JP6775635B2 - Display device - Google Patents

Description

The present invention relates to a method for transmitting a digital video signal and, for example, for receiving a digital broadcast signal.
Related to video processing devices such as STBs (Set top boxes) and television display devices.

With the spread of HD (High Definition) broadcasting by terrestrial digital broadcasting and the release of the Blu-ray (registered trademark) recorder that can record HD broadcasting, high-definition HD video can be recorded without deterioration.
There is an increasing need for a digital video interface that can transmit to V. As an interface for uncompressed video signal transmission, DVI (Digital Visual I) formulated by DDWG
HDMI (High Definition Multimedia) licensed by nterface), HDMI, and LLC
Interface (registered trademark). Further, as an interface for video signal transmission compressed by MPEG or the like, there are IEEE1394, LAN and the like. As a conventional technique for applying an interface for uncompressed video signal transmission to a television device, for example, Non-Patent Document 1 is described. This discloses that the video format information is packetized into an uncompressed video signal that has not been packetized and multiplex transmission is performed. In HDMI, voice data is also packetized and transmitted. As a prior art for applying a compressed video signal transmission interface to a television device, for example, Non-Patent Document 2 is described. In addition, as an example of the copyright protection technology used for these, HDCP (High-bandwidth Digital Conte) is used for uncompressed video.
nt Protection System), but for compressed video, DTCP (Digital Transmission Conte)
nt Protection).

Further, for example, Patent Document 1 describes an SDDI (Serial Digital Data Interface) method in which an uncompressed video signal and a compressed video signal are packetized and serially transmitted at the same time.

Japanese Unexamined Patent Publication No. 8-307455

Standard "CEA-861-B" US CEA 2002 Standard "CEA-775-B" US CEA 2004

It is expected that the types of signal sources will increase in the future, and TVs will increasingly be required to have input interfaces for uncompressed video signals and compressed video signals. However, when two types of interfaces with different connectors are provided in a television device (television receiver or the like), it is necessary to secure a connector space and prepare two types of cables. Patent Document 1
A method for simultaneously transmitting an uncompressed video signal and a compressed video signal is disclosed, which is a transmission method suitable for a broadcasting station. That is, in the transmission method described in Patent Document 1, since the uncompressed video signal is packetized, it is difficult to apply it to a television device for general households.

Also, the types of copyright protection technology used will increase depending on the type of interface handled. Even in such a case, it is necessary to appropriately deal with copyright protection technology.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique relating to an interface capable of transmitting both an uncompressed video signal and a compressed video signal. Another object of the present invention is to provide a technique capable of suitably protecting copyright.

In order to solve the above object, one aspect of the present invention is a display device , which includes a receiving unit capable of receiving a digital video signal and a clock signal from an external video signal source, and a tuner unit for receiving a digital broadcast signal. , video based on the digital video signal and a clock signal received by the receiving unit, or provided with a display unit for displaying an image based on the digital broadcast signal received by the tuner unit, the receiving unit, an external video signal The mode for receiving the digital video signal and the clock signal from the source has a first reception mode and a second reception mode, and the receiving unit is in the first reception mode and has an external video. An uncompressed first digital video signal and a first clock signal that is electrically or physically separated from the first digital video signal are received from a signal source, and the receiving unit receives the second digital video signal. In the reception mode, an uncompressed second digital video signal and a second clock signal superimposed on the second digital video signal are received from an external video signal source , and the display unit is the receiving unit. As the video based on the digital video signal and the clock signal received in the above, the video based on the first digital video signal and the first clock signal received when the receiving unit is in the first reception mode, or the video based on the first clock signal. The second digital video signal received when the receiving unit is in the second receiving mode and the video based on the second clock signal can be displayed, and the receiving unit uses the information as an external video signal source. It has a function of transmitting, and is characterized in that the display device transmits information indicating that reception in the second reception mode is possible to an external video signal source .

Further, one aspect of the present invention is characterized in that, in the display device, the receiving unit includes an extracting unit that extracts the second clock signal from the second digital video signal in the second receiving mode. To do.

According to the present invention, it is possible to provide an interface common to an uncompressed video signal and a compressed video signal. In addition, suitable copyright protection is possible.

