JP2009177600A - Signal transmission device, signal transmitter, and signal receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a signal transmission device, a signal transmitter, and a signal receiver, capable of reducing power consumption of a light transmitting part and a light receiving part based on the operating state of a display device. <P>SOLUTION: The signal transmission device 1 is composed of a transmission module 2 which converts an image electric signal input from a first host computer 4A to an image optical signal and transmits it through an optical fiber 10, and a reception module 3 which receives the image optical signal transmitted from the transmission module 2 and outputs it to an image display apparatus 5 by converting the received image optical signal to an image electric signal. The reception module 3 includes a power mode control part 38 to control power supplied to at least one of the transmission module 2 and the reception module 3, based on the operating state signal indicating the operating state of the image display apparatus 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a signal transmission device, a signal transmission device, and a signal reception device.

  2. Description of the Related Art Conventionally, there has been known an optical transmitter designed to reduce power consumption when a signal generator needs data transmission (see, for example, Patent Document 1).

The optical transmitter includes a drive circuit that drives the light emitting element based on an electrical signal from the signal generator, and a switch that turns on and off the connection between the drive circuit and a power source supplied to the drive circuit. The switch is turned on / off based on a control signal from the signal generator.
JP 2003-60571 A

  An object of the present invention is to provide a signal transmission device, a signal transmission device, and a signal reception device that can reduce the power consumption of an optical transmission unit or an optical reception unit based on the operating state of a display device.

  In order to achieve the above object, one embodiment of the present invention provides the following signal transmission device, signal transmission device, and signal reception device.

[1] An optical transmission unit that converts an image electrical signal input from a host device into an image optical signal and transmits the image optical signal via an optical transmission line, and the image transmitted from the optical transmission unit via the optical transmission line An optical receiver that receives an optical signal, converts the received image optical signal into an electrical image signal, and outputs the image electrical signal to a display device; and an optical transmission unit based on an operation state signal indicating an operation state of the display device; And a control unit that controls power supplied to at least one of the optical receivers.

[2] The control unit is a reception-side control unit provided in the optical reception unit, and the reception-side control unit controls power supplied to the optical reception unit based on the operation state signal. A power control signal for controlling the supplied power is transmitted to the optical transmission unit via an electric transmission path, and the optical transmission unit controls the supply power to the optical transmission unit based on the power control signal The signal transmission device according to [1], including a transmission-side control unit.

[3] The control unit is a transmission-side control unit provided in the optical transmission unit, and the transmission-side control unit controls power supplied to the optical transmission unit based on the operation state signal. A power control signal for controlling the supplied power is transmitted to the optical receiver via an electric transmission path, and the optical receiver controls the power supplied to the optical receiver based on the power control signal The signal transmission device according to [1], including a reception-side control unit.

[4] The optical transmission unit receives a connection status signal indicating a connection status between the higher-level device and the optical transmission unit from the higher-level device, and the control unit receives the connection status signal and the operation status signal. The signal transmission device according to any one of [1] to [3], which controls the supplied power based on the above.

[5] Further, an optical transmission path for transmitting an image optical signal between the optical transmitter and the optical receiver, and a power control signal for controlling the power supplied by the controller, the optical transmitter and the optical receiver. The signal transmission device according to any one of [1] to [4], further including an electrical transmission path for transmission between the two.

[6] An optical transmitter that converts an image electrical signal input from the host device into an image optical signal and transmits the image optical signal, and the image transmitted from the optical transmitter via the optical transmission path An optical receiver that receives an optical signal, converts the received image optical signal into an electrical image signal, and outputs the electrical signal to a display device; and switching of an operation state of the display device transmitted from the host device to the display device A signal transmission apparatus comprising: a control unit that controls power supplied to at least one of the optical transmission unit and the optical reception unit based on an instruction signal to be instructed.

[7] An electrical / optical conversion unit that converts an electrical image signal input from the host device into an optical image signal, and a transmission unit that transmits the optical image signal converted by the electrical / optical conversion unit via an optical transmission line And a control unit that controls power supplied to the electrical / optical conversion unit based on an operation state signal indicating an operation state of the display device.

