JP6821914B2 - Projector and projector control method - Google Patents

Description

The present invention relates to a projector and a method for controlling the projector.

Conventionally, the projector is equipped with a function of correcting the image quality of the projected image projected by the projector on the projection target (see, for example, Patent Documents 1 and 2).
The image processing system of Patent Document 1 corrects image distortion and color unevenness based on the image pickup information of the image pickup means. The image display device of Patent Document 2 adjusts the amount of light of the light source according to the light intensity of the light source detected by the light sensor.

Japanese Unexamined Patent Publication No. 2005-124133 JP-A-2015-129683

By the way, when performing image quality correction of a projected image using an image captured by an imaging means, the accuracy for image quality correction is high in an environment where indoor illumination light or sunlight locally hits the projection target. It may not be possible to obtain good correction information.
Further, in the case of correction using an optical sensor, the optical sensor is arranged in the middle of a light guide path that guides the light emitted from the light source. Therefore, it is not possible to detect the influence on the light guide path ahead of the light detected by the optical sensor. For example, some projection lenses that project image light have functions such as lens shift, but when the lens position is changed and the image projection conditions are changed, the brightness of the image light changes. There is.
Therefore, there has been a demand for a technique for optimally correcting the image quality of a projected image regardless of the environment and the projection conditions for projecting the image.
The present invention has been made in view of the above circumstances, and an object of the present invention is to optimally correct the image quality of a projected image regardless of the projection conditions and the environment.

In order to achieve the above object, the projector of the present invention has a light source, a projection unit that projects an image by modulating the light emitted by the light source, and a light source drive unit that drives the light source according to set drive conditions. A detection unit that detects the amount of light emitted from the light source, a projection image detection unit that detects the brightness of the projection image projected by the projection unit, and a light source control unit that sets the drive conditions of the light source drive unit. The light source control unit sets the drive condition so that the light amount of the light source becomes a preset target value based on the light amount detected by the detection unit, and the projection Based on the detection result of the brightness of the projected image detected by the image detection unit, the update process for updating the drive condition set in the drive condition setting process is executed.
According to the present invention, the driving conditions are set so that the light amount of the light source becomes a preset target value based on the light amount detected by the detection unit, and the detection result of the brightness of the projected image detected by the projection image detection unit. Based on, the drive condition set in the drive condition setting process is updated. Therefore, the image quality of the projected image can be optimally corrected regardless of the environment and projection conditions.

Further, in the present invention, in the projector, the light source control unit sets the drive information for driving the light source as a drive condition to control the light source drive unit, and the detection unit detects the light source in the drive condition setting process. The driving information is updated so that the light amount of the light source becomes a preset target value based on the light amount obtained, and the driving condition is set based on the updated driving information.
According to the present invention, drive conditions are set using drive information for driving a light source. Therefore, the light source driving unit can control the light source according to the set driving conditions as it is.

Further, the present invention is characterized in that, in the projector, the light source control unit updates the drive conditions based on the amount of light detected by the detection unit and the drive information in the update process.
According to the present invention, the driving conditions can be updated to the optimum conditions based on the amount of light detected by the detection unit and the driving information.

Further, the present invention is characterized in that, in the projector, the projected image detection unit includes an imaging unit that captures a projected image projected by the projection unit and outputs an captured image.
According to the present invention, the brightness of the projected image can be detected from the captured image obtained by capturing the projected image.

Further, the present invention is characterized in that, in the projector, the light source control unit executes the update process based on the captured image captured by the image pickup unit when the brightness adjustment image is projected by the projection unit. And.
According to the present invention, the brightness of the projected image can be detected based on the captured image obtained by capturing the projected brightness adjusting image, and the driving conditions can be updated based on the detected brightness.

Further, in the present invention, in the projector, the light source control unit obtains correction information for correcting the drive condition set in the drive condition setting process in the update process, and updates the drive condition using the obtained correction information. It is characterized by doing.
According to the present invention, the driving conditions can be updated using the correction information.

Further, according to the present invention, in the projector, the light source control unit executes the drive condition setting process at a preset cycle, and executes the update process when the execution of the update process is instructed. It is a feature.
According to the present invention, the drive condition setting process can be executed at a preset cycle, and the update process can be executed when the execution is instructed.

Further, according to the present invention, in the projector, the light source control unit executes the drive condition setting process in a preset first cycle, executes the update process in the second cycle, and executes the update process. The period is set to a period shorter than the second period.
According to the present invention, the drive condition setting process can be executed in a shorter cycle than the update process.

Further, the control method of the projector of the present invention includes a projection unit that has a light source and projects an image by modulating the light emitted by the light source, and a light source drive unit that drives the light source according to set drive conditions. A control method for a projector including a detection unit that detects the amount of light emitted from the light source and a projection image detection unit that detects the brightness of the projection image projected by the projection unit. A drive condition setting step for setting the drive conditions of the light source drive unit so that the light amount of the light source becomes a preset target value based on the light amount, and detection of the brightness of the projected image detected by the projected image detection unit. Based on the result, it is characterized by having an update step for updating the drive condition set in the drive condition setting step.
According to the present invention, the driving conditions are set so that the light amount of the light source becomes a preset target value based on the light amount detected by the detection unit, and based on the detection result of the brightness of the projected image detected by the projection unit. , The drive condition set in the drive condition setting process is updated. Therefore, the image quality of the projected image can be optimally corrected regardless of the environment and projection conditions.

A block diagram showing the configuration of a projector. The figure which shows the operation outline of the light source control part. The figure which shows the drive current-light quantity characteristic table. The figure which shows the duty ratio-light quantity characteristic table. A flowchart showing a light source calibration process. A flowchart showing a light source adjustment process. System configuration diagram of the image projection system. The figure which shows the operation outline of the light source control part. A flowchart showing constant light intensity control.

[First Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of the projector 100.
The projector 100 is a device that is connected to an external image supply device 200 such as a personal computer or various video players, and projects an image based on an image signal supplied from the image supply device 200 onto a projection target.
As the image supply device 200, a video playback device, a DVD (Digital Versatile Disk) playback device, a TV tuner device, a CATV (Cable television) set-top box, a video output device such as a video game device, a personal computer, or the like can be used. it can.
Further, the projection target may be an object that is not uniformly flat, such as a building or an object, or may have a flat projection surface such as a screen SC or a wall surface of a building. FIG. 1 shows a flat screen SC as a projection target.

