JP2005156751A - Projection type image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projection type image display device by which images can be immediately projected even in a case a power source is turned on right after the power source is turned off. <P>SOLUTION: Upon receiving a signal indicating power source OFF, a system control circuit 20 stops only the supply of power by an image processing circuit power source 23. The system control circuit 20 then gives a lamp power source 24 an instruction to supply minimum power. In addition, upon receiving the signal indicating the power source OFF, the system control circuit 20 drives a timer(not shown), and determines whether five min. has elapsed or not. After an elapse of five min., the system control circuit 20 stops the supply of power by the lamp power source 24. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a projection display apparatus such as a liquid crystal projector.

As a projection-type image display device, there is known a projector in which a lamp power source and a video display circuit power source are configured separately as in a liquid crystal projector described in Patent Document 1. When a discharge lamp is used as a lamp, re-lighting after turning off the lamp power is performed after the lamp is sufficiently cooled (for example, after forced cooling of the fan for 90 seconds after the lamp is turned off) in order to extend the lamp life. It is customary.
Jinpyeong 4-72234

  By the way, when the user mistakenly performs the power-off operation, the user may immediately perform the power-on operation. Such an operation does not cause any problem in a cathode ray tube television, a direct-view type liquid crystal monitor, a plasma display, or the like. However, as described above, the lamp cannot be re-lighted immediately in the projector, and the user is expected to be dissatisfied particularly when the projector is used as a home projector.

  In view of the above circumstances, an object of the present invention is to provide a projection display apparatus that can perform image projection immediately even when a power-on operation is performed immediately after a power-off operation.

  In order to solve the above-described problem, the projection display apparatus of the present invention receives a power-off command in a projection display apparatus that projects an image by modulating light emitted from a lamp with a light valve. The power supply to the video generation circuit is stopped later, and control means is provided to turn off the lamp when a predetermined time has elapsed after receiving the power OFF command.

  With the above configuration, when the power OFF command is received, the power supply to the video generation circuit is stopped, so that no video is projected on the screen. Even if the power OFF command is received, the lighting state of the lamp is maintained before the predetermined time elapses, so that the image can be projected immediately upon receiving the power ON command immediately after that.

  According to another aspect of the present invention, there is provided a projection display apparatus for projecting an image by modulating light emitted from a plurality of lamps with a light valve and receiving a power-off command to an image generation circuit. The power supply is stopped or the video output is stopped and part of the plurality of lamps is turned off. On the other hand, when a predetermined time has elapsed after the power-off command is received, the lamps are continuously turned on. Control means for turning off the inside lamp is provided.

  The predetermined time may be set longer than the time required for completion of lamp cooling. When the control means receives a power-on command before the completion of the cooling of the extinguished lamp before the predetermined time has elapsed, the control means resumes image projection using only the lamp that is lit continuously, and after the lamp cooling is completed, It should be lit. If the control means receives a power-on command after the completion of the cooling of the extinguished lamp before the predetermined time has elapsed, it is preferable that the control means immediately relights the extinguished lamp and starts image projection. When the control means receives a power ON command after the predetermined time has elapsed and before the completion of cooling of the extinguished lamp from this time point, the lamp that has been extinguished first is immediately lit again to project an image. It is recommended that the lamp be turned on again after the other lamps have been cooled. When the control means receives a power ON command after the predetermined time has elapsed and after completion of cooling of the extinguished lamp from this point of time, all the extinguished lamps are immediately turned on again and image projection is started. It is good.

  It is preferable to divide the plurality of lamps into three or more groups and perform lighting / extinguishing control of each group based on the determination before and after the elapse of the predetermined time and the determination before and after the completion of cooling of the extinguished lamp.

  It is preferable that the control means turns on the lamp that is continuously lit after the power-off command with lower power than the power when the power is turned on. The low power may be the minimum power required for the lamp to be driven.

  A shutter that passes / blocks light before modulation or light after modulation is provided, and the control unit performs light blocking by the shutter when receiving a power-off command, and allows light to pass when receiving a power-on command. It is good.

