JP2010113009A - Image display device, illuminance acquisition method, illuminance acquisition program, and recording medium - Google Patents

Abstract

An image display device, an illuminance acquisition method, an illuminance acquisition program, and a recording medium that can appropriately acquire the illuminance of ambient light.
An image display device (projector) 1 displays an image according to input image information, and includes a display unit 6 that displays an image and a detection unit 21 that detects the illuminance of a region in which the image is displayed. Based on the luminance acquisition means (APL acquisition unit) 78 for acquiring the average luminance level of the frames constituting the image information, and the display means 6 based on the average luminance level and the illuminance detected by the detection means 21. And an acquisition means (illuminance acquisition unit 80) for calculating the illuminance when is not displayed and acquiring the illuminance as the illuminance of the ambient light. According to this, when acquiring the illuminance of the ambient light, the influence of the light of the displayed image can be reduced, and the illuminance of the ambient light can be acquired without interrupting the display of the image according to the image information. Therefore, the convenience of the image display device can be improved.
[Selection] Figure 2

Description

  The present invention relates to an image display device, an illuminance acquisition method for acquiring the illuminance of ambient light, an illuminance acquisition program, and a recording medium.

  Conventionally, an image display apparatus that displays an image according to input image information is known. Examples of such an image display device include various displays, a light source device, a light modulation device that modulates a light beam emitted from the light source device according to image information, and forms image light, and the image A projector including a projection optical device that enlarges and projects light onto a projection surface such as a screen can be given.

  2. Description of the Related Art In recent years, an image display device that acquires the color of ambient light (such as the color of a lighting device that illuminates an interior) and illuminance to improve image visibility and save energy is known. In such an image display device, the visibility of the display image is improved by correcting the color of the display image in accordance with the color of the ambient light. In the image display device, when the illuminance of the ambient light is high (when the surroundings are bright), the visibility of the display image is improved by increasing the brightness of the display image, and when the illuminance of the ambient light is low (ambient When the image is dark), energy is saved by reducing the brightness of the display image.

By the way, in a front type (front projection type) projector, the projector and the projection surface are often separated from each other. Therefore, when detecting the illuminance of ambient light, it is more difficult to detect the ambient light than the projector. It is more suitable for the visual environment to detect the light. For this reason, a projector is proposed in which a color light sensor is provided on the front surface of the housing, that is, the surface of the housing where the projection optical device is exposed (see, for example, Patent Document 1).
In the projector described in Patent Document 1, the display color and brightness in the environment are adjusted by adjusting the correction amount by gamma correction based on the environment information (RGB or XYZ tristimulus values) acquired by the color light sensor. Displays a display image suitable for.

JP 2003-280629 A

  However, in the projector described in Patent Document 1, if the above-described environmental information is acquired by the color light sensor during the projection of the image light according to the input image information, the image light is affected by the image light. There is a problem that it is not possible to obtain environmental information. In particular, this problem becomes noticeable when displaying moving images in which the luminance of image light frequently changes. On the other hand, if the illuminance of ambient light is acquired without projecting image light, the image display by the projector is not performed, and there is a problem that the convenience of the projector is reduced. Also, in the various displays described above, since the light of the displayed image is detected by reflection on an object in the space where the display is arranged, it is possible to appropriately acquire the illuminance of the ambient light. There is a problem that you can not. For this reason, the structure which can acquire the illumination intensity of environmental light more appropriately has been desired.

  An object of the present invention is to provide an image display device, an illuminance acquisition method, an illuminance acquisition program, and a recording medium that can appropriately acquire the illuminance of ambient light.

  In order to achieve the above-described object, an image display device according to the present invention is an image display device that displays an image according to input image information, the display unit displaying the image, and the image being displayed. Based on the detection means for detecting the illuminance of the area to be obtained, the luminance acquisition means for acquiring the average luminance level of the frames constituting the image information, the average luminance level, and the illuminance detected by the detection means, Illuminance when the image is not displayed by the display means, and obtaining means for obtaining the illuminance as the illuminance of the ambient light.

