JP2008089836A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform appropriate correction by acquiring the deterioration in image quality accompanying the deterioration in all optical components including light source devices and optical modulation devices without requiring intricate processing. <P>SOLUTION: A cover member for closing a projection section of a projection optical device 8 is provided with an optical detection element 91 which is arranged within the area of the optical image projected from the projection optical device 8 when the projection section is closed, and which detects the brightness of the optical image. A controller 10 includes a means 15 for displaying calibration images for calibration on the optical modulation devices 61R, 61G, 61B, a means 16 for judging the image quality of the optical image on the basis of the brightness information in which the calibration image is detected by the optical detection element 91, a means 17 for correcting the input image information to be input on the basis of the judgement result of the image quality, and a means 12 for controlling the drive of the optical modulation devices 61R, 61G, 61B on the basis of the corrected image information. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projector.

Conventionally, a light source device, a light modulation device that modulates a light beam emitted from the light source device according to input image information to form an optical image, and an optical image formed by the light modulation device are enlarged and projected There is known a projector including a projection optical device, and a control device that controls the light source device and the light modulation device. Such a projector is widely used for home theater use, presentation use in conferences, and the like. .
By the way, such a projector may include a light modulation device and optical parts and the like may deteriorate due to long-term use. The deterioration of the optical parts and the like leads to deterioration of the image quality of the projected image. It is visually recognized by the observer as color change and partial color unevenness.

Therefore, in a projector having an RGB three-color LED light source and a light modulation device provided for each color LED light source, a photoelectric conversion element is provided close to the outer peripheral edge of the display area of the light modulation device, and incident from the LED light source There has been proposed a technique for controlling the amount of light emitted from a light source while measuring the amount of light of a light beam with a light detection element (see, for example, Patent Document 1).
There has also been proposed a projector in which an imaging unit is provided in a projector to capture a projection image and correct color unevenness of the projection image due to deterioration with time (see, for example, Patent Document 2).

JP 2004-317800 A JP 2004-228948 A

However, in the technique described in Patent Document 1, since the light detection element must be provided outside the display area so as not to interfere with the optical image formed by the light modulation device, the luminance of light in the original display area is accurately set. There is a problem that it cannot be detected. In addition, since the light detection element is provided on the substrate of the light modulation device, there is a problem in that deterioration of the image quality of the projected image due to deterioration of the light modulation device itself or deterioration of the polarizing plate in the latter stage of the optical path cannot be detected. is there.
On the other hand, in the technology described in Patent Document 2, an imaging unit for capturing a projection image for performing calibration must be provided separately. Furthermore, when imaging by the imaging unit, pattern matching processing or the like is used. Since it is necessary to detect the projection area, there is a problem that the processing becomes complicated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a projector capable of acquiring image quality deterioration accompanying deterioration of all optical components including a light source device and a light modulation device and performing appropriate correction without requiring complicated processing. There is.

The projector according to the present invention is
A light source device, a light modulation device that modulates a light beam emitted from the light source device according to input image information to form an optical image, and a projection that magnifies and projects the optical image formed by the light modulation device A projector comprising an optical device, and a control device for controlling the light source device and the light modulation device,
A cover member for closing the projection part of the projection optical device;
The cover member is provided with a light detection element that is disposed in a region of an optical image projected from the projection optical device when the projection unit is blocked, and detects the luminance of the optical image.
The controller is
Calibration image display means for displaying a calibration image for calibration on the light modulation device;
Image quality determination means for determining the image quality of the optical image projected from the projection optical device based on the luminance information detected by the light detection element for the displayed calibration image;
Input image correction means for correcting input image information based on the image quality determination result by the image quality determination means;
And a light modulation device drive control means for driving and controlling the light modulation device based on the corrected image information corrected by the input image correction means.

Here, as the light detection element provided in the cover member, a photoelectric conversion element that converts incident light into an electrical signal can be employed. For example, a phototransistor using a photodiode, a photo IC, or a CCD A (Charge Coupled Device) imaging device, a CMOS (Complementary Metal Oxide Semiconductor) sensor, or the like can be employed.
Further, as the light modulation device, for example, a transmission type liquid crystal panel, a reflection type liquid crystal panel, a device equipped with an element using a micromirror, etc. can be adopted, and the number of light modulation devices is also a single plate type or a three plate type. Either may be sufficient.
Furthermore, as a light source device, a device using a solid light source element such as an LED (Light-Emitting Diode) or an LD (Laser Diode) in addition to a discharge arc tube such as a metal halide lamp or an ultra-high pressure mercury lamp is adopted. be able to.