[8] A receiving unit that receives an image optical signal input via an optical transmission path, and an optical / electrical conversion that converts the image optical signal received by the receiving unit into an image electrical signal and outputs the image electrical signal to a display device And a control unit that controls power supplied to the optical / electrical converter based on an operation state signal indicating an operation state of the display device.

  According to the signal transmission device of the first aspect, the power consumption of the optical transmission unit or the optical reception unit can be reduced based on the operation state of the display device.

  According to the signal transmission device of the second aspect, the configuration for receiving the operation state signal from the display device can be simplified by providing the control unit in the light receiving unit.

  According to the signal transmission apparatus of the third aspect, the power transmission can be controlled mainly by the optical transmission unit.

  According to the signal transmission device of the fourth aspect, the power consumption of the optical transmission unit or the optical reception unit can be reduced based on the connection state with the host device in addition to the operation state of the display device.

  According to the signal transmission device of the fifth aspect, the optical transmission unit and the optical reception unit can be connected by the optical transmission path and the electrical transmission path, respectively.

  According to the signal transmission device of the sixth aspect, the power consumption of the optical transmission unit or the optical reception unit can be reduced based on the instruction signal for the display device.

  According to the signal transmission device of the seventh aspect, it is possible to reduce the power consumption of the electrical / optical conversion unit based on the operation state of the display device.

  According to the signal receiving device of the eighth aspect, it is possible to reduce the power consumption of the optical / electrical converter based on the operation state of the display device.

[First Embodiment]
FIG. 1 is an overall view showing an example of an image display system according to the first embodiment of the present invention. The image display system 100 displays images based on first and second host computers 4A and 4B as upper devices and image signals, audio signals and control signals from the first and second host computers 4A and 4B. , An image display device 5 for outputting sound, a transmission module (optical transmitter) 2 connected to each of the first and second host computers 4A and 4B, an optical fiber (optical transmission line) 10, and a metal cable (electrical) The transmission module 2 is connected to the transmission module 2 via the transmission line 11 and is also composed of a reception module (light receiving unit) 3 connected to the image display device 5. Note that the transmission module 2 and the reception module 3 constitute a signal transmission device 1.

  As a usage form of the image display system 100, the first and second host computers 4A and 4B and the image display device 5 are installed at a distance from each other in a facility such as a station, a school, or a hospital.

  The first host computer 4A has a connector for external output such as a DVI connector and a stereo mini jack, and operates according to an image reproduction program for reproducing image data in which images and sounds are recorded. Output audio signals to the outside.

  The second host computer 4B has, for example, a D-Sub 9-pin connector, and operates according to a remote operation program for controlling the image display device 5, thereby depending on the operation from the user, the timer set by the user, etc. Then, a control signal for instructing switching of power on / off of the image display device 5 or switching of an operation state (details will be described later) of the image display device 5 is output to the outside. Note that the first host computer 4A may have the function of the second host computer 4B and transmit a control signal.

  The transmission module 2 receives an image signal and an audio signal from the first host computer 4A via the DVI cable 12A and the audio cable 13A, and receives a control signal from the second host computer 4B via the control cable 14A. . The transmission module 2 converts the image signal into an optical signal (image optical signal), transmits the optical signal through the optical fiber 10, and transmits an electric signal based on the audio signal and the control signal to the metal cable 11. Send through.

  The reception module 3 receives an optical signal from the transmission module 2 via the optical fiber 10 and also receives an electrical signal via the metal cable 11. The reception module 3 is connected to the image display device 5 via the DVI cable 12B, the audio cable 13B, the control cable 14B, and the status signal cable 15, and the audio based on the image signal and the electric signal obtained by converting the received optical signal. The signal and the control signal are output to the image display device 5.

  The external power supply devices 6A and 6B are AC adapters, for example, which convert 100V AC power to 6V DC power and supply the DC power to the transmission module 2 and the reception module 3, respectively.

  The optical fiber 10 transmits three R, G, and B signals composed of R, G, and B based on DVI (Digital Visual Interface) standards and a clock signal as optical signals. 4 are provided. The optical fiber 10 is, for example, a multi-mode optical fiber having a core diameter of 50 μm, and has a length of 10 m or more.

  The metal cable 11 is an electrical transmission path for bidirectionally transmitting electrical signals between the transmission module 2 and the reception module 3, and for example, a category 5 UTP cable can be used.