  According to the present invention, the acquisition unit calculates the illuminance when the image display is not performed based on the average luminance level acquired by the luminance acquisition unit and the illuminance detected by the detection unit, and The illuminance is acquired as the illuminance of the ambient light. According to this, compared with the case where the illuminance actually detected by the detection means is acquired as the illuminance of the ambient light, the influence of the light of the image displayed by the display means can be reduced, and the actual illuminance of the ambient light The illuminance approximately corresponding to can be acquired. In addition, since the displayed image is not changed or the display of the image is not interrupted, the illuminance of the ambient light can be acquired while the desired image is displayed. Therefore, environmental light can be acquired more appropriately, and convenience of the image display device can be improved.

In this invention, the said display means is provided with the projection optical apparatus which projects the said image on a predetermined | prescribed projection surface, The said detection means of the said projection surface at the time of the said image from which the said average luminance level was acquired being projected It is preferable to detect the illuminance.
According to the present invention, since the detection means detects the illuminance of the projection surface on which the light beam is projected by the projection optical device, even if the position of the image display device and the position of the projection surface are separated from each other, The illuminance of the ambient light irradiated can be detected. Therefore, the illuminance of the environmental light that affects the visibility of the image can be appropriately acquired according to the visual environment.

In the present invention, there is provided determination means for determining whether or not the average luminance level is lower than a predetermined level, and the acquisition means is configured to determine whether the average light level is low when the determination means determines that the average luminance level is low. It is preferable to obtain by calculating the illuminance.
According to the present invention, the obtaining means calculates and obtains the illuminance of the ambient light based on the illuminance when the frame for which the average luminance level is determined to be lower than the predetermined level is displayed by the judging means. Thus, the influence of the light of the image displayed by the display unit can be further reduced in the illuminance detected by the detection unit. Therefore, the accuracy and reliability of the illuminance of the ambient light acquired by the calculation of the acquisition means can be improved.

In the present invention, the acquisition unit is configured to generate the ambient light based on the average luminance level of the plurality of frames acquired by the luminance acquisition unit and the illuminance when the plurality of frames are displayed. It is preferable to obtain by calculating the illuminance.
According to the present invention, since the illuminance of the ambient light is calculated and acquired by the acquisition unit based on each average luminance level and each illuminance, for example, an approximate curve corresponding to each of these average luminance levels and each illuminance is obtained. By generating, the illuminance when the average luminance level is 0, that is, the illuminance of the ambient light can be obtained more accurately. Therefore, the illuminance of ambient light can be acquired more appropriately.

In the present invention, it is preferable that image quality adjusting means for adjusting the image quality of the image based on the illuminance of the ambient light acquired by the acquiring means is provided.
According to the present invention, it is possible to perform image display according to the visual environment by adjusting the image quality of the image displayed by the image quality adjusting unit based on the illuminance of the acquired ambient light. Therefore, it is possible to display an image that is easier to visually recognize.

In addition, the illuminance acquisition method of the present invention is performed using an image display device that displays an image according to input image information, and illuminance acquisition that acquires the illuminance of ambient light referred to when the image is displayed. A method for displaying the image in a predetermined display area, a luminance acquisition procedure for acquiring an average luminance level of a frame constituting the image information, the average luminance level, and the average luminance level. Illuminance for calculating the illuminance when the image is not displayed based on the illuminance of the predetermined display area detected when the corresponding frame is displayed, and acquiring the illuminance as the illuminance of ambient light An acquisition procedure.
According to the present invention, the same effects as those of the above-described image display device can be obtained.

The illuminance acquisition program of the present invention is an illuminance acquisition program that is executed by an image display device that displays an image according to input image information and acquires the illuminance of ambient light referred to when the image is displayed. A display step of displaying the image in a predetermined display area; a luminance acquisition step of acquiring an average luminance level of a frame constituting the image information; the average luminance level; and the average luminance level Illuminance acquisition step of calculating the illuminance when the image is not displayed based on the illuminance of the predetermined display area detected when the frame is displayed, and acquiring the illuminance as the illuminance of ambient light Are executed.
According to the present invention, by executing the illuminance acquisition program on the image display device, it is possible to achieve the same effects as those of the image display device and the illuminance acquisition method described above.

