JPH07333571A - Liquid crystal projection device - Google Patents

Abstract

PURPOSE:To provide a liquid crystal projection device reducing power consumption, prolonging the life of a lamp and securing safety. CONSTITUTION:A stop control signal is generated by a stop control signal generation part 25 according to various detection outputs such as a temp. sensor 6 and a rotation detector 8 detecting abnormality of a device, a timer 24 detecting that it becomes several minutes before a setting time when a sleep timer is operated, an input detection part 23, etc., detecting that no video signal is inputted for a fixed time, and a warning display by a liquid crystal display plate 2 is performed by a warning display control part 26 according to the stop control signal, and the warning display by the on/off of a light emission element in a warning display part 28 is performed, and a power source of a light source 1 is interrupted by a power source control part 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projection device which emits image projection light from a light source through a liquid crystal display plate, and more particularly, it detects an abnormal heating state of the light source to automatically turn on a power source. The present invention relates to a liquid crystal projection device having a protective function of shutting off selectively.

[0002]

2. Description of the Related Art Conventionally, as a protection circuit for a power supply device or the like, one which operates by detecting overcurrent or heat generation has been known.

Further, in some devices equipped with a microcomputer (hereinafter, simply referred to as a microcomputer), a sensor signal is sent to the microcomputer to activate a protection circuit after processing by the sensor signal. Further, in this case, the warning display and the information incidental thereto can be notified to the outside.

In general, a liquid crystal projection device that emits image projection light from a light source through a liquid crystal display plate requires a high-intensity light source with a relatively large amount of heat generation, and therefore a cooling fan is rotated to blow air. By doing so, the temperature rise inside the device is reduced. In addition, if the temperature rises abnormally due to the heat generated by the light source or the power source that drives the light source, the liquid crystal display plate inside the device and its drive circuit may be destroyed, or a fire may occur. A protection circuit is provided to automatically shut off the power by detecting an abnormal heating state of the light source.

[0005]

By the way, in the conventional liquid crystal projector, the power supply suddenly stops when the protection circuit operates, so that the user cannot know the reason why the power supply is stopped. Similarly, even when the power supply device is stopped due to the sleep timer operation, the user cannot know the reason why the power supply device is stopped. Further, since the light source is energized when not projecting, there are problems that the power consumption is large and the life of the lamp is short.

Therefore, in view of the actual situation in such a conventional liquid crystal projection device, an object of the present invention is to provide a liquid crystal projection device which has good operability and safety. Another object of the present invention is to provide a liquid crystal projection device with low power consumption and long lamp life.

[0007]

In order to solve the above-mentioned problems, a liquid crystal projection device according to the present invention is a liquid crystal projection device which emits image projection light from a light source through a liquid crystal display plate. An abnormality detecting means for detecting an abnormality, a detecting means for detecting that a set time is several minutes before the sleep timer operates, and a warning display by the liquid crystal display plate according to the detection output of each detecting means. 1 warning display means, 2nd warning display means for displaying a warning by blinking a light emitting element according to the detection output by the abnormality detection means, detection means for detecting that a video signal is not input for a certain period of time, Power source control means for shutting off the power source of the light source according to the detection output from each detection means.

Further, the liquid crystal projection apparatus according to the present invention is characterized in that, in the abnormality detecting means, the temperature detecting means detects that the inside of the lamp house of the light source is in an abnormal overheated state.

Further, the liquid crystal projection apparatus according to the present invention is characterized in that, in the abnormality detecting means, the rotation detecting means detects that the rotation of the cooling fan has stopped.

[0010]

In the liquid crystal projection device according to the present invention, the abnormality of the device is detected by the abnormality detecting means, and is also detected by the detecting means for detecting that it is several minutes before the set time when the sleep timer is operating. Then, the first warning display means displays a warning on the liquid crystal display plate according to the detection output from each of the detection means. Further, the second warning display means displays a warning by blinking the light emitting element according to the detection output from the abnormality detection means. Further, the detection means detects that the video signal is not input for a certain period of time. And
The power supply control means shuts off the power supply of the light source according to the detection output from each of the detection means.

Further, in the liquid crystal projection device according to the present invention, the abnormality detecting means detects by the temperature detecting means that the inside of the lamp house of the light source is in an abnormally overheated state.

