Display device

Abstract

To provide a television display device which improves convenience when a video obtained by a portable video apparatus such as a camera and a cellular phone is displayed on a display device.SOLUTION: A system including a video device and a video display device selects a first image, a second image, or a third image based on image information acquired from an external device connected to the video display device via a predetermined interface, and displays the selected image on a display unit. The display unit performs slide show display at a predetermined time interval using a plurality of first images based on image information obtained by decompressing compressed image information input from an external device via the first interface unit by the decompression unit. In addition, the display unit performs slideshow display at predetermined time intervals using a plurality of second images based on the uncompressed image information input via the second interface unit. A display section displays an image and a voice output section outputs a voice.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a technique for displaying video information from a video device connected to a display device via an interface on the display device. [Background technology]

[0002] In order to connect a video device to another video device, i.e., a video display device, and view videos, a method of transmitting video and audio signals via an analog connection has been used. However, with the spread of digital devices, from the viewpoints of preventing deterioration in image quality and protecting copyrights, a method of transmitting digitally connected video and audio signals after encrypting them has come to be used.

[0003] One example of digital transmission is one that uses a single cable conforming to the IEEE 1394 standard. This involves mutual authentication between the sending and receiving devices, multiplexing the video and audio signals after that authentication, and then transmitting the multiplexed data after undergoing an encryption process called DTCP.

[0004] Another example is the HDMI standard, which time-division multiplexes a baseband signal of a high-definition video signal and an audio signal, and then performs an encryption process called HDCP to enable transmission.

[0005] A conventional technique for multiplexing and transmitting such digitized video and audio signals is disclosed in, for example, Patent Document 1 below. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-232377 Summary of the Invention [Problem to be solved by the invention]

[0007] The IEEE 1394 standard is used as a network and has a limited transmission rate, so it cannot transmit high-definition video signals with a large amount of information as baseband signals. Therefore, the IEEE 1394 standard has the problem that the baseband signals must be compressed to reduce the transmission rate before transmission. On the other hand, the HDMI system does not take into consideration the possibility of devices receiving transmitted high-definition video signals recording the received signals.

[0008] Furthermore, these methods all assume connections between stationary devices located in the home, and do not sufficiently consider the convenient connection of portable devices such as digital cameras and mobile phones to video display devices.

[0009] The present invention has been made in consideration of such problems, and provides a technology for improving convenience when displaying images obtained with portable video devices such as cameras and mobile phones on a display device. [Means for solving the problem]

[0010] The present invention is characterized in that it is possible to acquire and display multiple pieces of video information from an external video device by transmitting a video acquisition request to the external video device at predetermined periodic intervals to the external video device connected to the display device via a predetermined interface, in order to acquire the video information from the external video device.

[0011] The plurality of images thus obtained may be displayed in a so-called slide show format by switching between them at predetermined intervals, for example. Alternatively, a plurality of thumbnail images may be generated from the plurality of pieces of video information and displayed side by side on one screen of the display unit. [Effects of the Invention]

[0012] According to the present invention, it is possible to improve the convenience when displaying on a display device an image captured by a portable image device such as a camera or a mobile phone. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing an example of a system including a video device and a video display device according to an embodiment of the present invention. [Figure 2] 1 is a diagram showing an example of a video device 100 according to an embodiment of the present invention. [Figure 3] FIG. 2 is an explanatory diagram showing the order of compressed signal processing. [Figure 4] 1 is a diagram showing an example of a video display device 200 according to an embodiment of the present invention. [Figure 5] FIG. 2 is a diagram showing another example of the image display device 200 according to the embodiment of the present invention. [Figure 6] FIG. 1 is a diagram showing an example of a system in which two video devices are connected to each other. [Figure 7] FIG. 1 is a diagram showing an example of a system in which a video display device and a video device are connected. [Figure 8] FIG. 1 is a diagram showing an example of a system in which two video devices are wirelessly connected to each other. [Figure 9] FIG. 10 is a diagram showing another example of a system in which two video devices are wirelessly connected to each other. [Figure 10] 1 is a diagram showing an embodiment of a video display device according to the present invention; [Figure 11] FIG. 10 is a diagram showing another embodiment of a video display device according to the present invention. [Figure 12] FIG. 4 is a diagram showing an example of thumbnail display in the present embodiment. [Figure 13] FIG. 10 is a diagram showing another example of thumbnail display in the embodiment. [Figure 14] FIG. 10 is a diagram showing another example of thumbnail display in the embodiment. [Figure 15] 10 is a diagram showing an example of attribute information corresponding to each still image stored in memory 1018 of video device 1020. FIG. [Figure 16] FIG. 1 is a diagram showing an example of the configuration of an HDMI interface. [Figure 17] FIG. 2 is a diagram showing an example of a format of a remote control code. [Figure 18] FIG. 10 is a diagram showing an example of a method for transmitting a remote control code via a CEC line. [Figure 19] 10 is a diagram showing an example of a table of manufacturer codes and device codes corresponding to each interface stored in the video display device 200. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Preferred embodiments of the present invention will now be described with reference to the drawings. [Example]

[0015] FIG. 1 shows a first embodiment of the present invention. In FIG. 1, three video devices are shown. One is video device 100, which may be a portable video device capable of receiving digital broadcast signals from a mobile phone base station antenna 20 or a broadcast transmission tower 30; another is a video display device 200; and the other is a receiver 300, such as a tuner, capable of receiving digital broadcast signals from broadcast transmission tower 30. Video device 100 and video display device 200 are connected by, for example, a bidirectional interface 10, and video display device 200 and receiver 300 are further connected by another bidirectional interface 11. This enables bidirectional communication of video signals and other information and signals between the devices.

[0016] In this embodiment, the portable video device 100 is specifically a digital camera, a video camera, a mobile phone, a game console, a personal media player, etc. The components required for each type are not necessarily the same, but the embodiment shown in Fig. 1 mainly describes the components required for input and output to and from the outside.

[0017] In FIG. 1, a mobile phone base station antenna 20 and an antenna 102 of a video device 100 transmit and receive signals. When the video device 100 is used as a mobile phone, signal processing is performed as in a normal mobile phone. The video device 100 can also receive content such as movies transmitted from the mobile phone base station antenna 20. In this case, the content can be viewed on a display device and audio output device built into the video device 100, or can be viewed on a large screen on an external video display device 200 via a terminal 101, a connection cable 10, and a terminal 201. Furthermore, the content can be recorded on a storage medium built into the video device 100 or on a storage medium (e.g., memory 121) connected to the video device 100 while being viewed or for later viewing. The memory 121 can also be used as a recording medium for recording movies and the like.

[0018] Similarly, a program broadcast from broadcast transmission tower 30 is received by broadcast receiver 180 of video equipment 100 and can be viewed on video equipment 100, or can be recorded on a storage medium (not shown) built into video equipment 100 or a connected storage medium (for example, memory 121). Furthermore, the program can be viewed on video display device 200 via terminal 101, connection cable 10, and terminal 201.

[0019] Furthermore, a program broadcast from broadcast transmission tower 30 is received by receiving antenna 310 connected to receiver 300, input to receiver 300 via antenna terminal 302, and after appropriate signal processing, viewed on video display device 200 via terminal 301, connection cable 11, and terminal 202. Also, simultaneously with viewing, or separately from viewing, a selected program can be stored in memory 321 via a built-in storage medium (not shown) or memory interface 320. Memory 321 recorded in receiver 300 can also be connected to memory interface 120 of video device 100. By taking video device 100 outside the home and displaying the program on a display device (not shown) built into video device 100, it is possible to view a program recorded at home outside the home.

[0020] Furthermore, by mounting an imaging device 110 and a microphone 112 on the video equipment 100, still images and videos can be taken along with audio, and the images and videos can be stored in an appropriate built-in storage medium (not shown) or memory 121. The video and audio stored in the built-in storage medium or memory 121 can be viewed on the video display device 200 via the terminal 101, the connection cable 10, and the terminal 201.

