JP2003005714A - Light source control device and method, and projection display device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To constantly maintain a desired balance between the light outputs from a plurality of light sources. SOLUTION: A plurality of laser light sources 11R, 11G, 11 are provided.
The respective color lights from B are partially reflected by mirrors 13R, 13G, 13
The light is spatially partially separated by B, and the separated color lights are detected by the light intensity detectors 21R, 21G, and 21B. The detection signals of each color by the light intensity detectors 21R, 21G, 21B are converted into digital signals by the function of the AD converter 22, and the AD converted detection signals RBD, GB
D and BBD are output to the microprocessor 23. The microprocessor 23 outputs the detection signals RBD, GB
D, BBD, each variable power supply 12R, 12G, 1
2B, the laser light sources 11R, 11G, 1
1B is adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source control device and method for controlling the light output of a plurality of light sources, and a projection type display device for displaying an image using light from a plurality of light sources.

[0002]

2. Description of the Related Art Conventionally, a projection type display device (projector) which displays an image by intensity-modulating light from a light source using an optical modulator and projecting the modulated light on a screen is known. is there. Projection methods in a projector include a front projection method (front type) in which an image is projected from the front side of the screen and a rear projection method (rear type) in which an image is projected from the rear side. As the optical modulator, for example,
A liquid crystal panel (LCD; Liquid Crystal Display) or DMD (Digital Micromirror Device) is used.

In a projector for color display, for example, red (R), green (G) and blue (B) color lights are
Intensity modulation is performed by the light modulators, and the respective color lights are combined to generate a color image. In this case, a white light source such as a metal halide lamp is used as a light source, and the white light is color-separated by a dichroic mirror or the like to generate each color light.

On the other hand, as a light source, there is also a method of using a plurality of single-color light emitting type light sources which generate respective color lights, instead of a white light source. For example, in USP 5,317,348 and USP 5,253,073, image display is performed by using a plurality of laser light sources that generate R, G, B color lights and a plurality of R, G, B color modulation elements. Techniques relating to projectors are disclosed.

FIG. 12 shows a configuration example of a conventional projector using a plurality of laser light sources. This projector includes laser light sources 101, 102, 103 for respective colors that generate R, G, B color lights, and modulators 104 for the respective colors.
105 and 106 are provided. This projector is
Further, the total reflection mirror 111 provided on the optical path of the red light emitted from the R modulator 104 and the total reflection mirror 1 provided on the optical path of the blue light emitted from the B modulator 106.
12 and dichroic mirrors 107 and 108 provided on the optical path of the green light emitted from the G modulator 105 and having a function of combining the respective color lights. This projector further includes dichroic mirrors 107 and 108.
Each color light synthesized through the
A scanner 109 for dimensionally scanning, developing and projecting is provided.

In this projector, each laser light source 10
Red, green and blue laser lights are independently output from 1, 102 and 103, respectively. The intensity of each color light is modulated by the modulators 104, 105 and 106 for the respective colors. First, the green light emitted from the G modulator 105 is
It is incident on the dichroic mirror 107. R modulator 1
The red light emitted from 04 is reflected by the total reflection mirror 111 toward the dichroic mirror 107,
There it is mixed with green light. The mixed red light and green light then enter the dichroic mirror 108. On the other hand, the blue light emitted from the B modulator 106 is reflected by the total reflection mirror 112 toward the dichroic mirror 108, where it is mixed with the red light and the green light. This mixed light is two-dimensionally developed by the scanner 109, and it becomes projection light and becomes the screen 11
0, and a two-dimensional image is displayed on the screen 110.

[0007]

By the way, in a projector using a plurality of laser light sources as described above, when the light output of each light source changes individually, the color balance of the image projected on the screen is lost, and the image is projected. There is a problem that it becomes difficult to see. In particular, the light output of a light source generally decreases with time, and it is extremely rare that the light output reduction rates of a plurality of light sources are all equal. It may change from the ideal state.

The present invention has been made in view of the above problems, and an object thereof is to provide a light source control device and method capable of always maintaining a desired balance of light outputs from a plurality of light sources, and a projection type display. To provide a device.

[0009]

A light source control device according to the present invention is a detection means for detecting light output values of a plurality of light sources, and a light output of each of the plurality of light sources based on a detection result of the detection means. Control means for controlling the light output of each of the plurality of light sources so that the value or the relative value of each light output value always approaches a constant value.

The light source control method according to the present invention detects the light output value of each of the plurality of light sources, and based on the detection result, each light output value of the plurality of light sources or the relative value of each light output value. The light output of each of the plurality of light sources is controlled so that the value of is always close to a constant value.

The projection type display device according to the present invention includes a plurality of light sources which emit different colored light, a detection means which detects the light output value of each of the plurality of light sources, and a plurality of light sources based on the detection results of the detection means. So that the respective light output values or the relative values of the respective light output values always approach a constant value, a control means for controlling the light output of each of the plurality of light sources, and a plurality of control means controlled by the control means. It is provided with a modulating means for modulating each color light from the light source and a projecting means for projecting the modulated light by the modulating means as image light.