A block diagram showing a first embodiment of the video processing apparatus according to the present invention. A block diagram showing a configuration example of a transmitter and a receiver of a video processing device. Diagram showing an example of the packet structure of compressed video A block diagram showing a second embodiment of the video processing apparatus according to the present invention. Block diagram showing a third embodiment of the video processing apparatus according to the present invention. Block diagram showing the flow of the video signal of the video processing device in the third embodiment The figure which shows one configuration example of the output circuit and the input circuit in 3rd Example The figure which shows the basic configuration example of the output circuit and the input circuit of a video processing apparatus. A block diagram showing a fourth embodiment of the video processing apparatus according to the present invention. The figure which shows one configuration example of an output circuit and an input circuit in 4th Example

Hereinafter, the best working liquid of the present invention will be described below with reference to the drawings. The present invention simultaneously transmits an uncompressed video signal and a compressed video signal through a common (same) interface. And such transmission is realized while maintaining interoperability with uncompressed digital interfaces such as DVI and HDMI which have begun to spread. In the embodiment described how, the video processing device includes, for example, an STB having a built-in digital tuner, a television display device, and the like (hereinafter, referred to as “TV”). Of course, the following examples can be applied to devices other than these devices.

FIG. 1 is a block diagram of a first embodiment according to the present invention, and is an example of an image processing device, ST.
It includes a B (Set Top Box) 11, a TV 12 which is another example of a video processing device, and a mobile viewer 13 which allows viewing of video on the go. Examples of these operations will be described below.

The STB 11 receives an RF signal 101 supplied from a digital broadcast, a cable, or the like, and demodulates a transport stream (hereinafter abbreviated as TS) of a compressed image with a digital tuner 111. The demodulated TS is a program stream (hereinafter referred to as PS) by the TS / PS converter 112.
(Abbreviated as) is extracted, and an uncompressed video signal is obtained by the decoding unit 113. This uncompressed video signal and OSD
The video compositing unit 114 synthesizes the OSD screen generated by the unit 115. This uncompressed video signal is not packetized and is T from the transmission unit 117 via the video signal interface 103.
It is transmitted to the receiving unit 127 of V11. The uncompressed video signal received by the receiving unit 127 is sent to the display unit 129 via the video combining unit 124. The display unit 129 displays a real-time video screen based on the uncompressed video signal and provides it to the user. The control units 116 and 126 not only control the multiplexing and communication status of the transmission unit 117 and the reception unit 127, respectively, but also the TV.
The display capability of 12 (characteristics and specifications related to video display) is transmitted to STB11, and the video signal transmitted from STB11 is matched with the display characteristic of TV12. In addition, bidirectional communication control is also possible so that the STB11 and the TV12 can cooperate with each other by exchanging remote control codes and the like.

On the other hand, the TS output of the digital tuner 111 and the OSD output of the OSD unit 115 are the transmission unit 11.
It is also sent to 7. The transmission unit 117 multiplexes the TS and OSD packet data into an uncompressed video signal to generate a multiplexed video signal, and transmits the multiplexed video signal to the reception unit 127 via the interface 103. The receiving unit 127 includes an uncompressed video signal, a TS, and an OS from the received multiplexed video signal.
Separate from D. The TS and OSD separated or extracted by the receiving unit 127 are stored in the storage unit 12.
Accumulate in 8. The storage unit 128 is composed of, for example, a hard disk. It may be composed of a semiconductor memory such as a flash memory. As a result, video recording based on TS is performed. The recorded TS is read from the storage unit 128 according to the user's instruction, and the TS / PS
The conversion unit 122 extracts PS, and the decoding unit 123 obtains an uncompressed video signal. At the same time, OSD data is also read from the storage unit 128 as needed, and the OSD unit 125 forms an uncompressed OSD video signal. This OSD video signal is video-synthesized with the uncompressed video signal output from the decoding unit 123 in the video synthesis unit 124. The uncompressed video signal, which is a combination of the recorded video and the OSD, is displayed on the display unit 129 and is viewed in the time zone desired by the user (time-shift viewing).
can do.

If the TV 12 is equipped with the digital tuner 121, the TS can be recorded by the storage unit 128 for time-shifted viewing by receiving a digital broadcast or the like as in the STB 11. Further, the uncompressed video signal obtained through the TS / PS conversion unit 122 and the decoding unit 123, and the ST
The uncompressed video signal sent from B11 can be combined by the video synthesis unit 124 and displayed simultaneously on two screens by the display unit 129. The digital tuners 111 and 121 may receive different channels and synthesize two screens. Further, the video of the channel received by the terrestrial digital tuner and the video of the channel received by the cable TV tuner may be combined on two screens. S
If the TB 11 has a digital tuner 111 (that is, a digital tuner that can receive a channel that cannot be received by the digital tuner of the TV 12) different from the digital tuner built in the TV 12 with a digital tuner, real-time viewing of the channel that the TV 12 cannot receive It also has the effect of realizing time-shifted viewing. Further, even after the STB 11 is removed from the TV 12, there is an effect that the video received by the STB and remaining in the storage unit 128 can be viewed.