The recording medium of the present invention is characterized in that the above-described illuminance acquisition program is recorded in a computer-readable manner.
According to the present invention, the image display device reads and executes the illuminance acquisition program recorded on the recording medium so as to be readable by the computer, thereby achieving the same effect as the above-described image display device. As recording media, magnetic tapes such as DAT (Digital Audio Tape), magnetic disks such as FD (Flexible Disc), optical disks such as CD (Compact Disc) and DVD (Digital Versatile Disc), magneto-optical disks, hard disk devices, In addition, a semiconductor memory or the like can be used, and by using these, the illuminance acquisition program can be installed and executed on the image display device, and the illuminance acquisition program can be easily distributed.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[Configuration of projector]
FIG. 1 is a schematic perspective view showing a projector 1 according to the present embodiment.
The projector 1 is connected to, for example, an image output device (not shown) such as a PC (Personal Computer) or a disk-type recording medium playback device, and displays an image corresponding to image information input from the image output device with a screen SC. It is an image display device of the present invention displayed on the top. As shown in FIG. 1, the projector 1 includes a casing 2 having a substantially rectangular parallelepiped shape as a whole and an apparatus main body 3 (see FIG. 2) housed in the casing 2.

  The casing 2 is formed of synthetic resin, and an opening for exposing a projection optical device 63 (see FIG. 2) of the display unit 6 to be described later is formed on the front surface of the casing 2 although detailed illustration is omitted. Yes. The casing 2 is provided with detection means 21 so as to face the projection direction of the image light by the projection optical device 63. The detection means 21 includes a sensor that acquires an illuminance and chromaticity (RGB luminance value or XYZ tristimulus value) within the detection range, with the image projection range on the screen SC by the projection optical device 63 as a detection range. Has been. And the said detection means 21 outputs these detection results to the control means 7 (refer FIG. 2) mentioned later.

[Configuration of the device body]
FIG. 2 is a block diagram showing the configuration of the projector 1.
The apparatus main body 3 includes a receiving unit 4, a video input unit 5, a display unit 6, and a control unit 7. Although not shown, the apparatus main body 3 includes a cooling unit that cools the configuration of the apparatus main body 3 and a power supply unit that supplies power to the apparatus main body 3.

The receiving unit 4 receives a packet as image information transmitted from the above-described image output device (not shown), and outputs the packet to the control unit 7. Such a receiving means 4 can also be constituted by, for example, a USB (Universal Serial Bus) module or a wired and wireless LAN (Local Area Network) module.
The video input unit 5 is connected to another image output device (not shown) such as a DVD (Digital Versatile Disc) player, and outputs an input image signal to the control unit 7. Such video input means 5 can be composed of a video terminal (composite video terminal and component video terminal), a D-Sub (D-Subminiature) terminal, a DVI (Digital Visual Interface) terminal, and the like.

[Configuration of display means]
The display means 6 forms and projects image light corresponding to the drive signal input as an image signal from the control means 7 and displays an image on the screen SC. The display means 6 includes a light source device 61, a light modulation device 62, and a projection optical device 63.
The light source device 61 includes a light source lamp such as a high-pressure mercury lamp and a reflector that is a reflecting mirror, or a solid light source such as an LED, and irradiates the light modulation device 62 with a light beam.

Although not shown, the light modulation device 62 includes a liquid crystal panel that modulates a light beam emitted from the light source device 61 to form image light, and a driver that drives the liquid crystal panel according to an input drive signal. Configured. Note that the light modulation device 62 is not limited to a configuration including a liquid crystal panel, and a configuration other than liquid crystal, such as a device using a micromirror, may be employed.
The projection optical device 63 enlarges and projects the image light formed by the light modulation device 62 onto the projection surface, and is a combined lens including a lens barrel and a plurality of lenses housed in the lens barrel. It is configured.

