JP5262080B2 - Image display apparatus and image data transmission method - Google Patents

Description

The present invention relates to an image display device and an image data transmission method for displaying an image according to input image information.

2. Description of the Related Art Conventionally, an image display device that is connected to an image output device such as a PC (Personal Computer) and displays an image according to image information input from the image output device is known. As such an image display device, there is known a projector that modulates a light beam emitted from a light source according to the image information to form image light, and enlarges and projects the image light on a projection surface such as a screen. .
Such projectors are effectively used for presentations where many observers participate. Specifically, since the projector can easily form and display a large image, it is very useful when observing the same image with a large number of people. As such a projector, there is known a projector that displays an image related to image information input from a server via a network in addition to image information input from a connected image output device (for example, Patent Documents). 1).

JP 2007-256757 A

  However, if the display image is enlarged beyond the limit, the display image deteriorates. On the other hand, there is a demand for observing the image nearby. For this reason, when there is an image display apparatus in the hand of an observer, it is also possible to display the same image as the display image of the projector on the image display apparatus. However, in order to display the image on each image display device, it is necessary to distribute the image data in advance, and when there are a plurality of the image display devices, the data distribution is troublesome. Due to such complexity, a configuration that can easily display image data on a plurality of image display devices has been desired.

An object of the present invention is to provide an image display device and an image data transmission method capable of easily transmitting image data to a plurality of external devices.

In order to achieve the above object, an image display device of the present invention is an image display device for displaying an image, and a storage unit for storing image data included in received data as first image data; A data determination unit that determines whether or not the first image data is different from the second image data that is the image data included in the reception data after storing the first image data; and the data determination unit If it is determined that the first image data and the second image data are different from each other, the first image data stored in the storage unit is updated based on the second image data. An update unit, a limit information determination unit that determines whether the limit information included in the received data is information that allows transmission of external device data to an external device, and the limit information determination unit, Restriction information is If it is determined that the information allows the transmission of the external device data, the third image data based on at least one of the first image data and the second image data, and the restriction information A data generation unit that generates the external device data, and a data transmission unit that can wirelessly transmit the external device data to a plurality of external devices. The restriction information includes the image display device. When the external device that communicates with the image display device is the second layer and the other external device that communicates with the external device is the third layer, the external device as viewed from the device that transmits data. Information indicating the number of remaining hierarchies that are allowed to be transmitted is included, and the limit information determining unit determines that the limit information is for the external device if the number of hierarchies included in the limit information is equal to or greater than a predetermined value. Data If the number of layers is less than a predetermined value, it is determined that the restriction information is information that does not allow transmission of the external device data, and the data generation unit The external device data including the restriction information indicating the remaining number of hierarchies permitted to transmit the external device data is generated .

Here, wireless communication can be exemplified as communication with an external device, and as the wireless communication, an infrastructure mode for communicating with an external device via an access point, or an ad hoc mode for communicating with an external device without passing through an access point Can be mentioned.

According to the present invention, when the determination unit determines that the first image data and the second image data are different, the data generation unit selects at least one of the first image data and the second image data. External device data including the third image data and the restriction information is generated. At this time, the data generation unit generates data for the external device corresponding to the communication method with the external device. Then, the data transmission unit transmits the for that were generated external device data to the external device. According to this, the image display device can easily transmit the image data related to the image displayed by the image display device to a plurality of external devices (for example, other image display devices) as external device data. it can. Therefore, when the external device receives the external device data, and the external device includes a display unit, the external device displays an image similar to the image displayed by the image display device. Can do.
In addition, by changing the restriction information included in the external device data, it is possible to restrict the external device data transmitted from the image display device from being transmitted from the external device to another external device. The image data related to the external device data can be prevented from being duplicated.