[0021] In the embodiment shown in Fig. 1, terminal 101 of video device 100 is connected to terminal 201 of video display device 200, and terminal 301 of receiver 300 is connected to terminal 201 of video display device 200 using wired cables such as connection cables 10 and 11, respectively. However, when transmitting and receiving signals between these video devices, there is no need to use wired cables for connection; they may be connected wirelessly. A wireless connection eliminates the hassle of wiring and the need to organize the wiring. Using a connection cable has the advantage of being more resistant to interference such as noise than a wireless connection.

[0022] Fig. 2 shows a first embodiment of the present invention, specifically illustrating the configuration of the video device 100 of Fig. 1. In Fig. 2, an imaging device 110 captures moving and still images input through an optical system and converts them into electrical signals. A compression circuit 111 efficiently compresses the captured images using a compression method such as MPEG2, MPEG4, or AVC / H.264 for moving images, or a compression method such as JPEG for still images.

[0023] Meanwhile, the microphone 112 converts the sound waves into an electrical signal, and the compression circuit 113 efficiently compresses the captured audio signal into bits using a compression method such as MPEG audio.

[0024] When capturing a still image with the video equipment 100, the video equipment is rotated depending on the subject to be captured, and is used in either a horizontal or vertical position. The sensor 114 detects whether the video equipment 100 is used in a horizontal or vertical position. If used in a vertical position, the sensor 114 also detects whether the video equipment 100 is turned right-side up or left-side up. The information detected by the sensor 114 is input to the microprocessor 115.

[0025] The multiplexing circuit 116 receives the bit-compressed video and audio signals from the compression circuits 111 and 113, as well as various information from the microprocessor 115, and multiplexes them in accordance with a predetermined format. When a still image is captured, an audio signal is not normally captured, but an audio signal may be multiplexed in conjunction with the still image capture.

[0026] The various information from the microprocessor 115 includes position information (horizontal, right vertical, left vertical) using the sensor 114, date, exposure information at the time of shooting, and the like.

[0027] Fig. 3 shows the order of signal processing for each block that is generally performed in image compression. As shown in Fig. 3(a), signal processing is performed in order from left to right in the top row of the image, and then from left to right in the second row. As shown in Fig. 3(b), when the video equipment 100 is positioned vertically with the right side up, signal processing is performed from bottom to top in the left column, then from bottom to top in the second column from the left. As shown in Fig. 3(c), when the video equipment 100 is positioned vertically with the left side up, signal processing is performed from top to bottom in the right column, then from top to bottom in the second column from the right.

[0028] If the camera is held vertically during shooting, the captured image cannot be displayed on the display device exactly as it was shot unless there is information as to which side is up. For this reason, as described above, position information is multiplexed onto the video and audio signals as various information from the microprocessor 115. The compressed signal is expanded, and the expanded image is rotated 90 degrees using the position information in accordance with the output of the display device, allowing the image to be displayed exactly as it was shot.

[0029] Also, instead of multiplexing the position information, the microprocessor 115 provides the position information to the compression circuit 111 to control the compression circuit 111, as shown by the dotted line from the microprocessor 115 to the compression circuit 111 in Fig. 2. This allows the compression circuit 111 to perform compressed signal processing itself in accordance with the video shooting operation and the shooting position of the video equipment 100, thereby eliminating the need for rotation processing during playback. For example, as shown in (d) and (e) of Fig. 3, by performing compressed signal processing from left to right in the top row of the image at the time of shooting, and then from left to right in the second row, based on the position information, it is possible to display the image exactly as it was shot during playback.

[0030] When the imaging device 100 is capable of capturing both still images and moving images, as described above, some users may take still images in a horizontal position and some in a vertical position. Similarly, some users may consider using the imaging device 100 in a vertical position when capturing moving images.

[0031] In the case of moving images, signal processing for rotation is generally not provided, and if the image is displayed as is on the image display device 200, the image will be displayed rotated horizontally, which is an unintended capture for the user. Therefore, when capturing images in video mode, if the user rotates the imaging device 100, the sensor 114 detects that it is being used in portrait orientation, and the microprocessor 115 displays a warning message on the display device 160. The display device 160 is used as a monitor for the image captured by the imaging device 110, making it easy to check the message while capturing images, and if this is not intended, the display device warns the user to change to the normal landscape orientation for capturing images.

[0032] At the same time, when the video device is used in portrait orientation, the microprocessor 115 sends position information to the compression circuit 111 to control the compression circuit 111. As a result, the compression circuit 111 performs compression signal processing from left to right at the top of the portrait orientation, for example, as shown in (d) and (e) of Figure 3, so that the video can be played back in accordance with the video shooting operation and the shooting position of the video device 100. This allows viewing in portrait orientation even on current televisions. A detailed explanation of this will be given later.

[0033] 2, the signal multiplexed by multiplexing circuit 116 is stored in storage device 130 via encryption / decryption circuit 140. For example, a hard disk drive, an optical disk drive, a semiconductor memory device, etc. can be used as the storage device, and the type of storage device to be used can be determined taking into consideration the desired storage capacity, size, ease of removal of the storage medium, price, etc. Alternatively, the signal can be stored in memory 121 via signal processing circuit 124 and memory interface 120.

[0034] For information photographed by an individual, the copyright belongs to the person who photographed it, so encryption is usually not required when storing the information. However, since there is a possibility that the medium stored in storage device 130 may be lost, security can be increased by encrypting the output signal of multiplexing circuit 116 in encryption / decryption circuit 140 and then storing it in storage device 130 or memory 121.

[0035] The video device 100 may be compatible with removable memory, or may have a mobile phone function or a wireless LAN function. The memory interface 120 is an interface for removable memory 121, and by recording still images, moving images, and audio content in the memory 121 using another device and connecting it to the interface 120, the content can be recorded in the storage device 130 via the signal processing circuit 124 and the encryption / decryption circuit 140.

[0036] At this time, the signal processing circuit 124 detects whether the content recorded in the memory 121 is copyright protected and whether copying is restricted, and the content is encrypted in the encryption / decryption circuit 140 according to the conditions and transferred to the storage device 130.

[0037] Similarly, when still images, moving images, or audio content is received and input via the wireless interface 122, it is recorded in the storage device 130 via the signal processing circuit 124 and the encryption / decryption circuit 140. In this case, too, the encryption / decryption circuit 140 encrypts the content as necessary in accordance with the copyright protection and copy restriction conditions of the content.

[0038] When playing and viewing content stored in storage device 130, the content to be viewed is selected using input keys or a remote control (not shown), and the selected content is read out from storage device 130, decrypted by encryption / decryption circuit 140, and separated into a video signal and an audio signal by demultiplexing circuit 141.

[0039] Furthermore, when a broadcast is received by broadcast receiver 180, the encryption / decryption circuit 140 decrypts the broadcast code, and if necessary, encryption processing for storage is also performed by the encryption / decryption circuit 140, and the data is recorded in storage device 130 and memory 121. When the received broadcast is viewed directly, the video signal and audio signal are separated by demultiplexing circuit 141.

[0040] The separated and compressed video signal is expanded by an expansion circuit 142 and input to a signal processing circuit 150. The signal processing circuit 150 performs scanning line conversion in accordance with the scanning lines of a display device 160 and outputs the signal to the display device 160.

[0041] The separated and compressed audio signal is expanded by the expansion circuit 143 and output to the audio output device 161. In this way, since the video equipment 100 has the display device 160 and the audio output device 161, it is possible to view the video directly without connecting an external video display device. Note that a time difference between the video display and the audio output due to differences in the time required for the expansion processing of the video signal and the audio signal, the presence or absence of scanning line conversion processing, etc., can cause a sense of incongruity. In particular, if the video signal processing takes time and the audio signal precedes the video signal, this sense of incongruity becomes more pronounced. Therefore, for example, the audio signal is delayed during the expansion processing, and so-called lip-sync is performed. This can eliminate the sense of incongruity caused by a mismatch between the video signal and the audio signal.