  As described above, according to the present invention, even when a power-off command is received and a power-on command is received immediately after that, an image can be projected immediately. If a multi-lamp light source is provided and the continuation of lighting and the extinction are performed separately, an effect is obtained that image projection can be performed immediately when a power-on command is received at any time.

  A liquid crystal projector according to an embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 is a view showing a three-plate liquid crystal projector of this embodiment. The lamp 1 is composed of an ultra-high pressure mercury lamp, a metal halide lamp, or the like, and the irradiation light is emitted as parallel light by a parabolic reflector and guided to the integrator lens 4.

  The integrator lens 4 is composed of a pair of lens groups (fly eye lenses) 4a and 4b, and each lens portion guides light emitted from the lamp 1 to the entire surface of a liquid crystal panel described later. 1 is averaged to reduce the difference in light quantity between the center of the screen and the peripheral portion. The light passing through the integrator lens 4 is guided to the first dichroic mirror 7 after passing through the polarization conversion device 5 and the condenser lens 6.

  The polarization conversion device 5 is configured by a polarization beam splitter array (hereinafter referred to as a PBS array). The PBS array includes a polarization separation film and a phase difference plate (1 / 2λ plate). Each polarization separation film of the PBS array passes, for example, P-polarized light out of the light from the integrator lens 4 and changes the optical path of S-polarized light by 90 °. The optically polarized S-polarized light is reflected by the adjacent polarization separation film and emitted as it is. On the other hand, the P-polarized light transmitted through the polarization separation film is converted into S-polarized light by the retardation plate provided on the front side (light emitting side) and emitted. That is, in this case, almost all light is converted to S-polarized light.

  The first dichroic mirror 7 transmits light in the red wavelength band and reflects light in the cyan (green + blue) wavelength band. The light in the red wavelength band that has passed through the first dichroic mirror 7 is reflected by the reflection mirror 8 to change the optical path. The red light reflected by the reflection mirror 8 is light-modulated by passing through the lens 9 and the transmissive liquid crystal panel 31 for red light. On the other hand, the light in the cyan wavelength band reflected by the first dichroic mirror 7 is guided to the second dichroic mirror 10.

  The second dichroic mirror 10 transmits light in the blue wavelength band and reflects light in the green wavelength band. The light in the green wavelength band reflected by the second dichroic mirror 10 is guided to the transmissive liquid crystal panel 32 for green light through the lens 11 and is modulated by being transmitted therethrough. Further, the light in the blue wavelength band that has passed through the second dichroic mirror 10 is guided to the blue-light transmissive liquid crystal panel 33 through the total reflection mirror 12, the total reflection mirror 13, and the lens 14, and is transmitted therethrough. Is optically modulated.

  Each of the liquid crystal panels 31, 32, and 33 has panel portions 31b, 32b formed by enclosing liquid crystal between the incident side polarizing plates 31a, 32a, 33a and a pair of glass substrates (with pixel electrodes and alignment films formed). , 33b and output side polarizing plates 31c, 32c, 33c. The liquid crystal panels 31, 32, and 33 are in a light-impermeable state when no signal is supplied.

  The modulated light (each color video light) modulated by passing through the liquid crystal panels 31, 32, 33 is synthesized by the cross dichroic prism 15 to become color video light. The color image light is enlarged and projected by the projection lens 16, and is projected and displayed on a screen (not shown).

  FIG. 2A is a block diagram showing an image processing system, a lamp control system, and a cooling fan control system of the projection display apparatus. The video signal processing circuit 21 receives the video signal, performs frequency conversion (scan line number conversion), gamma correction processing in consideration of the applied voltage-light transmission characteristic of the liquid crystal panel, and the corrected video signal (video data). ) To the liquid crystal drive circuit 22. The liquid crystal drive circuit 22 drives the liquid crystal panels (31, 32, 33) based on the video signal. The system control circuit 20 controls operations of the video processing circuit power source 23, the lamp power source 24, and the lamp cooling power source 25. The video processing circuit power source 23 is a circuit for supplying / stopping power to the video processing circuit 21 and the like, the lamp power source 24 is a circuit for supplying / stopping power to the lamp 1 and adjusting the electric energy, and the lamp cooling power source 25 is for cooling the lamp. This is a circuit for supplying / stopping power to the fan 26.