In addition, such external device data transmission is performed when the determination unit determines that the first image data and the second image data are different from each other. Therefore, external device data including the same image data is frequently transmitted. Can be prevented from being sent to. Therefore, it is possible to reduce the amount of data to be transmitted.
Further, by the image display apparatus includes an updating unit, the second image data is replaced with the first image data, the comparison between the second image data input after the second image data reliably And can be done appropriately. Accordingly, the discretion tough, and image data to be originally transmitted data for an external device which can be reliably and compares the newly input image data, with a change in the image data, the image data It is possible to reliably generate and transmit data for external devices according to the above.

In the present invention, the data generating unit includes an extraction unit for extracting image data according to the first change area of the second image data for the image data as the third image data, said first image data and a positional information acquisition unit that acquires position information indicating a position of the change area in at least one of the second image data, wherein the external device data may include the previous SL location Is preferred.

Here, when the change area in the second image data is a square shape, the position information is information indicating the coordinates of each vertex of the square, or the coordinates closest to the origin and the size of the rectangle among the vertices. The information shown can be mentioned. Further, the position information may be information indicating the coordinates of the outer periphery of the change area.
According to the present invention, as compared with the case where part of the second image data is different from the first image data, and transmits including data of all areas of the second image data into data for an external device, The amount of data transmitted to the external device can be reduced. Since the external device data includes the position information of the change area, the external device replaces the area indicated by the position information in the already received image data with the image data in the newly input data. Thus, the same image as that displayed by the image display device can be displayed. Therefore, the amount of data to be transmitted can be further reduced, and the change area can be surely grasped by the external device.

In the present invention, the data generation unit includes: a compression unit that generates compressed image data obtained by compressing at least one of the first image data and the second image data in a predetermined compression format; A compression information acquisition unit that acquires compression information indicating a compression format, and the external device data preferably includes the compressed image data and the compression information as the third image data .
According to the present invention, it is possible to further reduce the data amount of the external device data as compared with the case where the image data is not compressed by the compression unit. In addition, since the compression information indicating the compression format is included in the external device data, the external device that has received the external device data can appropriately restore the image data based on the compression information. Further, when the generation unit includes the above-described extraction unit, it is possible to further reduce the data amount.

The image data transmission method of the present invention is an image data transmission method performed using an image display device that displays an image, and stores the image data included in the received data as first image data; A data determination step for determining whether or not the first image data is different from the second image data that is image data included in the received data after storing the first image data; An update step of updating the first image data based on the second image data when it is determined in the data determination step that the first image data and the second image data are different; A restriction information determination step for determining whether or not the restriction information included in the received data is information that allows transmission of external device data to an external device; and the restriction information determination step. If the restriction information is determined to be information that allows transmission of the external device data, a third based on at least one of the first image data and the second image data. wherein the data generation step of generating the data for an external device including the image data and the said restriction information, a transmission step of transmitting to at least one external device the data for an external device by radio, and the restriction The information includes data when the image display device is a first layer, an external device that communicates with the image display device is a second layer, and another external device that communicates with the external device is a third layer. Information indicating the remaining number of hierarchies allowed to transmit the external device data as seen from the transmitting device is included. In the limit information determining step, the number of hierarchies included in the limit information is less than a predetermined value. If so, it is determined that the restriction information is information that allows transmission of the external device data. If the number of layers is less than a predetermined value, the restriction information does not allow transmission of the external device data. It is determined that the information is information, and in the data generation step, the external device data including the restriction information indicating the number of remaining layers allowed to transmit the external device data is generated .
In the present invention, the data generation step includes an extraction procedure for extracting, as the third image data, image data related to a change area of the second image data with respect to the first image data, and the first image data. And a position information acquisition procedure for acquiring position information indicating the position of the change region in at least one of the second image data, and the external device data includes the position information. Is preferred.
In the present invention, the data generation step includes a compression procedure for generating compressed image data by compressing at least one of the first image data and the second image data in a predetermined compression format; A compression information acquisition procedure for acquiring compression information indicating the predetermined compression format, and the external device data preferably includes the compressed image data and the compression information as the third image data. .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[Overall configuration of image display system]
FIG. 1 is a schematic diagram showing an image display system 1 according to the present embodiment.
As shown in FIG. 1, the image display system 1 according to the present embodiment includes a projector 2 as an image display device and a PC (Personal Computer) 3 as an image information output device that outputs image information. Displays an image corresponding to the image information input from the PC 3, and the projector 2 wirelessly communicates image data related to the image information (in FIG. 1, PC4, PDA (Personal Digital Assistant) 5 and By transmitting to the projector 6), the external device 4-6 can also display an image displayed by the projector 2. The projector 2 and the projector 6 have the same configuration.