In the light source control device and method and the projection display device according to the present invention, the light output values of the plurality of light sources are detected, and based on the detection results, the light output values of the plurality of light sources or the light output values of the light sources are detected. The light output of each of the plurality of light sources is controlled so that the relative value of the light output value always approaches a constant value.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment] As shown in FIG. 1, the projection type display device according to the present embodiment has R, G, B
Laser light sources 11R, 11 for each color that generate each color light of
G, 11B and these laser light sources 11R, 11G, 1
Variable power supplies 12R, 12 for each color for driving 1B
G, 12B and modulators 14R, 14 for each color that intensity-modulate each color light from the laser light sources 11R, 11G, 11B.
G, 14B. In this projection display device, the total reflection mirror 15 provided in the optical path of the red light emitted from the R modulator 14R and the total reflection mirror 15 provided in the optical path of the blue light emitted from the B modulator 14B. Reflection mirror 17
And dichroic mirrors 16 and 18 provided on the optical path of the green light emitted from the G modulator 14G and having a function of combining the color lights. The projection display device further includes a scanner 19 that two-dimensionally scans, develops, and projects the respective color lights synthesized via the dichroic mirrors 16 and 18 on a screen 20.

This projection type display device further includes light intensity detectors 21R, 21G and 21B for each color having a function of detecting the light output values (light intensity, for example, brightness) of the laser light sources 11R, 11G and 11B. And the laser light source 11R,
The laser light sources 11R, 11G and 11 are provided in the optical path between the modulators 11G and 11B and the modulators 14R, 14G and 14B.
Partial reflection mirrors 13R, 13G, 13B for each color having a function of spatially separating a part of each color light output from B and reflecting it toward the light intensity detectors 21R, 21G, 21B.
It has and. This projection type display device also includes light intensity detectors 21R, 21G, 21B and variable power supplies 12R, 12B.
An analog / digital (hereinafter referred to as "AD") converter 2 provided in a signal path between the G and 12B.
2. A microprocessor 23 and a digital / analog (hereinafter referred to as “DA”) converter 24 are provided.

The variable power supplies 12R, 12G, 12B are connected to the laser light source 1 via current control terminals 25R, 25G, 25B.
It is connected to 1R, 11G, and 11B. Variable power supply 12
R, 12G, 12B are laser light sources 11R, 11G, 1
It has a function of supplying a driving current (variable) to 1B. The laser light sources 11R, 11G, 11B are composed of, for example, semiconductor lasers, and variable power sources 12R, 12G,
The optical output value changes according to the supply current from 12B.

The AD converter 22 is a light intensity detector 21.
It has a function of converting the detection signals of the respective colors from R, 21G, and 21B into digital signals and outputting them to the microprocessor 23. Below, the R, G, and B detection signals output to the microprocessor 23 are respectively referred to as RBD.
(R Bright Data), GBD (G Bright Data), BBD
(B Bright Data).

The microprocessor 23 is provided for each variable power source 1
2R, 12G, 12B drive control, laser light source 1
It has a function of adjusting the respective light output values of 1R, 11G, and 11B. The microprocessor 23 performs a predetermined calculation based on the AD-converted detection signals RBD, GBD, BBD from the light intensity detectors 21R, 21G, 21B, and outputs a control signal for adjusting the light output. ing. In the following, the control signals for adjusting the R, G, and B optical outputs output from the microprocessor 23 are respectively RSD (R Set Data), GSD (G Set Data),
It is referred to as BSD (B Set Data). The DA converter 24 is
Control signal R output from the microprocessor 23
It has a function of converting SD, GSD and BSD into analog signals and outputting them to the variable power supplies 12R, 12G and 12B. The microprocessor 23 uses the detection signal RB
Initial values of D, GBD, BBD and control signals RSD, GS
It has an internal memory for storing standard values of D and BSD.

The signal values of the control signals RSD, GSD, BSD are assumed to be proportional to the intensity (eg, brightness) of the light output from the laser light sources 11R, 11G, 11B.

In the present embodiment, the light intensity detectors 21R, 21G and 21B correspond to a specific example of "detecting means" in the present invention, and the microprocessor 23 is
This corresponds to a specific example of "control means" in the present invention. Further, the partial reflection mirrors 13R, 13G, 13B correspond to a specific example of "light separating means" in the invention. Also,
The scanner 19 corresponds to a specific but not limitative example of "projection means" in the present invention. Further, among the constituent elements in the apparatus of FIG. 1, mainly, the light intensity detectors 21R, 21G, 21B,
AD converter 22, microprocessor 23 and D
The A converter 24 corresponds to a specific example of "a light source control device" of the invention.

Next, the operation of the projection type display device having the above configuration will be described.

First, a basic image display operation of the present projection type display device will be described. In this projection-type display device, the laser light sources 11R, 11G, and 11B output red, green, and blue laser light independently of each other in accordance with the supply currents from the variable power supplies 12R, 12G, and 12B. Most of the output color lights are partially reflected by the mirror 13.
After passing through R, 13G, and 13B, they enter the modulators 14R, 14G, and 14B for the respective colors, where the intensity is modulated.