It is clear that the compressed video signal and the uncompressed video signal multiplexed by the transmission unit 117 may be different programs as long as the digital tuner 111 can simultaneously receive a plurality of channels. Also, the compressed video data multiplexed by the transmitter 117 is not TS, but TS /
It may be PS after PS conversion. Compared to TS, PS has the advantage of reducing the amount of data transmitted.

The compressed video signal recorded in the storage unit 128 is further compressed by the code conversion unit 130 and code conversion such as a transmission format is performed, and then the interface unit 131 such as USB or IEEE 1394, the interface 104, and the interface unit 132. Through the storage unit 1
Can be transferred to 38. After transferring the video signal, the mobile viewer 14 uses the interface 10
It is separated from 4 and can be carried anywhere. Then, the mobile viewer 14 decodes the video stored in the storage unit 138 by the decoding unit 133 and displays it on the display unit 139 in response to the user's instruction. This allows the user to view the desired video at any location using the mobile viewer 14.

FIG. 2 is a block diagram showing a configuration example of the transmitting unit 117 and the receiving unit 127. An operation example thereof will be described below. Audio data 20 corresponding to uncompressed video from the video compositing unit 114 (FIG. 1)
2. TS output 203 from digital tuner 111 (FIG. 1) and OSD unit 115 (FIG. 1).
) OSD data 204 is input to the packet generation units 211, 212 and 213 of the transmission unit 117, respectively. The packet generation units 211 to 213 form packets suitable for multiplexing with the uncompressed video signal based on the input signals, respectively. The buffer unit 214 receives the packets from the packet generation units 211 to 213, rearranges them according to the priority of packet transmission, and transmits them in order according to the return period of the uncompressed video signal. Buffer part 2
An error correction code is inserted in the ECC code unit 215 into the packets rearranged in 14. Then, the interleaving unit 216 performs bit-wise interleaving processing to increase the resistance to burst errors, and the interleaving unit 216 is sent to the multiple coding unit 217. The multiplexing code unit 217 includes a multiplexing unit 401 for multiplexing the interleaved packet on the uncompressed video signal output 201 from the video combining unit 114 (FIG. 1), and a copy control flag for the uncompressed video signal. Includes a copy flag-imparting unit 402 that imparts the above, an encryption processing unit 403 that encrypts the video signal, and a transmission coding unit 404 that performs transmission coding. The output of the multiplex coding unit 217 is transmitted to the input circuit 228 of the receiving unit 127 as a multiplexed video signal 207 via the output circuit 218.

The multiplexed video signal received by the input circuit 228 is sent to the multiplex decoding unit 227. The multiple decoding unit 227 includes a transmission decoding unit 411 that decodes the transmission coding, a decryption unit 412 that decrypts the video signal, a copy flag extraction unit 413 that extracts the copy flag, and an uncompressed video signal 291. And a separator 414 that separates other packet data. The packet data is interleaved by the deinterleaved circuit 226, restored to the original signal, error-corrected by the ECC decoding unit 225, and then transmitted to the buffer unit 224. Buffer part 2
24 temporarily holds the packet data and outputs the packet data to the packet decoding units 221 to 223, respectively. The packet decoding units 221 to 223 decode the packet data from the buffer unit 224 to obtain the audio data 292 of the uncompressed video signal, the TS293, and the OSD data 294. These are the data sent from the receiving unit 127 to the accumulating unit 128 in FIG.