  Among these, the PC 3 is a PC having a general video output terminal, and outputs an image signal as image information to the projector 2 via the video output terminal. In this embodiment, the PC 3 and the projector 2 are connected by a D-Sub (D-Subminiature) terminal, but the present invention is not limited to this, and other video output terminals such as a DVI (Digital Visual Interface) terminal and It may be connected by other connection terminals such as an HDMI (High-Definition Multimedia Interface) terminal. Further, the image information output device is not limited to the PC 3 and may include other devices such as various players configured to be able to reproduce a recording medium such as a DVD.

[Configuration of projector]
FIG. 2 is a block diagram showing the configuration of the projector 2.
As described above, the projector 2 forms an image according to input image information, and enlarges and projects the image on a projection surface such as a screen SC. Further, the projector 2 wirelessly transmits image data based on the image signal to the external devices 4 to 6 (PC4, PDA5, and projector 6).

As shown in FIG. 2, the projector 2 includes an image processing unit 21, a video memory 22, an image forming unit 23, a wireless communication unit 24, a data transmission unit 25, and a data reception unit 26.
Among these, the video memory 22 corresponds to a storage unit of the present invention, and is a memory such as a video random access memory (VRAM) configured to be referred to by the image processing unit 21, the data transmission unit 25, and the data reception unit 26. . Such video memory 22 stores image data.

[Configuration of image processing means]
The image processing means 21 processes the input image signal as image information. Then, the image processing unit 21 outputs a drive signal to a liquid crystal panel 232 described later of the image forming unit 23 based on the image signal, and causes the image forming unit 23 to form an image according to the image information. The image processing means 21 includes a DA converter 211, an image processing unit 212, and a panel driver 213.
The DA converter 211 digitally converts an analog signal input from the PC 3 through the D-Sub terminal, and outputs the converted digital signal to the image processing unit 212.

The image processing unit 212 generates image data from the input digital signal, stores the image data in the video memory 22, and outputs the image data to the panel driver 213. At this time, the image processing unit 212 expands / contracts the image data to an appropriate size in order to output a drive signal related to the generated image data to the liquid crystal panel 232, and performs correction such as hue adjustment and gamma correction of the image data. Perform processing.
The image processing unit 212 forms an image based on a digital signal input from the DA converter 211 according to a user's operation, and image data stored in the video memory 22 by the data receiving unit 26 described later. A switching unit (not shown) for switching between the case of forming an image based on the above. In the latter case, the image processing unit 212 refers to the video memory 22 to acquire image data, performs a predetermined correction process on the image data, and outputs the image data to the panel driver 213. To do.

  The panel driver 213 converts the input image data into a drive signal for the liquid crystal panel 232, and outputs the drive signal to the liquid crystal panel 232. As a result, an image corresponding to the drive signal is formed on the liquid crystal panel 232.

[Configuration of image forming means]
The image forming unit 23 forms image light corresponding to the drive signal input from the panel driver 213 and projects the image light to display an image related to the image light on the screen SC. The image forming unit 23 includes a light source device 231, a liquid crystal panel 232 as a light modulation device, and a projection optical device 233. Although not shown, the image forming unit 23 separates the light beams emitted from the light source device 231 into red (R), green (G), and blue (B) color lights in addition to these configurations. A color separation optical device and a color synthesis optical device such as a cross dichroic prism that synthesizes each color light are provided, and the liquid crystal panel is disposed on the optical path of each color light.