  The image display device 5 includes a display unit 5a corresponding to the DVI standard, such as a PDP (Plasma Display Panel), an LCD (Liquid Crystal Display), and the like, and further, a display control circuit for controlling the display unit 5a, an audio An amplifier circuit, a speaker, and a power supply circuit (all not shown) are provided.

  The display control circuit switches the operation state consisting of the normal state and the standby state based on the control signal from the second host computer 4B, and sends the operation state signal indicating the switched operation state via the state signal cable 15. Transmit to the reception module 3.

  Here, the “normal state” is a state in which image display and sound output based on the image signal and the audio signal are possible, and the “standby state” is that the power supplied to the display unit 5a is turned off or reduced, The image display is temporarily suspended. In addition to the control signal, the operation state may be switched based on, for example, a remote operation using a remote control included in the image display device 5 or a direct operation using an operation button included in the image display device 5.

(Configuration of transmission module)
FIG. 2 is a block diagram illustrating a schematic configuration of the transmission module 2. The transmission module 2 includes a DVI connector 20A, an audio connector 20B, an RS232C connector 20C, a power supply unit 21, an electrical / optical conversion unit 22, a display signal I / F unit 23A, an audio signal I / F unit 23B, and a control signal I / F. 23C, an encoding / decoding control unit 24, a differential signal I / F unit 25, a differential signal connector 26, and a switch 27.

  The DVI connector 20A, the audio connector 20B, and the RS232C connector 20C are connected to the DVI cable 12A, the audio cable 13A, and the control cable 14A, respectively.

  The DVI connector 20A receives a DDC (Display Data Channel) 5V signal, a DDC CLK (Clock) signal, a DDC Data signal, and an HPD (Hot Plug Detect) signal in addition to the R, G, B signal and clock signal described above. A plurality of pins.

  The DDC CLK signal and the DDC Data signal are display signals for obtaining property information such as resolution that can be displayed on the image display device 5 by the first host computer 4A. The DDC 5V signal and the HPD signal are 2 is a connection state signal for confirming the connection state between the host computer 4A and the image display device 5.

  The audio connector 20B has, for example, a shape such as a stereo mini jack, and includes a right audio pin R and a left audio pin L.

  The RS232C connector 20C is, for example, a D-Sub 9-pin connector, and includes a pin RxD to which a downstream control signal is input from the host computer 4A to the image display device 5, and an upstream direction from the image display device 5 to the host computer 4A. A pin TxD for outputting the control signal, a ground pin GND, a transmission request pin RTS, and a transmission enable pin CTS. In the present embodiment, the pin RTS and the pin CTS are connected.

  The power supply unit 21 converts the DC power supplied from the external power supply device 6 </ b> A into a plurality of voltage values, and supplies the converted voltage in accordance with the drive voltage of each unit of the transmission module 2.

  The electrical / optical conversion unit 22 outputs a buffer circuit that shapes the R, G, B signal, and clock signal, respectively, and outputs the waveform-shaped signal as an optical signal. An element, a drive circuit for driving four light emitting elements, and an optical connector such as an LC connector or an SC connector connected to the optical fiber 10 are provided.

  The display signal I / F unit 23A is connected to the DVI connector 20A and the encoding / decoding control unit 24, and acquires display data from the display signals (DDC CLK signal, DDC Data signal) input from the DVI connector 20A. The display data is output to the encoding / decoding control unit 24. The display signal I / F unit 23A outputs the display data input from the encoding / decoding control unit 24 to the DVI connector 20A as a display signal.

  The audio signal I / F unit 23B is connected to the audio connector 20B and the encoding / decoding control unit 24, and an analog audio signal input from the pins R and L of the audio connector 20B is sampled at a sampling frequency, for example, 44. The audio data is converted into 16-bit digital audio data of pins R and L at 1 kHz, and the audio data is output to the encoding / decoding control unit 24.

  The control signal I / F unit 23C is connected to the RS232C connector 20C and the encoding / decoding control unit 24, and encodes / decodes the control signal input from the pin RxD of the RS232C connector 20C as control data. 24. In addition, the control data input from the encoding / decoding control unit 24 is output as a control signal to the pin TxD.