  FIG. 3 is a flowchart showing the processing contents when the power of the liquid crystal projector is turned off by the system control circuit 20. For example, when the system control circuit 20 receives a signal indicating power OFF from a remote control signal light receiving unit (not shown), the system control circuit 20 stops only the power supply by the video processing circuit power source 23 (step S1). Then, a minimum power supply command is given to the lamp power supply 24 (step S2). This minimizes the amount of light emitted from the lamp. When the system control circuit 20 receives a signal indicating that the power is off, the system control circuit 20 drives a timer (not shown) and determines whether 5 minutes have elapsed (step S3). When 5 minutes have elapsed, the power supply by the lamp power supply 24 is stopped (step S4).

  With the above configuration, when the power-off command is received, the image generation is stopped, so that no image is projected on the screen. Even if the power-off command is received, the lighting state of the lamp 1 is maintained before the predetermined time elapses, so that the image can be projected immediately when the power-on command is received immediately after the power is turned off (in this embodiment, within 5 minutes). become. In this embodiment, the lamp is operated at a power lower than the power at the time of receiving the power-off command (minimum power in the above example) from when the power-off command is received until 5 minutes have elapsed. Since 1 is driven, an energy saving effect is obtained. Further, since the amount of light emitted from the lamp 1 is reduced, the screen after the power is turned off can be made darker.

  A shutter for passing / blocking image light may be provided on the image light emission side of the cross dichroic prism 15. Then, the system control circuit 20 preferably operates to shut off the shutter when receiving a power OFF command. According to this, the screen after the power OFF command can be further darkened. The shutter may be arranged on a lamp optical path such as on the integrator lens 4.

  The system control circuit 20 may continue to supply power even after the lamp is turned off for the lamp cooling power supply 25. For example, the power supply by the lamp cooling power supply 25 may be stopped after 6 minutes and 30 seconds have elapsed after receiving the power OFF command. . Further, the system control circuit 20 does not turn on the lamp again when the power-on command is received after the elapse of 5 minutes and before the elapse of 6 minutes and 30 seconds since the power-off command is received, since the lamp cooling is not completed. It is good to be.

  For example, when the lamp is of a four-lamp type, the two lamps (first group) are turned off immediately upon receiving a power OFF command, and cooling is continued for 90 seconds (cooling is completed after 90 seconds), and the other two lamps ( Only the second group) may be turned on for 5 minutes. The lamp power supply 24 may be provided for each group. It is better to drive the lamp that is lit continuously with the lowest power. When the system control circuit 20 receives the power-on command 90 seconds before the power-off command is received, the system control circuit 20 resumes the power supply by the video processing circuit power source 23 and the two lights (second group) that are continuously lit. The projection of the image is executed only, and the two lights (first group) that have been turned off after 90 seconds have elapsed are relighted. When the system control circuit 20 receives a power-on command 90 minutes after the power-off command and 5 minutes before the power-on command, the system control circuit 20 resumes the power supply by the video processing circuit power source 23 and controls the lamp power source 24. Relight the two lights (first group) that were turned off. When the system control circuit 20 receives the power-on command after 6 minutes and 30 seconds have elapsed after 5 minutes from the receipt of the power-off command, the system control circuit 20 resumes the power supply by the video processing circuit power supply 23 and is turned off first. The two lights (first group) that have been turned on are immediately turned on to perform image projection, and the remaining two lights (second group) are turned on again after 6 minutes and 30 have elapsed. As described above, if the multi-lamp type light source is provided and the continuation of lighting and the extinction are performed separately, image projection can be performed immediately upon receiving a power ON command at any time. A plurality of lamps may be divided into three or more groups, and lighting / extinguishing control of each group may be performed based on the determination before and after the elapse of the predetermined time and the determination before and after the completion of cooling of the extinguished lamp. The determination of the completion of cooling is not limited to time measurement, and may be determined by temperature measurement using a temperature sensor. Further, the first group may be turned off after a predetermined time (for example, 10 seconds) instead of turning off immediately after the power OFF command.