[0042] On the other hand, when the video signal and audio signal are viewed on an external video display device 200, the scan lines supported by the video display device 200 are checked, and if they match the scan lines of the video signal to be displayed, they are output as is. If they differ, the signal processing circuit 150 converts them to the required scan lines, and then the multiplexing circuit 170 time-domain multiplexes them with the audio signal processed by the signal processing circuit 151. The signal processing circuit 151 time-domain compresses the audio signal to a period equivalent to the blanking interval of the video signal and, if necessary, adjusts the time for lip synchronization. The video signal and audio signal multiplexed by the multiplexing circuit 170 are input to the encryption circuit 171, where they undergo encryption processing required for transmission between the video equipment 100 and the video display device 200, and are then output to the video display device 200 via the interface 172 and the terminal 101.

[0043] As described above, even if a moving image is being displayed, when the video device 100 is used in portrait orientation and signal compression processing is performed as shown in (d) and (e) of Figure 3, scanning line conversion is performed by the signal processing unit 150, and the signal is converted to the number of scanning lines that can be captured by the video display device 200 and output. In this case, there will be areas on the left and right of the screen where no signal is displayed. The image will be displayed on the display device 160 in a so-called side panel state.

[0044] When the signal output from terminal 101 is stored at the receiving end, the compressed signal is output without being decompressed. In this case, the compressed signal from encryption / decryption circuit 140 is input to encryption circuit 171, where it is encrypted as required for transmission and then output via interface 172 and terminal 101. In the above description, the video and audio signals captured from the imaging device 110 and microphone 112, and the content input from the memory 121 and wireless interface 122 are recorded in the storage device 130 and then played back. However, if storage is not required or if the content is to be viewed directly, the processing can be performed in the demultiplexing circuit 141 without performing encryption or decryption processing for storage in the encryption / decryption circuit 140. This makes it possible to view video and audio using the display device 160 and audio output device 161 built into the video equipment 100, or to view the video and audio on an external receiver connected via the output interface 172.

[0045] Fig. 4 shows a specific configuration of the image display device 200 shown in Fig. 1. The same parts are given the same reference numerals and will not be described in detail.

[0046] First, we will explain the case where the signal input from terminal 201 or terminal 202 is an uncompressed video baseband signal. The signal input from terminal 201 or terminal 202 is input to encryption / decryption circuit 211 via input / output interface 210. Encryption / decryption circuit 211, which corresponds to the encryption performed by encryption circuit 171 shown in FIG. 2, decrypts the signal encrypted by encryption circuit 171. The decrypted signal is input to demultiplexing circuit 250, and the video signal and audio signal are input to signal processing circuits 251 and 252, respectively. Signal processing circuit 251 performs scanning line conversion and resolution conversion to match the number of pixels that can be displayed on display 260. Signal processing circuit 252 expands the time axis of the audio signal that has been time-compressed and multiplexed onto the blanking of the video signal, and further performs lip-syncing and sound quality adjustment as necessary. The output signals from signal processing circuits 251 and 252 are input to display 260 and audio output device 270, respectively, for viewing.

[0047] Next, a description will be given of the case where a compressed video signal is input from terminal 201 or terminal 202. The purpose of inputting the compressed signal is to store the video signal in storage device 230 built into video display device 200.

[0048] A signal input from terminal 201 or terminal 202 is input to encryption / decryption circuit 211 via input / output interface 210. Encryption / decryption circuit 211 corresponds to the encryption by encryption circuit 171 shown in FIG. 2, and decrypts the signal encrypted by encryption circuit 171. The decrypted signal is input to encryption / decryption circuit 240. Encryption / decryption circuit 240 reads the copy control information of the content to be stored, and performs encryption processing for storage accordingly. The encrypted signal is input to storage device 230 and stored in a compressed state.

[0049] When a compressed signal input from terminal 201 or terminal 202 is to be stored and viewed, a signal equivalent to the compressed signal decrypted by encryption / decryption circuit 211 is first input from encryption / decryption circuit 240 to inverse multiplexing circuit 241. Next, in inverse multiplexing circuit 241, the signal is separated into a compressed video signal and an audio signal. The separated video and audio signals are expanded by expansion circuits 242 and 243, respectively, and returned to baseband, and then input to signal processing circuits 251 and 252, respectively. Subsequently, the signals are similarly input to display 260 and audio output device 270 for viewing.

[0050] When playing and viewing content stored in storage device 230, the titles of the content stored in storage device 230 are displayed on display 260, the user selects one, and the signal of the selected content is input from storage device 230 to encryption / decryption circuit 240. The encryption / decryption circuit 240 decrypts the signal of the selected content, inputs it to demultiplexing circuit 241, and the same processing is carried out thereafter, allowing the content to be viewed.

[0051] Similarly, content stored in memory 221 can also be played back. As with playing back content stored in storage device 230, content that the user wants to view is selected from the content stored in memory 221, and the selected content is input to encryption / decryption circuit 240 via memory interface 220 and signal processing circuit 224. Signal processing circuit 224 performs the processing required to read the content from memory 221, and inputs the compressed and multiplexed video and audio signals to encryption / decryption circuit 240. The subsequent signal processing is the same as when content is read from storage device 230.

[0052] Furthermore, similarly to storing content in storage device 230, content can also be stored in memory 221. Although a detailed description of the processing in this case will be omitted, content encrypted by encryption / decryption circuit 240 is stored in memory 221 via signal processing circuit 224 and memory interface 220.

[0053] The same processing is performed when viewing or storing content transmitted wirelessly. Compressed content transmitted wirelessly is input to the encryption / decryption circuit 240 via the wireless interface 222 and the signal processing circuit 224. The encryption / decryption circuit 240 decrypts the encryption required for wireless transmission. The subsequent processing is the same as that when playing back content from the storage device 230.

[0054] Even when an uncompressed baseband signal is input from terminal 201 or terminal 202, content can be efficiently stored in storage device 230 and memory 221. The operation in this case will be described below.

[0055] Content input from terminal 201 or 202 is separated into a video signal and an audio signal via input / output interface 210, encryption / decryption circuit 211, and inverse multiplexing circuit 250. The separated video signal and audio signal are input to compression circuits 281 and 282 via copy control circuit 280. Copy control circuit 280 reads the copy control information multiplexed onto the input content and determines whether copying is permitted. Copy control information can be multiplexed onto the video information or audio information itself by allocating bits to designated parts or by using digital watermark technology.

[0056] Compression circuit 281 compresses the video signal using a compression method such as MPEG2, MPEG4, or AVC / H.264. Compression circuit 282 compresses the audio signal using a compression method such as MPEG audio. The compressed video and audio signals are input to multiplexing circuit 283, where they are multiplexed, and then input to an encryption / decryption circuit, and can be stored in storage device 230 and memory 221 in the same manner. This allows content to be recorded efficiently for long periods of time in accordance with the copyright information.

[0057] Up to this point, this embodiment has been described mainly in terms of the case where a video signal and an audio signal output from a video device 100 are transmitted to a video display device 200. Furthermore, this embodiment will be described in terms of the case where two video devices 100 are connected to each other, using FIG. 6 . In FIG. 6 , video device 1 and video device 2 are both portable video devices 100, such as mobile phones or digital cameras, and their respective terminals 101 are connected by a connection cable 10, which is a bidirectional interface. With this configuration, content such as a movie received by video device 1 from a mobile phone base station antenna 20 can be transmitted to video device 2 via the connection cable 10 and displayed on a display device 160 within video device 2, or audio can be output using an audio output device 161 within video device 2. Furthermore, when transmitting content stored in a storage device 130 within video device 1, the desired content is read from storage device 130 based on the contents of a control signal from video device 2, and the encryption / decryption circuit 140 decrypts the content. Then, after encryption processing required for external transmission is performed in encryption circuit 171, the data is output via interface 172 and terminal 101. At this time, control signals from video equipment 2 include mutual authentication to confirm that video equipment 1 and video equipment 2 are legitimate equipment, a synchronization control signal to synchronize signal processing, a transmission request signal, and an identification signal to identify video equipment 1. Note that control signals are also sent from video equipment 1 to video equipment 2 as necessary.