  The encoding / decoding control unit 24 receives display data, audio data, and control data input from the display signal I / F unit 23A, the audio signal I / F unit 23B, and the control signal I / F unit 23C, respectively. A header identifiable on the side is added and encoded into a packet. Also, the encoding / decoding control unit 24 acquires display data and control data by decoding the packet transmitted from the receiving module 3 side, and displays the display signal I / F unit 23A and the control signal I / F unit. To 23C.

  In addition to the above display data and control data, the packet transmitted from the receiving module 3 side includes either the normal mode or the power saving mode as a power control signal for controlling the power supplied to the electrical / optical converter 22. The power mode switching signal indicating whether the power mode is switched is included, and the encoding / decoding control unit 24 outputs the power mode switching signal to the switch 27.

  In addition, the encoding / decoding control unit 24 has a function of performing error detection processing related to the optical transmission line and the electric transmission line with the receiving module 3. Details of the error detection process will be described later.

  The differential signal I / F unit 25 performs data transmission using differential signals such as RS-422 and RS485 for the packets encoded by the encoding / decoding control unit 24. Here, the band required for transmission of each signal is a maximum of 400 kbps for the display signal, 20 kbps for the control signal, and about 1.5 Mbps for the audio signal. Therefore, by performing time division multiplexing, the differential signal I / F unit The 25 transmission band can be set to 2.4 Mbps, for example. The differential signal connector 26 has a shape such as an RJ45 connector.

  The switch 27 switches on / off of supplied power supplied from the power supply unit 21 to the electrical / optical conversion unit 22 in accordance with a power mode switching signal from the encoding / decoding control unit 24. That is, the power supply unit side terminal 270 and the conversion unit side terminal 271 are connected when turned on, and the both terminals 270 and 271 are not contacted when turned off.

  Note that the switch 27 may switch the level of the supplied power between a normal level and a power saving level lower than the normal level instead of switching on and off the supplied power. Further, when the electrical / optical conversion unit 22 has a function of switching the power consumption mode, the power mode switching signal may be input to the electrical / optical conversion unit 22 instead of the switch 27.

(Reception module configuration)
FIG. 3 is a block diagram showing a schematic configuration of the receiving module 3. The receiving module 3 includes a DVI connector 30A, an audio connector 30B, an RS232C connector 30C, a status signal connector 30D, a power supply unit 31, an optical / electrical conversion unit 32, a display signal I / F unit 33A, an audio signal I / F unit 33B, A control signal I / F unit 33C, an encoding / decoding control unit 34, a differential signal I / F unit 35, a differential signal connector 36, a switch 37, and a power mode control unit (reception side control unit) 38 are provided.

  The DVI connector 30A, audio connector 30B, RS232C connector 30C, and status signal connector 30D are connected to the DVI cable 12B, audio cable 13B, control cable 14B, and status signal cable 15, respectively. The DVI connector 30A, audio connector 30B, and RS232C connector 30C have the same pin configuration as the DVI connector 20A, audio connector 20B, and RS232C connector 20C of the transmission module 2.

  The state signal connector 30 </ b> D receives an operation state signal from the image display device 5 and outputs the operation state signal to the power mode control unit 38.

  The power supply unit 31 converts the DC power supplied from the external power supply device 6B into a plurality of voltage values, and supplies the converted voltage to each unit of the reception module 3.

  The optical / electrical converter 32 converts an optical connector connected to the optical fiber 10 and four optical signals received through the optical connector into a minute current, for example, four light receiving elements such as photodiodes, An amplifier circuit that converts a minute current generated by the four light receiving elements into a voltage and amplifies the voltage, and outputs the R, G, B signals and clock signal amplified by the amplifier circuit to the DVI connector 30A.

  The differential signal I / F unit 35 extracts a packet from the differential electrical signal transmitted by the transmission module 2 via the differential signal connector 36 and outputs the packet to the encoding / decoding control unit 34. The differential signal I / F unit 35 transmits the packet encoded by the encoding / decoding control unit 34.

  The encoding / decoding control unit 34 sequentially decodes the packets input from the differential signal I / F unit 35, and acquires display data, audio data, and control data based on the header of the packet. The encoding / decoding control unit 34 displays the display data to the display signal I / F unit 33A, the audio data to the audio signal I / F unit 33B, and the control data to the control signal I / F according to the acquired data. Output to the unit 33C.