The modulators 14R, 14G, 14B are driven by a modulation signal from a signal source (not shown) given based on the video signal. The green light emitted from the G modulator 14G first enters the dichroic mirror 16. The red light emitted from the R modulator 14R is reflected by the total reflection mirror 15 toward the dichroic mirror 16 and mixed there with the green light. The mixed red light and green light then enter the dichroic mirror 18. On the other hand, the blue light emitted from the B modulator 14B is reflected by the total reflection mirror 17 toward the dichroic mirror 18, where it is mixed with the red light and the green light. The mixed light is two-dimensionally developed by the scanner 19 and projected as a projection light (image light) on the screen 20 to display a two-dimensional image on the screen 20.

By the way, each laser light source 11R, 11G,
Part of each color light output from 11B is spatially separated by the function of the partial reflection mirrors 13R, 13G, and 13B, and enters the light intensity detectors 21R, 21G, and 21B.
The light intensity detectors 21R, 21G, 21B detect the light output value (light intensity) of each incident color light. Light intensity detector 21
The detection signals of the respective colors R, 21G, 21B are converted into digital signals by the function of the AD converter 22, and the AD-converted detection signals RBD, GBD, BBD are output to the microprocessor 23. The microprocessor 23 controls the drive of each variable power source 12R, 12G, 12B based on the detection signals RBD, GBD, BBD, and adjusts the optical output value of each of the laser light sources 11R, 11G, 11B.

Next, the control operation of the optical output by the microprocessor 23 will be described in detail. In this projection type display device, first, for example, at the time of manufacturing or factory shipment, the light output values of the laser light sources 11R, 11G, and 11B are adjusted to perform initial adjustment of color balance (white balance) (adjustment mode). ) Then, when the device is actually used, the control operation of the light output is performed so that the color balance in the initial state is maintained (use mode).

First, referring to FIG. 2, the operation in the initial adjustment mode will be described. The microprocessor 23 first outputs standard values of the control signals RSD, GSD, BSD stored in an internal memory (not shown) (step S11). Variable power sources 12R, 12G, 12
B supplies a driving current to the laser light sources 11R, 11G and 11B based on the standard control signals RSD, GSD and BSD given via the DA converter 24. The laser light sources 11R, 11G, 11B output laser light in an amount corresponding to the supplied current.

Next, the microprocessor 23 increases or decreases the respective values of the control signals RSD, GSD, BSD to change the optical output values of the laser light sources 11R, 11G, 11B and adjust the white balance. (Step S12). For the white balance adjustment here, for example, an optical sensor (not shown) is provided on the screen 20, and the detection value of the optical sensor is set to the microprocessor 23.
It can be done automatically by giving feedback to. The respective values of the control signals RSD, GSD, BSD may be manually increased or decreased. If the white balance is not yet in an appropriate state (step S1)
3; N), the step S1 is repeated until the state becomes appropriate.
Use 2 to adjust the white balance.

On the other hand, if the white balance is within the desired range and is in an appropriate state (step S13;
Y), the microprocessor 23 stores the adjustment values of the control signals RSD, GSD, BSD at that time in the internal memory (step S14). Further, at this time, the microprocessor 23 accepts the input of the detection signals RBD, GBD, BBD of the light intensity of each color output via the AD converter 22 (step S15), and stores the value as an initial value in the internal memory. Yes (step S16). With the above, the adjustment mode process is completed.

Next, the operation in the use mode will be described with reference to FIG. The microprocessor 23 first outputs, via the DA converter 24, the adjustment values stored in step S14 of the adjustment mode described above as the control signals RSD, GSD, BSD to be given to the variable power supplies 12R, 12G, 12B (step S21). ). Each of the variable power supplies 12R, 12G, 12B supplies a driving current to the laser light sources 11R, 11G, 11B based on the control signals RSD, GSD, BSD provided via the DA converter 24. The laser light sources 11R, 11G and 11B are
Laser light of an amount corresponding to this supply current is output. At this time, the microprocessor 23 causes the light intensity detectors 21R, 21G, 21B output via the AD converter 22.
The input of the detection signals RBD, GBD, BBD of each color from is received (step S22), and the value is compared with the initial value stored in step S16 of the adjustment mode (step S23).

The microprocessor 23 determines the current detection signals RBD, GBD, B according to the result of comparison with the initial value.
The values of the control signals RSD, GSD, BSD are adjusted so that the respective values of BD approach the initial values. In particular,
Detection signals RBD, GBD, BB having a value larger than the initial value
If D is present, the microprocessor 23 decreases the values of the control signals RSD, GSD, BSD corresponding to it (step S24). On the other hand, on the contrary, when there are detection signals RBD, GBD, BBD having a value smaller than the initial value, the microprocessor 23 determines that the control signal RS corresponding to the detection signals RBD, GBD, BBD.
Increase the values of D, GSD and BSD (step S2
5). Further, the detection signals RBD and GB having the same value as the initial value
When there are D and BBD, the microprocessor 23 does not change the values of the corresponding control signals RSD, GSD and BSD.

The microprocessor 23 supplies the control signals RSD, GSD, BSD adjusted in this way to the variable power supplies 12R, 12G, 12B via the DA converter 24.
(Step S26). Laser light source 11R, 1
The control signals RS thus adjusted are provided for 1G and 11B.
A drive current based on D, GSD, BSD is given. After that, the microprocessor 23 again executes step S22.
Then, the adjustment of the control signals RSD, GSD, BSD based on the detection signals RBD, GBD, BBD is repeated. By performing such feedback control, the values of the detection signals RBD, GBD, and BBD are always maintained at the initial values. That is, each laser light source 11R, 11G, 11B
The feedback control is performed so that the optical output value of the optical signal always approaches a constant value, and the optical output value is always maintained at a constant value. This prevents the white balance from changing over time, and enables stable image display for a long period of time.