The capability transmission unit 229 transmits information regarding the display capability (display specifications and / or display characteristics) of the TV to the capability identification unit 219 via the communication line 208. The ability identification unit 219 identifies the display ability of the TV 12 based on the information regarding the display ability and outputs the identification result 205. The identification result 205 is transmitted to the control unit 116 (FIG. 1). Then, the control unit 116 controls the elements related to the video processing or the video output in the STB 11 so as to send out the video format suitable for the connected TV 12, and after confirming the display capability on the TV 12 side,
The multiplexed video signal according to this embodiment is transmitted. With such a configuration, the multiplexed video signal is not transmitted to a configuration that does not have a configuration capable of inputting the multiplexed video signal (that is, a TV having a conventional interface), and only the uncompressed video signal is transmitted. Therefore, interoperability with a TV having a conventional interface is ensured. As a configuration for transmitting the capability on the TV12 side, for example, it is preferable to use the EDID system defined by VESA. In this embodiment, the information regarding the display capability of the TV includes, for example, the horizontal and vertical resolutions of the display unit 129, the color reproduction range, the gamma characteristics, and the like. Furthermore, in order to make effective use of this embodiment,
In addition to the above, as information on the display capability of the TV, for example, a video format indicating the display timing of a multiplexed video signal, a bit rate of a compressed video, a list of decodable coding methods, a storage capacity of the storage unit 128, and a free capacity , It is good to add capabilities such as maximum recording speed and send.

In addition to the above, the capacity transmission unit 229 and the capacity identification unit 219 are also used for device authentication and capacity confirmation of encryption processing. For example, in DVI and HDMI, Digital Content Prot is used as this encryption process.
There is HDCP licensed by ection, LLC. In the future, with the diversification of content, it may be necessary to manage multiple cryptographic processes by content or country. In such a case, in this embodiment, a plurality of types of device authentication and encryption processing elements are provided on the receiving side of the video signal, and which processing is appropriate by referring to the device authentication start protocol from the transmitting side. An automatic discrimination / selection circuit may be provided for discriminating and selecting. On the other hand, the sender determines the type of content, the country of use, etc., and selects and switches the appropriate encryption process.
A selection circuit may be provided. For example, the region code recorded on the DVD disc may be read and encryption processing may be selected with the region code. Further, in television broadcasting, the broadcasting station may be identified and encryption processing may be selected.

Cryptographic processing may need to be fixed due to national and business regulations. In such a case, if a new dedicated video processing device is prepared, the development cost may increase. Therefore, the video processing device is provided with a plurality of encryption processing units capable of executing a plurality of types of encryption processing, and the type of encryption is determined.
A discrimination / selection circuit for selecting the encryption processing unit corresponding to the discrimination result may be provided. At this time, the discrimination / selection circuit may automatically discriminate the type of encryption and perform the selection operation. Further, a setting circuit may be provided so that the type of encryption processing can be set by the user. Also,
By this setting circuit, one of a plurality of encryption processes may be set and fixed in advance at the time of shipment. In this case, the procedure related to the setting change of the encryption processing (for example, STB11 or T) so that the user cannot change the setting of the encryption processing type by this setting circuit.
It is advisable to keep the command or password input for V12 secret from the user. When changing the encryption processing settings after shipment, make it possible to download the procedure related to the above setting changes from, for example, broadcasting and / or the Internet under specific conditions (for example, billing of charges from users). You may. In this way, the procedure for the concealed setting change is disclosed to the user under specific conditions, and the change in the encryption process by the user becomes effective. In implementing this example, such a service may be provided. Furthermore, the procedure related to the above setting change may be stored in a storage medium such as a DVD, and this may be distributed to the user as a setting change DVD.

Furthermore, when various types of encryption processing are used, the image quality can be changed by setting restrictions on the resolution, the bit rate of the compressed video signal, and the like depending on the grade of the encryption processing.

The communication circuits 220 and 230 perform bidirectional communication via the communication path 209, and the control unit 1 in FIG. 1
Control information is transmitted and received between 16 and 126. For example, as the two-way communication in this embodiment, a two-way communication configuration such as CEC defined by HDMI can be applied.
Further, when an error that cannot be corrected occurs in the ECC decoding unit 225, the TV 12 is set to the main communication path 2.
A retransmission request may be transmitted to the STB through 09, and the STB 11 may retransmit the compressed video signal in which an error has occurred in response to the retransmission request. This enables error-free recording. By assigning an identification number or symbol such as a time stamp to the compressed video signal packet included in the compressed / uncompressed video signal multiplexing signal 207, the TV 12 sends the error packet number or symbol to the STB11 together with a retransmission request. You may send it. This will
When a retransmission request occurs, STB11 can retransmit only the error packet by referring to the error packet number or symbol. Therefore, the STB 11 does not need to retransmit the error-free packet, so that the transfer efficiency is improved.