Further, in the liquid crystal projection device according to the present invention, the abnormality detecting means detects that the rotation of the cooling fan has stopped by the rotation detecting means.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the liquid crystal projection device according to the present invention will be described in detail below with reference to the drawings.

A liquid crystal projector according to the present invention is shown in FIG.
It is configured as shown in. This liquid crystal projection device includes a light source 1
The projection light of the image is emitted from the liquid crystal display plate 2 through the liquid crystal display plate 2, and the projection light is used to project the image on a screen (not shown) through the projection optical system 3.

The light source 1 is composed of, for example, a halogen lamp driven by the power supply device 4, and is provided in the lamp house 5.

The lamp house 5 is provided with a temperature sensor 6, and the internal temperature thereof is detected by the temperature sensor 6. Further, the lamp house 5 is provided with a cooling fan 7 driven by a commercial power source, and is cooled by blowing air by rotation of the cooling fan 8. Furthermore, the rotation of the cooling fan 7 is detected by a rotation detector 8 using, for example, a photo interrupter. The temperature sensor 6 and the rotation detector 8 are connected to the system controller 20, and each detection output is supplied to the system controller 20.

Further, the power supply device 4 is configured so that commercial power is supplied through the power supply line 10. A current fuse 11 having a predetermined capacity is provided in the power supply line 10 so that the current fuse 11 is blown when an abnormal overcurrent flows in the power supply device 4. A temperature sensor 9 is incorporated in the power supply device 4, and the internal temperature of the temperature sensor 9 is detected by the temperature sensor 9. The temperature sensor 9
Is connected to the power supply control unit 30.

A liquid crystal drive circuit 17 is connected to the liquid crystal display panel 2 and is driven by the liquid crystal drive circuit 17. The liquid crystal drive circuit 17
Is an RGB decoder 19 for converting a video signal supplied via the video input terminal 18 into three primary color signals R, G, B.
Are connected to drive the liquid crystal display panel 2 in accordance with the three primary color signals G, B supplied from the RGB decoder 19.

Here, the RGB decoder 19 has a function of superposing a warning display signal supplied from the character generator 27 connected to the system controller 20 on the video signal supplied through the video input terminal 18. .

Further, the system controller 20 is
It is composed of a microprocessor having a D / A conversion function. The system controller 20 includes a first abnormality detecting unit 21 for detecting that the inside of the lamp house 5 is in an overheated state in which the temperature has risen to a predetermined temperature or higher, based on the detection output of the temperature sensor 6, and the rotation detector. A second abnormality detecting section 22 that detects that the rotation of the cooling fan 8 has stopped based on the detection output of 9 and an input detecting section that detects that a video signal is supplied to the video input terminal 18. 23, a timer 24 for performing a sleep timer operation, and the power supply control unit 30 according to the outputs thereof.
A power cutoff command signal generation unit 25 for outputting a power cutoff command signal to a power cutoff command, and a warning display control for performing warning display control when the power cutoff command signal generation unit 25 generates a power cutoff command signal The unit 26 is provided.

Here, the input detection section 23 detects that a video signal is being supplied to the video input terminal 18, and detects that the supply of the video signal has been stopped for a predetermined time continuously. The output is supplied to the power cutoff command signal generation unit 25. Further, the timer 24 supplies a timer output for performing a sleep timer operation to the power cutoff command signal generation unit 25. The power shutdown command signal generator 25 operates according to the output of the first abnormality detector 21, the second abnormality detector 22, the input detector 23 or the timer 24, and the power controller 30. A power-off command signal for instructing power-off is output to. Further, the warning display control unit 26 controls the light emitting diode of the warning display unit 28 to blink when the power cutoff command signal generation unit 25 generates the power cutoff command signal, and displays the warning content in characters. The warning display signal is supplied from the character generator 27 to the RGB decoder 19.

Further, the power supply control unit 30 detects, based on the detection output of the temperature sensor 9, that the inside of the power supply unit 4 is in an overheated state in which the temperature rises above a predetermined temperature, and the abnormality detection unit 31 described above. When the abnormality detection unit 31 detects an abnormality, or when a power cutoff command signal is supplied from the power cutoff command signal generation unit 25 of the system controller 20, the operation of the power supply device 4 is stopped and the light source is stopped. 1 is provided with a protection circuit 32 for performing control for cutting off the power supply.

