JP2004317557A - Display device, projector, and driving method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device which performs display by time-dividing colored light emitted from a plurality of light sources having different colors of emitted light and which is in such a constitution that safe display operation can be secured by preventing display information from being lost along with burning out of a valve or the like of the light source, and a projector and a driving method therefor. <P>SOLUTION: The display device (the projector) is equipped with a plurality of light sources 20R, 20G, 20B having different colors of emitted light, and a liquid crystal light valve 40 for modulating the light irradiated from the light sources, and is so constituted that the plurality of light sources 20R, 20G, 20B sequentially emit light and the liquid crystal light valve 40 is sequentially driven in synchronization with the colored light irradiated from the light sources 20R, 20G, 20B. When the light emission quantity of any one of the plurality of light sources 20R, 20G, 20B becomes lower than prescribed light quantity, another light source emits light at the light emission timing of the light source. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a projector, a display device, and a driving method thereof.
[0002]
[Prior art]
In a conventional projector, a halogen lamp has been used as a light source in recent years, and a high-pressure mercury lamp (UHP) having high luminance, high efficiency, and long life has been widely used as a light source in recent years. However, these lamps require a high-voltage power supply circuit, and this large and heavy power supply circuit has hindered the reduction in size and weight of the projector.
Therefore, recently, attention has been paid to LEDs as new light sources. LEDs are ultra-compact, ultra-light, and long-lasting. It is also promising as a light source for projectors, and application development to small and portable small-screen projectors has already started (see Patent Document 1). At present, the efficiency of LED is still about 1/2 to 1/3 of UHP, but it is steadily improving year by year due to remarkable technological innovation, and it is expected to reach a level that can replace the current UHP in a few years. is there.
[0003]
Further, in the light source using the UHP which is a discharge type lamp, in addition to the above-described problems such as large size and short life, there is also a problem that it is almost impossible to control the light source (high-speed on / off, modulation). is there. That is, the discharge lamp is limited to use at a constant output and continuous lighting, and requires a long time of several minutes to start up. On the other hand, the LED has the advantage that the driving current can be controlled to turn on / off and adjust the amount of emitted light.
[0004]
[Patent Document 1]
JP-A-2000-112031
[0005]
[Problems to be solved by the invention]
By the way, particularly in a low-cost type projector that emphasizes portability, a so-called single-panel projector having only one light modulating unit such as a liquid crystal light valve is advantageous. In a single-panel projector using a white light source such as a UHP, a primary color light of RGB is selected in a time-division manner (time sequential) by using a rotating color filter, and each pixel of the spatial light modulator is synchronized with the primary light. The image is created by turning it on / off. On the other hand, since the LED light source projector can sequentially turn on the RGB LEDs at a high speed, it is a general idea to use this configuration to generate the primary color light in which the RGB is switched in a similar time sequential manner. It is.
[0006]
In the projector using the above LED as a light source, the LED has a long life, but it is necessary to consider the possibility of the ball breaking. While LEDs are becoming more efficient and replacing UHP, it is not hard to imagine that they will be used everywhere due to the lower prices and the established culture of image projection. Some of these applications are expected to be severe for the light source (long operating time, high temperature and vibration environment). In particular, small projectors that use one LED for each color (if the efficiency of the LED increases, For example, if one color (red LED) is cut off, the image information displayed in red will be lost.
In addition, in the LED drive system, when a large current drive is performed or heat generation becomes large, the LED may be turned off due to an overload on a drive circuit or the like other than the burnout of the ball. One color may be lost due to the protection operation of the control system or the drive IC alone.
[0007]
As described above, a single-plate projector using an LED as a light source has a problem that if one color of the light source is completely lost, the information is not displayed. Power source management, aeronautics, railway control, etc. (It is also a heavy burden on the light source of 24 hours display), small power saving LED light source projectors for automobiles and aircraft, etc. may be widely used as displays However, assuming use in these safety-critical applications, loss of image information must be absolutely avoided. At that time, if the display such as a red arrow disappears at the time of failure, it must be said that the device is incomplete. If a ball of one color is a natural image, it is easy to detect it from the color tone of the entire screen, but it may be difficult to recognize it in animation or CG (computer graphics).