[Configuration of control means]
The control means 7 is configured as a circuit board on which a CPU (Central Processing Unit) and the like are mounted, and controls the entire projector 1. For example, the control means 7 displays the image (hereinafter sometimes referred to as “input image”) based on the packets and image signals acquired by the receiving means 4 and the video input means 5 on the display means 6 as well as detection means. The input image is corrected based on the illuminance of the ambient light E (see FIG. 1) detected by 21 and the chromaticity of the screen SC. Such a control means 7 includes a main control unit 71, a packet analysis unit 72, a video demodulation unit 73, a frame memory 74, a color image generation unit 75, a drive control unit 76, a chromaticity acquisition unit 77, an APL acquisition unit 78, a level. A determination unit 79, an illuminance acquisition unit 80, an image quality adjustment unit 81, and a storage unit 82 are provided.

The storage unit 82 is a memory that stores various programs and data necessary for the function of the control means 7. As such a program, the storage unit 82 stores an image quality adjustment program for executing an image adjustment process described later. This image quality adjustment program includes the illuminance acquisition program of the present invention.
The storage unit 82 stores a plurality of color modes referred to by a drive control unit 76 and an image quality adjustment unit 81 described later. In these color modes, the amount of light emitted from the light source device 61 and the image quality of the display image (gamma correction amount (gamma value), sharpness, contrast, etc.) according to the illuminance of the ambient light detected by the detection means 21. Setting information for adjusting the settings is set. Further, the storage unit 82 stores hue information for adjusting the hue of the display image in accordance with the chromaticity detected by the detection unit 21.

  The main control unit 71 controls the entire control means 7 and thus the projector 1 as a whole. The main control unit 71 outputs a control signal to each of the function units 72 to 81 and controls the function units 72 to 81 to perform appropriate operations at appropriate times. For example, the main control unit 71 designates the address of the frame memory 74 in which image data is written to the packet analysis unit 72, the video demodulation unit 73, and the color image generation unit 75, and also reads the image data into the drive control unit 76. Specify 74 addresses.

The packet analysis unit 72 extracts a header part and a data part from the packet received by the receiving unit 4, reconstructs the data included in the data part based on the header information included in the header part, and inputs the input image Are generated on the frame memory 74.
The video demodulation unit 73 demodulates the image signal acquired by the video input unit 5 and generates an input image on the frame memory 74 for each frame.
The frame memory 74 is configured to be able to store images (image data) for a plurality of frames. An image is written to the frame memory 74 by the packet analysis unit 72, the video demodulation unit 73, and the color image generation unit 75, and an image is read by the drive control unit 76. Further, the frame memory 74 is referred to by the image quality adjustment unit 81, and the image stored in the frame memory 74 is corrected.

  The color image generation unit 75 generates a color image for performing correction (wall color correction) according to the color of the screen SC in image quality adjustment processing described later. Specifically, the color image generation unit 75 displays R (red), G (green), and B (displayed on the display unit 6 when the detection unit 21 detects the chromaticity of the screen SC in the image quality adjustment process. A single color image (hereinafter, sometimes referred to as “R image”, “G image”, and “B image”) for each frame of blue is generated on the frame memory 74.

The drive control unit 76 outputs a drive signal corresponding to the image stored in the frame memory 74 under the control of the main control unit 71 and causes the display unit 6 to display the image. Further, the drive control unit 76 outputs a control signal to the display unit 6 to control turning on and off of the light source device 61, and based on the color mode setting information selected by the image quality adjustment unit 81 to be described later, The light emission amount of the light source device 61 is controlled.
Here, when acquiring the chromaticity of the screen SC in the image quality adjustment process described later, the drive control unit 76 displays the color image generated by the color image generation unit 75 between the frames constituting the input image. In addition, a drive signal corresponding to each image is output to the display means 6.

FIG. 3 is a diagram illustrating transition of a display image when displaying each color image of RGB. That is, FIGS. 3A to 3C are diagrams illustrating transitions when displaying an R image, a G image, and a B image, respectively.
Specifically, as shown in FIG. 3A, when an input image is displayed at 60 frames / second, a frame FA indicated as “A” in FIG. , A drive signal corresponding to the R image PR is applied to each of the frames FA and FB so that the R image PR of the aforementioned color image is displayed between the frame FB and “B”. Inserted between the drive signals. At this time, the above-described light modulation device 62 is driven at 120 frames / second. Since such a drive signal corresponding to the R image PR is inserted a plurality of times, the R image PR is displayed a plurality of times, for example, between the frames FA and FB and between other frames.