[0058] The signals transmitted and received between video devices 1 and 2 may not only be signals received from the mobile phone base station antenna 20, but may also be signals received by broadcast receiver 180, content stored on storage device 130, content stored in memory 121, etc.

[0059] Video device 1 and video device 2 are, for example, the same video device 100. These video devices are connected to each other via a bidirectional interface as described above. While video device 1 may send information such as video and audio to video device 2, it is also possible to send information such as video and audio from video device 2 to video device 1. Here, the direction in which information is sent from video device 1 to video device 2 is referred to as "upstream," and the direction in which information is sent from video device 2 to video device 1 is defined as "downstream." Of course, the opposite directions may also be referred to as "upstream" and "downstream." The bidirectional interface connecting video device 1 and video device 2 has asymmetrical upstream and downstream transmission rates, i.e., different transmission rates. In the upstream direction, i.e., when sending wideband video or audio information from video device 1 to video device 2, a narrowband control signal (compared to the video, audio, etc.) is sent from video device 2 to video device 1. Conversely, in the downstream direction, i.e., when transmitting wideband video and audio information from video device 2 to video device 1, a narrowband control signal is transmitted from video device 1 to video device 2. Therefore, the transmission rate in the upstream and downstream directions for transmitting wideband video and audio is set high, while the transmission rate in the direction for transmitting narrowband control signals is set low. In this manner, in this embodiment, information and signals of different bandwidths are transmitted between multiple different video devices in the upstream and downstream directions. This allows video signals that require a wideband transmission and control signals that can be transmitted in a narrowband to be simultaneously used in a limited frequency band, thereby improving the efficiency of radio wave usage. Note that control signals are not transmitted only from one device, but are also transmitted from the device on the opposite side as needed.

[0060] Fig. 7 is a configuration diagram of the first embodiment in which the video display device 200 and the video device 100 are connected wirelessly. For ease of explanation, Fig. 7 does not show anything other than the input / output interface 210 and the interface 172. In this way, the bidirectional interface connecting the video devices is not limited to a wired cable, and may be configured wirelessly. In this case, the degree of freedom in arranging each device is increased.

[0061] FIG. 8 is an explanatory diagram illustrating a wireless connection between a video device 100 and a video display device 200. In FIG. 8, the video device 100 and the video display device 200 are the same as those described in FIGS. 1 and 2, respectively. For simplicity, FIG. 8 illustrates only the interface circuit 172 of the video device 100, without illustrating the other components. Similarly, for the video display device 200, only the input / output interface 210 is illustrated, without illustrating the other components. Here, the interface circuit 172 and the input / output interface 210 are both bidirectional interfaces, with asymmetric upstream and downstream transmission rates, as in the above example. In FIG. 8, the channels between antennas 81 and 84 and between antennas 82 and 85 are used for bidirectional transmission of video signals, audio signals, and control signals indicating copyright protection and copy restriction conditions for content. In contrast, the channel between antennas 83 and 86 is used for transmitting inter-device control signals. Furthermore, the bit selection circuits 811 and 812 receive inputs of video signals, audio signals, control signals indicating copyright protection and copy restriction conditions for content, and inter-device control signals. Regarding the modulation and demodulation methods mentioned above, the QPSK modulation and demodulation method has higher resistance to transmission errors than the 64QAM modulation and demodulation method. Meanwhile, the 64QAM modulation and demodulation method has higher transmission efficiency than the QPSK modulation and demodulation method. Here, we will explain the case where video, audio, and control signals indicating copyright protection and copy restriction conditions for content related to these are sent from the video device 100 to the video display device 200. Here, the direction in which information is sent from the video device 100 to the video display device 200 is referred to as upstream, and the opposite direction in which information is sent from the video display device 200 to the video device 100 is referred to as downstream.

[0062] When the video equipment 100 transmits information, it first checks using a carrier detection circuit (not shown) whether the channel being used is already occupied by another device. This carrier detection is performed by detecting whether a carrier wave is present in a predetermined frequency band for a predetermined period of time. If the carrier detection circuit detects that another device is using the channel, it waits for a while and then checks again whether the channel is available. If it subsequently detects that the channel is not being used by another device, it notifies the microprocessor 115 of the video equipment 100 that the channel is available. The microprocessor 115 outputs a channel use request signal from the QPSK modulation / demodulation circuit 803 as an inter-device control signal, thereby securing the right to use the channel. Next, the microprocessor 115 outputs a transmission request signal to the bit selection circuit 811. The error control circuit 843 adds error control bits for error detection and correction to this transmission request signal and sends it to the QPSK modulation / demodulation circuit 803. The QPSK modulation / demodulation circuit 803 performs QPSK modulation and transmits the radio signal to the video display device 200 via the antenna 83. Meanwhile, the video display device 200 QPSK demodulates the radio signal received by the antenna 86 using the QPSK modulation / demodulation circuit 806, and performs error detection and correction control using an error control circuit 847 to output an inter-device control signal and transmit it to the bit selection circuit 812.

[0063] The microprocessor in the video display device 200 decodes the received inter-device control signal and receives the transmission request signal from the video device 100, as well as device category information about the video device 100 (information for identifying the category, such as whether it is a display device or a recording device) and the device identification number of the video device 100. The display screen of the video display device 200 displays a message indicating whether or not to connect to the video device 100. Based on this message, the user issues a command to permit the connection using an input device, such as the remote control of the video display device 200. The video device 100 and the video display device 200 then exchange device category information and device identification numbers to identify each other, and exchange information to ensure compliance with content copyright protection and copy restriction conditions. If there are no problems, the connection is permitted. If the devices are input-only or output-only, making it meaningless to connect, or if the content copyright protection or copy restriction conditions are violated, the connection process is aborted and a message to that effect is displayed on each device. The following describes the case where there are no problems with content copyright protection or copy restriction conditions.

[0064] Of the control signals input to the interface circuit 172 that indicate copyright protection and copy restriction conditions for the video signal, audio signal, and related content, two bits are selected from the MSB of the video signal, and an error control circuit 841 adds control bits for error detection and correction to these two bits, and sends the selected bits to the QPSK modulation and demodulation circuit 801. The QPSK modulation and demodulation circuit 801 then QPSK-modulates this signal and transmits the signal as a radio signal from the antenna 81. The error control circuit 842 also adds control bits for error detection and correction to the remaining bits, from the third bit through the eighth bit, and sends the signal to the 64QAM modulation and demodulation circuit 802. The 64QAM modulation and demodulation circuit 802 then 64QAM-modulates this signal and transmits the signal as a radio signal from the antenna 82.

[0065] In the video display device 200, the QPSK modulation / demodulation circuit 804 demodulates the signal received by the antenna 84 using QPSK modulation and demodulation, and after error control by the error control circuit 845, outputs the most significant two bits of the video signal to the bit control circuit 812. The 64QAM modulation / demodulation circuit 805 demodulates the remaining signal received by the antenna 85 using 64QAM modulation and demodulation, and after error control by the error control circuit 846, outputs the remaining signal to the bit control circuit 812.

[0066] Here, we will explain the inter-device control signal. When an inter-device control signal is sent downstream, i.e., from the video display device 200 to the video device 100, it is passed from the bit selection circuit 812 through the error control circuit 847, modulated by the QPSK modulation / demodulation circuit 806, and output from the antenna 86. The video device 100 receives this signal at the antenna 83, passes it through the QPSK modulation / demodulation circuit 83, QPSK demodulates it by the QPSK modulation / demodulation circuit 803, and performs error detection and correction by the error control circuit 843, before transmitting it to the bit selection circuit 811. Conversely, when an inter-device control signal is sent upstream, i.e., from the video device 100 to the video display device 200, it is passed from the bit selection circuit 811 through the error control circuit 843, modulated by the QPSK modulation / demodulation circuit 803, and output from the antenna 83. The video display device 200 receives this signal via the antenna 86, QPSK demodulates it using the QPSK modulation / demodulation circuit 806, and performs error detection and correction using the error control circuit 847 before transmitting it to the bit selection circuit 812. This has the effect of reducing malfunctions of inter-device control signals, which are important in building a system, even in noisy environments.