  The light source device 231 includes a discharge-type light source lamp and a reflector that reflects the emitted light emitted from the light source lamp and converges it to a predetermined position. In the present embodiment, the light source lamp is composed of an ultra-high pressure mercury lamp, but may be composed of other discharge type light source lamps. The light source device 231 may be configured to include a solid light source such as an LED (Light Emitting Diode) and an LD (Laser Diode), and an organic EL (Electroluminescence) element instead of the light source lamp.

The liquid crystal panel 232 has a configuration in which a liquid crystal that is an electro-optical material is hermetically sealed between a pair of transparent glass substrates, and the alignment state of the liquid crystal is controlled according to a drive signal input from the panel driver 213. Modulates the polarization direction of the incident light beam. As described above, the liquid crystal panel 232 is disposed on the optical path of each color light of red (R), green (G), and blue (B) separated by the color synthesizing optical device. Then, image light relating to each color light is formed. Each of these image lights is synthesized by a color synthesizing optical device to form image light relating to a color image.
The projection optical device 233 enlarges and projects the image light combined by the color combining optical device. The projection optical device 233 is configured as a combined lens including a lens barrel and a plurality of lenses housed inside the lens barrel.

[Configuration of wireless communication means]
In this embodiment, the wireless communication unit 24 includes a wireless LAN (Local Area Network) module, and communicates with the external devices 4 to 6 wirelessly. At this time, if these external devices have a unique IP (Internet Protocol) address, the wireless communication means 24 communicates with the external device in the infrastructure mode and does not have a unique IP address. In this case, communication is performed with the external device using a predetermined channel in the ad hoc mode. Such a wireless communication unit 24 transmits the external device data generated by the data transmission unit 25 to the external devices 4 to 6, and receives external device data from other external devices. The data is output to the data receiving means 26.

[Configuration of data transmission means]
FIG. 3 is a block diagram showing the configuration of the data transmission unit 25.
The data transmission unit 25 generates data for external devices based on the image data stored in the video memory 22 and executes data transmission processing for transmitting the data to the external devices 4 to 6 via the wireless communication unit 24. To do. As shown in FIG. 3, the data transmission unit 25 includes a frame memory 251, a transmission destination information storage unit 252, and an external device data generation unit 253. The data transmission process will be described later in detail.

The frame memory 251 is used as a work memory by the external device data generation unit 253, and at least a part of the image data (input image data) stored in the video memory 22 is stored in the frame memory 251.
The destination information storage unit 252 stores an IP address of an external device to which data for external device is to be transmitted during communication in the infrastructure mode, and a channel used during communication in the ad hoc mode. These IP addresses and channels can be acquired by searching as well as being input by the user.

The external device data generation unit 253 generates the external device data described above. The external device data generation unit 253 includes a restriction information determination unit 254, a data determination unit 255, a data generation unit 256, a data update unit 257, and a data output unit 258.
Among these, the data determination unit 255 corresponds to the determination unit of the present invention, refers to the image data stored in the video memory 22 at a predetermined timing, and determines whether or not the image data has changed. Specifically, the data determination unit 255 stores the stored image data (corresponding to the first image data of the present invention) that is the image data stored in the video memory 22 and the image data , and determines the input image data is image data that is input immediately before (corresponding to the second image data of the present invention) or different or not. Such timing can be a timing at which the image data is updated, or can be a timing according to a vertical synchronization signal related to display of the image data.

Data generating unit 256, the data judging unit 255, when the change in the image data is determined to have occurred, and generates data for an external device on the basis of the image data stored in the video memory 22. The data generation unit 256 includes a position information acquisition unit 2561, a data extraction unit 2562, a data compression unit 2563, a compression information acquisition unit 2564, an identification information acquisition unit 2565, a restriction information acquisition unit 2566, and a packet generation unit 2567.

