JP2006098765A - Image display device, image display system, image output device, and refresh rate setting method for image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device and an image display system in which image quality is not significantly reduced by flicker even when still image content is displayed, and viewers are not discomforted by tearing even when moving image content is displayed. And provision of image output equipment.
In an image display device 5 including an image forming unit 21 and a control unit 22, a control unit 22 determines whether input image information is a moving image content or a still image content. If the image information is determined to be moving image content, the refresh rate of the output image by the image forming means 21 is set to be synchronized with the rate of the moving image content, and the image information is determined to be still image content. Then, a refresh rate setting unit 224 that sets the refresh rate of the output image by the image forming unit 21 to be higher than the rate of the still image content is provided.
[Selection] Figure 5

Description

  The present invention relates to an image display device, an image display system, an image output device, and a refresh rate setting method for an image display device.

Still images and moving images are displayed on an image display device attached to a personal computer (PC). In either case, it is required to display images with high quality.
For still image content, flickering of the screen often becomes a problem, and in order to prevent this, the refresh rate of the output image by the image display device is made higher than the rate of still image content 60 Hz, for example, , 72 Hz, and 85 Hz are generally performed.
On the other hand, for video content, the frame rate and refresh rate of the video content, the frame rate and the timing of writing to and reading from the image memory are important, and if there is a discrepancy between these, tearing will occur in the display image. (See Patent Document 1).
For example, in the case of NTSC video content, the frame rate is 30 Hz and considering interlace scanning, the video content rate is 60 Hz. However, when the refresh rate of the output image is 72 Hz, Since the frame switching and the refresh rate of the output image are not synchronized, the image of the previous frame and the image of the next frame may overlap and cause a shift, and the shift is displayed at what cycle. Some people feel uncomfortable for the observer.

JP 2004-133283 A

  Therefore, an object of the present invention is to display an image that does not cause a significant decrease in image quality due to flicker even when still image content is displayed, and does not cause discomfort to the observer due to tearing even when moving image content is displayed. An apparatus, an image display system, an image output device, and a refresh rate setting method for an image display apparatus.

  An image display device according to the present invention is an image display device including an image forming unit that forms an optical image according to input image information, and a control unit that controls the entire apparatus including the image forming unit. The control unit determines whether the input image information is a moving image content or a still image content. When the control unit determines that the image information is a moving image content, an output image by the image forming unit Is set to be synchronized with the rate of the moving image content, and when the image information is determined to be still image content, the refresh rate of the output image by the image forming means is set to the rate of the still image content. And a refresh rate setting unit for setting the value to be higher.

Here, for example, in the case of the NTSC system, the frame rate of the moving image content is 30 Hz, and considering the interlaced scanning, it can be considered to be 60 Hz that is twice that. In the case of the PAL system, the frame rate is 25 Hz. In view of interlaced scanning, it may be considered that the frequency is 50 Hz, and the refresh rate of the output image may be set to 60 Hz, 50 Hz, or the like according to the video system.
According to the present invention, since the content determination unit and the refresh rate setting unit are provided, the refresh rate can be appropriately changed according to the content type of the image information. Therefore, the quality of the display image can be improved by flicker, tearing, or the like. Does not decrease and does not cause discomfort to the observer.

In the present invention, it is preferable that the content determination unit described above determines the determination of a moving image or a still image of image information in a file format including the image information.
Specifically, it can be determined by an image file format that can be read by a computer. For example, if the extension is “.JPG”, it is a still image content, and if the extension is “.MPG”, it is a video. What is necessary is just to determine with content.
According to this invention, since the type of content can be determined only by the file format, particularly the extension code, the processing by the content determination unit can be simplified, and the load associated with the processing to the control means is increased. Can be reduced.

  An image display system according to the present invention is an image display system including an image output device and an image display device that forms an optical image based on image information output from the image output device. Comprises image forming means for forming an optical image according to input image information, and control means for controlling the entire apparatus including the image forming means, and the image output device outputs an image to be output to the image display device. Content determination means for determining whether the information is moving image content or still image content; if it is determined that the information is moving image content, moving image reproduction flag information is generated; if it is determined that the information is still image content, Flag information generating means for generating image playback flag information, and video rate acquisition for acquiring the rate of the video content if it is determined to be video content. Means and a flag / rate output means for outputting the generated flag and / or the rate of the acquired moving image content to the image display device, and the control means of the image display device outputs from the image output device. A flag determination unit for determining the type of the flag information, and if it is determined that the flag information is the moving image reproduction flag information, the refresh rate of the output image to the image forming unit is set to the moving image content acquired by the moving image rate acquiring unit. A refresh rate that is set to synchronize with the rate and sets the refresh rate of the output image to the image forming means to be higher than the rate of the still image content when it is determined that the still image reproduction flag information is set. And a setting unit.