[0008]
The present invention has been made in order to solve the above-described problems, and in a display device that performs time-division display of color light emitted from a plurality of light sources having different emission colors, the light source may have a broken bulb or the like. It is an object of the present invention to provide a display device, a projector, and a method for driving the display device having a configuration capable of preventing even display information from being lost at the time of the operation and ensuring a safe display operation.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the display device of the present invention includes a plurality of light sources having different emission colors, and light modulation means for modulating the color light emitted from the light sources, and emits the plurality of light sources in time sequence. And a display device that drives the light modulating means in a time-sequential manner in synchronization with the color light emitted from the light source, wherein when any one of the plurality of light sources emits a light amount equal to or less than a predetermined light amount, Another light source can emit light at the light emission timing of the light source.
According to the above configuration, even if one or a plurality of light sources out of the plurality of light sources is reduced in light quantity, burns out, or a turn-off operation is performed by a control circuit or a control IC, another light emission timing of the light source is used. Since the light source emits light, the color tone and the color balance of the displayed image change, but it is possible to prevent the loss of the display information due to the decrease in the light amount or the lack of the ball. Therefore, according to the present invention, it is possible to provide a display device that can sufficiently withstand use in applications important for safety and the like.
[0010]
Next, the display device of the present invention includes a photometric unit that measures the amount of light emitted from each of the light sources, and a light source control unit that can control the light emission timing of each of the light sources based on the photometric result output from the photometric unit. In the photometric result of the photometric means, when the light emission amount of any of the plurality of light sources is equal to or less than a predetermined light amount, the light source control means, at the light emission timing of the light source with the reduced light emission amount, And one or a plurality of light sources are selected to emit light.
[0011]
According to the above configuration, since the light emission amounts of the plurality of light sources are monitored by the photometry means, the light emission amounts of the light sources can be constantly monitored, and the light emission timing and output of each light source can be adjusted by the light source control means. . Therefore, even if one or a plurality of light sources has a reduced light amount or a broken bulb, replacement with another light source is performed, so that a situation in which display information is lost can be avoided, and a display can be performed safely. is there.
Further, even in a normal display mode, the display device of the present invention is configured to compare the output of the light source with the actual light emission amount by the light source control unit and adjust the output of the light source based on the comparison. Therefore, the light emission amount of the light source can be held stably, and high-quality display can be performed. This is particularly effective when a solid-state light-emitting element such as an LED, in which the luminance characteristic is likely to change with time due to temperature characteristics or the like, is used.
[0012]
Next, the display device of the present invention is configured such that, in the photometry result of the photometric unit, when the light emission amount of any of the plurality of light sources is equal to or less than a predetermined light amount, the other light source is continuously emitted by the light source control unit. It is characterized by that.
When the light emission amount of any one of the light sources becomes equal to or less than the predetermined light amount, the display device of the above configuration causes the light sources to emit light in a time-sequential manner and stops displaying, and continuously emits light from the other normally emitting light sources. This is a display device that performs grayscale image display. With such a display device, it is possible to prevent image information of a specific color from being displayed when one or a plurality of light sources have a reduced light amount or a broken bulb, and to perform safe display. It is possible.
[0013]
Next, the display device of the present invention is configured such that, in the photometry result of the photometry unit, when the light emission amount of any of the plurality of light sources is equal to or less than a predetermined light amount, the light source control unit controls the light source having the reduced light emission amount. Another light source emits light at an intensity that complements the amount of light emission.
According to the display device having this configuration, when the light amount is reduced in any of the light sources, the light source operates so that the light amount is reduced by another light source. Can be prevented from becoming difficult to see.
[0014]
Next, the display device of the present invention, when the light emission amount of any of the plurality of light sources is equal to or less than a predetermined light amount in the light measurement result of the light measurement unit, the light source control unit causes the light source control unit to switch to the light source having the reduced light emission amount. Is stopped.
According to the display device having this configuration, the amount of light emission is reduced, and by stopping power supply to the light source that cannot display the image information to the extent that the image information can be visually recognized normally, the light amount of the light source can be reduced. It is possible to suppress the power consumption of the display device when the ball is cut or the like. In addition, when the decrease in the light amount of the light source is caused by overheating of the control system, the control system can be cooled by performing the power stop, so that safety in the event of an abnormality can be easily ensured. It has the advantage that it can be performed.