In the liquid crystal projection device having such a structure,
As shown in the flowchart of FIG. 2, the system controller 10 determines whether or not a video signal is supplied to the video input terminal 18 in the input detection unit 23 (step 1), and the determination result is "YE
If "S", that is, the video signal is supplied, the counter is reset (step 2), and if the determination result is "NO", that is, the video signal is not supplied, the counter is counted up (step 3). Then, it is determined whether or not the value of the counter has reached the predetermined value N (step 4).

The determination result in step 4 is "YES".
That is, when the video signal is not supplied and the value of the counter reaches the predetermined value N, a detection output indicating that the supply of the video signal is continuously stopped for a predetermined time is supplied to the power cutoff command signal generation unit 25. Then, the process proceeds to step 13.

Further, the judgment result in the above step 4 is "N
"O", that is, when the value of the counter has not reached the predetermined value N, the process proceeds to step 5 to determine the setting state of the sleep timer.

In step 5, it is determined whether the timer 24 is in the on state or the off state. If the timer 24 is in the on state, the process proceeds to step 6,
If the timer 24 is off, the process proceeds to step 8.

In step 6, the sleep time setting time is compared with the current time, and if the current time is 3 minutes or more before the sleep time setting time, step 8 is executed.
When the current time reaches, for example, 3 minutes before the sleep time setting time, the process proceeds to step 7, and when the current time reaches the sleep time setting time, the process proceeds to step 13.

In step 7, the warning display control unit 26 sends a warning display signal, which is a character display of the warning content for warning that it is three minutes before the set time of the sleep time, from the character generator 27 to the RGB decoder 19. And then to step 8.

In step 8, the first abnormality detecting section 21 determines whether or not the inside of the lamp house 5 is overheated to a predetermined temperature or higher based on the detection output of the temperature sensor 6. To do. The determination result in step 8 is “YES”, that is, the lamp house 5
If the inside of the lamp house is in the overheated state where the temperature rises above the predetermined temperature, the process proceeds to step 9, and if the determination result is “NO”, that is, if the inside of the lamp house 5 is not in the overheated state where the temperature rises above the predetermined temperature. Proceeds to step 10.

In the step 9, the warning display control section 26 sends a warning display signal for displaying the warning contents, which warns that the inside of the lamp house 5 is overheated to a predetermined temperature or more, to the character generator 2 by the warning display signal.
After being supplied to the RGB decoder 19 from 7, the process proceeds to step 12.

In step 10, the second abnormality detecting section 22 determines whether or not the rotation of the cooling fan 8 is stopped, based on the detection output of the rotation detector 9. If the determination result in step 10 is "YES", that is, if the cooling fan 8 is in the abnormal state where the rotation of the cooling fan 8 is stopped, the process proceeds to step 11, and the determination result is "NO", that is, the cooling fan 8 rotates. If it is in the normal state, the process returns to the step 1 and the presence / absence of the input video signal is repeatedly determined.

In the step 11, the warning display control section 26 sends a warning display signal for displaying a warning content in a warning that the rotation of the cooling fan 8 is stopped in an abnormal state from the character generator 27.
After being supplied to the GB decoder 19, the process proceeds to step 12.

In step 12, the warning display control unit 26 controls the blinking of the light emitting diode of the warning display unit 28, and then the process proceeds to step 13.

In step 13, the power shutdown command signal generator 25 generates a power shutdown command signal and supplies it to the protection circuit 30 of the power controller 11.
The control of stopping the power supply of the light source 1 by stopping the operation of the power supply device 4 is performed.

In the liquid crystal projection device having such a structure, when the supply of the video signal to the video input terminal 18 is continuously stopped for a predetermined time, the power-off command is issued according to the detection output of the input detection section 23. The power generation command signal is generated by the signal generation unit 25, and the protection circuit 3 of the power supply control unit 11 is generated.
0 operates to automatically stop the operation of the power source device 4 and shuts off the power source of the light source 1, so that wasteful power consumption can be reduced and the life of the lamp of the light source 1 can be extended. be able to.

Further, when the sleep timer is set, the warning display control section 26 displays a warning display signal for displaying the warning content in a character to warn that it is three minutes before the set time of the sleep time. Since it is supplied from the character generator 27 to the RGB decoder 19, a warning display signal for displaying the warning content in characters is displayed on the R
By superimposing on the video signal in the GB decoder 19 and displaying the warning content as a projected image in characters, the user can be informed that the sleep time is three minutes before the set time.