As the image output device, it is preferable to employ an apparatus having an arithmetic processing function. For example, it is preferable to employ a computer.
According to the present invention, the image output device includes the content determination unit, the flag information generation unit, and the moving image rate acquisition unit, and the image display device includes the flag determination unit and the refresh rate setting unit. The image display device can set the refresh rate with simple processing based on flag determination, so that complicated processing can be performed by the image output device and the image display device. It can be apportioned and the processing burden on both can be reduced.

  An image output device of the present invention constitutes the invention according to the image display system, and is an image output device that outputs image information and forms an optical image on the image display device, and the image display device Content determination means for determining whether the image information to be output is video content or still image content, and if it is determined to be video content, video playback flag information is generated and determined to be still image content If it is determined, the flag information generating means for generating still image playback flag information, the moving picture rate acquiring means for acquiring the rate of the moving picture content when it is determined to be the moving picture content, the generated flag information and / or the acquired And a flag / rate output means for outputting the rate of the moving image content to the image display device.

An image display apparatus according to the present invention constitutes the invention according to the image display system, and includes an image forming unit that forms an optical image in accordance with input image information, and an entire apparatus including the image forming unit. An image display device comprising: a control unit that controls the type of flag information indicating whether the image information output from the image output device is moving image content or still image content If it is determined that the flag is a moving image reproduction flag information, the refresh rate of the output image to the image forming means is set to be synchronized with the rate of the moving image content, and the still image reproduction flag information The refresh rate for setting the refresh rate of the output image to the image forming means to be higher than the rate of the still image content. Characterized in that it comprises a rate setting unit.
According to such an image output device and an image display device, it is possible to constitute the invention according to the image display system described above, and the effects of the image display system can be achieved by the cooperation of both.

  The refresh rate setting method for an image display apparatus according to the present invention includes an image forming unit that forms an optical image in accordance with input image information, and a control unit that controls the entire apparatus including the image forming unit. A refresh rate setting method for an image display device, wherein the refresh rate of the image forming unit is set by the control unit in accordance with image information executed and input above, the image information being input by the control unit A content determination step for determining whether the image information is a moving image content, and a refresh rate of an output image by the image forming means is determined for the moving image content. If the image information is determined to be still image content, the image is set to be synchronized with the rate. The refresh rate of the output image by the forming means, and executes a refresh rate setting step of setting to be higher than the rate of the still picture content.

  The refresh rate setting method for an image display apparatus according to the present invention includes an image forming unit that forms an optical image according to input image information, and a control unit that controls the entire apparatus including the image forming unit. A refresh rate setting method for an image display device, which is executed on the control means of the display device and sets a refresh rate of the image forming means according to the image information, wherein the control means A flag determining step for determining the type of flag information indicating whether the content is still image content or a moving image reproduction flag information, and if the moving image reproduction flag information is determined, the refresh rate of the output image to the image forming unit is set to the moving image If it is set to be synchronized with the content rate and it is determined that it is still image reproduction flag information, The refresh rate of the power image, and executes a refresh rate setting step of setting to be higher than the rate of the still picture content.

Here, the refresh rate setting method of the image display device of the present invention described above can be realized as a program that can be executed by the arithmetic processing means of the image output device or the control means of the image display device, It can also be realized as a computer-readable recording medium on which this program is recorded.
According to such a refresh rate setting method of the present invention, the same operation and effect as those of the image display device and the image display system described above can be enjoyed, and the program can be realized as a program or a recording medium on which the program is recorded. As a result, the present invention can be executed by various image display devices and image output devices, so that versatility is greatly improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 shows a projection system according to a first embodiment of the present invention. This projection system includes a computer 1 such as a personal computer, a projector 2, an image output system cable 3 and a data input / output system cable 4 for connecting them, and image information output from the personal computer. In this system, the image is output to the projector 2 via the image output system cable 3 and is enlarged and projected onto a screen or the like.
As the image output system cable 3 for connecting the computer 1 and the projector 2, for example, a VGA cable such as analog RGB or a digital cable such as DVI can be used.
As the data input / output system cable 4, a serial cable such as RS232C or USB can be used.