[0067] The configuration of this embodiment enables transmission of the most significant two bits of a digital signal at a low transmission rate with excellent noise resistance. Taking advantage of the fact that the most significant bits of a video signal have a greater impact on image quality, two bits are extracted from the video signal starting from the MSB, and a transmission path using QPSK modulation is assigned to this information, minimizing image degradation. Meanwhile, in a system where audio information is more important than video, it is also possible to assign the most significant (e.g., the most significant) two bits of the audio signal to a transmission path using QPSK modulation.

[0068] Furthermore, when humans perceive images, there is a tendency for high-frequency components to be relatively insensitive compared to low-frequency components for both horizontal and vertical frequency components of the screen. Furthermore, there is a tendency for the human eye to be unable to keep up with fast-moving objects within the screen. Taking advantage of these tendencies, the horizontal direction of the screen may be divided into low-frequency and high-frequency components, with QPSK modulation applied to the low-frequency components and 64QAM modulation applied to the high-frequency components. This makes it possible to enhance noise tolerance for important information within a limited transmission bandwidth while ensuring overall transmission capacity. Similarly, the vertical direction of the screen may be divided into low-frequency and high-frequency components, with QPSK modulation applied to the low-frequency components and 64QAM modulation applied to the high-frequency components. This makes it possible to enhance noise tolerance for important information within a limited transmission bandwidth while ensuring overall transmission capacity. Furthermore, by combining the handling of frequency components in the horizontal direction and the vertical direction of the screen, it is possible to enhance noise tolerance for desired important information.

[0069] In the above explanation, the error control circuits 841, 842, and 843 are explained as adding error control information to each bit input to the error control circuits 841, 842, and 843, but it is also possible to treat the bits input to the error control circuits 841, 842, and 843 as a single word and add error control information to this single word. If configured in this way, the error control circuits are simple and easy to configure.

[0070] 8, for example, a plurality of still images captured by video device 1 can be switched at a predetermined interval, for example, every second, and transmitted to video display device 200 or video device 2, where the transmitted plurality of still images can be displayed. Video display device 200 or video device 2 transmits a video request signal to video device 1 to transmit an image, and based on this video request signal, video device 1 switches between the plurality of still images and transmits them to video display device 200 or video device 2. With this configuration, if the image cannot be reproduced on video display device 200 or video device 2, the video request signal can be sent again to video device 1, and this can be repeated until the image is correctly received. In this case, the video request signal is also QPSK modulated, providing excellent noise resistance.

[0071] An embodiment for obtaining an image from video equipment 1 using such a video request signal and displaying it on a display device will be described with reference to Fig. 10. This embodiment will be described taking as an example a case where a plurality of still images captured by video equipment 1 are switched and displayed on video display device 200, but the same can be done when displaying on video equipment 2.

[0072] FIG. 10 shows an embodiment of a display device configured to display still images from video device 1. In this embodiment, a television display device equipped with a high-definition HD display 1002 is used as the display device. In FIG. 10, video device 1020 is specifically a digital camera, a mobile phone, a game console, a personal media player, or the like. In this embodiment, still images are transmitted from video device 1020 to video display device 200 (television display device) via two interfaces. One is HDMI for transmitting the still images as baseband video information, and the other is USB for transmitting the still images as compressed video information. Here, it is assumed that the compressed video information transmitted via USB is compressed in JPEG format.

[0073] First, we will explain the configuration and operation of the video device 1020. When transmitting a still image of compressed video information, the video device 1020 reads a still image compressed in JPEG format from memory 1018, which is configured, for example, by a flash memory. This is supplied from a USB mass storage interface circuit 1019 to a USB terminal 1012, which is a first input section of the video display device 200, without undergoing signal processing such as expansion.

[0074] On the other hand, when transmitting a still image of baseband video information, the video device 1020 first reads the still image from the memory 1018. Since this still image is compressed in JPEG format, the signal processing circuit 1016 performs signal processing to expand the compressed image, thereby generating baseband video information. This baseband video information is transmitted from the HDMI interface circuit 1017 to the HDMI terminal 1005, which is the second input section of the video display device 200.

[0075] Next, the configuration and operation of the video display device 200 will be described. A still image of compressed video information input to a USB terminal 1012, which is a first input unit, is supplied to an image processing circuit 1006 via a USB host interface circuit 1011. The image processing circuit 1006 includes a JPEG data file access circuit 1010, a JPEG decoding circuit 1009, a resizing / effect adding circuit 1008, and an image stream signaling circuit 1007. The still image input to the USB terminal 1012 is supplied to the JPEG decoding circuit 1009 via the JPEG data file access circuit 1010, where the still image compressed in JPEG format is decoded, i.e., expanded. The resizing / effect adding circuit 1008 changes the display size (number of pixels in the horizontal and vertical directions) of the expanded still image and applies desired effect processing (for example, rotation, etc.). The still images that have been resized and processed by the resize effect adding circuit 1008 are converted into image signals for display by the image stream signal converting circuit 1007 and supplied to the HD display 1002 via the switching circuit 1003. As a result, the compressed still images input via the USB host interface circuit 1011 are displayed on the screen of the HD display 1002.

[0076] In this embodiment, a LAN terminal 1014 connectable to various networks 1015 such as a wireless LAN, a wired LAN, and the Internet is provided as a first input unit to which compressed video information is input. Therefore, in this embodiment, compressed video can be acquired not only through a USB interface but also through the network 1015. The compressed video information input to the LAN terminal 1014 is input to the image processing circuit 1006 via a LAN / DLNA (Digital Living Network Alliance) interface circuit. The processing in this image processing circuit 1006 is the same as the processing for compressed video information input via the USB terminal 1012 described above, and therefore a duplicated description will be omitted here.

[0077] Meanwhile, a still image of baseband video information input to an HDMI terminal 1005, which is a second input unit, undergoes a predetermined decoding process (decryption process) in an HDMI interface / decode circuit 1004. The decrypted still image is supplied to an HD display 1002 via a switching circuit 1003, and the still image is displayed on the screen of the HD display 1002.

[0078] The switching circuit 1003 selects either a still image input to the HDMI terminal 1005 or a still image input to the USB terminal or LAN terminal 1014, and supplies it to the HD display 1002, and is controlled by, for example, the user's operation of a remote control for the video display device 200. Therefore, the user can select either compressed video information or baseband video information according to preference and display it on the HD display 1002.

[0079] In the above embodiment, HDMI and USB interfaces are used as interfaces for connecting to the video device 1020, but it goes without saying that interfaces of other standards may also be used.

[0080] Before describing the operation of this embodiment based on a video request signal, a supplementary explanation of the HDMI interface is provided. Figure 16 shows an example of the configuration of an HDMI interface, which is primarily composed of a transmitting side and a receiving side. The transmitting side includes a transmitting unit 1601 and a transmitting side control unit 1603 that controls the transmitting unit 1601. The transmitting unit 1601 is configured to encode video signals (Y, Pb, Pr) and audio signals and output them to a receiving unit 1604. The transmitting unit 1601 further includes a TMDS encoding circuit 1602 that converts the video signals (Y, Pb, Pr) and audio signals into serial video data and serial audio data, respectively. On the other hand, the receiving side includes a receiving unit 1604 and a transmitting side control unit 1606 that controls the receiving unit 1604. The receiving unit 1604 TMDS-decodes the video data and audio data sent from the transmitting unit 1601 using a TMDS decoder 1605, and reproduces baseband video data and audio data. A CEC line 1607 constitutes a device control line for transmitting control signals for devices, and display specification information called DDC is transmitted via a DDC line 1608. In addition, the receiving side transmits an HPD (Hot Plug Detect) signal 1609 to the transmitting side, indicating that the transmitting side device and the receiving side device have been connected.