According to the present invention, when the projection optical device is covered with the cover member, the luminance of the calibration image projected from the projection optical device is detected by the light detection element, and the luminance information of the detected optical image is detected by the image quality determination means. This makes it possible to determine the image quality with high accuracy while directly detecting the projection image from the projection optical device. Therefore, the image quality of the projection image accompanying the deterioration of all optical components including the light source device and the light modulation device Can be accurately grasped.
Then, based on the result of the image quality determination based on such high-precision luminance information, the input image correction unit corrects the image information, and based on the corrected image information, the light modulation device driving unit performs the correction of the light modulation device. Since drive control is performed, the projected image can be corrected appropriately.

In the above,
A plurality of the light detection elements are arranged in a region of an optical image projected from the projection optical device,
The image quality judging means is
An overall image brightness determination unit that determines the brightness of the entire projected optical image based on brightness information detected by the plurality of light detection elements;
A luminance deviation determination unit that determines a deviation in luminance of the region of the optical image according to the arrangement of each light detection element based on the respective luminance information detected by each light detection element;
The input image correcting means includes
An overall image correction unit that corrects the entire input image information based on the determination result determined by the overall luminance determination unit;
A luminance deviation correction unit that corrects a deviation in luminance between regions of the optical image in accordance with the arrangement of the light detection elements of the input image information based on the determination result determined by the luminance deviation determination unit; It is preferable.

Here, the correction by the luminance deviation correction unit, for example, when a luminance deviation occurs between adjacent areas, performs correction to darken the image information of a portion corresponding to a bright area, or conversely corresponds to a dark area Correction for brightening the image information of the portion to be performed may be performed.
According to the present invention, after the entire image brightness determination unit and the entire image correction unit perform image correction of the entire projection image, the luminance deviation determination unit and the luminance deviation correction unit detect each of the plurality of light detection elements. Therefore, it is possible to correct luminance unevenness, color unevenness, and the like between the regions to be corrected, so that more appropriate correction can be performed.

In the present invention,
The control device includes a reference luminance information storage unit that stores reference luminance information to be originally output in accordance with input image information.
The image quality determination means determines the image quality by comparing the luminance information detected by the light detection element with the reference luminance information stored in the reference luminance information storage means,
The input image correction unit corrects input image information based on a difference between luminance information detected by the light detection element and reference luminance information stored in the reference luminance information storage unit. preferable.

Here, the reference luminance information storage means can be configured by a non-volatile memory such as E2PROM provided in the control device, for example.
According to the present invention, by including the reference luminance information storage means, the image quality determination means can determine the luminance information detected by the light detection element only by referring to the stored reference luminance information, Since the input image correction means only needs to correct the image information in accordance with the difference, the processing in the control device can be simplified.

The projector according to the present invention is
A light source device, a light modulation device that modulates a light beam emitted from the light source device according to input image information to form an optical image, and a projection that magnifies and projects the optical image formed by the light modulation device A projector comprising an optical device, and a control device for controlling the light source device and the light modulation device,
A cover member for closing the projection part of the projection optical device;
The cover member is provided with a light detection element that is disposed in a region of an optical image projected from the projection optical device when the projection unit is blocked, and detects the luminance of the optical image.
The controller is
Calibration image display means for displaying a calibration image for calibration on the light modulation device;
Image quality determination means for determining the image quality of the optical image projected from the projection optical device based on the luminance information detected by the light detection element for the displayed calibration image;
Light source luminance correction means for correcting the luminance of the light beam emitted from the light source device based on the image quality determination result by the image quality determination means;
And a light source device drive control unit configured to drive and control the light source device based on the corrected luminance information corrected by the light source luminance correction unit.

According to the present invention, as described above, when the projection optical device is covered with the cover member, the luminance of the optical image projected from the projection optical device is detected by the light detection element, and the luminance information of the detected optical image is obtained. By determining by the image quality determination means, it is possible to determine the image quality with high accuracy while directly detecting light from the projection image from the projection optical device, so that all optical components including the light source device and the light modulation device are deteriorated. It is possible to grasp the accompanying deterioration in the image quality of the projected image.
Then, since the luminance of the light beam emitted from the light source device can be corrected by the light source luminance correction unit based on the result of the image quality determination, the light source device drive control unit can select an appropriate optical according to the input image information. An image can be projected.

In the above,
The light source device includes a plurality of light sources that emit different colored lights,
The light modulation device is provided in a plurality according to each light source, forms an optical image according to each color light,
It is preferable to include a color combining optical device that combines optical images corresponding to the respective color lights formed by the respective light modulation devices.
According to the present invention, since the light sources corresponding to the plurality of color lights are provided, it is possible to correct the luminance of the light beams emitted from the light sources according to the respective color lights. Thus, the image quality of the corrected image can be further improved.