[0015]
Next, in the display device according to the present invention, when the light emission amount of the light source output from the photometric unit is substantially zero, the power supply to the light source is stopped by the light source control unit.
According to the display device having this configuration, since the power supply to the light source is stopped only when the light source is out of the bulb or completely turned off, for example, the decrease in the light amount of the light source is temporary and the photometry is performed. When the recovery of the light emission amount of the light source is detected by the means, the return operation of the display device can be easily performed.
[0016]
Next, a projector according to the invention includes the display device according to the invention described above, and projection means for projecting light modulated by the light modulation means.
According to this configuration, it is possible to provide a projector that can sufficiently withstand use in applications important for safety and the like.
[0017]
Next, the driving method of the display device according to the present invention includes a plurality of light sources having different emission colors, and a light modulation unit that modulates light emitted from the light sources, and causes the plurality of light sources to emit light sequentially in time. A driving method of a display device that drives the light modulating means in a time-sequential manner in synchronization with color light emitted from the light source, wherein when a light emission amount of any of the plurality of light sources becomes equal to or less than a predetermined light amount, The display is performed by causing another light source to emit light at the light emission timing of the light source.
According to this driving method, in a display device that performs display by causing the light sources of the plurality of light sources to emit light in time sequence, when any one of the light sources has a reduced light emission amount, or a broken bulb occurs, Since the display is performed by replacing the light source with another light source, it is possible to effectively prevent the display information from being lost due to a decrease in the light emission amount, a broken bulb, etc., and it is possible to perform the display safely. is there.
[0018]
Next, the driving method of the display device according to the present invention includes a plurality of light sources having different emission colors, and a light modulation unit that modulates light emitted from the light sources, and causes the plurality of light sources to emit light sequentially in time. A driving method of a display device that drives the light modulating means in a time-sequential manner in synchronization with color light emitted from the light source, wherein when a light emission amount of any of the plurality of light sources becomes equal to or less than a predetermined light amount, It is characterized in that display is performed by continuously emitting other light sources.
According to this driving method, when the light emission amount is reduced or the bulb is cut off in any of the light sources, the light sources are stopped from emitting light in time sequence, and the other light sources that normally emit light are continuously operated. By emitting light, gray scale display is performed, so that loss of display information due to a decrease in the amount of light emission, lack of a ball, or the like can be effectively prevented, and display can be performed safely.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Display device]
FIG. 1 is a schematic configuration diagram showing a projection display device (projector) as an embodiment of a display device according to the present invention, and FIG. 2 is a timing chart in a display operation of the projection display device of the present embodiment. It is. The projection type liquid crystal display device shown in FIG. 1 realizes color display by sequentially switching and projecting images corresponding to respective colors by one liquid crystal light valve (light modulation means). In the figure, reference numeral 10 denotes an illumination device, 30 denotes a light amount sensor (light measuring unit), 40 denotes a liquid crystal light valve (light modulating unit), and 50 denotes a projection unit (projection lens).
[0020]
The illumination device 10 mainly includes a light source 20R that emits red light, a light source 20G that emits green light, and a light source 20B that emits blue light. The output can be switched in time sequence every 1 / second. The light sources 20R, 20G, and 20B can be configured by a light emitting diode (LED), an organic electroluminescent element (organic EL element), an inorganic electroluminescent element (inorganic EL element), and the like.
The light amount sensor 30 may be one having an active element such as a photodiode or a phototransistor, for example, and is connected to a light source driving circuit (light source control means) 60. The light source drive circuit 60 is connected to the three light sources 20R, 20G, and 20B so that the light sources can be driven and controlled.
Although only one light amount sensor 30 is shown in FIG. 1, at least one light amount sensor 30 is provided corresponding to each of the light sources 20R, 20G, and 20B. The light emission amount of the light source can be measured independently.
[0021]
The projection type display device switches the display of the liquid crystal light valve 40 in time sequence in synchronization with each color light emitted from the lighting device 10 in time sequence, and transmits the color light modulated by the liquid crystal light valve 40 through the projection device 50. Projection on a screen or the like.