  The encoding / decoding control unit 34 sequentially encodes display data and control data input from the display signal I / F unit 33A and the control signal I / F unit 33C, respectively, into packets. The encoding / decoding control unit 34 also encodes the power mode switching signal from the power mode control unit 38 into a packet, and the encoded packet is output to the differential signal I / F unit 35. The encoding / decoding control unit 34 has a function of performing an error detection process with the encoding / decoding control unit 24 of the transmission module 2.

  The display signal I / F unit 33A is connected to the DVI connector 30A and the encoding / decoding control unit 34, acquires display data from the display signal input from the DVI connector 30A, and encodes / decodes the display data. Output to the control unit 34. The display signal I / F unit 33A outputs the display data input from the encoding / decoding control unit 34 to the DVI connector 30A as a display signal.

  The audio signal I / F unit 33B is connected to the audio connector 30B and the encoding / decoding control unit 34, converts the audio data input from the encoding / decoding control unit 34 into an analog audio signal, and the audio signal The signal is output to pins R and L of the audio connector 30B.

  The control signal I / F unit 33C is connected to the RS232C connector 30C and the encoding / decoding control unit 34, and outputs a control signal input from the pin RxD of the RS232C connector 30C to the encoding / decoding control unit 34. Further, the control data input from the encoding / decoding control unit 34 is output to the pin TxD.

  The switch 37 switches on / off of the power supplied from the power supply unit 31 to the optical / electrical conversion unit 32 in accordance with a power mode switching signal from the power mode control unit 38.

  The power mode control unit 38 determines the power mode based on the operation state signal input from the state signal connector 30D, and uses the determination result as a power mode switching signal to encode / decode the control unit 34 and the switch 37. Output to. In the present embodiment, the target for switching the power mode is both the electrical / optical conversion unit 22 and the optical / electrical conversion unit 32, but either one may be used.

(Operation of the first embodiment)
Next, the operation of the image display system 100 will be described below.

  First, as illustrated in FIG. 1, the user connects the first and second host computers 4A and 4B, the transmission module 2, the reception module 3, and the image display device 5 with respective cables. Further, the external power supply devices 6A and 6B are connected to the transmission module 2 and the reception module 3, respectively, and also connected to AC 100V.

  Thereafter, the user turns on the power of the first and second host computers 4A and 4B and the image display device 5. Then, when the first host computer 4A activates the image reproduction program and instructs the reproduction of the image data, the first host computer 4A generates an image signal and an audio signal based on the image data, and the DVI cable 12A and The data is output to the transmission module 2 via the audio cable 13A.

  The image signal output from the first host computer 4A is input to the transmission module 2 via the DVI connector 20A. The audio signal output from the first host computer 4A is input to the transmission module 2 via the audio connector 20B.

  Next, the electrical / optical converter 22 of the transmission module 2 drives the four light emitting elements by the drive circuit based on the R, G, B signal and the clock signal among the image signals input to the DVI connector 20A. The four optical signals are output to the optical fiber 10 through the optical connector.

  The display signal I / F unit 23A acquires display data based on the display signal among the image signals input to the DVI connector 20A and outputs the display data to the encoding / decoding control unit 24.

  The audio signal I / F unit 23B converts the audio signal input to the audio connector 20B into 16-bit digital audio data of pins R and L at the sampling frequency, and encodes / decodes the audio data. To the unit 24.

  Next, the encoding / decoding control unit 24 adds the display data and audio data output from the display signal I / F unit 23A and the audio signal I / F unit 23B to the header in accordance with the type of data. The packet is output to the metal cable 11 via the differential signal I / F unit 25 and the differential signal connector 26.

  Next, the optical / electrical conversion unit 32 of the receiving module converts the optical signal received from the optical fiber 10 into a minute electric signal by the light receiving element, and further amplifies the R, G, B signal and clock by the amplifier circuit. The signal is output to the DVI connector 30A.

  In addition, the encoding / decoding control unit 34 decodes the packet input via the metal cable 11, the differential signal connector 36, and the differential signal I / F unit 35, thereby obtaining display data and audio data. get. The display data is output as a display signal to the DVI connector 30A via the display signal I / F unit 33A, and the audio data is output as an audio signal to the audio connector 30B via the audio data I / F unit 33B. .