Even when displaying the G image and the B image, as shown in FIGS. 3B and 3C, the G image PG is displayed between two certain frames (between the frames FC and FD shown in FIG. 3B). In addition, the drive control unit 76 displays the G image PG and the B image PB so that the B image PB is displayed between the other two frames (between the frames FE and FF shown in FIG. 3C). A corresponding drive signal is output. These G image PG and B image PB are also displayed a plurality of times between a plurality of frames, similarly to the aforementioned R image PR.
That is, in the image quality adjustment process described later, one of the color images PR, PG, and PB for one frame is displayed between the two frames of the input image by the drive control unit 76 and the display unit 6, and these colors are displayed. Each image is displayed multiple times.
The display order of the RGB color images PR, PG, and PB may be set as appropriate.

  The chromaticity acquisition unit 77 acquires the chromaticity when the R image, the G image, and the B image generated by the color image generation unit 75 are displayed among the chromaticities detected by the detection unit 21. At this time, the chromaticity acquisition unit 77 acquires the chromaticity at the display timing of each color image displayed a plurality of times, and calculates the average value of the chromaticity acquired at the display timing of each color image. The chromaticity acquisition unit 77 calculates and acquires the chromaticity of the screen SC from each of these average values (average value when displaying the R image, average value when displaying the G image, and average value when displaying the B image). To do.

The APL acquisition unit 78 corresponds to the luminance acquisition unit of the present invention, and acquires an average luminance level (APL: Average Picture Level) of the input image generated on the frame memory 74 for each frame. The average luminance level acquired by the APL acquisition unit 78 is an average luminance level of an input image for one frame that has not been subjected to image quality adjustment by an image quality adjustment unit 81 described later.
The level determination unit 79 corresponds to the determination unit of the present invention, and whether or not the average luminance level acquired by the APL acquisition unit 78 is lower than a predetermined level, that is, the average luminance level of the displayed image for one frame. Is determined to be lower than a predetermined level.

The illuminance acquisition unit 80 corresponds to the acquisition unit of the present invention, and the average luminance level of the image for one frame acquired by the APL acquisition unit 78 and the detection unit 21 when the image for the one frame is displayed. Based on the detected illuminance, the illuminance of the ambient light is calculated and acquired.
Specifically, when the level determination unit 79 determines that the acquired average luminance level is lower than a predetermined level, the illuminance acquisition unit 80 displays an image for one frame from which the average luminance level is acquired. The illuminance at that time is acquired from the detection means 21. The illuminance acquisition unit 80 performs such acquisition of the average luminance level and illuminance a plurality of times. Then, based on each average luminance level and illuminance, an approximate curve corresponding to each average luminance level and illuminance is generated, and illuminance when the average luminance level is 0 (illuminance when the average luminance level is the lowest) The illuminance that can be regarded as not displaying an image by the display means 6 is calculated and obtained as the illuminance of the ambient light.

The image quality adjustment unit 81 corresponds to image quality adjustment means of the present invention. The image quality adjustment unit 81 corrects the input image generated on the frame memory 74 based on the chromaticity of the screen SC and the illuminance of ambient light acquired by the chromaticity acquisition unit 77 and the illuminance acquisition unit 80, and The image quality of the image displayed by the display means 6 is adjusted.
Specifically, the image quality adjustment unit 81 selects a color mode corresponding to the illuminance of the ambient light from the storage unit 82, and corrects the input image based on setting information set in the color mode. Further, the image quality adjustment unit 81 selects hue information corresponding to the chromaticity of the screen SC from the storage unit 82, and corrects the input image based on the hue information.