In the present invention,
The control device includes a reference luminance value storage unit that stores a reference luminance value that is a luminance to be output in accordance with input image information.
The image quality determination means determines the image quality by comparing the luminance information detected by the light detection element with the reference luminance value stored in the reference luminance value storage means,
The light source luminance correction means calculates the luminance of the light beam emitted from the light source device based on the difference between the luminance information detected by the light detection element and the reference luminance value stored in the reference luminance value storage means. It is preferable to correct.
With such a configuration, the same operations and effects as described above can be enjoyed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
[1] Overall Configuration FIG. 1 shows an optical system of a projector 1 according to an embodiment of the present invention. The projector 1 modulates a light beam emitted from a light source device in accordance with image information to produce a color image (optical). Image), and this color image is enlarged and projected onto the screen Sc.
The projector 1 includes a light source device 2, a uniform illumination optical device 3, a color separation optical device 4, a relay optical device 5, an optical device 6, a color synthesis optical device 7, a projection optical device 8, and a lens cover 9. The
The light source device 2 includes a light source lamp 21 and a parabolic reflector 22 each formed of a discharge arc tube, and a radial light beam emitted from the light source lamp 21 is reflected and collimated by the parabolic reflector 22 and emitted to the uniform illumination optical device 3. Is done.

The uniform illumination optical device 3 is an optical system that divides the light beam emitted from the light source device 2 into a plurality of partial light beams and illuminates an image forming region of a liquid crystal panel, which will be described later, substantially uniformly. The first lens array 31, a second lens array 32, a polarization conversion element 33, and a superimposing lens 34.
The first lens array 31 has a configuration in which first small lenses having a substantially rectangular outline when viewed from the incident optical axis direction are arranged in a matrix in a plane substantially orthogonal to the incident optical axis. . Each first small lens splits the light beam emitted from the light source device 2 into a plurality of partial light beams.
The second lens array 32 has substantially the same configuration as the first lens array 31, and has a configuration in which the second small lenses are arranged in a matrix. The second lens array 32 has a function of forming, together with the superimposing lens 34, a light source image of each first small lens of the first lens array 31 on a liquid crystal panel described later.

The polarization conversion element 33 is disposed between the second lens array 32 and the superimposing lens 34, and converts light from the second lens array 32 into substantially one type of polarized light.
Specifically, each partial light converted into approximately one type of polarized light by the polarization conversion element 33 is finally substantially superimposed on a liquid crystal panel (to be described later) by the superimposing lens 34. In the projector 1 using a liquid crystal panel of a type that modulates polarized light, only one type of polarized light can be used, and therefore approximately half of the light from the light source device 2 that emits randomly polarized light cannot be used. For this reason, by using the polarization conversion element 33, the light emitted from the light source device 2 is converted into approximately one type of polarized light, and the use efficiency of light in a liquid crystal panel described later is enhanced.

The color separation optical device 4 includes two dichroic mirrors 41 and 42 and a reflection mirror 43, and a plurality of partial light beams emitted from the uniform illumination optical device 3 by the dichroic mirrors 41 and 42 are converted into red (R), It has a function of separating into three color lights of green (G) and blue (B).
The relay optical device 5 includes an incident side lens 51, a relay lens 53, and reflection mirrors 52 and 54, and the red light separated by the color separation optical device 4 is transferred to the red light liquid crystal panel and the liquid crystal shutter of the optical device 6. Has a guiding function.

At this time, the dichroic mirror 41 of the color separation optical device 4 reflects the blue light component of the light beam emitted from the uniform illumination optical device 3 and transmits the red light component and the green light component. The blue light reflected by the dichroic mirror 41 is reflected by the reflection mirror 43, passes through the field lens 44, and reaches a later-described liquid crystal panel for blue light of the optical device 6.
The field lens 44 converts each partial light beam emitted from the second lens array 32 into a light beam parallel to the central axis (principal light beam). The same applies to the field lens 44 provided on the light beam incident side of the other liquid crystal panel for green light and red light.

Of the red light and green light transmitted through the dichroic mirror 41, the green light is reflected by the dichroic mirror 42, passes through the field lens 44, and reaches a later-described green light liquid crystal panel of the optical device 6.
On the other hand, the red light passes through the dichroic mirror 42, passes through the relay optical device 5, passes through the field lens 44, and reaches a later-described red light liquid crystal panel of the optical device 6.
Note that the relay optical device 5 is used for red light because the optical path length of the red light is longer than the optical path lengths of the other color lights, thereby preventing a reduction in light use efficiency due to light divergence or the like. It is to do. That is, this is to transmit the partial light beam incident on the incident side lens 51 to the field lens 44 as it is.

The optical device 6 is a portion that modulates light according to each color light RGB separated by the color separation optical device 4 to form an optical image, and includes liquid crystal panels 61R, 61G, and 61B as light modulation devices. Composed.
The liquid crystal panels 61R, 61G, and 61B include an image forming area in which a plurality of pixels are arranged in a matrix, and perform gradation display according to image information input in each pixel.
Each of the liquid crystal panels 61R, 61G, and 61B includes a configuration in which liquid crystal is sealed between a pair of transparent substrates, and the liquid crystal is driven by a TFT (Thin Film Transistor) formed on one substrate. Although not shown, an incident side polarizing plate and an exit side polarizing plate are provided on the light emitting side, and the orientation of the liquid crystal is controlled by using the TFT as a switching element, and the light emitted from the emitting side polarizing plate is controlled. The gradation is displayed according to the image information by adjusting the amount.