The projector 100 includes an image input interface unit (hereinafter, abbreviated as an image input I / F unit) 151.
The image input I / F unit 151 includes a connector for connecting a cable and an interface circuit (both are not shown), and inputs an image signal supplied from an image supply device 200 connected via the cable. The image input I / F unit 151 converts the input image signal into image data and outputs it to the image processing unit 153.
The interface included in the image input I / F unit 151 may be, for example, an interface for data communication such as Ethernet (registered trademark), IEEE1394, or USB. Further, the interface of the image input I / F unit 151 may be an interface for image data such as MHL (registered trademark), HDMI (registered trademark), and DisplayPort.
Further, the image input I / F unit 151 may be configured to include a VGA terminal into which an analog video signal is input and a DVI (Digital Visual Interface) terminal in which digital video data is input as a connector. Further, the image input I / F unit 151 is provided with an A / D conversion circuit, and when an analog video signal is input via the VGA terminal, the analog video signal is converted into image data by the A / D conversion circuit to obtain an image. Output to the processing unit 153.

The projector 100 includes a display unit 110 that forms an optical image and projects the image on the screen SC. The display unit 110 includes a light source unit 111, a color separation unit 112, an optical modulation device 113, and a projection optical system 114. The display unit 110 corresponds to the "projection unit" of the present invention. Further, the light source unit 111 corresponds to the "light source" of the present invention.

The light source unit 111 includes a solid light source. As the solid-state light source, a light source using a light emitting element such as an LED (Light Emitting Diode) or a semiconductor laser element can be used. As the semiconductor laser element, one composed of a single semiconductor laser element or one including a plurality of semiconductor laser elements arranged in a planar manner can be used. The light source unit 111 of the present embodiment includes a semiconductor laser element as a solid-state light source, and emits high-power blue light. Further, the light source unit 111 includes a phosphor wheel (not shown) having a phosphor, and converts blue light emitted from a solid light source into yellow light (fluorescence) including red light and green light by the phosphor wheel. Output to the color separator 112. Further, blue light transmitted through the phosphor wheel is output to the color separation unit 112.
Further, the light source unit 111 may be configured to include three solid light sources corresponding to each of the red, green, and blue colors. Hereinafter, the solid-state light source included in the light source unit 111 is simply referred to as a light source.
Further, the light source unit 111 may be configured to include an optical scanning element for scanning the light emitted from the light source and a lens group for enhancing the optical characteristics of the emitted light.

The light source unit 111 is driven by the light source drive unit 121. The light source driving unit 121 is connected to the internal bus 180.
The light source drive unit 121 controls the drive current for driving the light source unit 111 and the drive signal output to the light source unit 111 according to the control of the control unit 170, and the amount of light output by the light source of the light source unit 111 (hereinafter referred to as output light amount). ) Is controlled.

Information for designating the duty ratio of the PWM (pulse width modulation) signal is input to the PWM signal generation unit 122 from the control unit 170 described later. The PWM signal generation unit 122 generates a PWM signal having a duty ratio specified by the information input from the control unit 170, and outputs the PWM signal to the light source driving unit 121.

The color separation unit 112 includes a mirror and a lens, and the light emitted by the light source of the light source unit 111 is red light (hereinafter, also referred to as R light), green light (hereinafter, also referred to as G light), and blue light (hereinafter, B). It is separated into three colors of light (also called light) and guided to the light modulator 113.

The optical modulation device 113 includes a liquid crystal panel 115. The liquid crystal panel 115 includes, for example, three liquid crystal panels 115 corresponding to the three primary colors of R, G, and B. The colored lights of R, G, and B separated by the color separating unit 112 are incident on the liquid crystal panel 115 of the corresponding color, respectively. The liquid crystal panel 115 is a transmissive liquid crystal panel, and modulates the transmitted light to generate image light. The image light transmitted through each liquid crystal panel 115 and modulated is synthesized by a cross dichroic prism (not shown) and emitted to the projection optical system 114.

An optical modulation device driving unit 123 is connected to the optical modulation device 113. The optical modulator drive unit 123 is connected to the internal bus 180.
The optical modulation device driving unit 123 generates an image signal for each of the colors R, G, and B based on the display image signal (described later) input from the image processing unit 153. The optical modulation device driving unit 123 drives the liquid crystal panel 115 of the corresponding color of the optical modulation device 113 based on the generated image signals of R, G, and B, and draws the image light on the liquid crystal panel 115 of each color.

The projection optical system 114 includes a lens group that projects image light modulated by the optical modulation device 113 onto the screen SC to form an image on the screen SC. Further, the projection optical system 114 may include a zoom mechanism for enlarging / reducing the projected image of the screen SC and adjusting the focus, and a focus adjusting mechanism for adjusting the focus.

The projector 100 includes an optical sensor 117. The optical sensor 117 corresponds to the "detector" of the present invention.
For example, the optical sensor 117 detects the R light separated by the color separation unit 112, and outputs a sensor value (detection value) indicating the amount of the detected R light to the control unit 170. In the present embodiment, the light sensor 117 is provided with a sensor for detecting the amount of R light, but a sensor for detecting the amount of G light or B light may be provided, and any two colored lights (for example, R) may be provided. A sensor for detecting the amount of light (light and B light) may be provided for each.
The light sensor 117 is configured to detect the amount of R light because the R light is the color light that most reflects the brightness of the light source among the color lights input to the color separation unit 112.
Further, the amount of light emitted from the light source unit 111 and the fluorescent light generated by converting the B light by the phosphor wheel are in a proportional relationship. Therefore, if the output light amount of R light is measured using the light sensor 117, the light amount of B light and G light is also a value proportional to the sensor value of the light sensor 117.
As the optical sensor 117, various sensors such as a photodiode, an illuminance sensor, and color sensors of R, G, and B colors can be used.

The projector 100 includes an operation panel 141 and an input processing unit 143. The input processing unit 143 is connected to the internal bus 180.
The operation panel 141, which functions as a user interface, displays various operation keys and a display screen composed of a liquid crystal panel. When the operation keys displayed on the operation panel 141 are operated, the input processing unit 143 outputs the data corresponding to the operated keys to the control unit 170. Further, the input processing unit 143 causes the operation panel 141 to display various screens under the control of the control unit 170.
Further, a touch sensor for detecting contact with the operation panel 141 is superimposed and integrally formed on the operation panel 141. The input processing unit 143 detects the position of the operation panel 141 touched by the user's finger or the like as an input position, and outputs data corresponding to the detected input position to the control unit 170.

Further, the projector 100 includes a remote controller light receiving unit 142 that receives an infrared signal transmitted from the remote controller 5 used by the user. The remote control light receiving unit 142 is connected to the input processing unit 143.
The remote control light receiving unit 142 receives an infrared signal transmitted from the remote control 5. The input processing unit 143 decodes the infrared signal received by the remote control light receiving unit 142, generates data indicating the operation content of the remote controller 5, and outputs the data to the control unit 170.