The computer 1 is a general-purpose computer and includes a CPU 11 and a hard disk 12. Although not shown in FIG. 1, the computer 1 includes input devices such as a keyboard and a mouse, and outputs such as a display and a printer. The device is connected.
The CPU 11 includes a decoding unit 111, an image data generation unit 112, a content determination unit 113, a flag information generation unit 114, a moving image rate acquisition unit 115, and a communication control unit 116 that are expanded and executed on the OS. The storage device included in the computer 1 is not limited to the hard disk 12 described above, and various memory cards such as a writable flash memory can be employed.

The decoding unit 111 is a part that decodes image information recorded in the hard disk 12, for example, a part that reads an MPEG file that is a moving image content or a JPEG file that is a still image content, and converts it into RGB data or color difference data. It is.
The image data generation unit is a part that converts the RGB data converted by the decoding unit 111 into an analog RGB or DVI image format, and the data converted into a predetermined image format is connected to the projector via the image output system cable 3. 2 is output.

  The content determination unit 113 is a part that determines whether the image file read from the hard disk 12 is a moving image file or a still image file. Specifically, the content determination unit 113 determines based on the extension of the read file. is doing. For example, in the case of an MPEG file that is a moving image content, the file extension is “.MPG”, and in the case of a JPEG file that is a still image content, the file extension is “.JPG”. Based on the extension, it is determined whether or not it is a moving image. In addition to this, there are “.AVI” for video content and “.GIF” for still image content, but these file formats can also be installed on the computer 1 if playback software is installed. , Whether it is a moving image or a still image can be determined.

The flag information generation unit 114 is a part that generates flag information according to the result determined by the content determination unit 113. For example, if it is a moving image reproduction content, DI (Dynamic Image) or a still image reproduction content may be used. For example, flag information such as SI (Static Image) is generated.
The moving image rate acquisition unit 115 is a part that acquires the moving image rate written in the moving image file when the content determination unit 113 determines that the target file is moving image content.

As shown in FIG. 2, the MPEG file has a configuration in which a sequence layer SH (Sequence Header) and a GOP layer GOP (Group Of Pictures) are alternately repeated. The sequence layer SH is information for designating a screen format and the like. In this example, the sequence layer SH is attached to the head of each GOP layer to enable reproduction from the middle. The GOP layer GOP is a part constituting the minimum unit of the screen group, and the moving image content is recorded in the GOP layer GOP.
In such an MPEG file configuration, the moving image rate acquisition unit 115 is a PR (Picture Rate) among various screen format information SHC, HS, VS, PAR, PR, BR... Recorded in the sequence layer SH of the MPEG file. The picture rate is acquired with reference to the information PR recorded in (1). In this example, the rate of moving image content of 60 Hz (number of pictures / second) adapted to the NTSC system can be acquired from this MPEG file.

  The communication control unit 116 is a part that outputs data to the projector 2 via the serial transmission system data input / output system cable 4 such as USB, and the moving image reproduction flag information generated by the flag information generation unit 114 and the still image reproduction. It functions as a flag / rate output means for outputting the flag information and the rate information of the moving image content acquired by the moving image rate acquisition unit 115 to the projector 2. The communication control unit 116 also receives a response signal output from the projector 2, and the CPU 11 outputs image data and the like using the response signal from the projector 2 as a trigger.

The projector 2 includes an image forming unit 21 that forms a projection image, an MPU 22 as a control unit that controls the image forming unit 21, and a scan converter 23.
Although not shown, the image forming unit 21 has a light source, a light modulation device that modulates a light beam emitted from the light source according to image information, and projection optics that enlarges and projects the light beam modulated by the light modulation device. System. As the light modulation device, a liquid crystal panel, a device that performs light modulation with a micromirror, or the like can be used. It is also possible to employ a three-plate image forming means using a plurality of light modulation devices. In this case, a dichroic mirror that separates light source light into RGB three-color light before the three light modulation devices. And a color combining optical system such as a cross dichroic prism that combines light beams modulated with respect to the respective color lights is arranged at the subsequent stage of the three light modulation devices. In this example, a liquid crystal panel is employed as the light modulation device.

The MPU 22 as control means includes an image data processing unit 221, a communication control unit 222, a flag determination unit 223, and a refresh rate setting unit 224.
The image data processing unit 221 is a part that converts an image format such as analog RGB or DVI input via the image output system cable 3 into a digital RGB format, and by this conversion, processing by the MPU 22 is possible. It becomes.
The communication control unit 222 has the same structure as that of the communication control unit 116 of the computer 1, and the flag information and / or information such as the video content rate sent from the communication control unit 116 is sent to the flag determination unit 223 and the refresh rate setting. To the unit 224.