For example, when the illuminance of the ambient light is high, since the projection light from the projector 1 and the ambient light are additively mixed, the saturation of the image formed by the projection light is reduced. In particular, a low gradation region in an image is easily affected by ambient light, and the saturation is likely to increase.
On the other hand, the image quality adjustment unit 81 can reduce the influence of the ambient light on the image, for example, by selecting a gamma value corresponding to the illuminance of the ambient light. In the above-described example, by decreasing the gamma value (for example, by changing the gamma value from 2.2 to 1.0), it is possible to suppress a decrease in saturation in the low gradation region, and thus deterioration of the image. Can do.
By performing such correction by the image quality adjustment unit 81, it is possible to display an image with high visibility according to the illuminance of the ambient light, and to perform color correction of the image according to the color of the projection surface such as the screen SC. By performing (wall color correction), it is possible to perform image display with high color reproducibility.

[Image quality adjustment processing]
FIG. 4 is a flowchart showing image adjustment processing by the projector 1.
The projector 1 performs image quality adjustment processing described below at power-on and at a predetermined timing, and adjusts the image quality of the displayed image. This image quality adjustment processing is executed by causing the main control unit 71 to function the function units 72 to 80 in accordance with the image quality adjustment program stored in the storage unit 82.
In this image quality adjustment process, as shown in FIG. 4, first, the color image generation unit 75 generates an R image, a G image, and a B image on the frame memory 74, respectively. Then, under the control of the main control unit 71, the drive control unit 76 displays the RGB color images so that the R image, the G image, and the B image are inserted between different frames of the input image, respectively. 6 is displayed (step S01). This step S01 is performed a plurality of times for each of the R image, the G image, and the B image.

  Thereafter, the detection means 21 detects the chromaticity in the projection area on the screen SC when each of the RGB images is displayed, and the chromaticity acquisition unit 77 acquires the chromaticity (step S02). At this time, as described above, the chromaticity acquisition unit 77 calculates the average value of chromaticity when each RGB image is displayed, and calculates and acquires the chromaticity of the screen SC based on the average value.

Then, the image quality adjustment unit 81 corrects the input image generated on the frame memory 74 based on the acquired chromaticity of the screen SC (step S03). At this time, as described above, the image quality adjustment unit 81 selects the hue information corresponding to the chromaticity of the screen SC from the storage unit 82, and corrects the input image based on the hue information.
A drive signal corresponding to the input image corrected in this way is output to the display unit 6 by the drive control unit 76, so that the display unit 6 is input with the image quality corrected in accordance with the chromaticity of the screen SC. An image is displayed. That is, step S03 corresponds to the display procedure and display step of the present invention.

Thereafter, the APL acquisition unit 78 calculates and acquires the average luminance level of the input image (step S04). This step S04 corresponds to the luminance acquisition procedure and luminance acquisition step of the present invention.
Then, the level determination unit 79 determines whether or not the average luminance level is lower than a predetermined level (for example, a luminance level of 50%) (step S05).
If it is determined that the level is equal to or higher than the predetermined level, the control unit 7 repeats steps S04 and S05 until the average luminance level becomes lower than the predetermined level.
On the other hand, when it is determined that the input level is lower than the predetermined level, the illuminance acquisition unit 80 acquires the illuminance when the input image for one frame having the average luminance level is displayed from the detection unit 21 (Step S1). S06).

Thereafter, the illuminance acquisition unit 80 determines whether or not the illuminance acquisition in step S06 has been performed a predetermined number of times (for example, five times) (step S07).
If it is determined that the predetermined number of times has not been performed, the control unit 7 returns to step S04 to prepare for further illuminance acquisition.
On the other hand, if it is determined that the predetermined number of times has been performed, the illuminance acquisition unit 80 calculates the illuminance when the average luminance level is 0 from the acquired average luminance level and illuminance, and acquires the illuminance as the illuminance of ambient light. (Step S08). This step S08 corresponds to the illuminance acquisition procedure and the illuminance acquisition step of the present invention.

Then, the image quality adjustment unit 81 selects the color mode from the storage unit 82 based on the illuminance of the ambient light acquired in step S08, and based on the setting information of the color mode as described above, Along with the correction in step S03, the image quality of the input image generated on the frame memory 74 is adjusted (step S09).
The drive signal corresponding to the input image whose image quality has been adjusted in this way and the control signal for controlling the amount of light emitted from the light source device 61 are output to the display means 6 by the drive control unit 76, thereby being corrected. An input image is displayed by the display means 6.