The projector 100 includes a wireless communication unit 145. The wireless communication unit 145 is connected to the internal bus 180. The wireless communication unit 145 includes an antenna (not shown), an RF (Radio Frequency) circuit, and the like, and executes wireless communication with an external device under the control of the control unit 170. The wireless communication method of the wireless communication unit 145 is, for example, a short-range wireless communication method such as wireless LAN (Local Area Network), Bluetooh (registered trademark), UWB (Ultra Wide Band), infrared communication, or wireless using a mobile phone line. A communication method can be adopted.

The projector 100 includes an imaging unit 147. The imaging unit 147 corresponds to the "projected image detection unit" of the present invention.
The image pickup unit 147 includes a camera having an image pickup optical system, an image pickup element, an interface circuit, and the like, and under the control of the control unit 170, images the projection direction of the projection optical system 114 and generates captured image data. The imaging range of the imaging unit 147, that is, the angle of view is a range including the screen SC and its peripheral portion. The imaging unit 147 outputs the generated captured image data to the control unit 170.

The projector 100 includes an image processing system. The image processing system is mainly composed of a control unit 170 that controls the entire projector 100, and also includes an image processing unit 153, a frame memory 155, and a storage unit 160. The control unit 170, the image processing unit 153, and the storage unit 160 are connected to the internal bus 180.

The image processing unit 153 expands the image data input from the image input I / F unit 151 into the frame memory 155 under the control of the control unit 170, and executes image processing on the expanded image data. The image processing executed by the image processing unit 153 includes, for example, resolution conversion (scaling) processing, frame rate conversion processing, shape correction processing, zoom processing, color tone correction processing, brightness correction processing, and the like. Of course, it is also possible to execute a plurality of these processes in combination.

The resolution conversion process is a process in which the image processing unit 153 converts the resolution of the image data according to the resolution specified by the control unit 170, for example, the display resolution of the liquid crystal panel of the optical modulation device 113.
The frame rate conversion process is a process in which the image processing unit 153 converts the frame rate of the image data into a frame rate designated by the control unit 170.
The shape correction process is a process in which the image processing unit 153 converts the image data according to the correction parameters input from the control unit 170 to correct the shape of the image projected on the screen SC.
The zoom process is a process in which the image processing unit 153 enlarges / reduces the image when the zoom is instructed by the operation of the remote controller 5 or the operation panel 141.
The color tone correction process is a process of converting the color tone of the image data, and the image processing unit 153 changes the data of each pixel included in the image data according to the color tone designated by the control unit 170. In this process, the projector 100 can realize a color tone suitable for watching a movie, a color tone suitable for when the screen SC is installed in a bright environment, a color tone suitable for projecting on a non-white screen SC such as a blackboard, and the like. .. In addition to the color tone correction processing, contrast adjustment and the like may be performed.
The brightness correction process is a process in which the image processing unit 153 corrects the brightness of the image data. By the brightness correction process, the brightness of the image data is corrected to the brightness corresponding to the light emitting state of the light source unit 111, the brightness of the environment in which the projector 100 is installed, and the like.
The content and parameters of the above processing executed by the image processing unit 153, and the start and end timings of the processing are controlled by the control unit 170.
The image processing unit 153 reads the processed image data from the frame memory 155 and outputs it as a display image signal to the optical modulation device driving unit 123.

The storage unit 160 is composed of a non-volatile memory such as a flash memory and an EEPROM. The storage unit 160 non-volatilely stores the data processed by the control unit 170 and the control program executed by the control unit 170. Further, the storage unit 160 stores the set values of various processes executed by the image processing unit 153, the table referred to by the control unit 170, and the sensor values measured by the optical sensor 117.

The control unit 170 includes hardware such as a CPU, ROM, and RAM (all not shown). The ROM is a non-volatile storage device such as a flash ROM, and stores a control program and data. The RAM constitutes the work area of the CPU. The CPU expands the control program read from the ROM or the storage unit 160 into the RAM, executes the expanded control program, and controls each unit of the projector 100.

Further, the control unit 170 includes a projection control unit 171, an image pickup control unit 172, and a light source control unit 173 as functional blocks. These functional blocks are realized by the CPU executing a control program stored in the ROM or the storage unit 160. The image pickup control unit 172 corresponds to the "projected image detection unit" of the present invention.

The projection control unit 171 adjusts the display mode of the image on the display unit 110, and executes the projection of the image on the screen SC.
Specifically, the projection control unit 171 controls the image processing unit 153 to perform image processing on the image data input from the image input I / F unit 151. At this time, the projection control unit 171 may read the parameters required for processing by the image processing unit 153 from the storage unit 160 and output them to the image processing unit 153.

The image pickup control unit 172 causes the image pickup unit 147 to perform image pickup, and acquires the image pickup image data generated by the image pickup unit 147. The image pickup control unit 172 outputs the acquired captured image data to the light source control unit.

FIG. 2 is a diagram showing an outline of operation of the light source control unit 173.
The light source control unit 173 executes the light source calibration process and the light source adjustment process.
The light source calibration process is a process corresponding to the “drive condition setting process and drive condition setting step” of the present invention. The light source control unit 173 starts the light source calibration process with the cumulative lighting time of the light source and the operating time after starting the projector 100 satisfying a predetermined condition as a trigger. This predetermined condition can be changed depending on the type of the light source, the warm-up condition required for executing the light source calibration process, and the like. In the present embodiment, when the cumulative lighting time of the light source elapses for a predetermined time (for example, 100 hours), the light source calibration process is executed in the end sequence of turning off the power of the projector 100. Further, the user can operate the operation panel 141 and the remote controller 5 to execute the light source calibration process. The end sequence is a series of operations executed to turn off the power of the projector 100 when an operation for instructing the power to be turned off is performed, and may include a plurality of processes.
The light source control unit 173 sets the drive conditions so that the light amount of the light source becomes a preset target value based on the light amount detected by the light sensor 117 in the light source calibration process. The drive condition is information used by the light source drive unit 121 to drive the light source unit 111 (hereinafter referred to as drive information). For example, the current value of the drive current for driving the light source unit 111 or the drive to be output to the light source unit 111. The duty ratio of the signal (PWM signal) is included.