Specifically, as shown in FIG. 2, one frame is time-divided into three, and red light, blue light, and green light are sequentially emitted from the light sources 20R, 20G, and 20B, and from the light sources 20R, 20G, and 20B. The liquid crystal light valve 40 is driven in accordance with the light emission timing of the irradiated light, and an image signal corresponding to each color light is output. While the red light (R) is being output, the liquid crystal light valve 40 outputs an image signal SR corresponding to the red light (R). Similarly, while the green light (G) or the blue light (B) is being output from the light sources 20G and 20B, the image signals SG corresponding to the respective color lights are output by the liquid crystal light valve 40, or An image signal SB is output. A color image can be synthesized and displayed for each frame based on image signals SR, SG, and SB corresponding to red light, green light, and blue light.
[0022]
In the projection type display device of the present embodiment, the light amount sensor 30 measures the light emission amount of each of the light sources 20 </ b> R, 20 </ b> G, and 20 </ b> B during the display operation, and the measurement result is transmitted to the light source drive circuit 60. The light emission state of each light source is monitored, and the light emission state (output, light emission timing, etc.) of each light source can be changed by the light source drive circuit 60 based on the photometry result of the light amount sensor 30. It has become.
[0023]
It is preferable that the light source drive circuit 60 has a configuration including an arithmetic circuit capable of calculating a difference value of the light amount between the color lights, an average value of the luminance, and the like based on the photometry result of the light amount sensor 30. By doing so, the light emission amount of each of the light sources 20R, 20G, and 20B can be fed back to control the light emission amount, and a solid-state light-emitting element such as an LED whose luminance change with time due to temperature characteristics or the like is relatively large is used as the light source. Also when used, the amount of illumination light can be stably maintained.
[0024]
[Driving method]
The projection display apparatus according to the present embodiment has one or more alternative display modes in which, in addition to the normal display mode, when an abnormality occurs in the light source of the illumination device 10, the light source is replaced with another light source and image information is held. Have multiple. Hereinafter, a method of driving the projection display device will be described with reference to FIGS.
FIGS. 3 to 6 are timing charts for explaining the following four modes according to the alternative display mode of the display device of the present embodiment. FIG. FIG. 4 shows a mode in which other light sources are used alternately when one light source is out of bulb, FIG. 5 shows a mode in which another light source continuously emits light when one light source is out of bulb, and FIG. 2 shows a mode in which the light amount is compensated by another light source when the light amount decreases.
[0025]
(Alternative display mode for replacing a broken light source with another light source)
In the alternative display mode of this mode, when the display mode is shifted from the normal display mode, one of the other light sources is selected as a substitute for the light source whose light amount is reduced or the bulb is broken, and is used as the substitute light source. In the timing chart shown in FIG. 3, each waveform indicates the light emission timing of the light sources 20R, 20G, and 20B and the timing of the image signal output of the liquid crystal light valve 40, and the light emission amount or the signal intensity is indicated by the amplitude. Not something.
[0026]
As shown in FIG. 3, in the projection display device having the alternative display mode, when the light source 20 </ b> R is cut off at a certain point in the display operation, the projection display device according to the present embodiment first has the light amount sensor 30. The light source driving circuit 60 determines from the light metering result from the above that the ball has run out, and drives the light source 20B (or 20G) that normally emits light to emit light even at the light emission timing of the light source 20R. Therefore, after the light source 20R is out of the ball, the image element that was displayed in red in the normal state is displayed in blue. As described above, according to the display device and the driving method of the present embodiment, even when the light emission state of the light source is abnormal, the color tone of the display image is changed, but the image information itself is displayed. It is possible to withstand applications such as displaying information.
[0027]
In this alternative display mode, after the light source 20R is cut off, the light source 20B can be made to emit alternative light and the power supply to the light source 20R can be stopped. In this way, the power consumption of the display device can be reduced and, for example, when the light source 20R is turned off due to overheating or the like of the control system of the light source 20R, instead of turning off the bulb, the power to the light source is stopped. Therefore, there is an advantage that the load on the control system can be reduced.
[0028]
(Alternative display mode for replacing a broken light source with multiple other light sources)
In this alternative display mode, when shifting from the normal display mode, a plurality of light sources are used as a substitute for the light source whose light amount has decreased or the bulb has broken. In the timing chart shown in FIG. 4, each waveform conceptually indicates the light emission amount of each color light by its height in addition to the light emission timing of the light sources 20R, 20G, and 20B. Further, the timing chart of the liquid crystal light valve 40 shows only the output timing of the image signal as in FIG.