The flag determination unit 223 is a part that determines whether the image data output from the computer 1 is a moving image content or a still image content from the flag information generated by the flag information generation unit 114 of the computer 1.
The refresh rate setting unit 224 is a part that sets the refresh rate of the output image output from the image forming unit 21 based on the determination result of the flag determination unit 223.
Specifically, when it is determined that the image data is still image content, the rate of the still image content is generally set to 60 Hz in the case of the NTSC system, but a higher refresh rate than this, For example, it is set to 72 Hz or 85 Hz.

On the other hand, when it is determined that the image data is moving image content, the refresh rate of the output image output from the image forming unit 21 is synchronized with this based on the moving image rate input via the communication control unit 222. Set to. For example, if the video content rate is 60 Hz, the refresh rate is set to 60 Hz accordingly. The setting information set by the refresh rate setting unit 224 is sent to the scan converter 23.
The scan converter 23 has a function of changing a signal of a certain frequency to a signal of another scan frequency, and changes the frequency when the image data of a predetermined frequency is once sampled in the video memory and output. Thus, the refresh rate can be changed.

Next, the operation of the projection system having the above-described structure will be described with reference to the flowcharts shown in FIGS. 3 shows the processing on the computer 1 side, and FIG. 4 shows the processing on the projector 2 side. Since these are working together, the processing on the computer 1 side is represented by CS1... The processing on the projector 2 side is represented by PS1.
(1) When the computer 1 is operated to reproduce an image file, the decoding unit 111 reads “XX.MPG”, “XX.JPG”, etc. recorded on the hard disk 12 as shown in FIG. The file is read and decoding is started (CS1). At the time of reading, the content determination unit 113 determines whether the file is a moving image file from the extension portion of the file (process CS2: content determination step).

(2) When the content determination unit 113 determines that the file is a still image file, the flag information generation unit 114 generates, for example, flag information “SI” representing still image reproduction content (processing CS3: flag information generation step). The flag information is transmitted to the projector 2 via the communication control unit 116 (processing CS4: flag / rate output step).
(3) When the content determination unit 113 determines that the file is a moving image file, the flag information generation unit 114 generates, for example, flag information “DI” representing the moving image reproduction content (processing CS5: flag information generation step). Subsequently, the moving image rate acquisition unit 115 acquires the moving image content rate from the picture rate information recorded in the sequence layer SH of the read MPEG file (processing CS6: moving image rate acquisition step). The generated flag information and the acquired moving image rate are transmitted to the projector 2 via the communication control unit 116 (processing CS7: flag / rate output step).

(4) During the above processing on the computer 1 side, the communication control unit 222 of the projector 2 monitors the input of a flag signal including flag information (processing PS1). When the input of the flag signal is detected, the flag determination unit 223 determines whether the input flag information is flag information indicating moving image playback content or flag information indicating still image playback content (process PS2: flag Judgment step).
(5) When it is determined that the flag information is still image playback content, if the rate of the still image content is 60 Hz, the refresh rate setting unit 224 sets the refresh rate to 72 Hz or 85 Hz, and the set refresh rate Based on the rate, the scan converter 23 is controlled to change to a still image refresh rate (process PS3: refresh rate setting step).

(6) On the other hand, when it is determined that the flag information is the moving image reproduction content, the refresh rate setting unit 224 acquires the rate of the moving image content input to the communication control unit 222 (processing PS4), and based on the acquired rate. Thus, the refresh rate synchronization is set (process PS5: refresh rate setting step). Specifically, if the rate of the moving image content is 60 Hz, the refresh rate setting unit 224 sets the refresh rate to 60 Hz, and controls the scan converter 23 based on the set refresh rate to control the refresh rate for moving image. Change to
(7) When the refresh rate setting is completed, the communication control unit 222 transmits and outputs a response signal to that effect to the communication control unit 116 of the computer 1 (process PS6).

(8) Returning to FIG. 3, during the refresh rate setting in the projector 2, the communication control unit 116 of the computer 1 monitors the input of the response signal (process CS8).
(9) When the input of the response signal is detected, the decoding unit 111 performs conversion into RGB data or color difference data based on the MPEG file or JPEG file (processing CS9).
(10) Further, the image data generation unit 112 converts the decoded RGB data and color difference data into an analog RGB or DVI image format and outputs the converted image data to the projector 2 via the image output system cable 3.
(11) As shown in FIG. 4, the image data processing unit 221 of the projector 2 converts the format of the image data output from the computer 1 into digital RGB and outputs the digital RGB to the image forming unit 21. The image forming unit 21 Then, image output is performed based on the image data (process PS7). The image data is supplied to the projector 2 as serial data, and image output is performed until the content is completed.