[0081] FIG. 17 shows an example of the format of the remote control code transmitted over the CEC line 1607. As shown in FIG. 17, the remote control code is 48 bits long and includes a 16-bit manufacturer code for identifying the manufacturer and a 12-bit device code for identifying the device, such as the device's model number or serial number. The remote control code may have a format other than that shown in FIG. 17. Furthermore, the remote control code length is not limited to 48 bits and may be other bit lengths. Next, an example of a method for transmitting this remote control code over the CEC line will be described with reference to FIG. 18. First, when a video device and a display device are connected, the display device sends an HPD signal 1609 to the video device, indicating that the two devices are connected. Next, the display device 200 reads the manufacturer code and device code of the video device via the CEC line 1607 of the HDMI cable. The read manufacturer code and device code are then stored in the display device 200 along with the receiving interface number. The manufacturer code and device code may be stored in a memory within the display device 200, for example, a microcomputer (not shown). If another HDMI cable is connected, the same process is performed on that HDMI cable, and the corresponding manufacturer code and device code are recorded in the display device along with the receiving interface number. The manufacturer code and device code read in this way are stored as the table shown in Fig. 19. With this configuration, even if the connected display device 200 and video device 1020 are made by different manufacturers, communication between the two can be established by referencing the stored manufacturer code and device code, and the video device 1020 can control the display device 200 or send display specification information (DDC) to the video device 1020.

[0082] Returning to FIG. 10 , the operation of this embodiment based on a video request signal will be described. In FIG. 10 , a user operates an input device, such as a remote control or keyboard, of the video display device 200 to output a control command from the input device to set the display mode for switching between still images as described above. In response to this control command, the JPEG data file access circuit 1010 of the video display device 200 transmits a video request signal to the external video device 1020 via the USB host interface circuit 1011 and the USB terminal 1012, requesting that the external video device 1020 output a still image, which is compressed video information. That is, in this embodiment, the JPEG data file access circuit 1010 functions as a transmitter for transmitting the video request signal to the external video device 1020. This video request signal is transmitted from the video display device 200 to the video device 1020 at predetermined intervals (e.g., every second). Upon receiving this video request signal, the video device 1020 outputs the still image data stored in the memory 1018 via the USB mass storage interface circuit 1019. The USB host interface circuit 1011 takes in this still image data via the USB terminal 1012. The JPEG decoding circuit 1009 then JPEG-decodes the read JPEG data to restore it to the original image data. The resizing and effect adding circuit 1008 then performs resizing and effect processing, and the image stream signal conversion circuit 1007 converts it into an image signal for display and displays it on the HD display 1002.

[0083] By repeating the above-described processes from transmission of the video request signal to conversion of the display image signal by the image stream signal conversion circuit 1007 at predetermined intervals (for example, one second), it is possible to perform an image display method called a slide show, in which a plurality of still images acquired from the video device 1020 are switched and displayed at predetermined intervals. Naturally, this time interval can be set to a time other than one second, and this interval can be changed appropriately by the user using the above-described input device. Furthermore, the video request signal may be repeatedly output until all still images have been read from the video device 1020, or a predetermined period (for example, 10 seconds to one minute) may be set and the video request signal may be transmitted at predetermined intervals within the predetermined period.

[0084] It is also possible to send the above-mentioned video request signal from a microcomputer (not shown) of the video display device 200 to the video device 1020 via the HDMI interface / decode circuit 1004 and the HDMI terminal 1005. In this case, the HDMI interface is an interface for transmitting moving images as a transmission format, so that moving images that do not change over time are sent unless there is specific control.

[0085] First, the user operates an input device such as a remote control or keyboard of the video display device 200 to output a control command from the input device to set the display mode. In response to this control command, the HDMI interface / decode circuit 1004 transmits a video request signal to the video device 1020 via the CEC line in the HDMI terminal 1005. That is, in this example, the HDMI interface / decode circuit 1004 functions as a transmitter for transmitting the video request signal to the external video device 1020. As in the above example, this video request signal is transmitted from the video display device 200 to the video device 1020 at predetermined periodic intervals (e.g., every second) for, for example, several seconds to one minute. In response to this, the video device 1020 converts the still image data recorded in the memory 1018 into a signal format displayable as a moving image using the signal processing circuit 1016 and outputs the signal via the HDMI interface circuit 1017. The video display device 200 receives this data via the HDMI terminal 1005 and the HDMI interface circuit / decode circuit 1004 and displays it on the HD display. By repeating this process at predetermined time intervals, it is possible to similarly display images as a slide show. Naturally, this time interval may be configured to be changeable by the user as appropriate, as described above. Furthermore, the video request signal may be repeatedly output until all still images have been read from the video device 1020, or the video request signal may be transmitted at predetermined intervals within a predetermined period, as described above.

[0086] Furthermore, although the above description has been given of a method for displaying image information from the video device 1020 on the video display device 200, a slideshow display can also be performed in a similar manner when the image information exists on the network 1015. In this case, the JPEG data file access circuit 1010 of the video display device 200 receives a control command from an input device and transmits it to the network 1015 via the LAN / DLNA interface circuit 1013 and LAN terminal 1014. In this case, the network address (e.g., IP address) of the video device connected to the network is added to the video request signal. In response to the video request signal, a video signal corresponding to the address added to the video request signal transmits still image data as compressed video information. This still image data is input via the LAN terminal 1014 and the LAN / DLNA interface circuit 1013 and supplied to the JPEG decoding circuit 1009. The subsequent processing is the same as the processing for still images input to the USB terminal 1012 described above, and therefore a repeated description will be omitted here.

[0087] To achieve this network function, this embodiment is provided with a LAN terminal 1014 and a LAN / DLNA interface circuit 1013, but it is also possible to extend the HDMI interface or USB interface to provide similar functionality.

[0088] FIG. 11 shows the configuration of another embodiment of the present invention. In FIG. 11, the same components as in FIG. 10 are numbered the same. The configuration of FIG. 11 differs from FIG. 10 in that the signal paths from the USB terminal 1012 and the LAN terminal 1014 are eliminated from the display device 200 in FIG. 10. Another difference is that the video device 1020 includes a PTP (protocol for connecting a digital camera to a PC, etc. via USB, and transferring and controlling images) control circuit 1101 and a LAN interface circuit 1102 instead of the USB mass storage interface circuit 1019. The HDMI terminal path operates in the same way in FIG. 10 and FIG. 11, enabling slideshows. The configuration of FIG. 11 simplifies the configuration of the display device 200 and eliminates the need for complicated connections, thereby improving user convenience. That is, this embodiment can also be applied to a configuration that includes only a first input unit, i.e., a configuration that displays still images of baseband video information. In addition, although one HDMI interface system is used in this example, two or more systems may be provided.

[0089] 10, another display format of a plurality of still images captured by the video equipment 1 on the video display device 200 will be described. In this display format, a plurality of still images are simultaneously displayed in reduced size on one screen of the HD display 1002.

[0090] 10, the JPEG data file access circuit 1010 of the video display device 200 sends a video acquisition request for a still image to the video device 1020 via the USB host interface circuit 1011 and the USB terminal 1012. In response to this, the video device 1020 outputs still image data, which is compressed video information recorded in memory 1018, via the USB mass storage interface circuit 1019. The USB host interface circuit 1011 reads this still image data via the USB terminal 1012. The JPEG decoding circuit 1009 then JPEG-decodes the read JPEG data to restore the original image data. The resizing and effect application circuit 1008 then resizes and applies effects to the image, and temporarily stores it as an image corresponding to display position 1 in FIG. 12. In a similar manner, the JPEG data file access circuit 1010 sends a video acquisition request for the next still image to the video device 1020 via the USB host interface circuit 1011 and the USB terminal 1012. In response, the video device 1020 outputs the still image data, which is the next compressed video information recorded in memory 1018, via the USB mass storage interface circuit 1019. The USB host interface circuit 1011 reads this still image data via the USB terminal 1012. The JPEG decoding circuit 1009 then JPEG-decodes the read JPEG data to restore it to the original image data. The resizing and effect application circuit 1008 then resizes and applies effects to the image, and temporarily stores it as an image corresponding to display position 2 in FIG. 12. By repeating this process from the video acquisition request to the temporary image storage, for example, 12 times, it is possible to display multiple still images together, as shown in FIG. 12, in a manner known as thumbnail display. This process is performed by sending 12 video acquisition requests to the video device 1020 within a predetermined period of time (e.g., less than one second).