The control in the above-mentioned usage modes may be carried out at all times during the operation of the apparatus, or may be carried out at any time as required. For example, when the present projection type display device is used as a device for showing a movie, it is possible to use the projection type display device between movie showings.

As described above, according to the present embodiment, the respective color lights from the plurality of laser light sources 11R, 11G and 11B are spatially partially separated by the partial reflection mirrors 13R, 13G and 13B, and the separated respective colors. Light is detected by the light intensity detectors 21R, 21G, 21B, and based on the detection result, feedback is performed so that the same amount of color light as the initially adjusted light output value is output from each laser light source 11R, 11G, 11B. Since the control is performed, the white balance can always be kept constant in a desired state.
Also, the brightness can be kept constant. As a result, a good image display can be stably performed for a long period of time.

[Second Embodiment] Next, the second embodiment of the present invention will be described.
The embodiment will be described. In the following description, parts having substantially the same functions as those of the constituent elements shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The structure of the projection type display device according to this embodiment and the basic image display operation thereof are the same as those in the first embodiment, but in particular, the control operation in the use mode by the microprocessor 23. Is different. In the first embodiment, as described with reference to FIG. 3, the control is performed so that the light output values of the laser light sources 11R, 11G, and 11B are always constant, but in the present embodiment, , So that the relative value (light output ratio) of the light output of each of the laser light sources 11R, 11G, and 11B is kept constant.

The control operation in this use mode will be described with reference to FIG. Prior to this use mode, processing in the same adjustment mode as in FIG. 2 is performed.
First, the microprocessor 23 first detects each variable power source 12R,
Control signals RSD, GSD, BS given to 12G, 12B
As D, the adjustment value stored in step S14 of the adjustment mode in FIG. 2 is output via the DA converter 24 (step S31). Variable power sources 12R, 12G, 12
B is a laser light source 11 based on the control signals RSD, GSD, and BSD given via the DA converter 24.
A driving current is supplied to R, 11G, and 11B. The laser light sources 11R, 11G, 11B output laser light in an amount corresponding to the supplied current. At this time, the microprocessor 23 accepts the input of the detection signals RBD, GBD, BBD of each color from the light intensity detectors 21R, 21G, 21B output via the AD converter 22 (step S32). The processing up to this point is the same as the processing (steps S21 and S22 in FIG. 3) in the first embodiment.

The microprocessor 23 then corresponds to the optical output ratio of each laser light source 11R, 11G, 11B,
The relative value of each detection signal RBD, GBD, BBD, for example, the value of RBD / GBD and BBD / GBD is calculated (step S33). Next, the microprocessor 23
Is the calculated light output ratio (RBD / GBD, BBD / GB
D) is compared with the light output ratio in the initial state (step S).
34). The light output ratio in the initial state is, for example, the detection signals RBD, G obtained in step S16 (FIG. 2) of the adjustment mode.
It is also possible to calculate from the initial values of BD and BBD and store the values in the internal memory in advance at the adjustment mode stage, or at the execution stage of the use mode, the respective detection signals RBD, GBD, stored at the adjustment mode. You may make it calculate from the initial value of BBD.

The microprocessor 23 controls the control signals RSD, GS so that the current value of the light output ratio approaches the value of the initial state according to the result of comparison with the light output ratio in the initial state.
Adjust the D and BSD values. Specifically, when there is a light output ratio larger than that in the initial state, the microprocessor 23 decreases the value of the control signal corresponding to it (step S35). For example, if RBD / GBD is larger than the value in the initial state, the value of the control signal RSD is decreased, and if BBD / GBD is larger than the value in the initial state, the value of the control signal BSD is decreased. At this time, control may be performed such that the GSD value is increased. However, when controlling to increase the control signal, the laser light source 1
Care must be taken not to drive 1R, 11G, 11B beyond the maximum rated value.

On the other hand, for example, RBD / GBD or BBD
If the value of / GBD is smaller than the value in the initial state,
The microprocessor 23 decreases the value of the control signal GSD (step S36). At this time, control may be performed to increase the value of RSD or BSD. However, even in this case, the laser light sources 11R, 11G, 11
Care must be taken to ensure that B is not driven above the maximum rating. If the current light output ratio is the same as the value in the initial state, the values of the control signals RSD, GSD, BSD are not changed.

The microprocessor 23 supplies the control signals RSD, GSD, BSD thus adjusted to the variable power supplies 12R, 12G, 12B via the DA converter 24.
(Step S37). Laser light source 11R, 1
The control signals RS thus adjusted are provided for 1G and 11B.
A drive current based on D, GSD, BSD is given. After that, the microprocessor 23 again returns to step S32.
Then, the adjustment of the control signals RSD, GSD, BSD based on the ratio of the detection signals RBD, GBD, BBD is repeated.
By performing such feedback control, the ratio of the detection signals RBD, GBD, BBD is always kept the same as in the initial state. That is, each laser light source 11R, 11
In order that the light output ratio of G and 11B always approaches a constant value,
Feedback control is performed so that the light output ratio is always maintained at a constant value. This prevents the white balance from changing over time, and enables stable image display for a long period of time.
When the control for reducing the value of the control signal (steps S35 and S36 in FIG. 3) is performed, the overall brightness is lower than in the initial state, but the light output ratio is controlled to be constant. Therefore, the color balance is kept constant.

