Transmission system, transmission method, and transmission device

Abstract

The present technology pertains to a transmission system, a transmission method, and a transmission device that make it possible to inhibit reduction in quality of transmission signals while reducing the number of times of correcting the transmission signals in a case where a plurality of devices are daisy-chain connected. This transmission system is provided with a plurality of sub devices and a main device which are all daisy-chain connected. The main device is provided with a main connection unit which is connected to the leading one of the sub devices and through which transmission signals of a plurality of channels are outputted. The sub devices are each provided with: a first sub connection unit which is connected to a preceding-stage device and through which the transmission signals are inputted; correction units which are for correcting the transmission signals and which are disposed so as to be thinned out at a prescribed interval with respect to channels other than channels for signals for use in the device; and a second sub connection unit which outputs, from among the transmission signals inputted from the preceding-stage device, transmission signals other than the transmission signals for use in the device, through channels shifted by the number of channels for the signals for use in the device. The present technology can be applied to, for example, a multi-monitor system.

Description

Technical Field

[0001] The present technology relates to a transmission system, a transmission method, and a transmission device, and particularly relates to a transmission system, a transmission method, and a transmission device suitable for use when connecting a plurality of devices in a daisy chain connection.

Background Art

[0002] In recent years, as a device connection method when operating a plurality of devices in cooperation, daisy chain connection in which each device is connected in series has become widespread (see, for example, Patent Document 1).

[0003] In daisy chain connection, if one of the sub-devices is connected to the main device that is the output source of the transmission signal, other sub-devices can receive the transmission signal via adjacent sub-devices even if they are not directly connected to the main device. Therefore, daisy chain connection can simplify wiring compared to, for example, star connection in which the main device and each sub-device are connected peer-to-peer.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in daisy chain connection, as the number of connected devices increases, the loss of the transmission signal increases, and there is a risk that the quality of the transmission signal will not meet the desired level as the sub-devices further back are reached.

[0006] In contrast, for example, it is conceivable to provide a correction circuit for correcting the transmission signal in each sub-device. However, providing a correction circuit increases cost, circuit scale, power consumption, and heat generation.

[0007] The present technology has been made in view of such a situation, and when connecting a plurality of devices in a daisy chain connection, it is possible to suppress a decrease in the quality of a transmission signal while suppressing the number of correction times of the transmission signal.

Means for Solving the Problem

[0008] The transmission system according to the first aspect of the present technology has a main device and a plurality of sub-devices connected in a daisy chain. The main device is connected to the first sub-device at the head and includes a first main connection part which is a connection part that outputs transmission signals of a plurality of channels. The sub-device is connected to the device in the previous stage, and includes a first sub-connection part which is a connection part to which the transmission signal is input, a correction part which is arranged at a predetermined interval for channels other than the channels of the signal for the own device which is the transmission signal used by the own device and corrects the transmission signal, and when connected to the device in the next stage, a second sub-connection part which is a connection part that shifts the channels of the transmission signals other than the signal for the own device among the transmission signals input from the device in the previous stage by the number of channels of the signal for the own device and outputs them.

[0009] The transmission method according to the first aspect of the present technology has a main device and a plurality of sub-devices connected in a daisy chain. The main device outputs transmission signals of a plurality of channels to the first sub-device at the head. Each sub-device inputs the transmission signal from the device in the previous stage, performs thinning of the correction of the transmission signals other than the signal for the own device which is the transmission signal used by the own device at a predetermined channel interval, and when connected to the device in the next stage, shifts the channels of the transmission signals other than the signal for the own device among the transmission signals input from the device in the previous stage by the number of channels of the signal for the own device and outputs them to the device in the next stage.

[0010] In a first aspect of the present technology, a main device and a plurality of sub-devices are daisy-chain connected. The main device outputs transmission signals of a plurality of channels to the first sub-device at the head. Each sub-device corrects the transmission signals other than the signal for its own device, which is the transmission signal used by the device itself, by thinning at a predetermined channel interval. When connected to the next-stage device, the transmission signals other than the signal for its own device among the transmission signals input from the previous-stage device are output to the next-stage device with the channels shifted by the number of channels of the signal for its own device.

[0011] The transmission device according to the second aspect of the present technology is connected to a previous-stage device and includes a first connection portion to which a transmission signal is input, a correction portion that is arranged by thinning at a predetermined interval for channels other than the channels of the signal for its own device, which is the transmission signal used by the device itself, and that corrects the transmission signal, and a second connection portion that, when connected to a next-stage device, shifts the channels of the transmission signals other than the signal for its own device among the transmission signals input from the previous-stage device by the number of channels of the signal for its own device and outputs the shifted signals.

[0012] In a second aspect of the present technology, a transmission signal is input from a previous-stage device, and the correction portion, which is arranged by thinning at a predetermined interval for channels other than the channels of the signal for its own device, which is the transmission signal used by the device itself, corrects the transmission signal. When connected to a next-stage device, the transmission signals other than the signal for its own device among the transmission signals input from the previous-stage device are output with the channels shifted by the number of channels of the signal for its own device.

[0013] The transmission device according to the third aspect of the present technology is connected to the first sub-device at the head of a plurality of sub-devices connected in a daisy chain, and includes a first connection part that outputs transmission signals of a plurality of channels, and is connected to the last sub-device, and includes feedback information indicating the state of the transmission signal used by each sub-device, and a second connection part to which a control signal output from each sub-device is input, and a control part that controls the transmission signal based on the feedback information included in the control signal from each sub-device.

[0014] In the third aspect of the present technology, transmission signals of a plurality of channels are output to the first sub-device at the head of a plurality of sub-devices connected in a daisy chain, and feedback information indicating the state of the transmission signal used by each sub-device is included from the last sub-device, a control signal output from each sub-device is input, and the transmission signal is controlled based on the feedback information included in the control signal from each sub-device.

Brief Description of Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments for carrying out the present technology will be described. The description will be made in the following order. 1. Background of the Present Technology 2. First Embodiment 3. Second Embodiment 4. Third Embodiment 5. Modification Examples 6. Others

[0017] <<1. Background of the Present Technology>> First, with reference to FIGS. 1 to 3, the background of the present technology will be described.

[0018] FIG. 1 shows a configuration example of a transmission system 1 connected in a daisy chain using an optical interface.

[0019] The transmission system 1 includes a main device 11 and sub-devices 12-1 to 12-4. The main device 11 and the sub-device 12-1 are connected via an optical cable 13-1. The sub-device 12-1 and the sub-device 12-2 are connected via an optical cable 13-2. The sub-device 12-2 and the sub-device 12-3 are connected via an optical cable 13-3. The sub-device 12-3 and the sub-device 12-4 are connected via an optical cable 13-4.

[0020] Incidentally, hereinafter, an example will be described in which the transmission system 1 constitutes a multi-monitor system such as a multi-tile display that constructs one video by the sub-devices 12-1 to 12-4 cooperating to display videos of different channels.

[0021] FIG. 2 shows a configuration example of the main device 11 in FIG. 1 and the sub-device 12A-1 which is the first embodiment of the sub-device 12-1.

[0022] The main device 11 includes a control unit 31 and an optical connection unit 32.

[0023] The control unit 31 generates video signals for channels 1 to 4, generates optical signals for channels 1 to 4 each including the video signal of each channel, and supplies them to the optical connection unit 32.

[0024] The optical connection unit 32 outputs the optical signals for channels 1 to 4 to the sub-device 12A-1 via the optical cable 13-1.

[0025] The sub-device 12A-1 includes an optical connection unit 61, opto-electrical conversion units 62a to 62d, a signal processing unit 63, a display unit 64, electro-optical conversion units 65a to 65d, and an optical connection unit 66.

[0026] Incidentally, hereinafter, the opto-electrical conversion unit will be referred to as an O / E (Optic to Electric) unit. Also, hereinafter, the electro-optical conversion unit will be referred to as an E / O (Electric to Optic) unit.

[0027] The optical connection unit 61 receives the optical signals for channels 1 to 4 via the optical cable 13-1. The optical connection unit 61 supplies the optical signals for channels 1 to 4 to the O / E units 62a to 62d respectively.

[0028] The O / E units 62a to 62d convert the optical signals of channels 1 to 4 into electrical signals respectively, and supply the electrical signals of channels 1 to 4 to the E / O units 65a to 65d respectively. Further, the O / E unit 62a supplies the electrical signal of channel 1 to the signal processing unit 63.

[0029] The signal processing unit 63 performs predetermined signal processing on the electrical signal of channel 1, and supplies the obtained video signal of channel 1 to the display unit 64.