[0091] If there are 12 or more still images in the video device 1020, thumbnails are displayed for every 12 images. This type of display method has the advantage of being convenient because it allows multiple images to be viewed at the same time, making it easy to distinguish differences in color and subtle differences between scenes.

[0092] Here, one video device 1020 is connected to make it easier to understand the operation, but it is also possible to connect two video devices 1020, so that two video devices can be lined up side by side and viewed simultaneously, for example, six frames each. This has the effect of making it easy to select the desired image from the images of the two video devices, since it is possible to check differences in color and brightness due to variations between the two video devices 1020 and differences in shooting conditions.

[0093] This display function can also be realized using the configuration of FIG. 11. The same effects are achieved in operation between the configurations of FIG. 10 and FIG. 11, and it is possible to display multiple still images captured by the video device 1 together. Using the configuration of FIG. 11 simplifies the configuration of the display device 200 and eliminates the need for complicated connections, thereby improving user convenience. In this case, a memory for combining multiple small images is required. However, multiple small images may be combined in advance in memory 1018 on the video device 1020 and then sent to the video display device 200, or a memory (not shown) may be configured after the HDMI interface circuit and decode circuit 1004, and the small images may be generated using this memory. Either configuration achieves the same effects as FIG. 10.

[0094] In the above description, the number of still images displayed simultaneously was set to 12. However, as shown in FIG. 13, it is also possible to display them in two rows and two columns. As shown in FIG. 14, it is also possible to display them in two rows and two columns. When the number of divisions shown in FIGS. 13 and 14 is used, the resolution of each small screen is approximately 300 × 500, since the resolution of HD display 1002 is 1080 × 1920, making it easier to distinguish between images. Furthermore, as the small screens themselves become smaller, flickering can occur. However, this flickering can be reduced by using the division shown in FIGS. 13 and 14. On the other hand, when video is input from a digital camera, the aspect ratio of the video is approximately 4:3. Therefore, when the division shown in FIG. 12 is used, the video can be efficiently displayed side by side on HD display 1002, which has an aspect ratio of 16:9. Even when images are displayed side by side as shown in FIGS. 13 and 14, although some areas may not be displayed, a similar effect can be achieved.

[0095] Each image stored in the memory 1018 of the video device 1020 is assigned attribute information, such as image rotation information and erasure prevention lock information for preventing accidental erasure. In this embodiment, this attribute information is sent from the video display device 200 to the video device 1020 via the HDMI terminal 1005 and stored in the memory 1018 in response to an operation using the remote control or keyboard of the video display device 200. FIG. 15 shows an example of a management table of attribute information recorded in the memory 1018. As shown in FIG. 15, attribute information regarding whether erasure lock is enabled and the rotation angle can be added to and stored for each of the multiple still images stored in the memory 1018 of the video device 1020 in response to a signal from the video display device 200. With this configuration, the device directly controlled by the user is always the video display device 200. Therefore, even if any video device 1020 is connected, the same operations can be used to control the erasure prevention lock and image rotation. This eliminates the need to memorize complex operations for each video device 1020, thereby improving convenience.

[0096] Although the encryption process is not described in detail in the embodiment shown in Fig. 8, it is also possible to combine the encryption circuit 171 and the interface circuit 172 to perform the process as shown in Fig. 9. Fig. 9 shows an example of a configuration for performing encryption process in the system shown in Fig. 8, and the system in Fig. 9 is configured to include encryption / decryption circuits 821-826, interface circuits 830 and 831 that include encryption process, and error control circuits 841, 842, 843, 845, 846, and 847.

[0097] In the example shown in Fig. 9, as in the example of Fig. 8, predetermined bits are selected by bit selection circuit 811, and each bit is subjected to error control by error control circuits 841 and 842, after which it is encrypted by encryption / decryption circuits 821 and 822 and input to QPSK modulation / decryption circuit 801 and 64QAM modulation / decryption circuit 802. Furthermore, signals demodulated by QPSK modulation / decryption circuit 804 and 64QAM modulation / decryption circuit 805 are input to encryption / decryption circuits 824 and 825, where they are decrypted and then bit-combined by bit selection circuit 812. Processing in this manner enables signal processing according to importance, making important information less susceptible to errors, thereby enabling efficient transmission with less degradation in image quality.

[0098] Furthermore, by combining reversible codes with the encryption / decryption circuits 821-826, even more efficient transmission is possible. For example, in the example shown in Fig. 9, before encryption processing is performed by the encryption / decryption circuits 821-823, the bits to be transmitted are reduced using reversible arithmetic coding that uses statistical properties, for example, and then encryption is performed. In the video device display device 200, after encryption / decryption is performed by the encryption / decryption circuits 824-826, decryption is performed using reversible codes corresponding to the encryption / decryption circuits 821-823, error detection and correction is performed by the error control circuits 845-847, and the bits are combined by the bit selection circuit 812. By combining reversible codes, the transmission rate of the information to be transmitted can be reduced, thereby enabling even more efficient transmission.

[0099] Furthermore, a supplementary explanation about encryption is provided. If AES 128-bit encryption processing is used for all encryption circuits, highly secure protection processing can be achieved. In addition, if AES 128-bit encryption processing is used for the content encryption circuit 821 and DES encryption processing is used for the other encryption circuits, a balance between content protection, which is important for the system, and processing efficiency can be achieved, making it easier to configure the system.

[0100] Furthermore, the system may be configured to switch between baseband signal transmission and compressed signal transmission in accordance with an inter-device control signal. In this configuration, when a compressed signal is transmitted in response to requirements such as content protection, QPSK modulation is used for transmission, enabling transmission with excellent error tolerance on the transmission path. Furthermore, when a baseband signal is transmitted, 64QAM modulation enables transmission with high transmission efficiency.

[0101] The operations of the video equipment 100 and the video display device 200 in FIG. 9 are basically the same as those of the video equipment 100 and the video display device 200 in FIG. 8. To transmit, the video equipment 100 first checks, using a carrier wave detection circuit (not shown), whether the channel being used is already occupied by another device. This carrier wave detection is performed by detecting whether a carrier wave exists in a predetermined frequency band for a predetermined period of time. If the carrier wave detection circuit detects that another device is using the channel, it waits for a while and then checks again whether the channel is available. If it subsequently detects that the channel is not being used by another device, it notifies the microprocessor 115 of the video equipment 100 that the channel is available. The microprocessor 115 outputs a channel use request signal from the QPSK modulation / demodulation circuit 803 as an inter-device control signal to secure the right to use the channel. Next, the microprocessor 115 outputs a transmission request signal to the bit selection circuit 811.

[0102] The error control circuit 843 adds an error control bit for error detection and correction to this transmission request signal, which is then encrypted by the encryption / decryption circuit 823 and sent to the QPSK modulation / demodulation circuit 803. The QPSK modulation / demodulation circuit 803 performs QPSK modulation and transmits the radio signal to the video display device 200 via the antenna 83. Meanwhile, the video display device 200 QPSK demodulates the radio signal received by the antenna 86 using the QPSK modulation / demodulation circuit 806 and decrypts it using the encryption / decryption circuit 826. The error control circuit 847 performs error detection and correction control on this decrypted signal, outputting an inter-device control signal and transmitting it to the bit selection circuit 812. The microprocessor in the video display device 200 decodes the received inter-device control signal and receives the transmission request signal from the video device 100, as well as device category information about the video device 100 (information for identifying the category, such as whether it is a display device or a recording device) and the device identification number of the video device 100. The display screen of the video display device 200 displays a message indicating whether or not to connect to the video device 100. Based on this message, the user uses an input device such as a remote control for the video display device 200 to issue a command to permit the connection. Subsequently, the video device 100 and the video display device 200 exchange each other's device category information, identification numbers for identifying each other's devices, and other information to ensure compliance with content copyright protection and copy restriction conditions. If there are no problems, the connection is permitted. If the devices are input-only or output-only, making the connection meaningless, or if the content copyright protection and copy restriction conditions are violated, the connection process is aborted, and a message to that effect is displayed on each device. In this way, if there are no problems with the content copyright protection and copy restriction conditions, the connection is established, and video, audio, and the like are transmitted from the video device 100 to the video display device 200. [Example]

[0103] Figure 5 shows a second embodiment of the present invention, and is a diagram illustrating another configuration of the video display device 200 shown in Figure 1. Some parts of Figure 5 are common to the embodiment shown in Figure 4, and the common parts are assigned the same numbers and detailed descriptions thereof will be omitted. The video display device 200 shown in Figure 5 includes an encryption / decryption circuit 212, encryption / decryption circuits 245 and 290, compression / transcoding circuits 291 and 292, and a duplication control circuit 293 which is a multiplexing circuit.