In this embodiment, a plurality of laser light sources 11 are used.
Each color light from R, 11G and 11B is detected by the light intensity detector 21.
It is detected by R, 21G, and 21B, and feedback control is performed so that the light output ratio becomes the same as the light output ratio in the initial state. Therefore, the white balance should always be kept constant in a desired state. You can As a result, a good image display can be stably performed for a long period of time.

[Third Embodiment] Next, the third embodiment of the present invention will be described.
The embodiment will be described. In the following description, parts having substantially the same functions as those of the constituent elements shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The structure of the projection type display device according to the present embodiment and the basic image display operation thereof are the same as those of the first embodiment, but in particular, the control operation in the use mode by the microprocessor 23. Is different. In the first embodiment, as described with reference to FIG. 3, control is performed so that the light output values of the laser light sources 11R, 11G, and 11B are always constant. Further, in the second embodiment, as described with reference to FIG. 4, the laser light source 1
Control was performed so that the ratio of the respective light outputs of 1R, 11G, and 11B was always constant. In the present embodiment, initially, control is performed to keep the light output value constant, but as a result of the control, the laser light sources 11R, 11G, 11B that are driven to exceed the preset maximum allowable value are likely to come out. In this case, the control is switched to control to keep the light output ratio constant.

The control operation in the use mode in the present embodiment will be described with reference to FIGS. 5 and 6. Prior to this use mode, processing in the same adjustment mode as in FIG. 2 is performed. In the present embodiment, the laser light sources 11R, 11G, and 11B have preset drive limit values that are allowable in design according to their ratings, and the control signals RSD, GSD, and B are correspondingly set.
For SD, the maximum allowable value is set in advance. The maximum allowable values of the control signals RSD, GSD, BSD are stored in the internal memory of the microprocessor 23.

First, the microprocessor 23 first supplies a control signal RSD to the variable power supplies 12R, 12G and 12B.
As GSD and BSD, step S in the adjustment mode of FIG.
The adjustment value stored in 14 is output via the DA converter 24 (step S41). Then, the microprocessor 23 adjusts the control signals RSD, GSD, BSD based on the detection signals RBD, GBD, BBD, and performs feedback control so that the values of the detection signals RBD, GBD, BBD are always the initial values. (Step S
42-S46). The processing of these steps S41 to S46 is the same as the processing of steps S21 to S26 of FIG. As a result, the light output values of the laser light sources 11R, 11G, and 11B are controlled to be the same as in the initial state, and the brightness and white balance are kept constant.

In step S45, the control signals RSD, GSD, and BSD are increased in accordance with the current values of the detection signals RBD, GBD, and BBD. At this time, the microprocessor 23 controls the control signals. Signal R
It is determined whether or not any one of SD, GSD, and BSD exceeds a preset maximum allowable value (step S47). When none of the control signals RSD, GSD, and BSD exceeds the allowable maximum value even if the value is increased (step S47; Y), the microprocessor 23 proceeds to the process of step S46 and keeps the optical output value constant. Repeat the control.

On the other hand, when the value is increased, the control signal RSD,
If one of the GSD and BSD exceeds the preset allowable maximum value (step S47; N), the microprocessor 23 controls the optical output value to keep the optical output value constant. Control to keep constant (Fig. 6
Steps S48 to S52) of No. The processing of steps S48 to S52 for keeping the light output ratio constant is the same as the processing of steps S33 to S37 of FIG. In this process, the optical output ratio is kept constant only by reducing the values of the control signals RSD, GSD, BSD (steps S50, S51), so that the control signals RSD, GSD, BSD are kept.
Does not exceed the maximum value allowed. That is, the laser light sources 11R, 11G, and 11B are driven within a design allowable range. Thereby, the laser light sources 11R and 11R
The ratios of the light outputs of G and 11B are controlled to be the same as in the initial state, and the overall brightness is lower than in the initial state, but the white balance is kept constant.

As described above, according to the present embodiment, the detection signals RBD, GBD, BB are kept until the laser light sources 11R, 11G, 11B reach the designed drive limit value.
The control signals RSD, GSD, BSD are adjusted to increase or decrease based on D, so that each laser light source 11R, 11G, 11B outputs the same amount of color light as the initially adjusted light output value. Until 11R, 11G, and 11B reach the designed drive limit value, the white balance can be constantly kept in a desired state and the luminance can be kept constant. Then, the laser light source 11
When R, 11G, and 11B may reach the designed drive limit value, the control signals RSD, GSD, and BSD are not increased but only decreased, and the light output ratio becomes the same as the initial state. Since such control is performed, the overall brightness is reduced, but the white balance can always be kept in a desired state and constant. As a result, a good image display can be stably performed for a long period of time.

In the above description, the case where the control for keeping the light output value constant or the control for keeping the light output ratio constant is automatically performed has been described, but this switching is manually performed. It may be done in.