The projector 1 according to the present embodiment described above has the following effects.
The illuminance acquisition unit 80 is based on the average luminance level of each frame acquired by the APL acquisition unit 78 and the illuminance detected by the detection unit 21 when an image corresponding to each frame is displayed. The illuminance when the level is 0, that is, the illuminance when the image display is not performed is calculated, and the illuminance is acquired as the illuminance of the ambient light. According to this, compared with the case where the illuminance actually detected by the detection means 21 is acquired as the illuminance of the ambient light, the influence of the light of the image displayed by the display means 6 can be reduced, and the actual ambient light Illuminance close to the illuminance can be obtained. At this time, since the displayed image is an input image, the illuminance of the ambient light can be acquired without interrupting the display of the desired image. Therefore, the ambient light can be acquired more appropriately, and the convenience of the projector 1 can be improved.

  Since the detection means 21 detects the illuminance of the image projection area of the projection optical device 63 on the projection surface, the illuminance applied to the projection area is detected even if the position of the projector 1 and the position of the screen SC are separated. can do. Therefore, the illuminance of light (environment light) such as illumination light that affects the visibility of the image can be appropriately acquired according to the viewing environment.

  The illuminance acquisition unit 80 acquires the illuminance detected by the detection means 21 when it is determined that the average luminance level of the image (frame) displayed by the display means 6 is low, and based on these average luminance level and illuminance. Calculating the illuminance of the ambient light. According to this, the influence of the light projected by the projection optical device 63 and detected by the detection means 21 can be further reduced. Therefore, it is possible to detect the illuminance close to the state in which no image is projected, to obtain the illuminance of the ambient light more appropriately, and to improve the accuracy and reliability of the illuminance of the ambient light. .

Since the illuminance acquisition unit 80 calculates and acquires the illuminance of the ambient light based on the average luminance level of each frame and the illuminance when each frame is displayed, the average luminance level and the illuminance correspond to each other. An approximate curve can be generated with high accuracy. Therefore, the illuminance when the average luminance level is 0, that is, the illuminance of the ambient light can be acquired more accurately.
Further, the image quality adjustment unit 81 can perform image display according to the viewing environment by adjusting the image quality of the displayed input image based on the illuminance of the ambient light acquired in this way. Therefore, it is possible to display an image that is easier to visually recognize.

[Modification of Embodiment]
The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
In the above-described embodiment, in steps S01 to S03 of the image quality adjustment process, RGB color images are displayed, the chromaticity of the screen SC is acquired, and wall color correction according to the chromaticity is performed. The invention is not limited to this. That is, the above-described steps S01 and S02 may be omitted, and the input image may be displayed in step S03 without performing the wall color correction according to the chromaticity of the screen SC.

  In the embodiment, when the average luminance level is lower than a predetermined level, the detection unit 21 detects the illuminance when the frame having the average luminance level is displayed, and the illuminance acquisition unit 80 acquires the illuminance. However, the present invention is not limited to this. In other words, the illuminance of the ambient light may be obtained by calculation based on the average luminance level and the illuminance regardless of the average luminance level.

  In the embodiment, the illuminance of the ambient light is obtained by calculation based on the plurality of average luminance levels acquired from the plurality of frames and the illuminance detected by the detection unit 21 when each frame is displayed. However, the present invention is not limited to this. That is, the illuminance of the ambient light may be acquired based on at least one average luminance level and illuminance corresponding to each. In such a case, if the storage unit stores an LUT (Lookup Table) in which the average luminance level, the illuminance detected by the detection unit, and the actual ambient light illuminance measured in advance are associated, By referring to the LUT, the illuminance of the ambient light can be acquired more accurately.

  In the embodiment, the image quality adjustment program including the illuminance acquisition program of the present invention and for the projector 1 to execute the image quality adjustment processing is stored in the storage unit 82, but the present invention is not limited thereto. Absent. For example, when the program is stored in a disk-type recording medium such as a CD and a DVD and a magnetic disk device such as an HDD (Hard Disk Drive) and the image quality adjustment processing is executed, the projector 1 appropriately stores the program. You may comprise so that it may read.