The color synthesizing optical device 7 synthesizes each color light modulated for each color light emitted from the emission side polarizing plate of the liquid crystal panels 61R, 61G, 61B to form a color image. The color synthesizing optical device 7 has a substantially square shape in plan view in which four right-angle prisms are bonded together, and two dielectric multilayer films are formed on the interface where the right-angle prisms are bonded together. These dielectric multilayer films transmit the color light emitted from the liquid crystal panel 61G and reflect the color lights emitted from the liquid crystal panels 61R and 61B.
The projection optical device 8 is configured as a combined lens in which a plurality of lenses are housed in a cylindrical lens barrel, and a color image formed by the color synthesis optical device 7 is enlarged on the screen Sc by the projection optical device 8. Projected.

As shown in FIG. 2, the lens cover 9 as a cover member is slidably provided on the front surface portion of the exterior housing 1A of the projector 1, closes the projection portion of the projection optical device 8, and is carried around. A member that protects the projection unit of the projection optical device 8. In this embodiment, the lens cover 9 is slid electrically by operating a predetermined switch on the operation panel provided in the projector 1. 8 projections can be closed or exposed.
As shown in FIG. 3, four light detection elements 91 are provided on the surface of the lens cover 9 facing the projection unit of the projection optical device 8, that is, the inner surface. The arrangement of the four light detection elements 91 is within the projection area when the projection unit of the projection optical device 8 is closed with the lens cover 9 and a calibration image to be described later is displayed on the opposite surface of the lens cover 9, and This projection area is approximately the center of a rectangular divided area obtained by dividing the projection area into four.
The light detection element 91 is composed of a photoelectric conversion element such as a photodiode or a CMOS sensor, and outputs an electric signal as a detection value according to the amount of received light.

[2] Control Structure of Projector 1 Next, a control structure of the projector 1 having the above-described structure will be described.
FIG. 4 shows a control device 10 that controls the projector 1. The control device 10 performs predetermined image processing on the input image information VIDEO and controls the driving of the liquid crystal panels 61R, 61G, 61B to form an optical image on the liquid crystal panels 61R, 61G, 61B. Yes, image processing means 11, light modulation device drive control means 12, driver IC 13, operation signal acquisition means 14, calibration image display means 15, image quality determination means 16, input image correction means 17, reference luminance information storage means 18, and A memory 19 is provided.

The image processing means 11 includes a frame buffer for storing the input image information VIDEO in units of frames, and performs image processing for displaying an appropriate image on the display image data in units of frames stored in the frame buffer. Specifically, a monochrome expansion process, an IP conversion process, a γ correction process, a V-Tγ correction process, and the like are performed.
The light modulation device drive control means 12 is a part that generates a control signal for driving and controlling the liquid crystal panels 61R, 61G, 61B based on the image information processed by the image processing means 11, and is generated for each color light. The drive control signal is output to the driver IC 13.
The driver IC 13 is a part that drives the liquid crystal panels 61R, 61G, and 61B in units of pixels. In the present embodiment, the liquid crystal panels 61R, 61G, and 61B are set according to the RGB color lights. It is provided according to the number.

The operation signal acquisition means 14 is a part that acquires an operation signal when an observer operates the operation panel 1B provided on the exterior casing 1A of the projector 1, and according to the type of the acquired operation signal. A predetermined drive control portion in the control device 10 operates. Although not shown in FIG. 4, an operation button for executing calibration is provided on the operation panel 1 </ b> B. When this operation button is pressed, the lens cover is operated by a control command from the operation signal acquisition unit 14. 9 is electrically driven so as to cover the projection portion of the projection optical device 8.
The calibration execution command acquired by the operation signal acquisition unit 14 starts detection by the light detection element 91 and starts display of a calibration image by the calibration image display unit 15 described later.

The calibration image display unit 15 switches the input image information VIDEO when the calibration execution operation button described above is pressed, and displays a calibration image for calibration on the liquid crystal panels 61R, 61G, 61B. It is. The calibration image displayed by the calibration image display means 15 is single-color image information for each color light of RGB, and is composed of a plurality of images having different gradation values for each color light.
The image quality determination unit 16 is a part that determines the image quality of the optical image projected from the projection optical device 8 based on the luminance value of the calibration image detected by the light detection element 91. A luminance deviation determination unit 162 is provided.