[Fourth Embodiment] Next, a fourth embodiment of the present invention will be described.
The embodiment will be described. In the following description, parts having substantially the same functions as those of the constituent elements shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

In the apparatus configuration of FIG. 1, the laser light source 11R,
Partially reflecting mirrors 13R, 13G, 13B are provided in the optical path between 11G, 11B and modulators 14R, 14G, 14B to spatially separate a part of the output light from the laser light sources 11R, 11G, 11B. Light intensity detector 21
Output to R, 21G, 21B. In the present embodiment, the laser light sources 11R, 11G, 1 are provided by light separating means different from the partial reflection mirrors 13R, 13G, 13B.
The output light of 1B is extracted and the light intensity is detected.

As shown in FIG. 7, the projection display apparatus according to the present embodiment has partial reflection mirrors 13R, 13G, 1
Instead of 3B, a color wheel 3 is used as a light separating means.
1 and a drive motor 32 for driving the color wheel 31. The color wheel 31 has a common optical path for each color light after passing through the modulators 14R, 14G, and 14B, that is, the dichroic mirror 18 and the scanner 1.
9 is provided in the optical path between The projection display device also includes signal sources 41R, 41 for each color that output modulation signals for driving the modulators 14R, 14G, 14B.
G, 41B, the modulation signals of the respective colors output from the signal sources 41R, 41G, 41B, and the reference pulse signal 43 described later.
Signal synthesizers 42R, 42G and 42B for synthesizing R, 43G and 43B (FIGS. 9A to 9C) are provided.

As shown in FIG. 8, the color wheel 31 is formed in a disk shape as a whole, and R,
Reflective surfaces 31R and 31 for reflecting the respective color lights of G and B
G and 31B are provided. Reflective surfaces 31R, 31G,
A portion other than 31B is a transmissive portion 31T capable of transmitting each color light.
Has become. The drive motor 32 controls rotation of the color wheel 31 based on a control signal from the microprocessor 23.

Next, the operation of detecting the light output value in the present projection type display device will be described. Microprocessor 23
Outputs reference pulse signals 43R, 43G, 43B for each color as shown in FIGS. These reference pulse signals 43R, 43G, 43B are used by the light intensity detectors 21R, 21G, 21B to detect the light intensity. Each reference pulse signal 43R, 43G, 4
3B is combined with the modulation signal of each color output from the signal sources 41R, 41G, and 41B by the function of the signal combiners 42R, 42G, and 42B. 9D to 9F show the combined modulation signals 44R, 44G, and 44B of the respective colors output from the signal combiners 42R, 42G, and 42B. As shown in these figures. The microprocessor 23
For example, the reference pulse signals 43R, 43G, and 43B are generated at a rate of one color in three fields (or frames) of the image. These reference pulse signals 43R, 43G, 43B
Are inserted in the field (or frame) blanking interval Tblk of the video so as not to affect the normal video display interval Tf. Composite modulation signals 44R, 44
G and 44B are modulators 14R, 14G and 14 respectively.
Output to B. Each modulator 14R, 14G, 14B is
The intensity of each color light from the laser light sources 11R, 11G, and 11B is intensity-modulated based on the composite modulation signals 44R, 44G, and 44B of each color.

The microprocessor 23 also drives and controls the drive motor 32 in synchronization with the reference pulse signals 43R, 43G and 43B, and the reference pulse signals 43R and 43R.
G, 43B and each reflecting surface 31R, 3 of the color wheel 31
Control is performed so that the positions of 1G and 31B have a predetermined phase relationship. That is, the microprocessor 23 causes the modulators 14R, 14G, 14B to receive the reference pulse signals 43R,
When 43G and 43B are added, the reflecting surfaces 31R, 31G and 31B of the color wheel 31 are correspondingly
Are controlled so that they are located on the optical axis. Thereby, for example, from the R modulator 14R to the R reference pulse signal 4
When red light for detection based on 3R is emitted,
The R reflection surface 31R of the color wheel 31 is located on the optical axis, and the red light for detection is reflected toward the light intensity detector 21. The same applies to other colors.

In this way, in the field blanking interval Tblk of the video signal, the reference pulse signal 43
Each color light for detection emitted based on R, 43G, 43B is reflected by each reflection surface 31R, 31G of the color wheel 31,
The light is reflected toward the light intensity detector 21 at 31B. on the other hand,
In the normal video display section Tf, the signal sources 41R, 41G,
The modulated light of each color emitted based on the modulation signal from 41B passes through the transmissive portion 31T of the color wheel 31.

The light intensity detector 21 detects any one color light for each field (or one frame). Detection signals RBD, GBD, B in the light intensity detector 21
The BD is converted into a digital signal via the AD converter 22 and output to the microprocessor 23. Figure 9
The detection signals RBD, GBD, BBD output from the light intensity detector 21 are shown in (F). In the device configuration of FIG. 1, since the respective colored lights are not temporally separated, the colored lights are detected by the separate light intensity detectors 21R, 21G, and 21B. However, in the present embodiment, the respective colored lights for detection are temporally separated. Since they are separated from each other, the detection can be performed by only one light intensity detector 21. In addition, in the present embodiment,
Since the light used for detection is light that is not used for normal image display, there is no loss of light quantity. Therefore, in the present embodiment, the intensity of each color light can be detected without affecting the normal image display at all.