[0030] The display unit 64 displays a video based on the video signal of channel 1.

[0031] The E / O units 65a to 65d convert the electrical signals of channels 1 to 4 into optical signals respectively, and supply the optical signals of channels 1 to 4 to the optical connection unit 66 respectively.

[0032] The optical connection unit 66 outputs the optical signals of channels 1 to 4 to the next-stage sub-device 12A-2 via the optical cable 13-2.

[0033] Although detailed description and illustration are omitted, the sub-devices 12A-2 to 12A-4 also have the same configuration as the sub-device 12A-1 and perform the same processing. Further, the sub-devices 12A-2 to 12A-4 display videos based on the video signals of channels 2 to 4 respectively.

[0034] In the following, when it is not necessary to distinguish the sub-devices 12A-1 to 12A-4 individually, they are simply referred to as the sub-device 12A. In the following, when it is not necessary to distinguish the O / E units 62a to 62d individually, they are simply referred to as the O / E unit 62. In the following, when it is not necessary to distinguish the E / O units 65a to 65d individually, they are simply referred to as the E / O unit 65.

[0035] In this way, in each sub-device 12A, after the optical signals of all channels are converted into electrical signals, they are reconverted into optical signals. As a result, losses such as attenuation of optical signals caused by reflection, influence of position accuracy, etc. are corrected in the optical connection part 32 of the main device 11 and the optical connection parts 61 and 66 of the sub-device 12A. Therefore, the loss of optical signals generated by transmission between devices is suppressed, and the quality of the optical signals transmitted to each sub-device 12A is ensured.

[0036] However, since four O / E parts 62 and four E / O parts 65 are respectively provided in each sub-device 12A, the cost, circuit scale, power consumption, and heat generation increase. Also, the more the number of connections of the sub-device 12A and the more the number of channels of the optical signals increase, the more the cost, circuit scale, power consumption, and heat generation increase.

[0037] FIG. 3 shows a configuration example of the main device 11 in FIG. 1 and the sub-device 12B-1 which is a second embodiment of the sub-device 12-1. In the figure, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

[0038] The sub-device 12B-1 has the same configuration as the node of the optical communication system described in Patent Document 1 mentioned above. Specifically, the sub-device 12B-1 includes an optical connection part 61, an O / E part 62, a signal processing part 63, and an optical connection part 66.

[0039] In the sub-device 12B-1, among the optical signals of channels 1 to 4 input to the optical connection part 61, the optical signal of channel 1 is supplied to the O / E part 62.

[0040] The O / E part 62 converts the optical signal of channel 1 into an electrical signal and supplies the electrical signal of channel 1 to the signal processing part 63.

[0041] The signal processing part 63 performs predetermined signal processing on the electrical signal of channel 1.

[0042] On one hand, among the optical signals of channels 1 to 4 input to the optical connection unit 61, the optical signals of channels 2 to 4 are directly supplied to channels 1 to 3 of the optical connection unit 66.

[0043] As a result, the channels of the optical signals output from the optical connection unit 66 (sub-device 12B-1) are shifted one by one by the amount vacated by excluding the optical signal of channel 1. That is, the optical signals of channels 2 to 4 including the video signals of channels 2 to 4 are shifted to channels 1 to 3 and output from the sub-device 12B-1 to the sub-device 12B-2.

[0044] Although detailed explanations and illustrations are omitted, the sub-devices 12B-2 to 12B-4 also have the same configuration as the sub-device 12B-1 and perform the same processing. Also, the sub-devices 12B-2 to 12B-4 respectively display videos based on the video signals of channels 2 to 4.

[0045] Hereinafter, when it is not necessary to individually distinguish the sub-devices 12B-1 to 12B-4, they are simply referred to as the sub-device 12B.

[0046] Also, from each sub-device 12B, the optical signals excluding the optical signals used by the device itself are shifted by the number of channels vacated by excluding the optical signals used by the device itself (in this case, 1 channel) and output to the next-stage sub-device 12B. For example, from the sub-device 12B-2 to the sub-device 12B-3, the optical signals of channels 1 and 2 including the video signals of channels 3 and 4 are output. From the sub-device 12B-3 to the sub-device 12B-4, the optical signal of channel 1 including the video signal of channel 4 is output.

[0047] Thus, by simply daisy-chain connecting sub-devices 12B with the same configuration, a multi-monitor system can be constructed without any special settings or adjustments. That is, each sub-device 12B can realize a multi-monitor system by simply displaying a video based on the video signal included in the optical signal of channel 1 among the input optical signals.

[0048] On the other hand, since the correction of the optical signal transmitted to the next-stage sub-device 12B is not performed in each sub-device 12B, the loss of the optical signal becomes larger as the sub-device 12B at the rear is reached. For example, since the optical connection section is passed through 2n times until the optical signal reaches the n-th sub-device 12B, the loss of the optical signal increases in proportion to the connection order of the sub-devices 12B. Therefore, as the number of connected sub-devices 12B increases, there is a high possibility that problems such as a decrease in video quality or non-display of video will occur in the rear sub-devices 12B.

[0049] The present technology has been made in view of such a situation, and in daisy-chain connection, it is possible to suppress a decrease in the quality of the transmission signal while suppressing the number of correction times of the transmission signal.

[0050] <<2. First Embodiment>> Next, with reference to FIGS. 4 to 6, the first embodiment of the present technology will be described.

[0051] FIG. 4 shows a configuration example of a transmission system 101 which is a first embodiment of a transmission system to which the present technology is applied.

[0052] The transmission system 101 includes a main device 111 and sub-devices 112-1 to 112-4. The main device 111 and the sub-devices 112-1 to 112-4 are daisy-chain connected to form an open loop.

[0053] Specifically, the main device 111 and the sub-devices 112-1 are connected via an optical cable 113-1. The sub-devices 112-1 and 112-2 are connected via an optical cable 113-2. The sub-devices 112-2 and 112-3 are connected via an optical cable 113-3. The sub-devices 112-3 and 112-4 are connected via an optical cable 113-4.

[0054] The sub-devices 112-1 to 112-4 constitute a multi-monitor system such as a multi-tile display. That is, the sub-devices 112-1 to 112-4 cooperate to display different images and construct one image.

[0055] Hereinafter, when it is not necessary to distinguish the sub-devices 112-1 to 112-4 individually, they are simply referred to as the sub-device 112.

[0056] FIG. 5 is an enlarged view of the main device 111 and the sub-device 112-1 in FIG. 4.

[0057] The main device 111 includes a control unit 131 and an optical connection unit 132.

[0058] The control unit 131 generates video signals for channels 1 to 4, and generates optical signals for channels 1 to 4, which are transmission signals individually including the video signals for each channel. The control unit 131 supplies the optical signals for channels 1 to 4 to the optical connection unit 132.

[0059] The optical connection unit 132 is an output unit capable of outputting four-channel optical signals. The optical connection unit 132 is connected to the first sub-device 112-1 via the optical cable 113-1, and outputs the optical signals for channels 1 to 4 to the sub-device 112-1.

[0060] The sub-device 112-1 includes an optical connection unit 161, an O / E unit 162, a signal processing unit 163, a display unit 164, an O / E unit 165, an E / O unit 166, and an optical connection unit 167.

[0061] The optical connection unit 161 is an input unit capable of inputting 4-channel optical signals. The optical connection unit 161 is connected to the main device 111 via the optical cable 113-1, and optical signals of channels 1 to 4 are input. The optical connection unit 161 supplies the optical signal of channel 1 to the O / E unit 162. The optical connection unit 161 supplies the optical signal of channel 3 to the O / E unit 165. The optical connection unit 161 shifts the optical signals of channels 2 and 4 upward one channel at a time and supplies them to channels 1 and 3 of the optical connection unit 167, respectively.

[0062] The O / E unit 162 converts the optical signal of channel 1 into electrical signals with different modes and supplies the electrical signal of channel 1 to the signal processing unit 163.

[0063] The signal processing unit 163 performs display processing of the video based on the electrical signal of channel 1. Specifically, the signal processing unit 163 performs predetermined signal processing on the electrical signal of channel 1 and controls the display of the video by the display unit 164 by supplying the obtained video signal of channel 1 to the display unit 164.

[0064] The display unit 164 is composed of, for example, a display. The display unit 164 displays a video based on the video signal of channel 1.

[0065] Here, in the sub-device 112-1, the optical signal of channel 1 used for video display has losses caused by passing through two optical connection units, namely the optical connection unit 132 of the main device 111 and the optical connection unit 161 of the sub-device 112-1.