(12) Returning to FIG. 3 again, when the decoding unit 111 determines that the moving image or still image content has ended (processing CS12), the communication control unit 116 generates a content end signal, and connects the data input / output system cable 4 Then, an end signal is output to the projector 2 (process CS13).
(13) The communication control unit 222 monitors the input of the end signal during the processing of the computer 1 (process PS8), and when the end signal is input, the image indicating that the moving image or still image content has ended. The data is output to the data processing unit 221. Based on this, the image data processing unit 221 ends the processing of the image data.
(14) When the processing of the image data processing unit 221 is completed, the communication control unit 222 transmits a response signal to that effect to the computer 1 (processing PS9).
(15) The communication control unit 116 of the computer 1 monitors the input of the response signal. When the input of the response signal is confirmed, the entire image reproduction process is terminated.

  As described above, according to such a projection system, the refresh rate of the projector 2 is automatically changed according to the image information to be reproduced on the computer 1 side, and flicker occurs at a high refresh rate for still images. A projection system capable of providing an extremely high-quality projection image by preventing the occurrence of image disturbance such as tearing by synchronizing with the rate of the video content. can do.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the following description, the description of the same parts as those already described is omitted or simplified.
The first embodiment described above is configured as a projection system and employs a configuration in which the computer 1 and the projector 2 are connected by cables 3 and 4. For this reason, when image data is transmitted from the computer 1 to the projector 2, it is necessary to convert the image data so as to be adapted to the image data communication system.
On the other hand, as shown in FIG. 5, the projector 5 according to the second embodiment is different in that functions such as decoding in the computer, content determination, and moving image rate acquisition are built in the projector 5.

The projector 5 includes a hard disk 12, an MPU 52 as control means, an image forming means 21, and a scan converter 23. Note that the storage device of the projector 5 according to the second embodiment is not limited to the hard disk 12, and a flash memory or the like may be adopted.
In the projector 5, when the moving image or still image file read from the hard disk 12 is decoded by the decoding unit 111, it is output as it is to the image forming means 21 via the scan converter 23.
The determination of the moving image or still image by the content determination unit 113, the acquisition of the moving image content rate by the moving image rate acquisition unit 115, and the setting of the refresh rate by the refresh rate setting unit 224 are the same as those in the first embodiment, so the description thereof Omitted.

According to such a projector 5, since the function of displaying moving image or still image content is built in the projector 5, the reproduction of the moving image or still image can be performed easily and efficiently.
If input terminals such as DVI and VGA are provided on the input side of the projector 5, moving image or still image content input from these input terminals can be displayed by the image forming means 21 via the CPU 52. Therefore, by connecting an image output device such as a DVD player or a video deck, it is possible to display an image at an appropriate refresh rate while determining a moving image or a still image.

In addition, this invention is not limited to each embodiment mentioned above, The deformation | transformation as shown below is also included.
In the above embodiment, the projectors 2 and 5 are used as the image display device, but the present invention is not limited to this. That is, the present invention may be applied to a thin display, particularly a thin liquid crystal display, as an image display device.
In the first embodiment, the computer 1 and the projector 2 are connected by the cables 3 and 4. However, a computer insertion slot may be provided in the projector, and the computer may be attached thereto. In this case, since the computer and the projector are connected by a connector or the like, they are communicated by the same communication system as in the first embodiment.

In the first embodiment, the image output system cable 3 and the data input / output system cable 4 are separately provided. However, in the case of a cable for digital communication in recent years, data input / output communication is simultaneously performed on the image output system cable. A system can also be provided. Thereby, the connection cable between the computer and the projector is reduced, and the connection work can be simplified.
In addition, the specific structure, shape, and the like during the history of the present invention may be other structures as long as the object of the present invention can be achieved.

  The present invention can also be used for a liquid crystal television or a liquid crystal television system with a backlight, as can be used for the liquid crystal projector described above.