The overall image luminance determination unit 161 compares the luminance value detected by the light detection element 91 with the reference luminance value stored in the reference luminance information storage unit 18, and the difference between both luminance values exceeds a predetermined threshold value. If this occurs, it is determined that luminance correction should be performed. In the present embodiment, for comparison, the average value of the luminance values detected by the four photodetecting elements 91 is used.
As shown in FIG. 5, the reference luminance information storage means 18 has information based on a graph G1 in which the gradation value of the input image information is associated with the luminance output value Y of the image to be originally displayed. Stored. Actually, the reference luminance information storage means 18 stores the luminance output value Y corresponding to the gradation value set in stages as a table, and the calibration image described above. The multi-tone calibration image stored in the display unit 15 also corresponds to the tone value stored in the reference luminance information storage unit 18.

  The luminance deviation determination unit 162 is a part that determines whether or not there is a predetermined deviation or more between the four detection values based on the detection values by the four light detection elements 91 arranged in the projection area of the calibration image. is there. The luminance deviation determination unit 162 sets a threshold value of luminance value deviation that can be visually recognized by an observer in advance, and a deviation exceeding the luminance value is detected between the luminance values detected by the light detection elements 91. If it is, it is determined that luminance unevenness has occurred in the projection area of the optical image.

The input image correction unit 17 is a part that corrects input image information VIDEO based on the determination result of the image quality determination unit 16 described above, and includes an overall image luminance correction unit 171 and a luminance deviation correction unit 172. The
The overall image brightness correction unit 171 is a part that generates a correction value for correcting the input image information VIDEO when the overall image brightness determination unit 161 determines that a difference exceeding a predetermined threshold has occurred.
Specifically, as shown in FIG. 6, when a multi-gradation calibration image is displayed and the luminance value detected by the light detection element 91 at each gradation value is acquired as in the graph G2, The image brightness correction unit 171 generates a difference from the graph G1 that gives the reference brightness information and uses it as a correction value. That is, as shown in FIG. 6, when the luminance value detected by the light detection element 91 is Y1 when the gradation value of the calibration image is k1, the reference luminance output value Y2 at the gradation value k1 is Thus, Y1-Y2 is generated as a correction value.

The luminance deviation correction unit 172 generates a luminance unevenness correction value for correcting the luminance deviation when the luminance deviation determination unit 162 determines that the luminance values detected by the four light detection elements 91 are equal to or greater than a predetermined threshold value. It is a part to do.
Specifically, as shown in FIG. 7, the luminance values in the calibration image A1 detected by the four light detection elements 91 are Y11, Y12, Y21, and Y22, and the luminance value Y21 is another luminance value. When it is determined that the values are lower than Y11, Y12, and Y22, the luminance deviation correction unit 172 performs weighting correction like the image A2 on the input image information VIDEO. That is, the luminance deviation correction unit 172 generates a correction value H21 that does not change the luminance in the lower left area of the image A2, and the correction values H11, H12 that make the luminance smaller than the correction value H21 for the other areas. H22 is generated and used as a luminance unevenness correction value.

The luminance correction value and the luminance unevenness correction value generated by the overall image luminance correction unit 171 and the luminance deviation correction unit 172 in this way are stored in the memory 19, and specifically, generated by the overall image luminance correction unit 171. A correction value corresponding to a plurality of gradation values of the calibration image and a weighting correction value of the luminance value of the area corresponding to the arrangement of the light detection elements 91 of the calibration image generated by the luminance deviation correction unit 172 are stored. Has been.
The light modulation device drive control means 12 performs weighting correction on the image information VIDEO input via the image processing means 11 based on these correction values, and then the liquid crystal panels 61R, 61G, 61B. Drive control is performed.

[3] Action and Effect of Projector 1 Next, the action of the projector 1 having the above-described structure will be described based on the flowchart shown in FIG.
The operation signal acquisition unit 14 monitors whether or not the observer has pressed the calibration execution operation button on the operation panel 1B (processing S1). When the operation signal for calibration execution is acquired, the electric mechanism of the lens cover 9 is obtained. A control signal is output to the lens cover 9 so that the lens cover 9 is closed so that the lens cover 9 covers the projection unit of the projection optical device 8 (step S2).

Next, the calibration image display means 15 receives the signal from the operation signal acquisition means 14 and starts displaying the calibration image (processing S3). The calibration image is displayed separately for the liquid crystal panels 61R, 61G, and 61B because the projector 1 is a three-plate type. That is, for example, when calibrating the liquid crystal panel 61G, only green (G) light is output as a calibration image, and the other red (R) light and blue (B) light components are shut down. In addition, the calibration image is repeatedly displayed so as to gradually change from a gradation value to a high gradation value.
When the display of the calibration image is started, the acquisition of the luminance value of the calibration image by the light detection element 91 is started, and the luminance value detected by each light detection element 91 is output to the image quality determination means 16 (processing S4). .