The light source calibration process will be specifically described.
In the light source calibration process, the light source unit 111 is driven, the output light amount of the light source is measured by the optical sensor 117, and the sensor value of the light sensor 117 and the value of the drive current used to drive the light source or the duty of the PWM signal are used. It is a process to specify the relationship between. The light source control unit 173 generates a drive current-light amount characteristic table based on the relationship between the output light amount of the specified light source and the drive current. FIG. 3 shows an example of the drive current-light intensity characteristic table. Further, the light source control unit 173 generates a duty ratio-light quantity characteristic table based on the relationship between the output light quantity of the specified light source and the duty ratio of the PWM signal. FIG. 4 shows an example of the duty ratio-light intensity characteristic table.
When the output light amount of the light source changes due to deterioration over time or the usage environment, the relationship between the output light amount of the light source and the drive current of the light source or the output light amount of the light source and the duty ratio of the PWM signal is deviated. Therefore, the light source calibration process is executed to accurately identify the relationship between the duty ratio of the drive current or the PWM signal and the output light amount of the light source so that a desired output light amount can be obtained.

The output light amount of the light source is changed by controlling the duty ratio of the drive current or the PWM signal. Here, the reason why the output light amount of the light source is controlled based on the current value of the drive current and the duty ratio of the PWM signal will be described.
The light source controls the output light amount by changing the duty ratio of the PWM signal below the predetermined light amount (Lsm shown in FIGS. 3 and 4), and changes the drive current at the light amount above the light amount Lsm. , The amount of output light is controlled. When the amount of light is Lsm or less, the amount of output light of the light source can be controlled with higher accuracy by controlling by the duty ratio of the PWM signal than by controlling by the drive current. Therefore, when the amount of light is Lsm or less, the amount of output light of the light source is controlled by the duty ratio of the PWM signal.

The amount of light shown in the drive current-light amount characteristic table of FIG. 3 is indicated by the amount of light [%] relative to the amount of light Lmax at the current Imax set as the maximum current in the usable range in the drive constant current driveable range. The current Ism is a current value set as a lower limit current capable of emitting light even if the emission threshold current of the laser diode changes with time or in a usage environment. Further, it is more preferable that the drive current is within the range of 35% to 65% of the current Imax set as the maximum current in the use range in the current driveable range. In this way, when a laser diode is used as a solid-state light source, it is possible to maintain a wide dimming range until the end of the life of the laser diode.

In the drive current-light intensity characteristic table shown in FIG. 3, in the region where the light intensity is Lsm or more, the drive current increases as the light intensity increases, and in the region where the light intensity is lower than the light intensity Lsm, the same current value (regardless of the light intensity) ( The current is Ism). According to this drive current-light quantity characteristic table, in the region of the light quantity of the light quantity Lsm or more, for example, the drive current Ia that changes according to the change of the light quantity can be derived as the drive current corresponding to the light quantity La. Further, in a region where the light amount is lower than the light amount Lsm, the same current as the current Ism corresponding to the light amount Lsm can be derived.

In the duty ratio-light intensity characteristic table shown in FIG. 4, the light source can be driven by the drive current according to the drive current-light intensity characteristic table in the region of the light intensity Lsm or more, so that the duty of the PWM signal is 100%.
On the other hand, in the region where the light intensity is lower than the light intensity Lsm, the duty of the PWM signal changes from 0 to 100% according to the change from the light intensity 0% to Lsm [%]. According to this duty ratio-light intensity characteristic table, in the region of the light intensity Lsm or more, the same duty as the duty Dsm (100%) corresponding to the light intensity Lsm can be derived regardless of the magnitude of the light intensity. Further, in a region where the amount of light is lower than the amount of light Lsm, for example, the duty Db can be derived as the duty corresponding to the brightness Lb.

The light source control unit 173 executes the light source calibration process to acquire information for specifying the relationship between the drive current and the output light amount of the light source, and the relationship between the duty ratio of the PWM signal and the output light amount of the light source. Further, the light source control unit 173 uses the information acquired by the light source calibration process before starting the projection of the image data supplied from the image supply device 200 onto the screen SC, and uses the drive current-light quantity characteristic table and the duty. Generate a ratio-light intensity characteristic table.

Further, the light source adjustment process is a process corresponding to the "update process and update step" of the present invention. In the light source adjustment process, the light source control unit 173 updates the drive conditions set in the light source calibration process based on the detection result of the brightness of the captured image data generated by the image pickup unit 147.
The projection lens included in the projection optical system 114 has functions such as lens shift. When the lens position is changed by the lens shift, the projection conditions of the image are changed, and the brightness of the image light may change. Further, even if the same amount of light is projected onto the screen SC, the amount of reflected light may differ depending on the screen SC. By performing the light source adjustment process, the brightness of the projected image can be optimized according to the viewing environment of the user even if such projection conditions are changed.

The light source control unit 173 starts the light source adjustment process when the operation panel 141 or the remote controller 5 is operated and the start is instructed.
Further, the light source adjustment process may be executed at a preset cycle. The light source control unit 173 executes the light source calibration process in the first preset cycle, and executes the light source adjustment process in the second cycle. The first cycle may be set to a shorter cycle than the second cycle. The brightness of the projected image can be optimized by performing the light source adjustment process in a state where the relationship between the output light amount of the light source and the driving power is updated.

In the light source adjustment process, the light source control unit 173 causes the projection control unit 171 to project the brightness adjustment image onto the screen SC. The brightness adjustment image is an image prepared for adjusting the brightness of the light source, and is, for example, a white image. By projecting the brightness adjustment image onto the display unit 110, the light transmittance of the liquid crystal panel of the light modulation device 113 becomes 100%. When the brightness adjustment image is projected onto the screen SC, the light source control unit 173 controls the image pickup control unit 172 to generate captured image data obtained by capturing the brightness adjustment image.
The light source control unit 173 calculates the luminance information from the captured image data, and obtains the correction information for correcting the driving conditions so that the calculated luminance information becomes the target value of the preset luminance.
For example, the light source control unit 173 compares the brightness calculated from the captured image data when the light source unit 111 is turned on with an output light amount of 100% with the target value of the brightness when the output light amount is 100%. Find the correction information that corrects the driving conditions. The light source control unit 173 calculates the difference between the brightness calculated from the captured image data and the target value of the brightness when the output light amount is 100%, and calculates the brightness setting information based on the calculated difference in brightness.

Further, the light source control unit 173 may calculate the brightness setting information for each display mode included in the projector 100. The display mode is a mode for adjusting the image quality of the displayed image according to the type of the image, the viewing environment, and the like. The display mode includes, for example, a mode such as "dynamic" suitable for viewing in a bright environment where emphasis is placed on gradation expression in dark areas, and "living room" suitable for viewing in dim light. The light source control unit 173 lights the light source unit 111 with an output light amount preset for each display mode, and projects a brightness adjustment image onto the screen SC to generate captured image data. The light source control unit 173 calculates the brightness setting information in each display mode based on the captured image data generated for each display mode.