The position information acquisition unit 2561 acquires the position information of the area where the data determination unit 255 determines that the image data has changed. That is, the position information acquisition unit 2561 acquires position information of regions (change regions) that are different between the stored image data and the input image data. In the present embodiment, the position information acquisition unit 2561 acquires, as position information, the coordinates closest to the origin when the change area is rectangular and the size of the change area. However, the present invention is not limited to this, and the position information acquisition unit 2561 may acquire the coordinates of each vertex of the rectangular change area.
The data extraction unit 2562 corresponds to the extraction unit of the present invention, extracts image data related to the above-described change area (corresponding to the third image data of the present invention) from the input image data, and stores the image data in the frame memory 251. Remember me.

The data compression unit 2563 corresponds to the compression unit of the present invention, and compresses the image data stored in the frame memory 251 in a predetermined compression format. Examples of such a compression format include JPEG (Joint Photographic Experts Group) in the case of lossy compression and TIFF (Tagged Image File Format) in the case of lossless compression. Good. Such a compression format can be selected by the user.
The compression information acquisition unit 2564 acquires compression information indicating the type of compression format used in the compression processing by the data compression unit 2563.
The identification information acquisition unit 2565 acquires the identification information (IP address or channel) of the external device that is the transmission destination of the external device data from the transmission destination information storage unit 252.

  When the projector 2 is the data transmission side to the external devices 4 to 6, the restriction information acquisition unit 2566 displays the restriction information set by the user, and the projector 2 receives the data reception side from other devices. In such a case, the restriction information included in the data (external device data) received from the other device is acquired. This restriction information is information indicating whether or not external device data transmitted from the projector 2 to the external devices 4 to 6 is permitted to be transmitted to another external device. . Specifically, the restriction information includes the projector 2 as the first layer, the external devices 4 to 6 communicating with the projector 2 as the second layer, and another external device (projector 2) communicating with the external devices 4 to 6. 3), it is shown to which layer data transmission is permitted.

  Based on the image data extracted from the input image data and stored in the frame memory 251, and the above-described position information, compression information, identification information, and restriction information, the packet generation unit 2567 performs data transmission by the wireless communication unit 24. Data for the external device is generated in a suitable format, that is, in a format corresponding to the communication method with the external devices 4 to 6. Specifically, the packet generation unit 2567 generates a packet including the image data and various information. At this time, if the projector 2 is not in the first hierarchy, the packet generator 2567 generates a packet including restriction information indicating the remaining hierarchy in which data transmission is permitted. For example, when the projector 2 is in the second layer and the limit information included in the received external device data (packet) permits data transmission up to the third layer, the remaining information is the remaining one. This is information indicating that data transmission up to the hierarchy is possible. When the wireless communication unit 24 communicates in the ad hoc mode, the packet generation unit 2567 does not include the identification information including the channel in the packet, and outputs the identification information to the wireless communication unit 24.

The data update unit 257 corresponds to the update unit of the present invention, replaces stored image data stored in the video memory 22 with input image data, and updates the stored image data.
The data output unit 258 corresponds to the data transmission unit of the present invention together with the wireless communication unit 24, and outputs the packet (external device data) generated by the packet generation unit 2567 to the wireless communication unit 24. Transmits the packet to the external devices 4-6.

[Configuration of data receiving means]
Returning to FIG. 2, when receiving data for external devices from another external device different from the PC 3, the data receiving unit 26 processes the data received via the wireless communication unit 24. Specifically, the data receiving unit 26 restores the image data included in the data based on various information (for example, compression information) included in the received data, and copies the image data to the video memory 22. Further, the data receiving unit 26 acquires the restriction information included in the external device data and outputs the restriction information to the data transmission unit 25.

  As a result, the received image data related to the external device data is processed by the image processing means 21, and the image related to the image data is formed and displayed by the image forming means 23. Further, when data transmission to an external device of a lower hierarchy is permitted based on the restriction information included in the external device data, new data for external device is generated by the data transmission means 25. The wireless communication unit 24 transmits the data to another external device.

[Configuration of external devices]
Here, the PC 4 as an external device will be described. The PDA 5 has the same configuration as that of the PC 4 below, in addition to the configuration unique to the PDA 5 instead of the configuration unique to the PC 4. For this reason, description of PDA5 is abbreviate | omitted.