[0066] The O / E unit 165 is arranged at a predetermined interval for channels 2 to 4 other than channel 1 used by the signal processing unit 163. Specifically, the O / E unit 165 is arranged only on channel 3 and not on channels 2 and 4. Then, the O / E unit 165 converts the optical signal of channel 3 into electrical signals with different modes and supplies them to the E / O unit 166. Also, when an optical signal is input, the O / E unit 165 notifies the signal processing unit 163 that the optical signal has been input.

[0067] The E / O unit 166 is arranged on the same channel as the O / E unit 165. The E / O unit 166 converts the electrical signal of channel 3 into optical signals with different modes, shifts it up by one channel, and supplies it to channel 2 of the optical connection unit 167.

[0068] Here, the O / E unit 165 and the E / O unit 166 constitute a correction unit for correcting the optical signal of channel 3. That is, the optical signal of channel 3 is subjected to optoelectronic conversion by the O / E unit 165 and then electro - optical conversion (inverse conversion) by the E / O unit 166. Thereby, the loss of the optical signal of channel 3 caused by passing through the optical connection unit 132 of the main device 111 and the optical connection unit 161 of the sub - device 112 - 1 is corrected. Note that, for example, the correction unit may perform waveform shaping in addition to correcting the loss of the optical signal.

[0069] On the other hand, by performing the correction process (opto - electrical conversion and electro - optical conversion) of the optical signal of channel 3, a transmission delay occurs in the optical signal of channel 3.

[0070] In contrast, the optical signals of channels 2 and 4 are supplied to the optical connection unit 167 without correcting the loss caused by passing through the optical connection unit 132 of the main device 111 and the optical connection unit 161 of the sub - device 112 - 1.

[0071] On the other hand, since no correction process is performed on the optical signals of channels 2 and 4, no transmission delay occurs.

[0072] The optical connection unit 167 is an output unit capable of outputting 4-channel optical signals. The optical connection unit 167 is connected to the next-stage sub-device 112-2 via the optical cable 113-2, and outputs optical signals of channels 1 to 4.

[0073] Although detailed description is omitted, the sub-devices 112-2 to 112-4 have the same configuration as the sub-device 112-1 and perform the same processing as the sub-device 112-1.

[0074] FIG. 6 shows the content of signals transmitted between the devices of the transmission system 101. In FIG. 6, "main" indicates the main device 111, and "sub #1" to "sub #4" indicate the sub-devices 112-1 to 112-4, respectively. Video signals #1 to #4 indicate the video signals of channels 1 to 4, respectively.

[0075] Also, the channels indicated by thick frames and thick characters indicate the channels used for video display in each sub-device 112 at the transmission destination. The hatched channels indicate the channels for which optical signal correction is performed in each sub-device 112 at the transmission destination.

[0076] The main device 111 outputs optical signals of channels 1 to 4, each including the video signal of channels 1 to 4, to the sub-device 112-1.

[0077] The sub-device 112-1 displays a video based on the video signal of channel 1 included in the optical signal of channel 1. The video signal of channel 1 has suffered losses by passing through the two optical connection units, i.e., the optical connection unit 132 of the main device 111 and the optical connection unit 161 of the sub-device 112-1. Also, the sub-device 112-1 corrects the optical signal of channel 3 including the video signal of channel 3.

[0078] The sub-device 112-1 outputs to the next-stage sub-device 112-2, excluding the optical signal of channel 1 used by its own device, from the optical signal input from the main device 111. At this time, the sub-device 112-1 shifts the channels of the output optical signals by the number of channels (in this case, 1 channel) vacated by excluding the optical signal of channel 1. Therefore, the optical signals of channels 1 to 3 each containing the video signals of channels 2 to 4 are transmitted from the sub-device 112-1 to the sub-device 112-2.

[0079] The sub-device 112-2 displays the video based on the video signal of channel 2 included in the optical signal of channel 1. The video signal of channel 2 has incurred losses by passing through the four optical connection parts: the optical connection part 132 of the main device 111, the optical connection parts 161 and 167 of the sub-device 112-1, and the optical connection part 161 of the sub-device 112-2. Also, the sub-device 112-1 corrects the optical signal of channel 3 containing the video signal of channel 4.

[0080] The sub-device 112-2 outputs to the next-stage sub-device 112-3, excluding the optical signal of channel 1 used by its own device, from the optical signal input from the sub-device 112-1. At this time, the sub-device 112-2 shifts the channels of the output optical signals by the number of channels vacated by excluding the optical signal of channel 1. Therefore, the optical signals of channels 1 and 2 each containing the video signals of channels 3 and 4 are transmitted from the sub-device 112-2 to the sub-device 112-3.

[0081] The sub-device 112-3 displays the video based on the video signal of channel 3 included in the optical signal of channel 1. The video signal of channel 3 has incurred losses by passing through the four optical connection parts: the optical connection part 167 of the sub-device 112-1, the optical connection parts 161 and 167 of the sub-device 112-2, and the optical connection part 161 of the sub-device 112-3, after being corrected by the sub-device 111-1.

[0082] The sub-device 112-3 outputs to the next-stage sub-device 112-4, excluding the optical signal of channel 1 used by its own device, from the optical signal input from the sub-device 112-2. At this time, the sub-device 112-3 shifts the channels of the output optical signals by the number of channels made available by excluding the optical signal of channel 1. Therefore, the optical signal of channel 1 including the video signal of channel 4 is transmitted from the sub-device 112-3 to the sub-device 112-4.

[0083] The sub-device 112-4 displays a video based on the video signal of channel 4 included in the optical signal of channel 1. The video signal of channel 4 has incurred losses after being corrected by the sub-device 112-2 and passing through the four optical connection parts: the optical connection part 167 of the sub-device 112-2, the optical connection parts 161 and 167 of the sub-device 112-3, and the optical connection part 161 of the sub-device 112-4.

[0084] As described above, even if the correction part consisting of the O / E part 165 and the E / O part 166 is provided in a staggered manner without being provided for all channels, it is possible to suppress the loss of the video signal (optical signal) due to passing through the optical connection part and ensure the communication quality regardless of the connection order of the sub-devices 112. Specifically, the loss of the video signal of each channel is suppressed to the loss that occurs by passing through a maximum of four optical connection parts.

[0085] Note that the optical signal including the video signal of channel 1 used by the sub-device 112-1 and the optical signal including the video signal of channel 2 used by the sub-device 112-2 are not corrected (optical-to-electrical conversion and electrical-to-optical conversion) in the middle, so no transmission delay occurs. On the other hand, the optical signal including the video signal of channel 3 used by the sub-device 112-3 is corrected by the sub-device 112-1, so a transmission delay occurs. Also, the optical signal including the video signal of channel 4 used by the sub-device 112-4 is corrected by the sub-device 112-2, so a transmission delay occurs.

[0086] In this way, a difference in transmission delay occurs due to the path through which the video signal of each channel reaches the sub-device 112 to be used. Therefore, in order to accurately synchronize the timing of displaying the video at each sub-device 112, it is necessary to correct the transmission delay.

[0087] Here, when an optical signal is input to the O / E unit 165 of each sub-device 112, the O / E unit 165 notifies the signal processing unit 163 that the optical signal has been input. Therefore, the signal processing unit 163 of each sub-device 112 can detect the connection order of its own device, that is, which sub-device 112 it is from the main device 111, based on the presence or absence of the notification from the O / E unit 165.

[0088] For example, when there is a notification from the O / E unit 165, the signal processing unit 163 of each sub-device 112 can detect that its own device is the first (sub-device 112-1) or the second (sub-device 112-2) from the main device 111. On the other hand, when there is no notification from the O / E unit 165, the signal processing unit 163 of each sub-device 112 can detect that its own device is the third (sub-device 112-3) or the fourth (sub-device 112-4) from the main device 111.

[0089] Here, as described above, in sub-devices 112-1 and 112-2, there is no transmission delay in the video signal used by the device itself. On the other hand, in sub-devices 112-3 and 112-4, a transmission delay due to one correction process has occurred in the video signal used by the device itself.

[0090] In contrast, for example, the control unit 131 of the main device 111 adds a synchronization signal synchronized with the optical signal of each channel in time.

[0091] Then, the signal processing unit 163 of each sub-device 112 controls the timing for processing the video signal based on the connection order of its own device and the synchronization signal. For example, the signal processing units 163 of the sub-devices 112-3 and 112-4 that use video signals with transmission delays control to display the video at the timing based on the synchronization signal. On the other hand, the signal processing units 163 of the sub-devices 112-1 and 112-2 that use video signals without transmission delays control to display the video at the timing delayed by the time required for one correction process of the optical signal from the timing based on the synchronization signal.