FIG. 5 is a flowchart showing the procedure of the light source calibration process.
In this processing flow, the light source control unit 173 starts the light source calibration process in the end sequence of turning off the power of the projector 100, for example, when the cumulative lighting time of the light source elapses for a predetermined time (for example, 100 hours). To do.

The light source control unit 173 determines whether or not the cumulative lighting time of the light source has elapsed a predetermined time. When the light source control unit 173 determines that the cumulative lighting time of the light source has not passed the predetermined time, the light source control unit 173 does not start the light source calibration process (step S1 / NO). Further, when the light source control unit 173 determines that the cumulative lighting time of the light source has elapsed a predetermined time, the light source control unit 173 starts the light source calibration process in the power off sequence (step S1 / YES).

The light source control unit 173 first instructs the projection control unit 171 to project a black image. The projection control unit 171 reads out the black image data stored in the storage unit 160, controls the display unit 110, and causes the screen SC to display a black image based on the black image data. This is done in order to prevent the user from seeing the change in the brightness because the brightness of the light projected on the screen SC changes by executing the light source calibration process.

Next, the light source control unit 173 sets the current value of the drive current supplied to the light source unit 111 to the maximum value in a state where the black image is displayed on the screen SC (step S2), and the drive current of the set current value. Is instructed to the light source driving unit 121 to supply the light source unit 111. Further, the light source control unit 173 sets the duty ratio of the PWM signal to 100%, and instructs the PWM signal generation unit 122 to generate a PWM signal having the set duty ratio of 100%. The PWM signal generation unit 122 generates a PWM signal with a duty ratio of 100% specified by the light source control unit 173 and outputs it to the light source drive unit 121. As a result, the drive current having the maximum current value (Imax shown in FIG. 3) is supplied to the light source unit 111, a drive signal having a duty ratio of 100% is input, and the output light amount of the light source is maximized. When the output light amount of the light source becomes maximum, the light source control unit 173 acquires the sensor value measured by the light sensor 117 (step S3). The light source control unit 173 stores the acquired sensor value in a memory (not shown) or a storage unit 160.

Next, the light source control unit 173 sets an intermediate value for the current value of the drive current supplied to the light source unit 111 (step S4), and instructs the light source drive unit 121. Further, the light source control unit 173 sets the duty ratio of the PWM signal to 100%, and instructs the PWM signal generation unit 122 to generate a PWM signal having the set duty ratio of 100%. As the intermediate value, for example, an intermediate value (Ia shown in FIG. 3) between the maximum value and the minimum value of the preset drive current can be used.
When the light source unit 111 is driven by a drive signal having an intermediate current value and a duty ratio of 100%, the light source control unit 173 acquires a sensor value measured by the optical sensor 117 (step S5). .. The light source control unit 173 stores the acquired sensor value in a memory (not shown) or a storage unit 160.

Next, the light source control unit 173 sets a minimum value for the current value of the drive current supplied to the light source unit 111 (step S6), and instructs the light source drive unit 121. Further, the light source control unit 173 sets the duty ratio of the PWM signal to 100%, and instructs the PWM signal generation unit 122 to generate a PWM signal having the set duty ratio of 100%.
When the light source unit 111 is driven by a drive signal having the minimum current value (Ism shown in FIG. 3) and a duty ratio of 100%, the light source unit 173 has a sensor value measured by the optical sensor 117. (Step S7). The light source control unit 173 stores the acquired sensor value in a memory (not shown) or a storage unit 160.

Next, the light source control unit 173 sets a minimum value as the current value of the drive current supplied to the light source unit 111, and instructs the light source drive unit 121. Further, the light source control unit 173 sets a preset duty ratio as the duty ratio of the PWM signal (step S8), and instructs the PWM signal generation unit 122 to generate a PWM signal having the set duty ratio.
When the light source unit 111 is driven by the drive current having the minimum current value (Ism shown in FIG. 4) and the drive signal having the duty ratio set in advance, the light source unit 173 measures by the optical sensor 117. Acquire the sensor value to be performed (step S9). The light source control unit 173 stores the acquired sensor value in a memory (not shown) or a storage unit 160.

Next, the light source control unit 173 drives the light source unit 111 by designating all the duty ratios set in advance, and determines whether or not the sensor value measured by the optical sensor 117 has been acquired (step S10).
When the determination in step S10 is a negative determination, the light source control unit 173 shifts to the process of step S8, and specifies a preset duty ratio and an unset duty ratio as the duty ratio of the PWM signal to light source. The unit 111 is driven to acquire the sensor value measured by the optical sensor 117 (step S9).

If the determination in step S10 is affirmative, the light source control unit 173 executes an error determination process (step S11). The light source control unit 173 compares the sensor values measured in steps S3, S5, S7, and S9 with the sensor values measured in the previous light source calibration process. The storage unit 160 stores the sensor value measured by the previous light source school processing.
The light source control unit 173 compares the sensor value measured in the current light source calibration process with the sensor value measured in the previous light source calibration process, and calculates the rate of change of the sensor value. When the calculated rate of change is within a predetermined range set in advance, the light source control unit 173 determines that the sensor value measured in the current light source calibration process is within the range of measurement error. In this case, the light source control unit 173 discards the sensor value measured in the current light source calibration process, uses the sensor value measured in the previous light source calibration process, and uses the drive current-light intensity characteristic table and the duty ratio. -Update the light intensity characteristic table. Further, the light source control unit 173 does not update the drive current-light intensity characteristic table and the duty ratio-light intensity characteristic table.

When the light source calibration process shown in FIG. 5 is completed, the light source control unit 173 shows the drive current-light intensity characteristic table shown in FIG. 3 and the drive current-light intensity characteristic table shown in FIG. 4 based on the sensor values stored in the storage unit 160 or a memory (not shown). Update the duty ratio-light intensity characteristic table shown. The light source control unit 173 obtains the output light amount of the light source based on each of the sensor values of the light sensor 117 measured while changing the drive current.

The light source control unit 173 plots the points corresponding to the obtained output light amount of the light source and the drive current on the drive current-light amount characteristic table, and further connects the plotted points with a straight line to form the drive current-light amount characteristic table. Generate. The duty ratio-light intensity characteristic table is generated for the light source control unit 173 by the same procedure.

FIG. 6 is a flowchart showing the procedure of the light source adjustment process.
The light source control unit 173 determines whether or not an instruction for image quality adjustment has been received by operating the operation panel 141 or the remote controller 5 (step S21). When the instruction for image quality adjustment is not received (step S21 / NO), the light source control unit 173 waits for the start of the light source adjustment process until the instruction for image quality adjustment is received.
When the light source control unit 173 receives the instruction for image quality adjustment (step S21 / YES), the light source control unit 173 reads the pattern image data from the storage unit 160 and causes the image processing unit 153 to process the pattern image data. The image processing unit 153 expands the input pattern image data into the frame memory 155 for processing, and outputs the processed pattern image data to the display unit 110 as display image data. The display unit 110 projects an image (hereinafter, referred to as a pattern image) based on the input display image data (pattern image data) on the screen SC (step S22). The pattern image data is, for example, a grid pattern, which is image data in which predetermined marks are formed at the four corners of the pattern image data. The predetermined marks are used when detecting the four corners of the pattern image data.