FIG. 4 is a block diagram showing the configuration of the PC 4.
As described above, the PC 4 receives the data (external device data) transmitted from the projector 2 and forms an image related to the image data included in the data, and the external device 7 connected to the PC 4. It is possible to form an image related to the image information input from. As shown in FIG. 4, the PC 4 includes an image processing unit 41, a video memory 42, a display unit 43, a wireless communication unit 44, and a data receiving unit 45.
The configurations and functions of the video memory 42, the wireless communication unit 44, and the data receiving unit 45 are the same as those of the video memory 22, the wireless communication unit 24, and the data receiving unit 26 described above, and thus the description thereof is omitted.

The image processing unit 41 has the same configuration as the above-described image processing unit 21, processes an image signal as image information input from the external device 7, and generates image data on the video memory 42. Then, the image processing unit 41 outputs a drive signal based on the image data to the display unit 43. In addition, when the image processing unit 41 is operated to display an image related to the received data (external device data), the image processing unit 41 stores the image data stored in the video memory 42 by the data receiving unit 45 described later. Processing is performed to output a drive signal based on the image data to the display means 43.
The display unit 43 is a display device such as a liquid crystal panel, for example, and displays an image corresponding to the drive signal input from the image processing unit 41.

[Data transmission processing]
FIG. 5 is a flowchart showing data transmission processing by the projector 2.
As described above, the projector 2 executes the data transmission process.
In this data transmission process, as shown in FIG. 5, first, the restriction information determination unit 254 constituting the data transmission unit 25 refers to the restriction information and transmits the data for the external device to the external devices 4 to 6. It is determined whether or not it is permitted (step S01). Here, when the restriction information determination unit 254 determines that it is not permitted, the projector 2 ends the data transmission process.

  On the other hand, when the restriction information determination unit 254 determines that the permission is permitted, the data determination unit 255 compares the stored image data with the input image data to determine whether or not a change has occurred in the input image data. Determination is made (step S02). Here, if the data determination unit 255 determines that no change has occurred, the data determination unit 255 continues to monitor the input image data updated by the image processing unit 212.

  On the other hand, when the data determination unit 255 determines that a change has occurred in the input image data, the position information acquisition unit 2561 of the data generation unit 256 determines a region (change region) in which the change has occurred in the input image data. Position information is acquired (step S03). Then, the data extraction unit 2562 extracts the image data of the change area from the input image data (step S04), and the data compression unit 2563 compresses the extracted image data in a predetermined compression format (step S05). Further, the compression information acquisition unit 2564 acquires the compression information indicating the compression format (step S06). Furthermore, the identification information acquisition unit 2565 refers to the transmission destination information storage unit 252 to acquire identification information of the external devices 4 to 6 (step S07), and the restriction information acquisition unit 2566 acquires the above-described restriction information. (Step S08).

Next, the packet generation unit 2567 generates external device data (packet) based on the compressed image data (corresponding to the compressed image data of the present invention) and various information (step S09), and the data output unit 258 Then, the data is transmitted and output to the external devices 4 to 6 through the wireless communication means 24 (step S10).
Thereafter, the data updating unit 257 replaces the input image data on the video memory 22 with the stored image data, and updates the stored image data (step S11).
As described above, the data transmission process ends, but the data transmission process is repeatedly executed, so that the external device data is transmitted to each of the external devices 4 to 6 every time the input image data changes.

The projector 2 according to the present embodiment described above has the following effects.
(1) When the data determination unit 255 determines that the stored image data is different from the input image data, the data generation unit 256 uses the external communication device 24 according to the communication method of the wireless communication unit 24 based on the input image data. Generate data (packets). Then, the data output unit 258 transmits the external device data to the external devices 4 to 6 via the wireless communication unit 24. According to this, the image data related to the image displayed by the projector 2 can be easily transmitted to the plurality of external devices 4 to 6. Accordingly, similar images can be displayed on the projector 2 and the external devices 4 to 6.