The overall image luminance determination unit 161 of the image quality determination unit 16 compares the acquired luminance value with the reference luminance output value stored in the reference luminance information storage unit 18 and determines whether the difference is within a predetermined threshold. It is determined whether or not (processing S5).
If it is determined that it does not fall, the overall image brightness correction unit 171 of the input image correction unit 17 takes the difference between the reference brightness output value and the detected brightness value to generate a brightness correction value (step S6). The generated brightness correction value is written in the memory 19 (process S7).
On the other hand, when it is determined that the difference between the luminance value and the reference luminance output value is within a predetermined threshold, the image quality determination unit 16 does not generate the above correction value for all the gradation values. It is determined whether or not a determination has been made (step S8).

When it is determined that the calibration image has not been determined for all the gradation values, the image quality determination means 16 causes the calibration image display means 15 to display a calibration image of the next gradation value (processing). S9), a series of steps from step S3 to step S7 are repeated.
If it is determined that the calibration image determination has been completed for all the gradation values, the image quality determination unit 16 causes the calibration image display unit 15 to display a calibration image of an intermediate gradation, and from each of the light detection elements 91. Brightness values, in this embodiment, four brightness values are acquired (step S10).

The luminance deviation determination unit 162 of the image quality determination unit 16 calculates the deviation of the luminance value detected by each light detection element 91 (processing S11), and determines whether the calculated luminance deviation is within a predetermined threshold. (Processing S12).
When it is determined that the luminance deviation is not within the predetermined threshold value, the luminance deviation correction unit 172 of the input image correction unit 17 generates a luminance unevenness correction value for correcting the luminance unevenness (processing S13), and the generated correction value is stored in the memory. 19 is written (process S14).
On the other hand, when it is determined that the luminance deviation is within the predetermined threshold, the image quality determination unit 16 determines whether the calibration for all the liquid crystal panels 61R, 61G, 61B has been completed (step S15).

If it is determined that the process has not been completed, the image quality determination unit 16 causes the calibration image display unit 15 to switch the calibration image so that the calibration image is displayed on the next liquid crystal panels 61R and 61B (processing). S16) For the switched liquid crystal panels 61R and 61B, a series of processing from processing S3 to processing S14 is repeated.
On the other hand, when it is determined that the calibration has been completed for all the liquid crystal panels 61R, 61G, 61B, the image quality determination unit 16 ends the display of the calibration image by the calibration image display unit 15 and is input as an image. The display based on the information VIDEO is restored (process S17), and the lens cover 9 is opened by the electric mechanism of the lens cover 9 (process S18).

After returning to the display of the input image, the light modulation device drive control means 12 uses the two types of correction values generated in the memory 19 in addition to the image information image-processed by the image processing means 11 to obtain image information. After performing the weighting correction, the drive control of the liquid crystal panels 61R, 61G, 61B is performed.
By performing the calibration of the liquid crystal panels 61R, 61G, and 61B as described above, the calibration is performed in a state in which the projected image is directly viewed, so that a correction value can be generated with high accuracy. By displaying an image by using it, an appropriate and high-quality image can be displayed.

Further, since the luminance value is detected after the projection optical device 8, even if various optical components disposed between the light source device 2 and the projection optical device 8 are deteriorated, the state is surely corrected. Can do.
Then, by performing calibration on each of the liquid crystal panels 61R, 61G, and 61B, it is possible to perform correction of hue and color unevenness simultaneously with luminance correction, so that the color image synthesized by the color synthesizing optical device 7 is also appropriate. Color reproducibility can be realized.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the following description, parts that are the same as those already described are given the same reference numerals and description thereof is omitted.
In the projector 1 according to the first embodiment described above, the light source lamp 21 formed of a discharge arc tube is used as the light source device 2, the light beam emitted from the light source device 2 is separated into RGB by the color separation optical device 4, and the liquid crystal panel It was comprised so that 61R, 61G, and 61B might be illuminated.
On the other hand, in the projector 70 according to the present embodiment, as shown in FIG. 9, three LED light sources 71R, 71G, and 71B that emit color lights of RGB are used as the light source device, and each is a liquid crystal panel. The difference is that 61R, 61G, and 61B are individually illuminated.

In the first embodiment, the image quality determination unit 16 performs determination based on the luminance value detected by the light detection element 91, the input image correction unit 17 generates a correction value, and the correction value is used. The projection image is optimized by performing weight correction of the input image information VIDEO.
On the other hand, in the present embodiment, the process is the same until the image quality determination unit 74 determines based on the luminance value detected by the light detection element 91, but the light source luminance correction unit 75 uses the LED light sources 71R, 71G, and 71B. The difference is that the projection image is optimized by controlling the output.

That is, as shown in FIG. 9, the projector 70 includes LED light sources 71R, 71G, and 71B arranged on the light incident side of the liquid crystal panels 61R, 61G, and 61B.
These LED light sources 71R, 71G, 71B are planar light emitters composed of light emitting diodes as solid light source elements. When a voltage is applied, light is emitted in a planar shape, and the liquid crystal panels 61R, 61G, 61B. The image forming area is uniformly illuminated.
The light source driving circuit 72 is a part that applies a voltage to the LED light sources 71R, 71G, and 71B, and is configured to be able to apply a voltage independently to each of the LED light sources 71R, 71G, and 71B.