It is assumed that the image quality adjustment instructed here is an adjustment for correcting the deterioration of the image quality of the projected image projected on the screen SC and returning the image quality to the image quality at the time of manufacturing the projector 100. For example, the characteristics of the light source included in the light source unit 111 change due to temperature changes, aging deterioration, and the like, so it is necessary to correct the amount of light so as to obtain desired image brightness.
In addition, the image quality adjustment included in the projector 100 includes an image quality adjustment that corrects the tint of the screen SC and the ambient lighting to correct the tint of the projected image to a preset tint, and a plurality of projectors 100. There is an image quality adjustment or the like that matches the hue of the projected image projected by. For these image quality adjustments, correction data can be generated by the same procedure shown below.

When the pattern image is projected onto the screen SC, the image pickup control unit 172 controls the image pickup unit 147 to image the screen SC direction and generate the image capture image data (step S23). The image pickup control unit 172 outputs the generated captured image data to the light source control unit 173.

The light source control unit 173 associates the coordinates in the captured image data (hereinafter referred to as imaging coordinates) with the coordinates in the liquid crystal panel 115 of the optical modulation device 113 (hereinafter referred to as panel coordinates) based on the input captured image data. (Step S24).
The light source control unit 173 detects the marks of the pattern image captured in the captured image data, identifies the positions of the four corners of the pattern image captured in the captured image data, and specifies the pixel positions of the four corners in the captured image data. Further, the light source control unit 173 specifies the pixel position of the liquid crystal panel on which the mark formed in the pattern image data is developed, and associates the pixel position in the captured image data with the pixel position in the liquid crystal panel. As a result, the imaging coordinates and the panel coordinates are associated with each other.
For example, the pixel position of the liquid crystal panel on which the mark formed in the pattern image data is developed is preset, and the light source control unit 173 provides information on the pixel position of the liquid crystal panel on which the mark is developed from the storage unit 160. You may get it.
Further, when the image processing unit 153 expands the pattern image into the frame memory 155, the pixel position of the liquid crystal panel 115 is specified based on the pixel position of the frame memory 155 where the mark is expanded, and the pixel position of the liquid crystal panel 115 is specified. Information indicating the above may be output to the control unit 170. It is assumed that the information for associating the pixels of the frame memory 155 with the pixels of the liquid crystal panel is prepared in advance and stored in, for example, the storage unit 160.

When the imaging coordinates and the panel coordinates are associated with each other, the light source control unit 173 reads out the brightness adjustment image data from the storage unit 160, causes the image processing unit 153 to process it, and projects it on the screen SC by the display unit 110. A brightness adjustment image, which is an image based on the brightness adjustment image data, is projected on the screen SC (step S25). At this time, the light source control unit 173 refers to the drive current-light intensity characteristic table and the duty ratio-light intensity characteristic table generated by the light source calibration process shown in FIG. 5 so that the output light intensity of the light source unit 111 becomes 100%. Controls the light source unit 111. Specifically, the light source control unit 173 acquires the current value of the drive current when the output light amount of the light source unit 111 is 100% with reference to the drive current-light amount characteristic table. Further, the light source control unit 173 acquires the duty ratio of the drive signal when the output light amount of the light source unit 111 is 100% with reference to the duty ratio-light amount characteristic table.
The light source control unit 173 instructs the light source drive unit 121 to supply the drive current of the acquired current value to the light source unit 111. Further, the light source control unit 173 instructs the PWM signal generation unit 122 to generate a PWM signal having a duty ratio of 100%. As a result, the drive current and the drive signal with the output light amount of the light source unit 111 as 100% are supplied.

When the brightness adjustment image is projected onto the screen SC, the image pickup control unit 172 controls the image pickup unit 147 to image the screen SC direction and generate the image capture image data (step S26). The image pickup control unit 172 outputs the generated captured image data to the light source control unit 173.

The light source control unit 173 calculates the luminance information from the input captured image data.
The light source control unit 173 obtains the difference (or ratio) between the calculated brightness information and the target value of the brightness when the output light amount is 100%, and corrects the driving condition based on the obtained difference (or ratio). The setting information is generated (step S28).

Further, the light source control unit 173 changes the output light amount of the light source unit 111 to the output light amount corresponding to the display mode of the projector 100, calculates the brightness information from the captured image data obtained by capturing the brightness adjustment image, and displays the display mode. Compare with the target value of brightness in. Then, the light source control unit 173 may calculate the brightness setting information for each display mode.

Next, the light source control unit 173 executes the light source adjustment for adjusting the light amount of the light source unit 111 by using the calculated brightness setting information (step S29). For example, when "90%" is calculated as the brightness setting for the output light amount of 100%, the light source control unit 173 outputs the drive conditions (drive current, duty ratio of the drive signal) when the output light amount is 100%. Correct the driving conditions when the amount of light is 90%.

Next, the light source control unit 173 executes color adjustment.
First, the light source control unit 173 reads out the color adjustment image data from the storage unit 160, causes the image processing unit 153 to process the image data, and causes the display unit 110 to project the image data on the screen SC. The color adjustment image is a single color raster image of each of R, G, and B, and is prepared with a plurality of preset gradations (for example, 8 gradations). A color adjustment image, which is an image based on the color adjustment image data, is projected on the screen SC (step S30).

When the color adjustment image is projected onto the screen SC, the image pickup control unit 172 controls the image pickup unit 147 to image the screen SC direction and generate the image capture image data (step S31). The image pickup control unit 172 outputs the generated captured image data to the light source control unit 173.
The light source control unit 173 and the image pickup control unit 172 repeat the above processing for each of R, G, and B colors and for each gradation, and generate captured image data of a color adjustment image in a plurality of colors and a plurality of gradations. ..

Next, the light source control unit 173 sets a target value for color adjustment (step S32). The target value for color tone adjustment can be, for example, the pixel value (XYZ value) at the center of the captured image data. Further, the target value for color tone adjustment may be the target value (XYZ value) when gamma correction is performed. Further, the target value of the color tone adjustment may be a preset value for each of the R, G, and B colors and each gradation.

When the target value for color tone adjustment is set, the light source control unit 173 calculates the correction value (step S33). The light source control unit 173 converts the pixel value of the pixel corresponding to the panel coordinates of the captured image data into an XYZ value, compares the converted XYZ value with the target value for color tone adjustment, and generates a correction value.