[0092] Thereby, it is possible to synchronize the timing for displaying the video in each sub-device 112 without using complex processes or mechanisms.

[0093] <<3. Second Embodiment>> Next, with reference to FIGS. 7 to 9, a second embodiment of the present technology will be described.

[0094] FIG. 7 shows a configuration example of a transmission system 201 which is a second embodiment of the transmission system to which the present technology is applied. In the figure, the parts corresponding to the transmission system 101 in FIG. 4 are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0095] The transmission system 201 includes a main device 211 and sub-devices 212-1 to 212-4. The main device 211 and the sub-devices 212-1 to 212-4 are daisy-chain connected to form a closed loop.

[0096] Specifically, the main device 211 and the sub-device 212-1 are connected via the optical cable 113-1. The sub-device 212-1 and the sub-device 212-2 are connected via the optical cable 113-2. The sub-device 212-2 and the sub-device 212-3 are connected via the optical cable 113-3. The sub-device 212-3 and the sub-device 212-4 are connected via the optical cable 113-4. The sub-device 212-4 and the main device 211 are connected via the optical cable 113-5.

[0097] Hereinafter, when it is not necessary to distinguish the sub-devices 212-1 to 212-4 individually, they are simply referred to as the sub-device 212.

[0098] FIG. 8 is an enlarged view of the main device 211 and the sub-device 212-1 in FIG. 7. In the figure, the parts corresponding to the main device 111 and the sub-device 112-1 in FIG. 5 are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

[0099] The main device 211 is identical to the main device 111 in that it includes the optical connection unit 132, but is different in that a control unit 231 is provided instead of the control unit 131 and an optical connection unit 232 is added.

[0100] Similar to the control unit 131 of the main device 111, the control unit 231 generates video signals for channels 1 to 4 and generates optical signals for channels 1 to 4 that individually include the video signals for each channel. The control unit 231 supplies the optical signals for channels 1 to 4 to the optical connection unit 132.

[0101] Also, as will be described later, the control unit 231 controls the transmission signal based on the feedback information included in the control signal supplied from each sub-device 212.

[0102] The optical connection unit 132 is connected to the first sub-device 212-1 via the optical cable 113-1 and outputs the optical signals for channels 1 to 4 to the sub-device 212-1.

[0103] The optical connection unit 232 is an input unit capable of inputting 4-channel optical signals. The optical connection unit 232 is connected to the last sub-device 212-4 via the optical cable 113-5, and optical signals of channels 1 to 4 are inputted thereto.

[0104] The sub-device 212-1 is identical to the sub-device 112-1 in FIG. 5 in that it includes an optical connection unit 161, an O / E unit 162, a display unit 164, an E / O unit 166, and an optical connection unit 167. On the other hand, the sub-device 212-1 is different from the sub-device 112-1 in that a signal processing unit 261 is provided instead of the signal processing unit 163, and an E / O unit 262 is added.

[0105] Similar to the signal processing unit 163 of the sub-device 112, the signal processing unit 261 performs predetermined processing on the electrical signal of channel 1 and supplies the obtained video signal of channel 1 to the display unit 164.

[0106] Also, the signal processing unit 261 detects the states of the optical signal and the electrical signal (video signal of channel 1) of channel 1 used and generates feedback information indicating the detection result. Specifically, the signal processing unit 261 generates, for example, feedback information indicating the detection results of the intensities of the optical signal and the electrical signal of channel 1, and the accurate delay times occurring in the O / E unit 165 and the E / O unit 166 of channel 3. The signal processing unit 261 generates an electrical signal including a control signal including the feedback information and supplies the generated electrical signal to the E / O unit 262.

[0107] The E / O unit 262 converts the electrical signal including the control signal into an optical signal and supplies the optical signal including the control signal to channel 4 of the optical connection unit 167.

[0108] The optical connection unit 167 is connected to the next-stage sub-device 212-2 via the optical cable 113-2 and outputs optical signals of channels 1 to 4.

[0109] Although detailed description is omitted, the sub-devices 212-2 to 212-4 have the same configuration as the sub-device 212-1 and perform the same processing as the sub-device 212-1.

[0110] FIG. 9 shows the content of signals transmitted between the devices of the transmission system 201, similar to FIG. 6. In FIG. 9, "main" indicates the main device 211, and "sub #1" to "sub #4" respectively indicate the sub-devices 212-1 to 212-4. Video signals #1 to #4 respectively indicate the video signals of channels 1 to 4. Control signals #1 to #4 respectively indicate the control signals of the sub-devices 212-1 to 212-4.

[0111] Also, the channels indicated by thick frames and bold characters indicate the channels used for video display in each sub-device 212 at the transmission destination. The hatched channels indicate the channels for which optical signal correction is performed in each sub-device 212 at the transmission destination.

[0112] Comparing FIG. 9 with FIG. 6, in each sub-device 212, an optical signal including the control signal of the own device is added to and output to the channels vacated by shifting the channels by the amount excluding the channels used by the own device. Also, it is different in that a signal is transmitted from the sub-device 212-4 to the main device 211.

[0113] Specifically, the sub-devices 212-1 to 212-4 respectively display videos based on the video signals of channels 1 to 4.

[0114] Also, each sub-device 212 corrects the optical signal of channel 3. Note that not only the optical signal including the video signal but also the optical signal including the control signal is a correction target.

[0115] Furthermore, each sub-device 212 outputs optical signals other than the optical signals to be used by the own device among the optical signals input from the previous-stage device to the next-stage device. At this time, each sub-device 212 shifts the channels of the output optical signals by the number of channels made available by excluding the optical signals to be used by the own device. Also, each sub-device 212 adds an optical signal including the control signal of the own device to the available channel (the last channel 4) and outputs it to the next-stage device.

[0116] Specifically, the sub-device 212-1 shifts the optical signals respectively including the video signals of channels 2 to 4 to channels 1 to 3 and outputs them to the sub-device 212-2. Also, the sub-device 212-1 adds an optical signal including the control signal of the sub-device 212-1 to channel 4 and outputs it to the sub-device 212-2.

[0117] The sub-device 212-2 shifts the optical signals respectively including the video signals of channels 3 and 4 and the control signal from the sub-device 212-1 before the sub-device 212-2 to channels 1 to 3 and outputs them to the sub-device 212-3. Also, the sub-device 212-2 adds an optical signal including the control signal of the sub-device 212-2 to channel 4 and outputs it to the sub-device 212-3.

[0118] The sub-device 212-3 shifts the optical signals respectively including the video signal of channel 4 and the control signals from the sub-devices 212-1 and 212-2 before the sub-device 212-2 to channels 1 to 3 and outputs them to the sub-device 212-4. Also, the sub-device 212-3 adds an optical signal including the control signal of the sub-device 212-3 to channel 4 and outputs it to the sub-device 212-4.

[0119] The sub-device 212-4 shifts optical signals respectively containing control signals from the sub-devices 212-1 to 212-3 before the sub-device 212-4 to channels 1 to 3, and outputs them to the main device 211. Further, the sub-device 212-4 adds an optical signal containing the control signal of the sub-device 212-4 to channel 4 and outputs it to the main device 211.

[0120] In this way, the main device 211 can acquire the feedback information of each sub-device 212. Then, the control unit 231 of the main device 211 performs control of the transmission signal based on the feedback information of each sub-device 212, for example.

[0121] For example, the control unit 231 detects the delay time of the video signal used in each sub-device 212 based on the feedback information from each sub-device 212.

[0122] For example, as described above, correction processing is performed on the optical signal including the video signal of channel 3 and the video signal of channel 4, so a transmission delay occurs. Hereinafter, the case where the delay time of the video signal of channel 3 is t3 and the delay time of the video signal of channel 4 is t4, and the delay time t3 > the delay time t4 will be described.

[0123] For example, the control unit 231 controls the timing of outputting the optical signal of each channel based on the delay time of the video signal used in each sub-device 212.

[0124] Specifically, the control unit 231 causes the optical signal of channel 3 including the video signal of channel 3 with the largest delay time to be output from the optical connection unit 132 without performing time correction. Next, the control unit 231 causes the optical signal of channel 4 including the video signal of channel 4 with the second largest delay time to be output from the optical connection unit 132 at the time point when a delay time of t3 - t4 has elapsed since the optical signal of channel 3 was output. Next, the control unit 231 causes the optical signal of channel 1 including the video signal of channel 1 with no transmission delay and the optical signal of channel 2 including the video signal of channel 2 to be output from the optical connection unit 132 at the time point when a delay time of t3 has elapsed since the optical signal of channel 3 was output.