The packet transmission process in the buffer unit 214 described above, that is, the packet rearrangement process according to the priority order will be described below. There is a limit to the transmission capacity of packets transmitted by multiplexing into uncompressed video signals. The packet that should be sent with the highest priority is the audio of an uncompressed video signal that needs to be reproduced in real time in synchronization with the video. Therefore, the audio packet of this uncompressed video signal has the highest priority, and its arrangement is determined with the highest priority. Compressed video packets and OSD packets are placed in the remaining area. The priority of the compressed video packet and the OSD packet is arbitrarily determined, but if the OSD is related to (or highly related to) the uncompressed video signal, the priority of the OSD packet is set higher than that of the compressed video packet. You may. When the necessity of using the compressed video in the TV 12 is high, the priority of the compressed video packet may be higher than that of the OSD packet.

When sending the compressed video to the storage unit 128, it is necessary to arrange the packets so as not to exceed the maximum recording speed of the storage unit 128. Alternatively, the flow control may be performed by the communication path 209 to control the packet transmission amount. When the compressed video is reproduced on the TV 12 in substantially real time, it is necessary to control the packet transmission amount according to the coding speed of the compressed video.

Depending on the format of the uncompressed video signal, the packet transmission capability for multiplexing the compressed video signal may be insufficient. In this case, a format in which the pixel clock of the uncompressed video signal is multiplied by n (n is 2 or more) or the return period of the uncompressed video signal is extended may be used. In this way, the packet transmission capability of the compressed video signal can be improved.

FIG. 3 is a diagram showing an example of a packet structure of compressed video. TS as shown in FIG.
Packet is a 4-byte header and 184-byte adaptation (or payload)
It is composed of a total of 188 bytes. On the other hand, T in the gap of the uncompressed video signal (for example, blanking interval)
In order to multiplex S, it is better that the packet size is small. FIG. 3 shows a case where a packet is composed of a 3-byte header and a 28-byte payload. TS packet 188
It is preferable to divide the bytes into the payloads of seven compressed video packets and transmit them.

An example of the header configuration will be described below. The first byte represents a packet type such as compressed video or audio. A total of 16 bits in the second and third bytes may be allocated to the order of the 7-divided TS packets (3 bits), the TS packet number (11 bits), and the copy control flag (2 bits). The TS itself also has a time stamp, and by diverting this, the 11 bits of the above TS packet number in the header may be omitted, but it is easier to use if it is described in the header part. Using this TS packet number as an identification number for identifying the packet, the retransmission request packet is specified when the transmission error occurs as described above.

For example, when transmitting HD video at 20 Mbps, 106,000 188-byte TS packets are transmitted per second. When a playback request is made to the transmitting side when a transmission error occurs, if the speed of the communication path 209 is slow (that is, the transfer rate is low) and 100 mS is required for transmitting error information, a TS that discriminates at least 10,000 TS packets. Packet number is required. That is, 14 bits are required for the TS packet number, and 11 bits in the header portion is insufficient. On the other hand, as shown in the figure, the payload of the 7th compressed video packet has 8 bytes free. Therefore, 1 byte of this free area may be used to describe the missing TS packet number. Of course, 2 to 3 bytes may be used if necessary. Also, the copy flag may be described in this free area instead of the header. If there is room in the area, the number of copies, the storage time limit for permitting time-shifted viewing after transmission, and / or CGMS-D and the like can also be described. If more information is required, eight compressed video packets instead of seven may be applied to one TS packet.

FIG. 4 is a block diagram showing another embodiment of the present invention. In this embodiment, in the system configuration shown in FIG. 1, the transmitting unit 117 and the receiving unit 127 are changed to the transmitting unit 230 and the receiving unit 250 of FIG. 4, respectively. In this embodiment, the transmission unit 230 and the reception unit 250 are connected to each other by an interface including three data lines 271, 272, 273 for transmitting a video signal and a clock line 274 for transmitting a clock signal. To do. The three data lines are used, for example, for transmitting red, green, and blue uncompressed video signals. The clock line transmits a reference clock for data reception. Further, the data line shall transmit 10 pieces of data during the clock period passing through the clock line. Multiple coding units 231 to 233 and 2
35, output circuits 241 to 244, input circuits 251 to 254, and multiple decoding units 261 to 264 are the multiple coding unit 217, output circuit 218, input circuit 228, and multiple decoding unit 2 of FIG. 2, respectively.
It corresponds to 27, and detailed description thereof will be omitted. The description of the other blocks shown in FIG. 2 is omitted here.