When the correction value is calculated, the light source control unit 173 performs color tone correction (step S34). The light source control unit 173 outputs the generated correction value to, for example, the image processing unit 153. The image processing unit 153 corrects the image data supplied from the image supply device 200 by using the correction value input from the control unit 170.

As described above, in the present embodiment, the driving conditions are set so that the light amount of the light source becomes a preset target value based on the light amount detected by the light sensor 117, and the light amount is detected by the captured image data of the imaging unit 147. The drive conditions set in the light source calibration process are updated based on the detection result of the brightness of the projected image. Therefore, the image quality of the projected image can be optimally corrected regardless of the environment and projection conditions.

In addition, drive conditions are set using the drive information that drives the light source. Therefore, the light source driving unit 121 can control the light source according to the set driving conditions as it is.

Further, the light source control unit 173 updates the drive conditions based on the amount of light detected by the light sensor 117 and the drive information in the light source adjustment process. Therefore, the driving conditions can be updated based on the amount of light detected by the optical sensor 117 and the driving information.

In addition, an imaging unit 147 that captures a projected image projected by the display unit 110 and outputs the captured image is provided.
The light source control unit 173 executes the light source adjustment process based on the image captured by the image pickup unit 147 when the brightness adjustment image is projected by the display unit 110. Therefore, the brightness of the projected image can be detected based on the captured image obtained by capturing the projected brightness adjustment image, and the driving condition can be updated based on the detected brightness.

Further, the light source control unit 173 obtains the brightness setting for correcting the drive condition set in the light source calibration process as correction information in the light source adjustment process, and updates the drive condition using the obtained brightness setting. Therefore, the driving conditions can be updated by setting the brightness of the light source.

Further, the light source control unit 173 executes the light source calibration process at a preset cycle. The light source control unit 173 is characterized in that the light source adjustment process is executed when the execution of the light source adjustment process is instructed. Therefore, the light source calibration process can be executed at a preset cycle, and the light source adjustment process can be executed when the execution is instructed.

Further, the light source control unit 173 executes the light source calibration process in the first preset cycle, and executes the light source adjustment process in the second cycle. The first cycle is set to be shorter than the second cycle. Therefore, the brightness of the projected image can be optimized by performing the update process in the state where the relationship between the output light amount of the light source and the driving condition is updated.

[Second Embodiment]
FIG. 7 is a system configuration diagram of the image projection system 1.
The image projection system 1 shown in FIG. 7 includes a plurality of projectors. The image projection system 1 of the present embodiment includes four projectors 100, a projector 100A, a projector 100B, a projector 100C, and a projector 100D. Hereinafter, when the projector 100A, the projector 100B, the projector 100C, and the projector 100D are generically referred to, they are referred to as the projector 100.
Further, the image projection system 1 of the present embodiment is configured by arranging four projectors 100 in two vertical rows and two horizontal rows.
The number of projectors 100 constituting the image projection system 1 is not limited to four, and may be two, three, or four or more.
Further, the arrangement of the plurality of projectors 100 is not limited to two vertical rows and two horizontal rows, and for example, four projectors 100 may be arranged side by side in one horizontal row.

The projectors 100A to 100D are connected by a communication line 6 to transmit and receive various data. In the present embodiment, the cases where the projectors 100A to 100D are connected by wire are shown, but the master projector 100A and each sub-projector 105 may be connected by wireless communication such as wireless LAN or Bluetooth.
Further, each of the projectors 100A to 100D is connected to the image supply device 200 and projects an image based on the image signal supplied from the image supply device 200 onto the screen SC. Although only the cable connecting the projector 100A and the image supply device 200 is shown in FIG. 7, other projectors 100B to 100D are also connected to the image supply device 200 and receive an image signal from the image supply device 200.

FIG. 8 is a diagram showing an outline of operation of the light source control unit 173 of the second embodiment.
In addition to the above-mentioned light source calibration processing and light source adjustment processing, the light source control unit 173 of each projector 100 constituting the image projection system 1 performs constant light amount control for controlling the brightness of the projected image projected on the screen SC to be constant. It is carried out at a predetermined timing.
In the image projection system 1, the light source adjustment process shown in FIG. 6 is executed in each projector 100, the target value of the brightness adjustment set in step S27 is set, and the brightness setting information is calculated in step S28. The projector 100 transmits the calculated brightness setting information to another projector 100.
When the other projector 100 that has input the brightness setting information performs constant light intensity control, the other projector 100 stops this control and performs the light source adjustment process shown in FIG. Then, the other projector 100 performs constant light intensity control according to the input brightness setting.

FIG. 9 is a flowchart showing an operation of constant light intensity control executed by the light source control unit 173.
The light source control unit 173 determines whether or not the light source adjustment process is executed and the updated brightness setting is input (step S41). When there is no input of the updated brightness setting (step S41 / NO), the light source control unit 173 waits until the input of the brightness setting is input.

When the updated brightness setting is input (step S41 / YES), the light source control unit 173 acquires the reference light sensor value from the storage unit 160 (step S42). The reference light sensor value is a sensor value of the light sensor 117 measured by the light source calibration process shown in FIG. The reference optical sensor value is a sensor value measured by the optical sensor 117 when the light source unit 111 is driven with the drive current set to the maximum value and the PWM signal duty ratio set to 100%.

Next, the light source control unit 173 sets the light source drive unit 121 so that the current value of the drive current supplied to the light source unit 111 becomes the maximum value. Further, the light source control unit 173 instructs the PWM signal generation unit 122 to generate a PWM signal having a duty ratio of 100%. As a result, the drive current having the maximum current value is supplied to the light source unit 111, a drive signal having a duty ratio of 100% is input, and the output light amount of the light source is maximized. When the output light amount of the light source becomes maximum, the light source control unit 173 acquires the sensor value measured by the light sensor 117. The sensor value acquired by the light source control unit 173 is hereinafter referred to as a measured value.

Next, the light source control unit 173 calculates the set value (step S43). This set value is a set value for setting the output light amount of the light source to the light amount indicated by the brightness setting set by the light source adjustment process or the light source configuration process. This set value is referred to as a constant amount of light below. The constant light intensity output is calculated by the formula shown below.
Constant light intensity output = light intensity indicated by the input brightness setting x (reference light sensor value / measured value)

For example, it is assumed that the amount of light indicated by the input brightness setting is 70% and the sensor value of the reference light sensor acquired from the storage unit 160 is 700. Further, it is assumed that the measured value measured by the optical sensor 117 is also 700.
In this case, the constant light intensity output is 70% by 70% × (700/700). When the deterioration of the light source has not progressed and the measured value is the same as the reference light sensor value acquired by the light source calibration process, the constant light amount specified by the input brightness setting becomes the constant light amount output as it is.