The light source device drive control means 73 is a part that controls the voltage applied from the light source drive circuit 72 to each of the LED light sources 71R, 71G, 71B.
Similar to the first embodiment, the image quality determination unit 74 is a part that determines the image quality of the optical image projected from the projection optical device based on the luminance value of the calibration image detected by the light detection element. However, in the present embodiment, only the brightness adjustment of the entire image is performed, and the function of correcting the deviation between the brightness values detected by the four light detection elements 91 is not provided.
The light source luminance correction means 75 is a part that corrects the luminance of the light source output from each LED light source 71R, 71G, 71B based on the determination result of the image quality determination means 74, and is the same as in the case of the first embodiment. Comparing the reference luminance output value stored in the luminance information storage means 18 with the luminance value detected by the light detection element 91 to generate a correction value for returning the detected luminance value to the reference luminance output value; Store in the memory 19.

The projector 70 according to the second embodiment operates as follows.
First, as in the case of the first embodiment, after starting calibration by the processing S1 and the processing S2, the light source device drive control means 73 turns on one of the LED light sources 71R, 71G, 71B, and turns off the others. Then, the light source drive circuit 72 is driven and controlled (step S21).
Subsequently, the calibration image display means 15 displays a calibration image (process S22), and the image quality determination means 74 acquires the luminance value detected by the light detection element 91 (process S23).
The image quality determination unit 74 compares the acquired luminance value with the reference luminance output value in the reference luminance information storage unit 18 and determines whether or not the deviation is within a predetermined threshold (process S24). If it is determined that the value is within the predetermined threshold, the process proceeds to the next process without generating a correction value.
When it is determined that the deviation is equal to or greater than the predetermined threshold, the light source luminance correction unit 75 determines whether or not the acquired luminance value is greater than the reference luminance output value (processing S25).

When it is determined that the acquired luminance value is larger than the reference luminance output value, the light source luminance correcting unit 75 generates a correction value for reducing the output of the light source (processing S26), and writes the correction value in the memory 19 (processing). S27).
On the other hand, when it is determined that the acquired luminance value is smaller than the reference luminance output value, the light source luminance correcting unit 75 generates a correction value for reducing the output of the light source (processing S28), and writes the correction value in the memory 19. (Processing S27).
The image quality determination means 74 determines whether the calibration of all the LED light sources 71R, 71G, 71B has been completed (process S29). If not completed, the LED light sources 71R, 71G, 71B are switched (process S30). ), Step S21 to Step S28 are repeated.

On the other hand, if it is determined that the calibration for all the LED light sources 71R, 71G, 71B has been completed, the calibration is terminated, the process returns to the input image (processing S31), and the electric mechanism performs the lens cover opening operation. (Process S32).
When displaying an image based on the input image information VIDEO after the calibration is completed, the light source device drive control means 73 uses the LED light source 71R based on the correction values of the LED light sources 71R, 71G, 71B stored in the memory 19. , 71G, 71B.
As a result, an appropriate projection image can be displayed only by performing output control of the LED light sources 71R, 71G, and 71B completely different from the image quality adjustment of the input image information VIDEO.

[Modification of Embodiment]
In addition, this invention is not limited to each embodiment mentioned above, The deformation | transformation as shown below is also included.
In each of the above-described embodiments, the transmissive liquid crystal panels 61R, 61G, and 61B are used as the light modulation device, but the present invention is not limited to this. That is, the present invention may be applied to a projector including a reflective liquid crystal panel as a light modulation device, and further to a projector including a device using a micromirror.
In the second embodiment, the present invention is applied to the three-plate projectors 1 and 70. However, the present invention is not limited to this, and the present invention is also applied to a single-panel projector that displays RGB in a time division manner. May be.

In the above embodiment, the lens cover 9 is configured to automatically cover the projection unit of the projection optical device 8 by the electric mechanism when the calibration execution button is operated. The present invention may be applied to a projector that opens and closes.
In the above-described embodiment, the four light detection elements 91 are provided on the lens cover 9. However, the present invention is not limited to this, and the number of the light detection elements 91 may be one or four or more. It should be noted that at least two or more are required when correcting luminance unevenness and color unevenness of a projected image.
In addition, the specific structure, shape, and the like in the implementation of the present invention may be other structures as long as the object of the present invention can be achieved.