The case where the switch 245 selects the clock supply unit 234 corresponds to the embodiment of FIG.
In this embodiment, when it is necessary to increase the speed of video data transmission, the switch 245 is set to the multiple coding unit 2.
By switching to 35, the clock line is also used as the data line, and the video data transmission amount is multiplied by 4/3. In this case, the reference clock for reproducing the input data on the TV 12 side may be used by extracting the reference clock from the signal of each data line instead of the clock signal transmitted by the clock line. For this purpose, all or at least one of the received signals of each input circuit 251 to 254 may be guided to the PLL 256, and the clock component may be extracted from the input data. A bandpass filter or the like may be combined with a PLL or the like to extract the clock component. Of course, P
LL may be replaced with DLL.

By the way, there are various formats for video data, and there are many reference clocks. When the clock is extracted from the data line and used as the reference clock as described above, it is necessary to accurately detect the reference clock period, which requires a great deal of time. In this embodiment, the switch 245 selects the clock supply unit 235 in the initial state, and transmits the reference clock from the clock supply unit 235 to the reception unit 250 by the clock line 274. As a result, the reference clock period can be easily transmitted to the receiving unit 250. Therefore, according to this embodiment, there is an effect that the time for initial setting related to the cycle of the reference clock can be shortened.

Using the configuration for transmitting information about the display capability of the TV 12 to the STB 11 described in the form of FIG. 2, the transmitting unit 230 determines whether the receiving unit 250 has a mode in which the clock line is used as a data line. Can be told to. The time required for the default clock cycle extraction can also be reported. Further, by using the bidirectional communication path 209 shown in FIG. 2, it is possible to notify the transmitting unit 230 from the receiving unit 250 that the initial setting has been completed.

FIG. 5 is a block diagram showing another embodiment of the present invention. In this embodiment, in the system configuration shown in FIG. 1, the transmitting unit 117 and the receiving unit 127 are changed to the transmitting unit 240 and the receiving unit 260 of FIG. 4, respectively. The same components as those in the embodiment shown in FIG. 4 are numbered the same. In this embodiment, the PLL portion shown in FIG. 4 is also required as a component, but the description is omitted for the sake of simplification of the drawings. Then, in this embodiment, an input circuit 255, a multiple decoding unit 265, a multiple coding unit 258, and an output circuit 257 are added to the embodiment shown in FIG.

In FIG. 5, when sending data using the clock line, the STB11 to the TV12 are not used.
On the contrary, it is characterized by having a function of transmitting data from the TV 12 to the STB 11. In the initial state, the output circuit 257 is in the OFF state, and data and a clock are transmitted from the transmitting unit 240 of the STB 11 to the receiving unit 260, as in the embodiment shown in FIG. After the clock extraction operation of each data is started, the data can be transmitted even on the clock line. At this timing, after turning off the output circuit 244, the operation of the output circuit 257 is started.
Data is sent back from the receiving unit 260 to the transmitting unit 240. At this time, if the clock period is set to the same clock period as the initial state, the clock extraction can be performed in the same manner as other data lines even with this back-fed clock line. Of course, while the data is back-transmitted on the clock line, the video data is continuously transmitted from the transmitting unit 240 to the receiving unit 260 on the data line.

FIG. 6 shows an example of the flow of a video signal when the function of data transmission in the reverse direction is used in the system configuration shown in FIG. The TV 12 sends the compressed video signal recorded in the storage unit 128 to the STB 11 by data transmission in the reverse direction by this clock line, and ST
The TS / PS conversion unit 112 and the decoding unit 113 of the B11 decode the uncompressed video signal. Then, it is sent back to the TV 12 through the data line, and the display unit 129 can display the video based on the decoded video signal. If it is necessary to display the OSD recorded in the storage unit, the OSD may be similarly sent to the OSD circuit of the STB11 by a clock line, and the uncompressed video signal and the video synthesizer may be combined with the video synthesizer 114 and sent to the TV 12.

With this function, even a TV having no decoding unit can reproduce and display the video signal recorded in the storage unit for viewing. The same applies to a TV having a decoding unit when the decoding unit does not support the coding method used for the compressed video. Furthermore, there is an advantage that the TV recording function and the time-shift viewing function can be used even when high-compression broadcasting using a new coding method that did not exist at the time of TV release has started. In addition to encoding, even when a compressed video that uses a copyright protection method that is not supported by the TV is recorded on the TV, the STB
If is compatible with the method, the recorded compressed video signal may be sent to the STB to perform copyright protection processing and decoding processing. Then, in the same manner as described above, by sending back the video signal that has undergone copyright protection processing and decoding processing to the TV side as an uncompressed video signal, it is possible to display the video based on the video signal.