The microprocessor 23 controls the drive of each variable power source 12R, 12G, 12B based on the detection signals RBD, GBD, BBD output as described above, and each of the laser light sources 11R, 11G, 11B. Adjust the light output value of. The control operation of the light output by the microprocessor 23 can be performed in the same manner as the control operation (FIGS. 2 to 6) of the first to third embodiments.

FIG. 10 shows detection signals RBD, GBD, BB.
The operation procedure of the microprocessor 23 for obtaining D is shown. The process shown in FIG. 10 is performed in step S1 of FIG.
5, step S22 of FIG. 3, step S32 of FIG. 4, and step S42 of FIG. The microprocessor 23 drives and controls the drive motor 32 to control the R reflection surface 31R of the color wheel 31 so as to be located on the optical axis, and outputs the R reference pulse signal 43R (step S61). The light intensity detector 21 detects the red light emitted from the R modulator 14R based on the R reference pulse signal 43R and reflected by the R reflection surface 31R of the color wheel 31. The microprocessor 23 acquires the signal detected by the light intensity detector 21 and AD-converted by the AD converter 22 as the R detection signal RBD (step S62). Thereafter, the G detection signal GBD and the B detection signal BBD are similarly obtained (steps S63 and S64).

As described above, according to the present embodiment, the color wheel 31 is used to obtain the color light for detecting the light intensity, which is temporally separated from the color light used for the image display. Therefore, there is no loss of light amount due to light detection, and the intensity of each color light can be detected and used for controlling the light output without affecting the normal image display at all. Also,
By disposing the color wheel 31 in the subsequent stage of the modulators 14R, 14G, 14B, the modulators 14R, 14G, 1
Since the light passing through 4B is detected, in addition to the change in the optical output of the laser light sources 11R, 11G, and 11B itself, the optical output gain in consideration of the optical output gain in the modulators 14R, 14G, and 14B is also taken. It becomes possible to control. For example modulator 1
When the gain of the optical output of any one of 4R, 14G, and 14B is less than 5%, the corresponding laser light source 11
It is possible to control the output of R, 11G, 11B so as to be automatically increased by 5%.

In the above description, the color wheel 3
Although the case where only one is provided has been described, the color wheel 31 may be provided for each optical path of each color light. For example, modulators 14R, 14G, 14B and mirrors 15, 1
A total of 3 color wheels in each optical path between 6 and 17
You may provide one.

[Fifth Embodiment] Next, the fifth embodiment of the present invention will be described.
The embodiment will be described. In the following description, parts having substantially the same functions as those of the constituent elements shown in FIGS. 1 and 7 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

Although FIG. 1 and FIG. 7 show the projection type display device which two-dimensionally scans the laser light by the scanner 19 to display an image, the projection type display device according to the present embodiment is the scanner 19. Without using, a two-dimensional modulator is used to display an image.

The projection type display apparatus according to the present embodiment shown in FIG. 11 is obtained by changing the configuration of the optical system after the partial reflection mirrors 13R, 13G and 13B in the apparatus configuration of FIG. This projection display device includes a beam expander 5 for each color having a function of two-dimensionally expanding each color light.
1R, 51G, 51B and two-dimensional modulators 52R, 52G for each color having a function of two-dimensionally modulating each color light
52B and. This projection type display device also
Synthetic prism 53 having a function of synthesizing modulated lights of respective colors
And a projection lens 54 for projecting the combined modulated light toward the screen 20. Two-dimensional modulator 52
As R, 52G, 52B, for example, LCD or DM
Any value such as D can be used.

In this projection type display device, the laser light source 11R passing through the partial reflection mirrors 13R, 13G and 13B,
Each color light from 11G and 11B is emitted by the beam expander 5.
It is two-dimensionally enlarged by the functions of 1R, 51G, and 51B and is emitted to the modulators 52R, 52G, and 52B for each color. Each modulator 52R, 52G, 52B two-dimensionally modulates each color light expanded by the beam expanders 51R, 51G, 51B and emits it. The modulated lights of the respective colors are combined by the combining prism 53 and then projected by the projection lens 54.
Is projected toward the screen 20. As a result, the image is displayed on the screen 20.

The control operation of the light output in the projection type display device shown in FIG. 11 is the same as the control operation (FIGS. 2 to 6) of the first to third embodiments.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made. For example, the present invention is applicable not only to the laser light source but also to a case where a plurality of other light sources such as a discharge lamp, a light emitting diode, and electroluminescence are used as the light source. Further, in each of the above-described embodiments, the case where three light sources of R, G, and B are used has been described, but in the present invention, the light sources are R, G, and B.
However, the combination is not limited to the above. For example, it is also applicable when a white light source and a monochromatic (for example, R) light source are combined. It is also applicable when using a monochromatic light source other than R, G, and B.

Although not shown, for example, GLV (Gratin
like a projection type display device using g Light Valve)
The present invention is also applicable to a display device in which a one-dimensional laser light source is modulated and the modulated light is scanned by a one-dimensional scanner to display a two-dimensional image on a screen.