[0125] As a result, the timings at which the video signals of channels 1 to 4 reach the respective sub-devices 212 that use the video signals are synchronized. Then, the videos of each channel are displayed more accurately in synchronization.

[0126] Note that, for example, the control unit 231 may control the timings at which the signal processing units 261 of the respective sub-devices 212 process the video signals of each channel based on the delay times of the video signals used in the respective sub-devices 212.

[0127] For example, the control unit 231 includes delay time control information indicating a delay time of t3 in the video signals of channels 1 and 2, includes delay time control information indicating a delay time of 0 in the video signal of channel 3, and includes delay time control information indicating a delay time of t3 - t4 in the video signal of channel 4.

[0128] On the other hand, the signal processing unit 261 of each sub-device 212 controls the timing at which the video is displayed based on the delay time control information.

[0129] For example, the signal processing unit 261 of the sub-device 212-1 delays the timing of outputting and displaying the video based on the video signal of channel 1 to the display unit 164 by the delay time t3. The signal processing unit 261 of the sub-device 212-2 delays the timing of outputting and displaying the video based on the video signal of channel 2 to the display unit 164 by the delay time t3. The signal processing unit 261 of the sub-device 212-3 does not delay the timing of outputting and displaying the video based on the video signal of channel 3 to the display unit 164. The signal processing unit 261 of the sub-device 212-4 delays the timing of outputting and displaying the video based on the video signal of channel 4 to the display unit 164 by the delay time t3 - t4.

[0130] As a result, the videos of each channel are displayed more accurately in synchronization.

[0131] Also, the control unit 231 detects the intensity of the video signal (including optical and electrical signals) used in each sub-device 212 based on the feedback information from each sub-device 212. Then, the control unit 231 controls the intensity of the optical signal of each channel based on the intensity of the video signal used in each sub-device 212.

[0132] For example, when the intensity of the video signal of channel 1, for which no correction process is performed in any of the sub-devices 212, is low, the control unit 231 adjusts the output intensity of the optical signal of channel 1 so that the intensity of the video signal of channel 1 becomes equal to or higher than a predetermined level. Similarly, when the intensity of the video signal of channel 2, for which no correction process is performed in any of the sub-devices 212, is low, the control unit 231 adjusts the output intensity of the optical signal of channel 2 so that the intensity of the video signal of channel 2 becomes equal to or higher than a predetermined level.

[0133] Further, when the intensity of the video signal of channel 3 in which correction processing is performed in the sub-device 212-1 is low, the control unit 231 instructs the E / O unit 166 of the sub-device 212-1 to increase the intensity of the output optical signal. That is, the control unit 231 instructs the E / O unit 166 of the sub-device 212-1 so that the intensity of the optical signal (after correction) after converting the electrical signal including the video signal of channel 3 becomes equal to or higher than a predetermined level.

[0134] On the other hand, when converting the electrical signal including the video signal of channel 3 into an optical signal, the E / O unit 166 of the sub-device 212-1 controls so that the intensity of the converted optical signal becomes equal to or higher than a predetermined level.

[0135] Similarly, when the intensity of the video signal of channel 4 in which correction processing is performed in the sub-device 212-2 is low, the control unit 231 instructs the E / O unit 166 of the sub-device 212-2 to increase the intensity of the output optical signal. That is, the control unit 231 instructs the E / O unit 166 of the sub-device 212-2 so that the intensity of the optical signal (after correction) after converting the electrical signal including the video signal of channel 4 becomes equal to or higher than a predetermined level.

[0136] On the other hand, when converting the electrical signal including the video signal of channel 4 into an optical signal, the E / O unit 166 of the sub-device 212-2 controls so that the intensity of the converted optical signal becomes equal to or higher than a predetermined level.

[0137] As a result, the intensity of the optical signal of each channel is optimized, enabling high-quality signal transmission.

[0138] <<4. Third Embodiment>> Next, with reference to FIGS. 10 to 12, a third embodiment of the present technology will be described.

[0139] FIG. 10 shows a configuration example of a transmission system 301 which is a third embodiment of a transmission system to which the present technology is applied.

[0140] The transmission system 301 is significantly different from the transmission system 201 in FIG. 7 in that the number of sub-devices has increased from 4 to 8.

[0141] The transmission system 301 includes a main device 311 and sub-devices 312-1 to 312-8. The main device 311 and the sub-devices 312-1 to 312-8 are daisy-chain connected to form a closed loop.

[0142] Specifically, the main device 311 and the sub-device 312-1 are connected via an optical cable 313-1. The sub-device 312-1 and the sub-device 312-2 are connected via an optical cable 313-2. The sub-device 312-2 and the sub-device 312-3 are connected via an optical cable 313-3. The sub-device 312-3 and the sub-device 312-4 are connected via an optical cable 313-4. The sub-device 312-4 and the sub-device 312-5 are connected via an optical cable 313-5. The sub-device 312-5 and the sub-device 312-6 are connected via an optical cable 313-6. The sub-device 312-6 and the sub-device 312-7 are connected via an optical cable 313-7. The sub-device 312-7 and the sub-device 312-8 are connected via an optical cable 313-8. The sub-device 312-8 and the main device 311 are connected via an optical cable 313-9.

[0143] Hereinafter, when it is not necessary to individually distinguish the sub-devices 312-1 to 312-8, they are simply referred to as sub-devices 312.

[0144] FIG. 11 is an enlarged view of the main device 311 and the sub-device 312-1 in FIG. 10. In the figure, the parts corresponding to the sub-device 312-1 in FIG. 8 are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

[0145] The main device 311 includes a control unit 331, an optical connection unit 332, and an optical connection unit 333.

[0146] Similar to the control unit 231 of the main device 211 in FIG. 8, the control unit 331 generates video signals for channels 1 to 8 and generates optical signals for channels 1 to 8 that individually contain the video signals for each channel. The control unit 331 supplies the optical signals for channels 1 to 8 to the optical connection unit 332.

[0147] Also, similar to the control unit 231 of the main device 211, the control unit 331 controls the transmission signal based on the feedback information included in the control signal supplied from each sub-device 312.

[0148] The optical connection unit 332 is an output unit capable of outputting 8-channel optical signals. The optical connection unit 332 is connected to the first sub-device 312-1 via the optical cable 313-1 and outputs the optical signals for channels 1 to 8 to the sub-device 312-1.

[0149] The optical connection unit 333 is an input unit capable of inputting 8-channel optical signals. The optical connection unit 333 is connected to the last sub-device 312-8 via the optical cable 313-9, and the optical signals for channels 1 to 8 are input thereto.

[0150] The sub-device 312-1 is identical to the sub-device 212-1 in FIG. 8 in that it includes an O / E unit 162, a display unit 164, a signal processing unit 261, and an E / O unit 262. On the other hand, compared with the sub-device 212-1, the sub-device 312-1 is different in that the O / E unit 165 is increased to three, namely the O / E units 165a to 165c, the E / O unit 166 is increased to three, namely the E / O units 166a to 166c, and instead of the optical connection units 161 and 167, it includes optical connection units 361 and 362.

[0151] Hereinafter, when there is no need to individually distinguish the O / E units 165a to 165c, they are simply referred to as the O / E unit 165. Hereinafter, when there is no need to individually distinguish the E / O units 166a to 166c, they are simply referred to as the E / O unit 166.

[0152] The optical connection unit 361 is an input unit capable of inputting 8-channel optical signals. The optical connection unit 361 is connected to the main device 311 via the optical cable 313-1, and optical signals of channels 1 to 8 are input from the main device 311. The optical connection unit 361 supplies the optical signal of channel 1 to the O / E unit 162. The optical connection unit 361 supplies the optical signals of channels 3, 5, and 7 to the O / E units 165a to 165c, respectively. The optical connection unit 361 shifts the optical signals of channels 2, 4, 6, and 8 upward by one channel each and supplies them to channels 1, 3, 5, and 7 of the optical connection unit 362, respectively.

[0153] The O / E units 165a to 165c are arranged at predetermined intervals for channels 2 to 8 excluding channel 1 used by the signal processing unit 261. Specifically, the O / E units 165a to 165c are arranged at every other channel for channels 3, 5, and 7. The O / E units 165a to 165c convert the optical signals of channels 3, 5, and 7 into electrical signals, respectively, and supply them to the E / O units 166a to 166c, respectively.

[0154] The E / O units 166a to 166c are arranged in the same channels as the O / E units 165a to 165c, respectively. The E / O units 166a to 166c convert the electrical signals of channels 3, 5, and 7 into optical signals, respectively, shift them upward by one channel each, and supply them to channels 2, 4, and 6 of the optical connection unit 362.