[0029]
As shown in FIG. 4, in the projection type display device provided with this mode, when the light source 20R is detected to be out of the light source 20R, the light source driving circuit 60 causes the light source 20G and the light source 20B to emit light at the light emission timing of the broken light source 20R. To emit light. Then, the image element that was displayed in red in the normal state is displayed in a color (green to cyan to blue) in which green light and blue light emitted from these light sources are mixed. Therefore, according to the display device of the present embodiment and the driving method thereof, although the color tone of the display image changes, the image information itself is displayed, so that it can sufficiently withstand applications such as displaying important information. It is possible.
[0030]
Further, in the alternative display mode, two primary colors of green light and blue light are displayed. However, in the mode of the present embodiment, the green light of the light source 20G and the blue light of the light source 20B are mixed. Since it is used as an alternative light source for 20R, pseudo three primary colors can be realized, and the visibility of the display can be kept relatively good.
In this alternative display mode, the output of the light sources 20G and 20B when emitting light at the emission timing of the light source 20R can be any output. Since the brightness of the image element displayed by the light source becomes extremely high and the visibility of the display decreases, the light source driving circuit 60 performs an operation based on the photometry result of the light amount sensor 30 and the light intensity after the color mixture is almost the same as the normal state. It is preferable to adjust the output of each of the light sources 20G and 20B so as to be equivalent.
[0031]
Also in this alternative display mode, after the light source 20R is cut off, the other light sources 20G and 20B can be made to emit alternative light, and the power supply to the light source 20R can be stopped. In this way, the power consumption of the display device can be reduced and, for example, when the light source 20R is turned off due to overheating or the like of the control system of the light source 20R, instead of turning off the bulb, the power to the light source is stopped. Therefore, there is an advantage that the load on the control system can be reduced.
[0032]
(Alternative display mode in which another light source emits light continuously when the light source burns out)
This alternative display mode uses a plurality of light sources as a substitute for a light source with a reduced light quantity or a broken bulb when shifting from the normal display mode, and does not intermittently emit those light sources, but instead emits continuously. Mode. In the timing chart shown in FIG. 5, each waveform conceptually indicates the light emission amount of each color light by its height in addition to the light emission timing of the light sources 20R, 20G, and 20B. Further, the timing chart of the liquid crystal light valve 40 shows only the output timing of the image signal as in FIG.
[0033]
As shown in FIG. 5, in the projection type display device provided with the present alternative display mode, when it is detected that the light source 20R is out of a ball, the light source driving circuit 60 operates the light sources 20R, 20G, and 20B in order of time. Is stopped, and the light sources 20G and 20B that emit light normally emit light continuously at a predetermined output. Then, the image information corresponding to all colors including the image element displayed in red at the time of normal is mixed with green light and blue light emitted from these light sources 20G and 20B (green to cyan to blue). To display. That is, this alternative display mode is a mode in which display is performed in a gray scale between the mixed color light and black. Therefore, according to the display device of the present embodiment and the driving method thereof, although the image is displayed in monochrome, the image information itself is displayed, so that it can sufficiently withstand applications such as displaying important information. is there.
Further, in this alternative display mode, a transition from color display to monochrome display is performed, so that the user can easily recognize that the light emission amount has decreased or the ball has run out in the lighting device 10, and the maintenance work of the display device can be performed. Can be reliably performed.
[0034]
In this alternative display mode, the outputs of the light sources 20G and 20B during continuous light emission can be any outputs. However, if the outputs of both light sources are made equal to the original outputs, the display luminance becomes extremely high. It is preferable that an operation is performed by the light source driving circuit 60 based on the photometry result of the light amount sensor 30 and the outputs of the light sources 20G and 20B are respectively adjusted so that the light intensity after the color mixture is substantially equal to that in the normal state.
[0035]
In this alternative display mode, the liquid crystal light valve 40 can be operated by selecting two types of operation modes indicated by reference numerals (A) and (B) in FIG. The operation mode (A) is a mode in which the image signals SR, SG, and SB are output in a time-sequential manner corresponding to the color light irradiated in a time-sequential manner, similarly to the normal display mode, even after the transition to the alternative display mode. On the other hand, in the operation mode (B), the image signal output from the liquid crystal light valve 40 in the alternative display mode is a grayscale image signal S before being separated into image signals for each color light. The operation modes (A) and (B) of the liquid crystal light valve 40 may be any mode.