Further, the first or second abnormality detecting section 2
When an abnormality is detected by the power supply cutoff command signal 1 or 22, the power supply cutoff command signal generation unit 25 generates a power supply cutoff command signal according to the detection output of the first or second abnormality detection unit 21 or 22. The protection circuit 30 of the power supply control unit 11 operates to automatically stop the operation of the power supply device 4 and shut off the power supply of the light source 1, so that the liquid crystal projection device is protected from burning or the like. The first or second abnormality detection unit 2
When an abnormality is detected by the first or second abnormality detection unit 22, the warning display control unit 26 blinks the light emitting diode of the warning display unit 24 to detect the abnormality by the first or second abnormality detection unit 21 or 22. The user can be notified of the fact. Further, the character generator 27 supplies the RGB decoder 19 with a warning display signal for displaying a warning content for warning that the abnormality is detected by the first or second abnormality detection unit 21, 22. By superimposing the warning display signal for displaying the warning content on the video signal in the RGB decoder 19 and displaying the warning content as a projected image by the character, the first or second abnormality detection unit 21, 22 detects an abnormality. The user can be notified of the detection.

When an abnormal overcurrent flows in the power supply device 4, the current fuse 11 provided in the power supply line 10 is blown to stop the operation. As a result, this liquid crystal projection device is protected from burning or the like.

[0039]

As is apparent from the above description, in the liquid crystal projection device according to the present invention, the abnormality of the device is detected by the abnormality detecting means, and the time set by the sleep timer is several minutes before the set time. It is detected by the detection means for detecting that. The first warning display means displays a warning on the liquid crystal display plate according to the detection output from each of the detection means, so that the device is in an abnormal state, or a few minutes of the set time during sleep timer operation. The user can be informed by the projection image that he is in front. Also, the second
The warning display means displays the warning by blinking the light emitting element in accordance with the detection output from the abnormality detection means, so that the user can be informed that the device is in an abnormal state.
The power source control means shuts off the power source of the light source in accordance with the output detected by the abnormality detecting means, so that the device can be protected from burning and the safety can be ensured. further,
Since the detection means detects that the video signal is not input for a certain period of time, and the power source control means shuts off the power source of the light source, it is possible to reduce wasteful power consumption and extend the life of the lamp of the light source. .

Further, in the liquid crystal projection device according to the present invention, the abnormality detecting means detects that the inside of the lamp house of the light source is in an abnormally overheated state, so that the lamp house is in an abnormally overheated state. When this happens, the power of the light source is automatically shut off to protect the device from burnout, etc., and safety can be ensured.

Further, in the liquid crystal projection device according to the present invention,
Since the abnormality detection means detects that the rotation of the cooling fan has stopped by the rotation detection means, the stop of the rotation of the cooling fan may cause the lamp house to be in an abnormally overheated state. The light source can be turned off.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a liquid crystal projection device according to the present invention.

FIG. 2 is a flowchart showing the operation of the liquid crystal projection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 light source 2 liquid crystal display board 4 power supply device 5 lamp house 6 temperature sensor 7 cooling fan 8 rotation detector 9 temperature sensor 10 power supply line 17 liquid crystal drive circuit 18 video input terminal 19 RGB decoder 20 system controller 21, 22 abnormality detection unit 23 Input detection unit 24 Timer 25 Stop control signal generation unit 26 Warning display control unit 27 Character generator 28 Warning display unit 30 Power supply control unit 31 Abnormality detection unit 32 Protection circuit

Claims (3)

[Claims] 1. A liquid crystal projection device for emitting image projection light from a light source through a liquid crystal display plate, comprising: abnormality detecting means for detecting abnormality of the device; and a few minutes before a set time when a sleep timer is operating. Detecting means for detecting the fact, first warning display means for displaying a warning on the liquid crystal display plate according to the detection output by each of the detection means, and blinking of the light emitting element according to the detection output by the abnormality detecting means. A second warning display means for displaying a warning by means of, a detection means for detecting that a video signal is not input for a certain period of time, and a power supply control means for shutting off the power source of the light source according to the detection output by each of the detection means. A liquid crystal projection device comprising: 2. The liquid crystal projection device according to claim 1, wherein the abnormality detecting means detects, by the temperature detecting means, that the lamp house of the light source is in an abnormally overheated state. 3. The liquid crystal projection device according to claim 2, wherein the abnormality detecting means detects that the rotation of the cooling fan has stopped by the rotation detecting means.