[0155] The E / O unit 262 converts the electrical signal including the control signal supplied from the signal processing unit 261 into an optical signal and supplies it to channel 8 of the optical connection unit 362.

[0156] The optical connection unit 362 is an output unit capable of outputting an 8-channel optical signal. The optical connection unit 362 is connected to the sub-device 312-2 via the optical cable 313-2 and outputs the optical signals of channels 1 to 8 to the sub-device 312-2.

[0157] Although detailed description is omitted, the sub-devices 312-2 to 312-8 have the same configuration as the sub-device 312-1 and perform the same processing as the sub-device 312-1.

[0158] Similar to FIGS. 6 and 9, FIG. 12 shows the content of the signals transmitted between the devices of the transmission system 301. In FIG. 12, "main" indicates the main device 311, and "sub #1" to "sub #8" respectively indicate the sub-devices 312-1 to 312-8. Video signals #1 to #8 respectively indicate the video signals of channels 1 to 8. Control signals #1 to #8 respectively indicate the control signals of the sub-devices 312-1 to 312-8.

[0159] Also, the channels indicated by thick frames and bold characters indicate the channels used for video display in each of the destination sub-devices 312. The hatched channels indicate the channels for which optical signal correction is performed in each of the destination sub-devices 312.

[0160] Comparing FIG. 12 with FIG. 9, there are significant differences in that the number of sub-devices 312 has increased, the number of channels has increased, and the number of channels for which correction is performed in each sub-device 312 has increased.

[0161] The sub-devices 312-1 to 312-8 respectively display videos based on the video signals of channels 1 to 8.

[0162] Also, each sub-device 312 corrects the optical signals of channels 3, 5, and 7. Note that not only the optical signals including video signals but also the optical signals including control signals are targets for correction.

[0163] Furthermore, each sub-device 312 outputs to the next-stage device an optical signal input from the previous-stage device, excluding the optical signal of the channel used by its own device. At this time, each sub-device 312 shifts the channels of the output optical signal by the number of channels made available by excluding the optical signal used by its own device. Also, each sub-device 312 adds an optical signal including its own control signal to the available channel (the last channel 8) and outputs it to the next-stage device.

[0164] Here, the number of correction times and the number of loss occurrences of the video signal for each channel in the transmission system 301 will be described.

[0165] Note that the number of correction times of the video signal for each channel is equal to the number of correction units (a combination of the O / E unit 165 and the E / O unit 166) through which the video signal (including the optical signal and the electrical signal) of each channel passes from the time it is output from the control unit 331 of the main device 311 until it reaches the signal processing unit 261 of the sub-device 312 that uses the video signal. Also, the number of loss occurrences of the video signal for each channel is equal to the number of optical connection units through which the video signal (including the optical signal) of each channel passes from the time it is output from the control unit 331 of the main device 311 or after being corrected by each sub-device 312 until it reaches the signal processing unit 261 of the sub-device 312 that uses the video signal.

[0166] The video signal of channel 1 is used by the signal processing unit 261 of the sub-device 312-1. And, between the time the video signal of channel 1 is output from the control unit 331 of the main device 311 until it reaches the signal processing unit 261 of the sub-device 312-1, it does not pass through the correction unit of any sub-device 312. Therefore, the number of correction times of the video signal of channel 1 is 0 times.

[0167] Also, between the time when the video signal of Channel 1 is output from the control unit 331 of the main device 311 and the time when it reaches the signal processing unit 261 of the sub-device 312-1, it passes through two optical connection parts, namely the optical connection part 332 of the main device 311 and the optical connection part 361 of the sub-device 312-1. Therefore, the number of times of loss occurrence of the video signal of Channel 1 is two times.

[0168] The video signal of Channel 2 is used by the signal processing unit 261 of the sub-device 312-2. And between the time when the video signal of Channel 2 is output from the control unit 331 of the main device 311 and the time when it reaches the signal processing unit 261 of the sub-device 312-2, it does not pass through the correction part of any sub-device 312. Therefore, the number of times of correction of the video signal of Channel 2 is zero times.

[0169] Also, between the time when the video signal of Channel 2 is output from the control unit 331 of the main device 311 and the time when it reaches the signal processing unit 261 of the sub-device 312-2, it passes through four optical connection parts, namely the optical connection part 332 of the main device 311, the optical connection part 361 and the optical connection part 362 of the sub-device 312-1, and the optical connection part 361 of the sub-device 312-2. Therefore, the number of times of loss occurrence of the video signal of Channel 2 is four times.

[0170] The video signal of Channel 3 is used by the signal processing unit 261 of the sub-device 312-3. And between the time when the video signal of Channel 3 is output from the control unit 331 of the main device 311 and the time when it reaches the signal processing unit 261 of the sub-device 312-3, it passes through the correction part of the sub-device 312-1. Therefore, the number of times of correction of the video signal of Channel 3 is one time.

[0171] Also, between the time when the video signal of Channel 3 is corrected by the correction part of the sub-device 312-1 and the time when it reaches the signal processing unit 261 of the sub-device 312-3, it passes through four optical connection parts, namely the optical connection part 362 of the sub-device 312-1, the optical connection part 361 and the optical connection part 362 of the sub-device 312-2, and the optical connection part 361 of the sub-device 312-3. Therefore, the number of times of loss occurrence of the video signal of Channel 3 is four times.

[0172] The video signal of Channel 4 is used by the signal processing unit 261 of the sub-device 312-4. And, between when the video signal of Channel 4 is output from the control unit 331 of the main device 311 and reaches the signal processing unit 261 of the sub-device 312-4, it passes through the correction unit of the sub-device 312-2. Therefore, the number of correction times of the video signal of Channel 4 is 1 time.

[0173] Also, between when the video signal of Channel 4 is corrected by the correction unit of the sub-device 312-2 and reaches the signal processing unit 261 of the sub-device 312-4, it passes through four optical connection parts, namely the optical connection part 362 of the sub-device 312-2, the optical connection parts 361 and 362 of the sub-device 312-3, and the optical connection part 361 of the sub-device 312-4. Therefore, the number of times of loss occurrence of the video signal of Channel 4 is 4 times.

[0174] The video signal of Channel 5 is used by the signal processing unit 261 of the sub-device 312-5. And, between when the video signal of Channel 5 is output from the control unit 331 of the main device 311 and reaches the signal processing unit 261 of the sub-device 312-5, it passes through the correction units of the sub-devices 312-1 and 312-3. Therefore, the number of correction times of the video signal of Channel 5 is 2 times.

[0175] Also, between when the video signal of Channel 5 is corrected by the correction unit of the sub-device 312-3 and reaches the signal processing unit 261 of the sub-device 312-5, it passes through four optical connection parts, namely the optical connection part 362 of the sub-device 312-3, the optical connection parts 361 and 362 of the sub-device 312-4, and the optical connection part 361 of the sub-device 312-5. Therefore, the number of times of loss occurrence of the video signal of Channel 5 is 4 times.

[0176] The video signal of Channel 6 is used by the signal processing unit 261 of the sub-device 312-6. And, between when the video signal of Channel 6 is output from the control unit 331 of the main device 311 and reaches the signal processing unit 261 of the sub-device 312-6, it passes through the correction units of the sub-devices 312-2 and 312-4. Therefore, the number of correction times for the video signal of Channel 6 is two times.

[0177] Also, between when the video signal of Channel 6 is corrected by the correction unit of the sub-device 312-4 and reaches the signal processing unit 261 of the sub-device 312-6, it passes through four optical connection parts, namely the optical connection part 362 of the sub-device 312-4, the optical connection parts 361 and 362 of the sub-device 312-5, and the optical connection part 361 of the sub-device 312-6. Therefore, the number of times of loss occurrence for the video signal of Channel 6 is four times.

[0178] The video signal of Channel 7 is used by the signal processing unit 261 of the sub-device 312-7. And, between when the video signal of Channel 7 is output from the control unit 331 of the main device 311 and reaches the signal processing unit 261 of the sub-device 312-7, it passes through the correction units of the sub-devices 312-1, 312-3, and 312-5. Therefore, the number of correction times for the video signal of Channel 7 is three times.

[0179] Also, between when the video signal of Channel 7 is corrected by the correction unit of the sub-device 312-5 and reaches the signal processing unit 261 of the sub-device 312-7, it passes through four optical connection parts, namely the optical connection part 362 of the sub-device 312-5, the optical connection parts 361 and 362 of the sub-device 312-6, and the optical connection part 361 of the sub-device 312-7. Therefore, the number of times of loss occurrence for the video signal of Channel 7 is four times.