[0036]
Also in the alternative display mode, after the light source 20R is cut off, the other light sources 20G and 20B can emit light continuously and the power supply to the light source 20R can be stopped. In this way, the power consumption of the display device can be reduced and, for example, when the light source 20R is turned off due to overheating or the like of the control system of the light source 20R, instead of turning off the bulb, the power to the light source is stopped. Therefore, there is an advantage that the load on the control system can be reduced.
[0037]
(Alternative display mode for compensating for a decrease in the light intensity of a specific light source with another light source)
In this alternative display mode, when a decrease in the light emission amount of the light source is detected and the display mode is shifted from the normal display mode, the ball does not run out and another light emission timing of the light source having a certain light emission amount is used. In this mode, a light source that normally emits light is emitted, and the reduced light amount is compensated. In the timing chart shown in FIG. 6, each waveform conceptually indicates the light emission amount of each color light by its height in addition to the light emission timing of the light sources 20R, 20G, and 20B. Further, the timing chart of the liquid crystal light valve 40 shows only the output timing of the image signal as in FIG.
[0038]
As shown in FIG. 6, in the projection type display device having the alternative display mode, when a decrease in the light amount of the light source 20 </ b> R is detected and the shift to the alternative display mode is selected by the light source driving circuit 60, the light source The drive circuit 60 causes the light source 20G and the light source 20B to emit light at the light emission timing of the light source 20R whose light quantity has decreased. Then, the image element that was displayed in red in the normal state is displayed in a color obtained by mixing the color lights emitted from these light sources 20R, 20G, and 20B. Therefore, according to the display device of the present embodiment and the driving method thereof, although the color balance of the displayed image changes, the image information itself is displayed, so that it can sufficiently withstand applications such as displaying important information. Is possible.
[0039]
When compensating the light amount of the light source 20R by the light sources 20G and 20B, the difference between the normal light emission amount of the light source 20R and the reduced light emission amount is determined by a light source driving circuit so that the display luminance after the compensation does not greatly change. Preferably, the light amount is calculated by using the light sources 20G and 20B.
[0040]
Further, in this alternative display mode, since the light source 20R is not cut off, only the color of the red image element changes, and the image visibility is not reduced as compared with the case of displaying two complete primary colors. It is possible to suppress.
Furthermore, this alternative display mode is a suitable mode in combination with the above three alternative display modes. That is, when the light emission amount of the light source (for example, the light source 20R) is reduced, but the ball does not run out, the display mode is shifted to the alternative display mode and the light amount of the light source 20R is compensated so that the color information can be reduced as much as possible. Can be maintained, and when the light source 20R is burned out thereafter, the display can be shifted to one of the above three alternative display modes to perform display.
[0041]
FIG. 6 shows a case where the light amount of the light source 20R is compensated for by the light sources 20G and 20B in cooperation with each other. However, the light amount of the light source 20R is compensated for by one of the light sources 20G and 20B. Of course, it is good.
[0042]
In each of the above-described driving methods, the case where one light source 20R has a broken ball or a reduced light amount has been described. However, the same light source 20G or 20B or a plurality of light sources has a similar broken ball or a reduced light amount. In addition, each of the above alternative display modes can be applied without any problem. At the light emission timing of the light source in which the bulb has been cut or the light amount has been reduced, the other normal light source is caused to emit light so that image information is not lost. Can be
Further, when the light source driving circuit 60 determines that the light emission amount of the light source has decreased, and the light source driving circuit 60 shifts to the alternative display mode using another light source and the light emission amount of the light source recovers for some reason, the light source driving circuit 60 60 can release the alternative display mode and return to the normal display mode.
[0043]
The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, a projection display device has been described as an example of the display device according to the present invention. However, a direct-view display device in which light modulated and output by the liquid crystal light valve 40 directly reaches an observer may be used. The present invention can be applied without any problem.
Further, an example using a transmissive liquid crystal light valve as the light modulating means has been described, but the present invention is also applicable to a display device using a reflective liquid crystal light valve or a DMD (digital mirror device).