[0069]

As described above, according to the first to sixth aspects.
The light source control device according to claim 1, or claim 7.
According to the light source control method described above or the projection display apparatus according to claim 8, the light output values of the plurality of light sources are detected, and the light output values of the plurality of light sources or the light output values of the plurality of light sources are detected based on the detection results. Since the light output of each of the multiple light sources is controlled so that the relative value of each light output value always approaches a constant value, the balance of the optical output from the multiple light sources is always in the desired state. Can be kept at Particularly, when the control for keeping the light output value constant is performed, not only the balance of the light output but also the light amount can be always kept constant.

Particularly, according to the light source control device of the third aspect, there is a possibility that the control means may be driven beyond the preset maximum allowable value as a result of performing the control for keeping the light output value constant. When there is a light source, the control that keeps the light output value constant is automatically switched to the control that keeps the relative value of each light output value constant, so that the light source does not exceed the maximum allowable value. While being driven, the balance of light output and the amount of light can be always kept in a desired state. After that, even if a light source that may be driven beyond the maximum allowable value is emitted, at least the balance of the light output can always be kept in a desired state.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a projection type display device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a control operation in an adjustment mode performed by the projection display apparatus according to the first embodiment of the present invention.

FIG. 3 is a flow chart showing a control operation in a use mode performed by the projection display apparatus according to the first embodiment of the present invention.

FIG. 4 is a flow chart showing a control operation in a use mode, which is performed in the projection display apparatus according to the second embodiment of the present invention.

FIG. 5 is a flowchart showing a control operation in a use mode, which is performed in the projection display apparatus according to the third embodiment of the invention.

FIG. 6 is a flowchart following FIG. 5;

FIG. 7 is a block diagram showing a configuration of a projection type display device according to a fourth embodiment of the present invention.

FIG. 8 is a front view showing the structure of a color wheel used in a projection type display device according to a fourth embodiment of the invention.

FIG. 9 is a waveform diagram for explaining various signals used in the projection type display device according to the fourth embodiment of the invention.

FIG. 10 is a flowchart for explaining the operation of the projection type display device according to the fourth embodiment of the invention.

FIG. 11 is a block diagram showing a configuration of a projection type display device according to a fifth embodiment of the present invention.

FIG. 12 is a block diagram showing a configuration example of a conventional projector.

[Explanation of symbols]

11R, 11G, 11B ... Laser light source, 12R, 12
G, 12B ... Variable power source, 14R, 14G, 14B ... Modulator, 19 ... Scanner, 21R, 21G, 21B ... Light intensity detector, 23 ... Microprocessor, 31 ... Color wheel, 32 ... Drive motor, 54 ... Projection lens.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G09G 3/20 G09G 3/20 642P 680 680C 3/36 3/36 H04N 5/74 H04N 5/74 B 9 / 31 9/31 C 17/04 17/04 C F term (reference) 5C006 AA01 AA22 AF46 AF51 AF52 AF53 AF54 AF63 AF81 AF82 BB11 BF15 BF39 EA01 EC11 FA56 5C058 EA12 EA26 EA51 5C060 GB02 HA18 HB27 HC21 JA11 5C061 BB15 CC080 EE AA10 BB05 CC03 DD04 EE30 JJ02 JJ07

Claims (8)

[Claims] 1. A light source control device for controlling a plurality of light sources that generate different colored light, comprising: detection means for detecting light output values of the plurality of light sources; and detection results of the detection means. Based on the light output value of each of the plurality of light sources or a relative value of each light output value, a control means for controlling the light output of each of the plurality of light sources so that the relative value of each light output value always approaches a constant value. A light source control device characterized by being provided. 2. The control means is configured to be manually or automatically switchable between controlling the light output value to be constant and controlling the relative value of each light output value to be constant. The light source control device according to claim 1, wherein: 3. The control means controls the light output value to be constant, and as a result, when there is a light source that may be driven beyond a preset allowable maximum value, the light output value is changed. The light source control device according to claim 2, wherein the light source control device is configured to automatically switch from the control for keeping constant to the control for keeping the relative value of each light output value constant. 4. A light separating unit that spatially separates a part of each color light emitted from the plurality of light sources, and the detecting unit includes each color spatially separated by the light separating unit. The light source control device according to claim 1, wherein the light source control device is configured to detect a light intensity of light. 5. Further, a light separation means is provided for temporally separating a part of each color light emitted from the plurality of light sources, and the detection means is provided for each color separated by the light separation means. The light source control device according to claim 1, wherein the light source control device is configured to detect a light intensity of light. 6. The light source control device according to claim 5, wherein one of the light separating means is provided on the same optical path of each color light, and has a single function of temporally separating each color light. . 7. A light source control method for controlling a plurality of light sources that generate different colored light, wherein the light output values of the plurality of light sources are detected, and the plurality of light sources are detected based on the detection result. A light source control method, wherein the light output of each of the plurality of light sources is controlled so that the light output value of each light source or the relative value of each light output value always approaches a constant value. 8. A plurality of light sources that generate different color lights, a detection unit that detects the light output value of each of the plurality of light sources, and a light source of each of the plurality of light sources based on the detection result of the detection unit. Control means for controlling the light output of each of the plurality of light sources so that the output value or the relative value of each light output value always approaches a constant value, and the plurality of light sources controlled by the control means 1. A projection type display device, comprising: a modulation unit that modulates each color light from the device and a projection unit that projects the light modulated by the modulation unit as image light.