[0180] The video signal of Channel 8 is used by the signal processing unit 261 of the sub-device 312-8. And, between the time when the video signal of Channel 8 is output from the control unit 331 of the main device 311 and reaches the signal processing unit 261 of the sub-device 312-8, it passes through the correction units of the sub-devices 312-2, 312-4, and 312-6. Therefore, the number of times the video signal of Channel 8 is corrected is three times.

[0181] Also, between the time when the video signal of Channel 8 is corrected by the correction unit of the sub-device 312-6 and reaches the signal processing unit 261 of the sub-device 312-8, it passes through four optical connection parts: the optical connection part 362 of the sub-device 312-6, the optical connection parts 361 and 362 of the sub-device 312-7, and the optical connection part 361 of the sub-device 312-8. Therefore, the number of times loss occurs in the video signal of Channel 8 is four times.

[0182] As described above, even if the number of sub-devices 312 is increased and the O / E unit 165 and E / O unit 166 are provided at intervals without being provided for all channels, it is possible to suppress the loss of the video signal (optical signal) passing through the optical connection part and ensure the communication quality regardless of the connection order of the sub-devices 312. Specifically, the loss of the video signal of each channel is suppressed to the loss caused by passing through a maximum of four optical connection parts.

[0183] Also, the number of times the video signal of each channel is corrected can be suppressed to a maximum of three times, and the transmission delay of the optical signal can be suppressed.

[0184] <<5. Modification Example>> Hereinafter, a modification example of the above-described embodiment of the present technology will be described.

[0185] For example, in the present technology, the number of sub-devices connected in daisy chain can be set to any number of three or more. Note that the number of channels of the optical signal output from the main device is set to be equal to or more than the number of sub-devices.

[0186] For example, in the above, an example in which the correction unit including the O / E unit and the E / O unit is arranged every other channel has been shown, but it is also possible to arrange them at a predetermined interval of two or more channels.

[0187] For example, in each sub-device, two or more n-channel signals may be used. In this case, for example, in each sub-device, among the optical signals input from the previous device, the optical signals other than the optical signals used by the own device are shifted by the number of channels n of the optical signals used by the own device and output to the next-stage device.

[0188] For example, the present technology can also be applied when signals in forms other than optical signals are transmitted by daisy chain connection. For example, the present technology can also be applied when electrical signals are transmitted by daisy chain connection. In this case, the correction unit that corrects the electrical signal in each sub-device is constituted by, for example, a combination of a D / A (digital / analog) converter and an A / D (analog / digital) converter, or an amplifier.

[0189] For example, not only sub-devices but also main devices may perform the same signal processing as sub-devices. For example, in the above-described embodiment, the main device may also perform video display processing.

[0190] For example, the content of the information included in the control signal output from each sub-device can be appropriately changed. For example, the control signal may include only one of the delay time and intensity of the video signal used in each sub-device. Also, for example, the control signal may include information other than the above-described feedback information. Further, for example, in each sub-device, the information included in the control signal output from the sub-device before the own device may be used. In this case, when the main device does not use the information included in the control signal of each sub-device (when feedback of information from each sub-device to the main device is not necessary), it is not always necessary to connect the last sub-device and the main device.

[0191] For example, in addition to the multi-monitor system described above, the present technology can also be applied to a system that uses signals of different channels in each sub-device connected in a daisy chain.

[0192] <<6. Others>> <Configuration Example of Computer> The above-described series of processes can be executed by hardware or by software. When the series of processes are executed by software, the programs constituting the software are installed in a computer. Here, the computer includes a computer incorporated in dedicated hardware, and for example, a general-purpose personal computer that can execute various functions by installing various programs.

[0193] FIG. 13 is a block diagram showing a configuration example of the hardware of a computer that executes the above-described series of processes by a program.

[0194] In computer 1000, a CPU (Central Processing Unit) 1001, a ROM (Read Only Memory) 1002, and a RAM (Random Access Memory) 1003 are interconnected by a bus 1004.

[0195] Further connected to bus 1004 is an input / output interface 1005. Connected to input / output interface 1005 are an input unit 1006, an output unit 1007, a recording unit 1008, a communication unit 1009, and a drive 1010.

[0196] The input unit 1006 consists of an input switch, buttons, a microphone, an imaging device, etc. The output unit 1007 consists of a display, a speaker, etc. The recording unit 1008 consists of a hard disk, a non-volatile memory, etc. The communication unit 1009 consists of a network interface, etc. The drive 1010 drives a removable medium 1011 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.

[0197] In the computer 1000 configured as described above, the CPU 1001 loads and executes, for example, a program recorded in the recording unit 1008 via the input / output interface 1005 and the bus 1004 into the RAM 1003, whereby the above-described series of processes are performed.

[0198] The program executed by the computer 1000 (CPU 1001) can be recorded and provided, for example, on a removable medium 1011 as a package medium or the like. Further, the program can be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

[0199] In the computer 1000, the program can be installed in the recording unit 1008 via the input / output interface 1005 by mounting the removable medium 1011 on the drive 1010. Further, the program can be received by the communication unit 1009 via a wired or wireless transmission medium and installed in the recording unit 1008. In addition, the program can be installed in advance in the ROM 1002 or the recording unit 1008.

[0200] Note that the program executed by the computer may be a program in which processing is performed in time series in the order described in this specification, or may be a program in which processing is performed in parallel or at a necessary timing such as when a call is made.

[0201] In addition, in this specification, a system means a collection of a plurality of components (devices, modules (parts), etc.), regardless of whether all the components are in the same housing. Therefore, a plurality of devices housed in separate housings and connected via a network, and a single device in which a plurality of modules are housed in one housing are both systems.

[0202] Furthermore, the embodiments of the present technology are not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present technology.

[0203] <Example of configuration combination> The present technology can also have the following configuration.

[0204] (1) The main device and a plurality of sub-devices are daisy-chain connected, The main device is a first main connection part that is connected to the first sub-device at the head and outputs transmission signals of a plurality of channels. and includes The sub-device is a first sub-connection part that is connected to the previous device and to which the transmission signal is input, and a correction part that is arranged at a predetermined interval for channels other than the channel of the signal for the own device, which is the transmission signal used by the own device, and corrects the transmission signal, and when connected to the next device, a second sub-connection part that shifts the channels of the transmission signals other than the signal for the own device among the transmission signals input from the previous device by the number of channels of the signal for the own device and outputs them. and includes a transmission system. (2) The sub-device further includes a signal processing part that processes the signal for the own device. The transmission system according to (1) above. (3) The signal processing unit detects the connection order of its own device based on the presence or absence of the input of the transmission signal to the correction unit. The transmission system according to (2) above. (4) Based on the detected connection order of its own device, the signal processing unit controls the timing for processing the signal for its own device. The transmission system according to (3) above. (5) The first sub-connection unit receives the transmission signal and the control signals from each of the sub-devices before its own device. The second sub-connection unit outputs the transmission signal other than the signal for its own device among the transmission signals input from the previous-stage device, the control signals from each of the sub-devices before its own device, and the control signal of its own device. The transmission system according to any one of (2) to (4) above. (6) The signal processing unit generates a signal including feedback information indicating the state of the signal for its own device as the control signal of its own device. The transmission system according to (5) above. (7) The main device is connected to the last sub-device and has a second main connection unit which is a connection unit for receiving the control signals from each of the sub-devices, and a control unit for controlling the transmission signal based on the feedback information included in the control signals from each of the sub-devices. and further includes The transmission system according to (6) above. (8) The feedback information includes at least one of the delay time and intensity of the transmission signal used by each of the sub-devices. The transmission system according to (7) above. (9) Based on the delay time of the transmission signal used by each of the sub-devices, the control unit controls the timing for outputting the transmission signal of each channel from the first main connection unit. The transmission system according to (8) above. (10) The control unit controls the timing at which the signal processing unit of each sub-device processes the transmission signal based on the delay time of the transmission signal used by each sub-device. The transmission system according to (8) or (9) above. (11) The control unit controls the intensity of the transmission signal of each channel based on the intensity of the transmission signal used by each sub-device. The transmission system according to any one of (8) to (10) above. (12) The control unit controls the intensity of the transmission signal after correction by the correction unit of each sub-device based on the intensity of the transmission signal used by each sub-device. The transmission system according to (11) above. (13) The second sub-connection unit shifts the channels of the transmission signals other than the transmission signal input from the previous-stage device and the control signals from each of the sub-devices before the own device by the number of channels of the signal for the own device and outputs them, and outputs the control signal of the own device from the channels vacated by shifting the channels. The transmission system according to any one of (5) to (12) above. (14) The transmission signal includes a video signal. The signal processing unit performs display processing of the video based on the video signal included in the signal for the own device. The transmission system according to any one of (2) to (13) above. (15) The correction unit includes a conversion unit that converts the mode of the transmission signal, and an inverse conversion unit that performs inverse conversion of the mode of the transmission signal converted by the conversion unit. and is provided with The transmission system according to any one of (1) to (14) above. (16) The transmission signal is an optical signal. The conversion unit performs optoelectronic conversion of the transmission signal. The inverse conversion unit performs electro-optical conversion of the transmission signal. The transmission system according to (15) above. (17) The second sub-connection part of the last sub-device is not connected to the next-stage device. The transmission system according to any one of (1) to (6) and (13) to (16) above. (18) The main device and a plurality of sub-devices are daisy-chain connected. The main device outputs transmission signals of a plurality of channels to the first sub-device at the head. Each of the sub-devices receives the transmission signal input from the previous-stage device. decimates the correction of the transmission signal other than the signal for the own device, which is the transmission signal used by the own device, at a predetermined channel interval. When connected to the next-stage device, the transmission signal other than the signal for the own device among the transmission signals input from the previous-stage device is shifted by the number of channels of the signal for the own device and output to the next-stage device. Transmission method. (19) A first connection part connected to the previous-stage device and receiving the transmission signal. A correction part that is arranged at a predetermined interval for channels other than the channel of the signal for the own device, which is the transmission signal used by the own device, and corrects the transmission signal. A second connection part that, when connected to the next-stage device, shifts the transmission signal other than the signal for the own device among the transmission signals input from the previous-stage device by the number of channels of the signal for the own device and outputs it. A transmission device comprising the above. (20) A first connection part connected to the first sub-device at the head among the plurality of sub-devices connected in daisy-chain and outputting transmission signals of a plurality of channels. Connected to the last sub-device, including feedback information indicating the state of the transmission signal used by each sub-device, and a second connection part to which a control signal output from each sub-device is input, A control unit that controls the transmission signal based on the feedback information included in the control signal from each sub-device A transmission device comprising the same.