Next, an example of the circuit configuration of the input circuits 254 and 255 and the output circuits 244 and 257 shown in FIG. 5 is shown in FIG. Before the description of FIG. 7, a basic configuration example of the input circuit and the output circuit is shown in FIG. 8 and its operation will be described. The output circuit 31 includes an output control unit 311 and transistors 312 and 31.
3. In the constant current source 314, the input circuit 32 includes a terminating resistor 336, 337, and a differential discrimination unit 338.

The output control unit 311 performs ON / OFF operation of the transistors 312 and 313 (ON-OF).
It is switched so as to be a combination of F) or (OFF-ON). At (ON-OFF), the same current as the constant current source 314 flows through the signal line 321 and a voltage is generated across the terminating resistor 336.
Since no current flows through the signal line 322, the voltage across the terminating resistor 337 becomes zero. (OFF-
When (ON), no current flows through the signal line 321, so the voltage across the terminating resistor 336 is 0, and the signal line 3
The same current as the constant current source 314 flows through 22, and a voltage is generated across the terminating resistor 337. This is so-called differential transmission. The potential difference of this terminating resistor is detected by the differential discrimination unit 338 to determine the logic level.

The configuration of FIG. 7 is a configuration in which the configurations of the input circuit and the output circuit shown in FIG. 8 are used as they are and are connected in parallel. Since two output circuits connected in parallel cannot be operated at the same time,
The output control unit 331 (or 311) of the output circuit that is not in the operating state controls the transistors 312 and 313 (or the transistors 332 and 333) so as to be (OFF-OFF). Both input circuits may be in the operating state, or the terminating resistors 316 and 3 on the unused side.
17 (or 336, 337) may be separated. Further, the differential discrimination unit 318 (or 338)
) May be stopped to reduce power consumption.

FIG. 9 is a block diagram showing another embodiment of the present invention, and shows two TVs 15 as video processing devices.
And 16 are used. That is, this embodiment is an example in which the STB11 shown in FIG. 1 has a display unit and becomes a TV. Video interface 10 as in the embodiment shown in FIG.
A multiplexed video signal obtained by multiplexing an uncompressed video signal and a compressed video signal is sent from the TV 15 to the TV 16 through 4, and the uncompressed video signal is displayed on the display unit 129 of the TV 16. On the other hand, the compressed video is recorded by the storage unit 128, reproduced at a time desired by the user, and displayed on the display unit 129.

FIG. 10 shows a configuration example of the transmission / reception units 157 and 167. In this example, both the data line 271 and the clock line 274 are capable of bidirectional transmission. The specific configuration of the input circuit and the output circuit may be the same as in FIG. 7. When data is transmitted from the transmission / reception unit 157 to 167, the data is transmitted from the multiplex coding unit 231 to the output circuit 241 to the input circuit 251 and the multiple decoding unit 26.
It is supplied to 1. On the other hand, the clock signal is supplied from the clock supply unit 235 to the input circuit 254 and the PLL 283 via the output circuit 244. On the contrary, when data is transmitted from the transmission / reception unit 167 to 157, the data is transmitted from the multiplex coding unit 282 to the input circuit 27 via the output circuit 281.
It is supplied to 1 and the multiple decoding unit 272. On the other hand, the clock signal is transmitted from the clock supply unit 284 to the input circuit 255 and the PLL 274 via the output circuit 257.

In this way, if the TV 15 or 16 has a function of transmitting a video signal in the reverse direction, the operation is as follows. That is, as shown by the broken line in FIG. 9, the compressed video recorded by the storage unit 128 of the TV 16 is sent to the TV 15, the TS / PS conversion unit 152 and the decoding unit 153 of the TV 15 form an uncompressed video signal, and the display unit 159. It can be displayed with. Of course, the TS of TV16
After the uncompressed video signal is formed by the / PS conversion unit 122 and the decoding unit 123, it is transmitted to the TV15.
It may be displayed on the display unit 159.

According to this embodiment, various resources such as a digital tuner, a storage unit, a decoding unit, and copyright protection can be exchanged between two TVs (video processing devices) connected to each other.

In the above examples, STB and TV are shown as video processing devices, but recorders and DVs have been shown.
Similar effects can be expected with a combination of a video signal source such as a D player and a monitor.