1 is a block diagram illustrating an image display system according to a first embodiment of the present invention. It is a schematic diagram for demonstrating the structure of the MPEG file in the said embodiment. It is a flowchart showing the effect | action of the image display system in the said embodiment. It is a flowchart showing the effect | action of the image display system in the said embodiment. It is a block diagram showing the image display apparatus which concerns on 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Computer (image output apparatus) 2, 5 ... Projector (image display apparatus), 21 ... Image formation means, 22, 52 ... MPU (control means), 113 ... Content determination part, 114 ... Flag information generation part, 115 ... Video rate acquisition unit (video rate acquisition unit), 116 ... Communication control unit (flag / rate output unit), 223 ... Flag determination unit, 224 ... Refresh rate setting unit

Claims (7)

Image forming means for forming an optical image in accordance with input image information;
An image display device comprising control means for controlling the entire apparatus including the image forming means,
The control means includes
A content determination unit that determines whether the image information to be input is video content or still image content;
If it is determined that the image information is moving image content, the refresh rate of the output image by the image forming unit is set to be synchronized with the rate of the moving image content,
A refresh rate setting unit configured to set a refresh rate of an output image by the image forming unit so as to be higher than a rate of the still image content when the image information is determined to be still image content; An image display device characterized by the above. The image display device according to claim 1,
The image display device, wherein the image determination unit determines a determination of a moving image or a still image of the image information in a file format including the image information. An image display system comprising an image output device and an image display device that forms an optical image based on image information output from the image output device,
The image display device includes:
Image forming means for forming an optical image in accordance with input image information;
Control means for controlling the entire apparatus including the image forming means,
The image output device is:
Content determination means for determining whether the image information to be output to the image display device is moving image content or still image content;
When it is determined that the content is a moving image content, the flag information generating unit generates video playback flag information, and when the content is determined to be a still image content, flag information generating means for generating still image playback flag information;
If the video content is determined to be video content, a video rate acquisition means for acquiring the video content rate,
Flag / rate output means for outputting the generated flag information and / or the rate of the acquired moving image content to the image display device;
The control means of the image display device includes:
A flag determination unit for determining the type of flag information output from the image output device;
If it is determined that the video reproduction flag information, the refresh rate of the output image to the image forming unit is set to synchronize with the rate of the video content acquired by the video rate acquisition unit,
A refresh rate setting unit configured to set a refresh rate of an output image to the image forming unit to be higher than a rate of the still image content when it is determined that the still image reproduction flag information is determined. A featured image display system. An image output device that outputs image information and forms an optical image on an image display device,
Content determination means for determining whether the image information to be output to the image display device is moving image content or still image content;
When it is determined that the content is a moving image content, the flag information generating unit generates video playback flag information, and when the content is determined to be a still image content, flag information generating means for generating still image playback flag information;
If the video content is determined to be video content, a video rate acquisition means for acquiring the video content rate,
An image output device comprising: flag / rate output means for outputting the generated flag information and / or the rate of the acquired moving image content to the image display device. An image display device comprising image forming means for forming an optical image in accordance with input image information and control means for controlling the entire apparatus including the image forming means,
The control means includes
A flag determination unit that determines the type of flag information indicating whether the input image information is moving image content or still image content;
If it is determined that the video playback flag information, the refresh rate of the output image to the image forming means is set to synchronize with the rate of the video content,
A refresh rate setting unit configured to set a refresh rate of an output image to the image forming unit to be higher than a rate of the still image content when it is determined that the still image reproduction flag information is determined. A characteristic image display device. Executed on an image display device including an image forming unit that forms an optical image according to input image information and a control unit that controls the entire apparatus including the image forming unit, and according to input image information. A refresh rate setting method for an image display device, wherein the refresh rate of the image forming means is set by the control means,
The control means is
A content determination step for determining whether the image information to be input is video content or still image content;
If it is determined that the image information is moving image content, the refresh rate of the output image by the image forming unit is set to be synchronized with the rate of the moving image content,
If it is determined that the image information is still image content, a refresh rate setting step of setting a refresh rate of the output image by the image forming unit to be higher than the rate of the still image content is executed. A refresh rate setting method for an image display device. An image forming unit that forms an optical image according to input image information, and a control unit that controls the entire apparatus including the image forming unit. A refresh rate setting method for an image display device that sets a refresh rate for the image forming unit in response.
The control means is
A flag determination step of determining a type of flag information indicating whether the image information is moving image content or still image content;
If it is determined that the video playback flag information, the refresh rate of the output image to the image forming means is set to synchronize with the rate of the video content,
A refresh rate setting step of setting a refresh rate of an output image to the image forming means so as to be higher than a rate of the still image content when it is determined that the still image playback flag information. A refresh rate setting method for the image display device.

Images