[0044]
Further, the embodiment of the present invention includes a multicolor light emitting device that includes a plurality of light sources having different emission colors and is configured to output a plurality of color lights independently. Also in this embodiment, in the multicolor light emitting device according to the present invention, when any one of the plurality of light sources has a light emission amount equal to or less than a predetermined light amount, another light source emits light at the light emission timing of the light source. Specific examples of the multicolor light-emitting device include, for example, a lighting fixture configured to emit a plurality of color lights, an electric decoration using a plurality of colors, and the like.
The multicolor light emitting device according to the present invention can emit color light using another light source as an alternative light source even if an abnormality such as a decrease in light amount or a broken bulb occurs in any of the plurality of light sources.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a projection display device as an embodiment of a display device according to the present invention.
FIG. 2 is a timing chart of a display operation of the projection display device according to the embodiment;
FIG. 3 is a timing chart of a mode in which another light source is used alternately when one light source is out of a ball;
FIG. 4 is a timing chart of a mode in which a plurality of other light sources are used alternately when one light source is out of the bulb;
FIG. 5 is a timing chart of a mode in which another light source continuously emits light when one light source is out of a ball;
FIG. 6 is a timing chart of a mode for compensating the light amount with another light source when the light amount of one light source is reduced.
[Explanation of symbols]
Reference Signs List 10 lighting device, 20R, 20G, 20B light source, 30 light quantity sensor (light measuring means), 40 liquid crystal light valve (light modulating means), 50 projecting means, 60 light source driving circuit (light source controlling means)

Claims (9)

A plurality of light sources having different emission colors, and light modulating means for modulating the color light emitted from the light source, and emits the plurality of light sources in time sequence, and in synchronization with the color light emitted from the light source, A display device for driving the light modulating means in a time-sequential manner,
A display device, wherein when one of the plurality of light sources has a light emission amount equal to or less than a predetermined light amount, another light source can emit light at the light emission timing of the light source. Light measuring means for measuring the light emission amount of each light source, and light source control means capable of controlling the light emission timing of each light source based on the light measurement result output from the light measuring means,
In the photometric result of the photometric unit, when the light emission amount of any of the plurality of light sources is equal to or less than a predetermined light amount,
2. The display device according to claim 1, wherein the light source control unit selects one or a plurality of light sources from other light sources to emit light at the light emission timing of the light source whose light emission amount has decreased. 3. In the photometric result of the photometric unit, when the light emission amount of any of the plurality of light sources is equal to or less than a predetermined light amount,
The display device according to claim 2, wherein the other light source emits light continuously by the light source control means. In the photometric result of the photometric unit, when the light emission amount of any of the plurality of light sources is equal to or less than a predetermined light amount,
3. The display device according to claim 2, wherein the light source control unit causes another light source to emit light at an intensity that complements the light emission amount of the light source with the reduced light emission amount. 4. In the photometric result of the photometric unit, when the light emission amount of any of the plurality of light sources is equal to or less than a predetermined light amount,
4. The display device according to claim 2, wherein the light source control unit stops supplying power to the light source whose light emission amount has decreased. 5. 6. The display device according to claim 5, wherein when the light emission amount of the light source output from the photometric unit is substantially zero, the power supply to the light source is stopped by the light source control unit. 7. A projector comprising: the display device according to claim 1; and a projection unit configured to project light modulated by the light modulation unit. A plurality of light sources having different emission colors and light modulation means for modulating light emitted from the light sources are provided, and the plurality of light sources are sequentially emitted in time, and the light is emitted in synchronization with the color light emitted from the light sources. A driving method of a display device that drives the light modulating means in time sequence,
When one of the plurality of light sources has a light emission amount equal to or less than a predetermined light amount, another light source is caused to emit light at the light emission timing of the light source to perform display. A plurality of light sources having different emission colors and light modulation means for modulating light emitted from the light sources are provided, and the plurality of light sources are sequentially emitted in time, and the light is emitted in synchronization with the color light emitted from the light sources. A driving method of a display device that drives the light modulating means in time sequence,
When one of the plurality of light sources has a light emission amount equal to or less than a predetermined light amount, the other light sources emit light continuously to perform display.

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