube with respect to the elapsed time after the time t7 is not shown in the figure because it is not so much converted.

However, in this embodiment, it is possible to turn on the light again without reaching the coldest point.

Now, it is assumed that the temperature at which the lamp of the lamp body 2 can be turned on again is, for example, a temperature A (shown in the figure). In this case, the temperature sensor 3 mounted on the lamp body 2 uses a temperature set so as to output a temperature detection signal when the temperature exceeds the relighting temperature A. In addition, the temperature sensor 3
Is a variable type, the temperature setting of the temperature sensor 3 is set to be the temperature A at which relighting is possible.

Then, after the lamp 2 is turned on by the lamp lighting control by the microcomputer 4, when the temperature of the lamp body 2 (arc tube) reaches the maximum temperature C as shown in the figure (time t2), Assuming that the lamp 2 is turned off, the temperature of the lamp 2 gradually decreases as shown by the characteristics in the figure.

At this time, when the temperature of the lamp 2 gradually decreasing reaches the preset temperature A, the temperature sensor 3 generates a temperature detection signal at this time, that is, at time t6. A temperature detection signal is given to the microcomputer 4 via the input terminal 4b.

Then, the microcomputer 4 operates the temperature sensor 3
Is supplied, a signal that recognizes that the temperature of the lamp body 2 (the arc tube) has reached a temperature at which relighting is possible from the temperature detection signal, and informs that the lamp is in a relightable state. Is generated and supplied to the notifying means 5. Thereby, the notification means 5 displays to the user that re-lighting is possible, and the user can immediately perform the operation of re-lighting when this display is made. In other words, in the past, it was necessary to wait until the lamp reached the coldest point. However, according to the present invention, when the temperature detection signal was supplied, that is, when the temperature reached the temperature at which relighting was possible, the lamp reached its maximum. Lighting can be enabled.

Therefore, according to the present embodiment, (t6−t2) from the lamp extinguishing time t2 to the above time t6.
It is possible for the user to re-light only by waiting for a time, that is, it is possible to reduce the re-lighting start time by the time of t7-t6) compared to the prior art.

After the lamp 2 is turned on by the lamp lighting control by the microcomputer 4, when the temperature of the lamp body 2 (arc tube) reaches the middle temperature B as shown in the figure (time t1), It is assumed that the lamp 2 is turned off.
Then, the temperature of the lamp 2 gradually decreases as indicated by the characteristic shown by the solid line in the figure.

At this time, when the temperature of the lamp 2 gradually decreasing reaches the preset temperature A, the temperature sensor 3 generates a temperature detection signal at this time, that is, at time t3, and generates the temperature detection signal. A temperature detection signal is given to the microcomputer 4 via the input terminal 4b.

Then, the microcomputer 4 operates the temperature sensor 3
When the temperature detection signal is supplied from the controller, it recognizes from the temperature detection signal that the temperature of the lamp body 2 (the arc tube) has reached a temperature at which re-lighting is possible, and generates a signal indicating that re-lighting is possible. I do.

As a result, the user can turn on the lamp again only by waiting for (t3-t1) from the lamp extinguishing time t1 to the time t3.

An example in which two temperature sensors (temporarily sensors 31 and 32) are used in the present invention will be described in detail with reference to FIG. FIG. 3 is a characteristic diagram for explaining another embodiment of the discharge lamp lighting device according to the present invention.

In this embodiment, the temperature sensors 31 and 32
The sensor 31 generates a detection output when the temperature A2 is detected, and the sensor 32 generates a detection output when the temperature A1 is detected.

For example, assuming that the lamp is turned off when the temperature of the lamp is C, the temperature decreases as shown by a characteristic b in FIG. When this descending state is detected by the sensors 31, 31, the slope of the characteristic b is obtained from the data from the time t4 when the temperature reaches the temperature A2 to the time t5 until the temperature reaches the temperature A1. That is, the slope of the characteristic b is (A2-A1) and (t5-t4)
Can be obtained by using the data of
As a result, it is possible to calculate the time t6 at which the temperature becomes the relightable temperature A, and when the calculated time t6 is reached, a signal indicating that relighting is possible is output.

Similarly, even when the light is turned off at the temperature B, the slope of the characteristic b can be obtained from the data of (A2-A1) and (t2-t1). Therefore,
From the slope b, it is possible to calculate a time t3 at which the temperature becomes relightable temperature A, and when the calculated time t3 is reached, a signal indicating that relighting is possible is output.

In this embodiment, the case where a metal halide lamp, which is a high-voltage discharge lamp, is used as a lamp type has been described. However, the present invention is not limited to this. It is clear that it is possible to cope with all the optimum lamps and to obtain the same effect as that of the above embodiment.

[0052]

As described above, according to the present invention, the relighting of the lamp can be controlled based on the temperature detection signal from the temperature sensor mounted on the lamp body and detecting the relightable temperature. This allows the lamp to be turned on again with a minimum required waiting time. Further, regardless of the length of the lighting time of the lamp, the lamp can be re-lit in the minimum necessary time, and the restart time of the lamp can be greatly reduced as compared with the conventional case.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of a discharge lamp lighting device according to the present invention.

FIG. 2 is a characteristic diagram showing a relationship between a temperature of an arc tube and an elapsed time based on turning on and off of a lamp.

FIG. 3 is a characteristic diagram for explaining another embodiment.

[Explanation of symbols]

1. Lamp lighting device 2. Lamp (lamp body) 3. Lamp
Temperature detecting means (temperature sensor), 4 ... control section (microcomputer), 5 ... notifying means.

Claims (5)

[Claims] 1. A lamp body provided with a lamp as a light source, provided at a lamp lighting portion of the lamp body, detecting a temperature change of the lamp, detecting that a preset temperature has been reached, and detecting a detection result. A temperature sensor to output, and a control unit that monitors a temperature detected by the temperature sensor, recognizes that the lamp is at a temperature at which the lamp can be relighted based on the detection result, and generates information for notifying a relightable state. And a notifying unit that is supplied with the information from the control unit and notifies that the lamp can be turned on again. 2. The lamp lighting circuit according to claim 1, wherein the temperature sensor detects a re-lightable temperature of the lamp. 3. The temperature sensor comprises means for detecting a plurality of different temperatures set in advance, and the control unit comprises:
When the lamp is turned off, a tendency of a temperature change is obtained based on a detection result supplied from the temperature sensor, a time until the lamp reaches a temperature at which the lamp can be relighted is calculated, and the notifying unit is used based on the calculation result. The lamp lighting device according to claim 2, wherein notification control is performed. 4. The lamp lighting circuit according to claim 1, wherein the temperature sensor is detachably mounted on a lighting portion of the lamp body. 5. The lamp according to claim 1, wherein the lamp is a high-pressure discharge lamp used in a liquid crystal projector.
The lamp lighting device according to claim 1.