  In the above-described embodiment, the front-type projector 1 in which the projection direction of the image light with respect to the screen SC and the observation direction of the image related to the image light are substantially the same is exemplified as the image display device. Not exclusively. For example, the present invention can be applied to a rear type projector in which the projection direction and the observation direction are opposite directions. Further, the present invention can be applied to displays such as liquid crystal, plasma, organic EL (electroluminescence), and CRT (Cathode Ray Tube). In these rear-type projectors and various displays, the light of the displayed image affects the illuminance of the ambient light to be acquired. By adopting the present invention, the influence can be reduced.

  The present invention can be used for an image display device, and in particular, can be suitably used for a projector that projects an image on a projection surface.

1 is a schematic perspective view showing a projector according to an embodiment of the invention. The block diagram which shows the structure of the projector in the said embodiment. The figure which shows the transition of the display image at the time of displaying the color image in the said embodiment. 5 is a flowchart showing image quality adjustment processing in the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Projector (image display apparatus), 6 ... Display means, 21 ... Detection means, 63 ... Projection optical apparatus, 78 ... APL acquisition part (luminance acquisition means), 79 ... Level determination part (determination means), 80 ... Illuminance acquisition Unit (acquisition unit), 81... Image quality adjustment unit (image quality adjustment unit)

Claims (8)

An image display device that displays an image according to input image information,
Display means for displaying the image;
Detecting means for detecting illuminance of a region where the image is displayed;
Luminance acquisition means for acquiring an average luminance level of frames constituting the image information;
Based on the average luminance level and the illuminance detected by the detection means, the illuminance when the image is not displayed by the display means is calculated, and the illuminance is acquired as illuminance of ambient light. When,
An image display device comprising: The image display device according to claim 1,
The display means includes a projection optical device that projects the image onto a predetermined projection surface,
The image display apparatus characterized in that the detection means detects the illuminance of the projection surface when the image from which the average luminance level is acquired is projected. The image display device according to claim 1 or 2,
Determination means for determining whether the average luminance level is lower than a predetermined level;
The image display apparatus according to claim 1, wherein the acquisition unit calculates and acquires the illuminance of the ambient light when the determination unit determines that the average luminance level is low. The image display device according to any one of claims 1 to 3,
The acquisition unit calculates the illuminance of the ambient light based on the average luminance levels of the plurality of frames acquired by the luminance acquisition unit and the illuminance when the plurality of frames are respectively displayed. An image display device characterized in that the image display device is obtained as a result. The image display device according to any one of claims 1 to 4,
An image display device comprising image quality adjusting means for adjusting the image quality of the image based on the illuminance of the ambient light acquired by the acquiring means. An illuminance acquisition method that is performed using an image display device that displays an image according to input image information and acquires the illuminance of ambient light referred to when displaying the image,
A display procedure for displaying the image in a predetermined display area;
A luminance acquisition procedure for acquiring an average luminance level of frames constituting the image information;
Based on the average luminance level and the illuminance of the predetermined display area detected when the frame corresponding to the average luminance level is displayed, the illuminance when the image is not displayed is calculated. Illuminance acquisition procedure for acquiring the illuminance as ambient light illuminance;
An illuminance acquisition method characterized by comprising: An illuminance acquisition program that is executed by an image display device that displays an image according to input image information and acquires the illuminance of ambient light referred to when displaying the image,
A display step of displaying the image in a predetermined display area;
A luminance acquisition step of acquiring an average luminance level of frames constituting the image information;
Based on the average luminance level and the illuminance of the predetermined display area detected when the frame corresponding to the average luminance level is displayed, the illuminance when the image is not displayed is calculated. Illuminance acquisition step of acquiring the illuminance as the illuminance of ambient light;
An illuminance acquisition program characterized in that is executed.   A recording medium in which the illuminance acquisition program according to claim 7 is recorded so as to be readable by a computer.

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