Further, it is assumed that the constant amount of light specified by the input brightness setting is 70%, the reference light sensor value acquired from the storage unit 160 is 700, and the measured value is 612.
In this case, the constant light quantity output becomes 80% by 70% × (700/612).

The light source control unit 173 outputs the generated constant light amount output as a parameter (step S44). The light source control unit 173 sets the current value of the drive current and sets the duty ratio of the drive signal based on the generated parameters.

Next, when the operation of step S44 is executed, the light source control unit 173 determines whether or not the light source calibration process has been performed (step S45). When the determination in step S45 is an affirmative determination (step S45 / YES), the light source control unit 173 shifts to the process in step S43, reacquires the updated reference light sensor value, and repeats the processes in steps S42 to S44. .. If the determination in step S45 is a negative determination (step S45 / NO), the light source control unit 173 determines whether or not to end the constant light intensity control (step S46). In the case of a negative determination, the light source control unit 173 returns to the process of step S44 and outputs a constant light amount output as a parameter (step S44). Further, in the case of an affirmative determination (step S46 / YES), the light source control unit 173 ends this processing flow.

By performing the above-mentioned constant light intensity control, even if the brightness setting is changed by the light source adjustment process in the image projection system 1, the constant light intensity control is performed so that each projector 100 has the newly set brightness setting. Do. By this process, the brightness of the projected image of each projector 100 can be made uniform.

The above-described embodiment is a preferred embodiment of the present invention. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.
For example, in the above-described embodiment, the configuration using three transmissive liquid crystal panels corresponding to each color of RGB as the optical modulation device 113 for modulating the light emitted by the light source has been described as an example. The invention is not limited to this. For example, a configuration using three reflective liquid crystal panels may be used, or a method in which one liquid crystal panel and a color wheel are combined may be used. Alternatively, it may be configured by a method using three digital mirror devices (DMD), a DMD method in which one digital mirror device and a color wheel are combined, or the like. When only one liquid crystal panel or DMD is used as the optical modulation device, a member corresponding to a synthetic optical system such as a cross dichroic prism is unnecessary. In addition to the liquid crystal panel and DMD, any optical modulator capable of modulating the light emitted by the light source can be adopted without any problem.

Further, in the above-described embodiment, the front projection type projector 100 that projects from the front of the screen SC is shown as the projector 100, but the present invention is not limited to this.
Further, each functional unit shown in FIG. 1 shows a functional configuration, and a specific mounting form is not particularly limited. That is, it is not always necessary to implement hardware corresponding to each functional unit individually, and it is of course possible to realize a configuration in which the functions of a plurality of functional units are realized by executing a program by one processor. Further, a part of the functions realized by the software in the above embodiment may be realized by the hardware, or a part of the functions realized by the hardware may be realized by the software. In addition, the specific detailed configuration of each other part of the projector 100 can be arbitrarily changed without departing from the spirit of the present invention.

1 ... Image projection system, 5 ... Remote control, 6 ... Communication line, 100, 100A, 100B, 100C, 100D ... Projector, 105 ... Sub projector, 110 ... Display unit (projection unit), 111 ... Light source unit (light source), 112 ... color separation unit, 113 ... optical modulator, 114 ... projection optical system, 115 ... liquid crystal panel, 117 ... optical sensor (detection unit), 121 ... light source drive unit, 122 ... PWM signal generation unit, 123 ... optical modulator drive Unit, 141 ... Operation panel, 142 ... Remote control light receiving unit, 143 ... Input processing unit, 145 ... Wireless communication unit, 147 ... Imaging unit (projected image detection unit), 151 ... Image input I / F unit, 153 ... Image processing unit , 155 ... Frame memory, 160 ... Storage unit, 170 ... Control unit, 171 ... Projection control unit, 172 ... Imaging control unit (projection image detection unit), 173 ... Light source control unit, 200 ... Image supply device, SC ... Screen.

Claims (7)

A projection unit that has a light source and projects an image by modulating the light emitted by the light source.
A light source drive unit that drives the light source according to the set drive conditions,
A detector that detects the amount of light emitted from the light source,
A projection image detection unit that detects the brightness of the projection image projected by the projection unit, and
A light source control unit for setting the drive conditions of the light source drive unit is provided.
The light source control unit sets the drive condition so that the light amount of the light source becomes a preset target value based on the light amount detected by the detection unit, and the projection image detection unit detects the drive condition setting process. Based on the detection result of the brightness of the projected image, the update process for updating the drive condition set in the drive condition setting process is executed .
The light source control unit executes the drive condition setting process in a preset first cycle, and executes the update process in a preset second cycle.
A projector characterized in that the first cycle is set to a cycle shorter than the second cycle . The light source control unit drives the light source under a plurality of preset drive conditions in the drive condition setting process, and stores the amount of light detected by the detection unit when the light source is driven under the plurality of drive conditions. Let each department remember
The first aspect of the present invention, wherein the driving condition is set so that the light amount of the light source becomes a preset target value based on the plurality of the driving conditions and the amount of light stored in the storage unit. projector. The light source control unit is characterized in that, in the update process, correction information for correcting the drive condition set in the drive condition setting process is obtained, and the drive condition is updated using the obtained correction information. The projector according to claim 1 or 2. The projector according to claim 3, wherein the projected image detection unit includes an imaging unit that captures a projected image projected by the projection unit and outputs the captured image. The projector according to claim 4, wherein the light source control unit projects a brightness adjusting image as the projected image by the projection unit, and executes the update process based on the captured image captured by the imaging unit. .. In the update process, the light source control unit lights the light source with a preset output light amount and projects the brightness adjustment image onto the projection unit.
The feature is that the correction information is obtained based on the difference between the brightness calculated based on the captured image obtained by capturing the brightness adjustment image and the target value of the brightness in the case of the preset output light amount. The projector according to claim 5. A control method for a projector having a light source and including a projection unit that projects an image by modulating the light emitted by the light source.
The step of driving the light source according to the set driving conditions and
The step of detecting the amount of light emitted from the light source and
A step of detecting the brightness of the projected image projected by the projection unit, and
And Luz step to set the detected based on the light intensity, driving conditions of the light source so that the light quantity of the light source becomes a predetermined target value,
Wherein based on the brightness of the detection result of the projected image, comprising the steps of: updating said driving condition set in the step of setting,
The set step is executed in a preset first cycle, and the update step is executed in a preset second cycle.
A method for controlling a projector, wherein the first cycle is set to a cycle shorter than the second cycle .

Images