The generation and transmission of the external device data is performed when the data determination unit 255 determines that the stored image data is different from the input image data. According to this, it is possible to prevent external device data including the same image data from being frequently transmitted, and to reduce the amount of data to be transmitted.
Further, since the stored image data is updated by the input image data related to the generated external device data by the data update unit 257, it is possible to appropriately determine whether or not there is a change in the input image data. .

  (2) The image data included in the external device data is image data related to the change area extracted by the data extraction unit 2562. According to this, it is possible to reduce the amount of data to be transmitted compared to the case where image data relating to the entire area of the input image data is included in the external device data and transmitted. In addition, since the external device data includes position information in the input image data of the change area, the external devices 4 to 6 have externally input the area indicated by the position information in the already received image data. By replacing the image data with the device data, the same image as the image displayed by the projector 2 that is the transmission source can be displayed.

  (3) The external device data includes image data extracted as a change area from the input image data by the data extraction unit 2562 and compressed by the data compression unit 2563. According to this, compared with the case where the said image data is not compressed, the data amount of the transmitted data can be made still smaller. In addition, since the external device data includes compression information, the external devices 4 to 6 can appropriately restore the image data included in the data.

  (4) The external device data includes restriction information for restricting transmission of the data to other external devices. According to this, when the restriction information permits data transmission up to the second layer, from the external devices 4 to 6 that have received the external device data to other external devices located in the third layer. The transmission of the data can be restricted. Therefore, it is possible to prevent the external device data from being copied indefinitely.

[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 embodiment, the data generation unit 256 includes the position information acquisition unit 2561 and the data extraction unit 2562, and the data compression unit 2563 and the compression information acquisition unit 2564. However, the present invention is not limited to this. That is, the data generation unit 256 may include only the position information acquisition unit 2561 and the data extraction unit 2562 in addition to the packet generation unit 2567, or may include only the data compression unit 2563 and the compression information acquisition unit 2564. The structure provided may be sufficient. That is, the entire input image data may be transmitted without extracting the image data relating to the change area, or may be transmitted without being compressed.

  In the embodiment, the restriction information is added to the external device data, but the present invention is not limited to this. That is, if the transmission of the external device data received by the external device to other external devices is not restricted, the restriction information may not be added.

  In the embodiment, the projector 2 includes the three liquid crystal panels 232 as the light modulation device, but the present invention is not limited to this. That is, the present invention can also be applied to a projector using two or less or four or more liquid crystal panels. Further, as long as it is a light modulation device that modulates an incident light beam according to image information to form image light, a light modulation device having another configuration may be adopted. For example, the present invention can be applied to a projector using a light modulation device other than liquid crystal, such as a device using a micromirror.

  In the above-described embodiment, the front-type projector 2 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 as the image display device is illustrated. 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. In addition to the projector, the present invention can also be applied to various image display devices such as a liquid crystal display, a plasma display, an organic EL (Electroluminescence) display, and a CRT (Cathode Ray Tube) display. In addition, although the PC 4, PDA 5, and projector 6 are illustrated as external devices, the present invention is not limited to this, and other devices may be used as long as they can receive data for external devices.

  The present invention can be used for an image display device, and can be preferably used particularly for a projector used for a presentation.

1 is a schematic diagram showing an image display system according to an embodiment of the present invention. The block diagram which shows the structure of the projector in the said embodiment. The block diagram which shows the structure of the data transmission means in the said embodiment. The block diagram which shows the structure of PC as an external apparatus in the said embodiment. The flowchart which shows the data transmission process in the said embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Projector (image display apparatus), 22 ... Video | video memory (memory | storage part ), 24 ... Wireless communication means ( data transmission part ), 255 ... Data determination part (determination part), 256 ... Data generation part, 257 ... Data update part (Update unit), 258 ... Data output unit ( data transmission unit), 2561 ... Position information acquisition unit, 2562 ... Data extraction unit (extraction unit), 2563 ... Data compression unit (compression unit), 2564 ... Compression information acquisition unit, 2566: Restriction information acquisition unit.