[0104] In the embodiment shown in FIG. 5, when a baseband signal is input from terminal 201 or terminal 202, the operation is the same as in the embodiment shown in FIG. 4. Compression / transcoding circuits 292 and 291 operate as compression circuits for baseband signals. When a compressed signal is input from terminal 201 or terminal 202, the encryption required for transmission is decrypted by encryption / decryption circuit 212 via input / output interface 210, and the signal is separated into a compressed video signal and a compressed audio signal by inverse multiplexing circuit 250. Each signal is input to copy control circuit 290, which determines whether copying is permitted based on information indicating whether copying is permitted. If copying is permitted, the compression / transcoding circuits 291 and 292 reduce the bit rates of the compressed video signal and compressed audio signal as necessary, for example, by using a compression method with higher compression efficiency. The output signals of compression / transcoding circuits 291 and 292 are multiplexed by multiplexing circuit 293 and input to encryption / decryption circuit 245. If the copy control circuit 290 detects that copying is permitted, the encryption / decryption circuit 245 appropriately encrypts the input signal for storage and stores it in the storage device 230 and / or memory 221. When the stored signal is to be played back, the playback signal from the storage device 230 or memory 221 is decrypted by the encryption / decryption circuit 245 and separated into a video signal and an audio signal by the inverse multiplexing circuit 241, and the signal can be viewed by processing it in the same manner as above. Even when viewing while storing the signal in the storage device 230 or memory 221, the signal from the multiplexing circuit 293 is input to the inverse multiplexing circuit 241 via the encryption / decryption circuit 245 and processed in the same manner. In this case, the transcoded image quality can be confirmed. Note that when viewing directly without storage, the signal is input from the encryption / decryption circuit 212 to the inverse multiplexing circuit 241 via the encryption / decryption circuit 245, where it is separated into a video signal and an audio signal and processed in the same manner.

[0105] In the embodiment shown in Figure 5, even when a compressed signal is input, transcoding enables efficient storage at a higher compression rate. This embodiment also shows an example in which the signal processing means, including the compression circuits 111 and 113, are implemented by circuits. However, the various circuit elements may be configured by software to perform the above-described processing, and similar effects can be achieved in this case. The present invention does not limit how signal processing is implemented. [Explanation of symbols]

[0106] 100 Video equipment 121, 221, 321 memory 122, 222 wireless interface 110 Imaging device 111, 113, 281, 282, 291, 292 Compression circuit 112 Mike 114 Sensors 116, 170, 283, 293 multiplex circuit 124, 150, 151, 224, 251, 252 Signal processing circuit 130, 230 Storage device 140, 240, 245 Encryption / Decryption Circuit 141, 250, 241 inverse multiplex circuit 142, 143, 242, 243 expansion circuit 160 Display device 161, 270 Audio output device 171 Encryption Circuit 180 Broadcast receiver 200 Video display device 211, 212 encryption / decryption circuit 260 display 280 Reproduction Control Circuit 300 receiver

Claims

1. In a television display device, a first interface unit capable of inputting uncompressed image information from an external device via a wired connection; a second interface unit capable of inputting compressed image information from an external device via a wire; an expansion unit capable of expanding compressed image information input to the second interface unit; a display unit capable of displaying a first image based on uncompressed image information input to the first interface unit or a second image based on image information obtained by decompressing compressed image information input to the second interface unit by the decompression unit; an audio output unit that outputs audio, the display unit is further configured to be able to display a received television broadcast program, whether the first image or the second image is to be displayed on the display unit can be selected in accordance with an operation on an input device of the display device; When the display of the first image is selected, based on an operation for slideshow display on an input device of the display device, the first interface unit transmits a first signal to the external device via a wired connection, for causing the external device to convert compressed image information into uncompressed image information and output the uncompressed image information, and the display unit inputs the uncompressed image information output from the external device via a wired connection, thereby performing a slideshow display at a predetermined time interval using a plurality of first images based on the input uncompressed image information; When the display of the second image is selected, based on an operation for slideshow display on an input device of the display device, the second interface unit transmits a second signal to the external device by wire for outputting compressed image information from the external device, and receives the compressed image information output from the external device by wire, whereby the display unit performs a slideshow display at a predetermined time interval using a plurality of second images based on image information obtained by decompressing the input compressed image information by the decompression unit; The display unit displays an image and the audio output unit outputs audio. A television display device characterized by:

2. 2. The television display device according to claim 1, wherein the predetermined time interval for displaying the slide show using the first image or the predetermined time interval for displaying the slide show using the second image can be changed by operating an input device of the display device.

3. 2. The television display device according to claim 1, wherein an image based on compressed image information input to said second interface unit can be rotated based on an operation on said input device and displayed on said display unit.

4. 2. The television display device according to claim 1, wherein attribute information of the compressed image information stored in the external device can be added or changed in response to an operation on an input device of the display device.

5. 2. The television display device according to claim 1, wherein attribute information of compressed image information stored in the external device can be added or changed in response to an operation on an input device of the display device, and the attribute information is transmitted from the first interface unit to the external device.

6. In a television display device, an HDMI interface unit capable of inputting uncompressed image information from an external device; a USB interface unit capable of inputting compressed image information from an external device; an expansion unit capable of expanding compressed image information input to the USB interface unit; a display unit capable of displaying a first image based on uncompressed image information input to the HDMI interface unit or a second image based on image information obtained by decompressing compressed image information input to the USB interface unit by the decompression unit; an audio output unit that outputs audio, the display unit is further configured to be able to display a received television broadcast program, whether the first image or the second image is to be displayed on the display unit can be selected in accordance with an operation on an input device of the display device; When the display of the first image is selected, based on an operation for slideshow display on an input device of the display device, the HDMI interface unit transmits to the external device a second signal for converting compressed image information into uncompressed image information and outputting the uncompressed image information by the external device, and by inputting the uncompressed image information output from the external device, the display unit performs a slideshow display at a predetermined time interval using a plurality of first images based on the input uncompressed image information; When the display of the second image is selected, based on an operation for slideshow display on an input device of the display device, the USB interface unit transmits a second signal to the external device for outputting compressed image information from the external device, and the display unit inputs the compressed image information output from the external device, thereby performing a slideshow display at a predetermined time interval using a plurality of second images based on image information obtained by decompressing the input compressed image information by the decompression unit; The display unit displays an image and the audio output unit outputs audio. A television display device characterized by:

7. 7. The television display device according to claim 6, wherein the predetermined time interval for displaying the slide show using the first image or the predetermined time interval for displaying the slide show using the second image can be changed by operating an input device of the display device.

8. 7. The television display device according to claim 6, wherein an image based on compressed image information input to said USB interface section can be rotated based on an operation of said input device and displayed on said display section.

9. 7. The television display device according to claim 6, wherein attribute information of the compressed image information stored in the external device can be added or changed in response to an operation on an input device of the display device.

10. 7. The television display device according to claim 6, wherein attribute information of compressed image information stored in the external device can be added or changed in response to an operation on an input device of the display device, and the attribute information is transmitted from the HDMI interface unit to the external device.

11. 7. A television display device according to claim 1, wherein the input device of said display device is a remote control or a keyboard of said display device.

12. 11. A television display device according to claim 4, wherein the attribute information includes information relating to protection of the compressed image information from being erased.

13. 11. A television display device according to claim 4, wherein the attribute information includes information relating to rotation of the compressed image information.

Images