1 is a schematic diagram showing the structure of an optical system of a projector according to a first embodiment of the invention. The front view of the projector in the said embodiment. FIG. 3 is a schematic diagram illustrating a light detection element arrangement provided on a lens cover in the embodiment. The block diagram showing the structure of the control apparatus of the projector in the said embodiment. The graph for demonstrating the luminance information stored in the reference | standard luminance information storage means in the said embodiment. The graph for demonstrating the correction | amendment procedure by the input image correction | amendment means in the said embodiment. The schematic diagram for demonstrating the method of brightness nonuniformity correction in the said embodiment. The flowchart for demonstrating the effect | action in the said embodiment. The block diagram showing the structure of the optical system of the projector and control apparatus which concern on 2nd Embodiment of this invention. The flowchart for demonstrating the effect | action in the said embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Projector, 8 ... Projection optical apparatus, 9 ... Lens cover, 10 ... Control apparatus, 12 ... Light modulation apparatus drive control means, 15 ... Calibration image display means, 16 ... Image quality determination means, 17 ... Input image correction means, 18. Reference brightness information storage means, 61R, 61G, 61B ... Liquid crystal panel, 70 ... Projector, 71R, 71G, 71B ... LED light source, 73 ... Light source device drive control means, 74 ... Image quality determination means, 75 ... Light source brightness correction means , 91... Photodetection element, 161... Whole image brightness determination unit, 162... Brightness deviation judgment unit, 171... Whole image brightness correction unit, 172.

Claims (6)

A light source device, a light modulation device that modulates a light beam emitted from the light source device according to input image information to form an optical image, and a projection that magnifies and projects the optical image formed by the light modulation device A projector comprising an optical device, and a control device for controlling the light source device and the light modulation device,
A cover member for closing the projection part of the projection optical device;
The cover member is provided with a light detection element that is disposed in a region of an optical image projected from the projection optical device when the projection unit is blocked, and detects the luminance of the optical image.
The controller is
Calibration image display means for displaying a calibration image for calibration on the light modulation device;
Image quality determination means for determining the image quality of the optical image projected from the projection optical device based on the luminance information detected by the light detection element for the displayed calibration image;
Input image correction means for correcting input image information based on the image quality determination result by the image quality determination means;
A projector comprising: a light modulation device drive control unit configured to drive and control the light modulation device based on the corrected image information corrected by the input image correction unit. The projector according to claim 1, wherein
A plurality of the light detection elements are arranged in a region of an optical image projected from the projection optical device,
The image quality judging means is
An overall image brightness determination unit that determines the brightness of the entire projected optical image based on brightness information detected by the plurality of light detection elements;
A luminance deviation determination unit that determines a deviation in luminance of the region of the optical image according to the arrangement of each light detection element based on the respective luminance information detected by each light detection element;
The input image correcting means includes
An overall image brightness correction unit that corrects the entire input image information based on the determination result determined by the overall brightness determination unit;
A luminance deviation correction unit that corrects a deviation in luminance between regions of the optical image in accordance with the arrangement of the light detection elements of the input image information based on the determination result determined by the luminance deviation determination unit; A projector characterized by having In the projector according to claim 1 or 2,
The control device includes a reference luminance information storage unit that stores reference luminance information to be originally output in accordance with input image information.
The image quality determination means determines the image quality by comparing the luminance information detected by the light detection element with the reference luminance information stored in the reference luminance information storage means,
The input image correction unit corrects input image information based on a difference between luminance information detected by the light detection element and reference luminance information stored in the reference luminance information storage unit. Characteristic projector. A light source device, a light modulation device that modulates a light beam emitted from the light source device according to input image information to form an optical image, and a projection that magnifies and projects the optical image formed by the light modulation device A projector comprising an optical device, and a control device for controlling the light source device and the light modulation device,
A cover member for closing the projection part of the projection optical device;
The cover member is provided with a light detection element that is disposed in a region of an optical image projected from the projection optical device when the projection unit is blocked, and detects the luminance of the optical image.
The controller is
Calibration image display means for displaying a calibration image for calibration on the light modulation device;
Image quality determination means for determining the image quality of the optical image projected from the projection optical device based on the luminance information detected by the light detection element for the displayed calibration image;
Light source luminance correction means for correcting the luminance of the light beam emitted from the light source device based on the image quality determination result by the image quality determination means;
A projector comprising: a light source device drive control unit that drives and controls the light source device based on the corrected luminance information corrected by the light source luminance correction unit. The projector according to claim 4, wherein
The light source device includes a plurality of light sources that emit different colored lights,
The light modulation device is provided in a plurality according to each light source, forms an optical image according to each color light,
A projector comprising a color synthesizing optical device for synthesizing an optical image corresponding to each color light formed by each light modulation device. In the projector according to claim 4 or 5,
The control device includes a reference luminance value storage unit that stores a reference luminance value that is a luminance to be output in accordance with input image information.
The image quality determination means determines the image quality by comparing the luminance information detected by the light detection element with the reference luminance value stored in the reference luminance value storage means,
The light source luminance correction means calculates the luminance of the light beam emitted from the light source device based on the difference between the luminance information detected by the light detection element and the reference luminance value stored in the reference luminance value storage means. A projector characterized by correcting.

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