Claims (6)

An image display device for displaying an image,
A storage unit for storing image data included in the received data as first image data;
A data determination unit that determines whether or not the first image data is different from the second image data that is image data included in the reception data after storing the first image data;
When the data determination unit determines that the first image data and the second image data are different, the first image data stored in the storage unit is used as the second image data. An update unit to update based on;
A restriction information determination unit that determines whether or not the restriction information included in the received data is information that allows transmission of external device data to an external device;
When the restriction information determination unit determines that the restriction information is information that allows transmission of the external device data, it is based on at least one of the first image data and the second image data. A data generation unit that generates the external device data including third image data and the restriction information;
A data transmission unit capable of wirelessly transmitting the external device data to a plurality of external devices ,
In the restriction information, when the image display device is a first layer, an external device that communicates with the image display device is a second layer, and another external device that communicates with the external device is a third layer, Information indicating the number of remaining layers allowed to transmit the data for the external device as seen from the device transmitting the data,
If the number of hierarchies included in the restriction information is equal to or greater than a predetermined value, the restriction information determination unit determines that the restriction information is information that allows transmission of the external device data, and the number of hierarchy is a predetermined value If it is less, it is determined that the restriction information is information that does not allow transmission of the external device data,
The data generation unit generates the external device data including the restriction information indicating the number of remaining layers in which transmission of the external device data is permitted.
An image display device comprising a call. The image display device according to claim 1,
The data generator is
An extraction unit that extracts, as the third image data, image data related to a change area of the second image data with respect to the first image data;
A position information acquisition unit that acquires position information indicating the position of the change region in at least one of the first image data and the second image data;
The image display apparatus, wherein the external device data includes the position information. The image display device according to claim 1 or 2,
The data generator is
A compression unit that generates compressed image data obtained by compressing at least one of the first image data and the second image data in a predetermined compression format;
A compression information acquisition unit that acquires compression information indicating the predetermined compression format;
The image display apparatus, wherein the external device data includes the compressed image data and the compression information as the third image data. An image data transmission method performed using an image display device for displaying an image,
A storage step of storing image data included in the received data as first image data;
A data determination step for determining whether or not the first image data is different from the second image data which is image data included in the reception data after storing the first image data;
An update step of updating the first image data based on the second image data when it is determined in the data determination step that the first image data and the second image data are different. When,
A restriction information determination step for determining whether or not the restriction information included in the received data is information that allows transmission of external device data to an external device;
If it is determined in the restriction information determination step that the restriction information is information that allows transmission of the external device data, the restriction information determination step may include at least one of the first image data and the second image data. A data generation step of generating the external device data including the third image data based on the restriction information;
Wirelessly transmitting the external device data to at least one external device, and
In the restriction information, when the image display device is a first layer, an external device that communicates with the image display device is a second layer, and another external device that communicates with the external device is a third layer, Information indicating the number of remaining layers allowed to transmit the data for the external device as seen from the device transmitting the data,
In the restriction information determination step, if the number of layers included in the restriction information is equal to or greater than a predetermined value, it is determined that the restriction information is information that allows transmission of the external device data, and the number of layers is a predetermined value. If it is less, it is determined that the restriction information is information that does not allow transmission of the external device data,
In the data generation step, the external device data including the restriction information indicating the number of remaining layers allowed to transmit the external device data is generated.
Image data transmission wherein a call. The image data transmission method according to claim 4 ,
The data generation step includes
An extraction procedure for extracting, as the third image data, image data relating to a change area of the second image data with respect to the first image data;
A position information acquisition procedure for acquiring position information indicating a position of the change area in at least one of the first image data and the second image data;
The image data transmission method, wherein the external device data includes the position information. In the image data transmission method according to claim 4 or 5 ,
The data generation step includes
A compression procedure for generating compressed image data by compressing at least one of the first image data and the second image data in a predetermined compression format;
A compression information acquisition procedure for acquiring compression information indicating the predetermined compression format,
The image data transmission method, wherein the external device data includes the compressed image data and the compression information as the third image data.

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