By utilizing the embodiment of the present invention described in detail above, an unpacketized real-time uncompressed video signal and a packetized compressed video signal can be simultaneously transmitted to one interface. That is, it is possible to transmit a plurality of digital video signals according to different standards with one interface. In a video processing device such as a TV using this, an uncompressed video signal from a signal source such as an STB is displayed in real time on the display unit of the TV, and a compressed video signal transmitted at the same time is displayed on the HDD built in the TV. It becomes possible to record in a storage device such as, etc. and watch it at another time. That is, it is possible to simultaneously display both the real-time video of a certain video content and the time-shifted video on one screen, and both real-time viewing and time-shifted viewing of the video content are possible.

Furthermore, by using the physical layer capable of high-speed transmission of the uncompressed video transmission interface for data transmission, when transmission of uncompressed video signals is unnecessary, transmission of a large number of compressed video signals and video transfer in a short time There is also an effect that makes it possible.

Further, according to the above embodiment, it is possible to appropriately deal with various copyright protection technologies, and there is also an effect that good viewing within fair use conditions can be realized.

The present invention is applied to a video signal transmission method for multiplexing and transmitting an uncompressed video signal and a compressed video signal with one interface. In particular, it is effective when transmitting and receiving video signals between video processing devices, for example, between a video signal source such as an STB and a video display device such as a TV.

11 ... STB, 12 ... TV, 14 ... Mobile viewer, 31 ... Output circuit, 32 ... Input circuit, 33-34 ... Input / output circuit, 101-102 ... RF signal, 103-104 ... Video signal interface, 111-121 ... Digital tuner, 112 to 122 ... TS / PS conversion unit, 113, 123, 133 ... Decoding unit, 114, 124 ... Video composition unit, 115, 125 ...
OSD unit, 116, 126 ... Control unit 117, 230, 240 ... Transmission unit 127, 250
, 260 ... Receiver unit, 128, 138 ... Storage unit, 129, 139 ... Display unit, 130 ... Code conversion unit, 131, 132 ... Interface unit, 211, 212, 213 ... Packet generation unit, 214, 224 ... Buffer, 215 ... ECC coding unit, 216 ... Interface unit, 21
7 ... Multiple coding unit, 218 ... Output circuit, 219 ... Capability identification unit, 220, 230 ... Communication circuit, 221-223 ... Packet decoding unit, 225 ... ECC decoding unit, 226 ... Deinterleaved unit, 227 ... Multiple decoding Unit 228 ... Input circuit, 229 ... Capacity transmission unit, 231 to 234, 2
58, 282 ... Multiple coding section, 241-244, 257 ... Output circuit, 235, 284 ... Clock supply section, 251-255 ... Input circuit, 256, 274, 283 ... PLL section, 261
~ 265, 272 ... Multiple decoding unit, 311, 331 ... Output control unit, 312-313, 332
~ 333 ... Transistor, 314, 334 ... Current source, 316 to 317, 337 to 336 ...
Termination resistor, 318, 338 ... Differential discrimination unit, 401 ... Multiplexing unit, 402 ... Copy flag addition unit, 403 ... Encryption processing unit, 404 ... Transmission coding unit 411 ... Transmission code decoding unit 412
... Cryptanalysis unit, 413 ... Copy flag extraction unit, 414 ... Separation unit

Claims (2)

It ’s a display device ,
A receiver that can receive digital video signals and clock signals from an external video signal source ,
A tuner that receives digital broadcast signals and
A display unit for displaying a video based on a digital video signal and a clock signal received by the receiving unit or a video based on a digital broadcasting signal received by the tuner unit is provided .
The receiving unit has a first receiving mode and a second receiving mode as modes for receiving a digital video signal and a clock signal from an external video signal source.
When the receiving unit is in the first receiving mode, the uncompressed first digital video signal and the first digital video signal are electrically or physically separated from the external video signal source. Receives the clock signal of 1 and
The receiving unit receives an uncompressed second digital video signal and a second clock signal superimposed on the second digital video signal from an external video signal source in the second receiving mode. ,
The display unit is the first digital video signal received when the receiving unit is in the first receiving mode and the first digital video signal as an image based on the digital video signal and the clock signal received by the receiving unit. It is possible to display an image based on a clock signal, or an image based on the second digital image signal and the second clock signal received when the receiving unit is in the second receiving mode.
The receiving unit has a function of transmitting information to an external video signal source, and transmits information indicating that the display device can receive in the second receiving mode to the external video signal source.
A display device characterized by that. In the display device of claim 1,
The receiving unit is a display device including an extraction unit that extracts the second clock signal from the second digital video signal in the second receiving mode .

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