  When the liquid crystal projector includes a TV tuner and a tuner power supply, and the system control circuit 20 controls the power supply to the tuner power supply, the system control circuit 20 receives the power-off command when the video processing circuit power supply is received. It is preferable not only to stop power supply by the power supply 23 but also to stop power supply to the tuner power supply. In the above embodiments, a three-plate type liquid crystal projector using a liquid crystal display panel has been described. However, the present invention can also be applied to a projection type video display device having another video light generation system.

1 is a configuration diagram showing an optical system of a liquid crystal projector of an embodiment of the present invention. It is a block diagram showing a liquid crystal projector image processing system, a lamp control system, and a fan control system. It is the flowchart which showed the processing content.

Explanation of symbols

1 Lamp 20 System Control Circuit 23 Video Processing Circuit Power Supply 24 Lamp Power Supply 25 Lamp Cooling Power Supply 26 Cooling Fan 31, 32, 33 Liquid Crystal Panel

Claims (11)

In a projection display apparatus for projecting an image by modulating light emitted from a lamp with a light valve, power supply to an image generation circuit is stopped after receiving a power OFF command, and after receiving a power OFF command. A projection display apparatus comprising a control unit that turns off a lamp when a predetermined time has elapsed. In a projection-type image display device that projects light by modulating light emitted from a plurality of lamps with a light valve, power supply to an image generation circuit is stopped or image output is stopped after receiving a power-off command. And a control unit that turns off a part of the plurality of lamps while turning off a lamp that is continuously lit among the plurality of lamps when a predetermined time has elapsed since the power-off command was received. Projection-type image display device characterized by the above. 3. The projection display apparatus according to claim 2, wherein the predetermined time is set longer than a time required for completion of lamp cooling. 4. The projection display apparatus according to claim 3, wherein when the control means receives a power-on command before completion of cooling of the extinguished lamp before the predetermined time has elapsed, an image only by the lamp that is lit continuously. A projection display apparatus, wherein projection is resumed, and the lamp is turned on again after lamp cooling is completed. 5. The projection display apparatus according to claim 3 or 4, wherein when the control unit receives a power-on command after completion of cooling of the turn-off lamp before the predetermined time has elapsed, the control means immediately resets the turn-off lamp. A projection-type image display device that is turned on to start image projection. 6. The projection display apparatus according to claim 3, wherein the control unit receives a power-on command after the predetermined time has elapsed and before completion of cooling of the extinguished lamp from this time point. In this case, the projection type image display apparatus is characterized in that the lamp that has been previously turned off is immediately turned on again to start image projection, and the lamp is turned on again after cooling of the other turned off lamps is completed. 7. The projection display apparatus according to claim 3, wherein the control means receives a power-on command after the predetermined time has elapsed and after completion of cooling of the extinguished lamp from this time point. Includes a projection-type image display device that starts image projection by immediately turning on all the lamps that have been turned off. 4. The projection display apparatus according to claim 2 or 3, wherein a plurality of lamps are divided into three or more groups, and based on the determination before and after the elapse of the predetermined time and the determination before and after completion of cooling of the extinguished lamp. A projection type image display apparatus that performs on / off control of each group. 9. The projection display apparatus according to claim 1, wherein the control unit turns on a lamp that is continuously lit after a power-off command with lower power than that when the power is turned on. Projection-type image display device characterized by the above. 10. The projection display apparatus according to claim 9, wherein the low power is a minimum power required for driving the lamp. 11. The projection display apparatus according to claim 1, further comprising a shutter that passes / blocks light before modulation or light after modulation, and the control unit receives the power OFF command when the shutter is turned off. A projection-type image display device characterized in that the light is blocked by and the light is allowed to pass when a power-on command is received.

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