[0205] Note that the effects described in this specification are merely illustrative and not limiting, and there may be other effects.

Explanation of Reference Numerals

[0206] 101 Transmission system, 111 Main device, 112-1 to 112-4 Sub-devices, 131 Control unit, 132 Optical connection part, 161 Optical connection part, 162 Optoelectronic conversion part, 163 Signal processing part, 164 Display part, 165, 165a to 165c Optoelectronic conversion parts, 166, 166a to 166c Electro-optical conversion parts, 167 Optical connection part, 201 Transmission system, 211 Main device, 212-1 to 212-4 Sub-devices, 231 Control unit, 232 Optical connection part, 261 Signal processing part, 262 Electro-optical conversion part, 301 Transmission system, 311 Main device, 312-1 to 312-8 Sub-devices, 331 Control unit, 332, 333 Optical connection parts, 361, 362 Optical connection parts

Claims

1. A main device and a plurality of sub-devices are connected in a daisy chain, The main device is provided with a first main connection part which is a connection part connected to the first sub-device at the head and outputs transmission signals of a plurality of channels, and The sub-device is provided with a first sub-connection part which is a connection part connected to the device in the previous stage and to which the transmission signal is input, and a correction part which is arranged at a predetermined channel interval with respect to channels other than the channel of the signal for the own device which is the transmission signal used by the own device, and corrects the transmission signal, and when connected to the device in the next stage, a second sub-connection part which is a connection part that shifts the channels of the transmission signals other than the signal for the own device among the transmission signals input from the device in the previous stage by the number of channels of the signal for the own device and outputs them and is provided with a transmission system.

2. The sub-device further includes a signal processing part that processes the signal for the own device The transmission system according to claim 1.

3. The signal processing part detects the connection order of the own device based on whether or not the transmission signal is input to the correction part. The transmission system according to claim 2.

4. The signal processing part controls the timing for processing the signal for the own device based on the detected connection order of the own device. The transmission system according to claim 3.

5. The first sub-connection part receives the transmission signal and control signals from each of the sub-devices before the own device, The second sub-connection part outputs the transmission signals other than the signal for the own device among the transmission signals input from the device in the previous stage, the control signals from each of the sub-devices before the own device, and the control signal of the own device. The transmission system according to claim 2.

6. The signal processing unit generates a signal including feedback information indicating the state of the signal for the own device as the control signal of the own device. The transmission system according to claim 5.

7. The main device is connected to the last sub-device, and is a second main connection part which is a connection part to which control signals from each of the sub-devices are input, and further includes a control part which controls the transmission signal based on the feedback information included in the control signals from each of the sub-devices. The transmission system according to claim 6.

8. The feedback information includes at least one of the delay time and the intensity of the transmission signal used by each of the sub-devices. The transmission system according to claim 7.

9. The control part controls the timing of outputting the transmission signals of each channel from the first main connection part based on the delay time of the transmission signal used by each of the sub-devices. The transmission system according to claim 8.

10. The control part controls the timing of the signal processing unit of each of the sub-devices processing the transmission signal based on the delay time of the transmission signal used by each of the sub-devices. The transmission system according to claim 8.

11. The control part controls the intensity of the transmission signal of each channel based on the intensity of the transmission signal used by each of the sub-devices. The transmission system according to claim 8.

12. The control unit controls the intensity of the transmission signal after correction by the correction unit of each sub-device based on the intensity of the transmission signal used by each sub-device. The transmission system according to claim 11.

13. The second sub-connection unit shifts the channels of the transmission signals other than the transmission signal input from the previous-stage device and the control signals from each of the sub-devices before the own device by the number of channels of the signal for the own device and outputs them, and outputs the control signal of the own device from the channels vacated by shifting the channels. The transmission system according to claim 5.

14. The transmission signal includes a video signal. The signal processing unit performs display processing of the video based on the video signal included in the signal for the own device. The transmission system according to claim 2.

15. The correction unit includes a conversion unit that converts the mode of the transmission signal, and an inverse conversion unit that performs inverse conversion of the mode of the transmission signal converted by the conversion unit. and is provided with The transmission system according to claim 1.

16. The transmission signal is an optical signal. The conversion unit performs optoelectronic conversion of the transmission signal. The inverse conversion unit performs electro-optical conversion of the transmission signal. The transmission system according to claim 15.

17. The second sub-connection unit of the last sub-device is not connected to the next-stage device. The transmission system according to claim 1.

18. The main device and a plurality of sub-devices are daisy-chain connected. The main device Output the transmission signals of a plurality of channels to the head sub-device. Each of the sub-devices receives the transmission signal input from the previous device decimates the correction of the transmission signal other than the signal for the own device, which is the transmission signal used by the own device, at a predetermined interval When connected to the next-stage device, the transmission signals other than the signal for the own device among the transmission signals input from the previous-stage device are output to the next-stage device with the channels shifted by the number of channels of the signal for the own device. Transmission method.

19. A first connection part connected to the previous-stage device and receiving the transmission signal, a correction part arranged at a predetermined interval for channels other than the channels of the signal for the own device, which is the transmission signal used by the own device, and performing correction of the transmission signal, a second connection part that, when connected to the next-stage device, shifts the channels of the transmission signals other than the signal for the own device among the transmission signals input from the previous-stage device by the number of channels of the signal for the own device and outputs them A transmission device comprising:

20. A first connection part connected to the head sub-device among a plurality of sub-devices connected in daisy chain and outputting transmission signals of a plurality of channels, a second connection part connected to the last sub-device and including feedback information including at least one of the delay time and intensity of the transmission signal used by each sub-device, and receiving the control signals output from each sub-device, a control part that controls the transmission signal based on at least one of the delay time and intensity of the transmission signal used by each sub-device A transmission device comprising:

21. The control part controls the timing of outputting the transmission signals of each channel from the first connection part based on the delay time of the transmission signal used by each sub-device. The transmission device according to claim 20. **Claim 22**: The control unit controls the timing at which each of the sub-devices processes the transmission signal based on the delay time of the transmission signal used by each of the sub-devices. The transmission device according to claim 20. **Claim 23**: The control unit controls the intensity of the transmission signal for each channel based on the intensity of the transmission signal used by each of the sub-devices. The transmission device according to claim 20. **Claim 24**: The control unit controls the intensity of the corrected transmission signal for each of the sub-devices based on the intensity of the transmission signal used by each of the sub-devices. The transmission device according to claim 23.

Images