  Next, the image signal and the display signal are transmitted to the image display device 5 via the DVI cable 12B, and the audio signal is transmitted to the image display device 5 via the audio cable 13B.

  The image display device 5 performs image processing by the display control circuit based on the transmitted image signal and display signal, displays an image on the display unit 5a, amplifies the sound signal by the sound amplification circuit, and performs sound from the speaker. Is output.

(Power mode control)
In this way, image display and audio output are performed by the image display device 5, and the operation when the user performs the operation state switching operation on the image display device 5 in the second host computer 4B is shown in FIG. This will be described below with reference to the flowchart.

  First, when the user activates the remote operation program in the second host computer 4B and instructs to switch the operation state to the standby state, for example, the second host computer 4B controls the control signal indicating that effect. The data is output to the transmission module 2 via the cable 14A.

  The control signal input to the transmission module 2 is sent to the encoding / decoding control unit 24 as control data by the control signal I / F unit 33C. Then, the encoding / decoding control unit 24 encodes the control data into a packet and transmits the packet to the metal cable 11 via the differential signal I / F unit 25 and the differential signal connector 26.

  The packet transmitted from the transmission module 2 is sent to the encoding / decoding control unit 34 via the differential signal I / F unit 35 and the differential signal connector 36 of the reception module 3. Then, the encoding / decoding control unit 34 acquires control data by decoding the packet, and outputs the control data to the RS232C connector 30C via the control signal I / F unit 33C.

  Then, the image display device 5 receives a control signal via the control cable 14B. Here, since the control signal is a signal for instructing to switch to the standby state, the image display device 5 interrupts the display of the image by the display unit 5a and switches its operation state to the standby state. Then, the image display device 5 transmits an operation state signal indicating the standby state to the receiving module 3 via the state signal cable 15 (S10).

  Next, the power mode control unit 38 of the receiving module 3 determines the power mode based on the operation state signal received via the state signal cable 15 (S20). Specifically, when the operation state signal indicates a normal state, it is determined that the power mode is switched to the normal power mode, and when the operation state signal indicates a standby state, it is determined that the power mode is switched to the power saving mode. .

  Next, the power mode control unit 38 outputs a power mode switching signal to the encoding / decoding control unit 34 and the switch 37 based on the determination result.

  The encoding / decoding control unit 34 to which the power mode switching signal is input encodes the packet and transmits the packet to the transmission module 2 (S21).

  Next, when receiving the power mode switching signal by decoding the packet, the encoding / decoding control unit 24 of the transmission module 2 outputs the power mode switching signal to the switch 27.

  Then, the switch 27 switches on / off of the power supplied to the electrical / optical converter 22 according to the power mode switching signal (S30). Here, since the power mode switching signal indicates the power saving mode, the power supplied to the electrical / optical converter 22 is turned off.

  In addition, in the switch 37 of the receiving module 3 to which the power mode switching signal is input from the power mode control unit 38, the supply power to the optical / electrical conversion unit 32 is turned on / off according to the power mode switching signal, as described above. (S31).

(Error detection processing for electrical transmission lines)
Next, error detection processing relating to the electric transmission line, that is, the metal cable 11 will be described with reference to the flowchart of FIG.

  First, the transmission module 2 sends a confirmation command for confirming whether the signal transmission through the metal cable 11 is operating normally by the encoding / decoding control unit 24 to the reception module 3 at a constant cycle, for example. (S101). Then, the transmission module 2 shifts to a reception waiting state for the confirmation response command from the reception module 3 (S102).

  On the other hand, the reception module 3 is in a state of waiting for a confirmation command from the transmission module 2 by the encoding / decoding control unit 34 as a steady state (S201), and receives a confirmation command via the metal cable 11 ( S201: Yes), the confirmation response command is transmitted to the transmission module 2 (S202).

  When the transmission module 2 receives the confirmation response command from the reception module 3 (S102: Yes), the transmission module 2 waits until a predetermined time elapses (S103), and determines whether the initialization command from the reception module 3 has been received ( If not received (S109: No), the process returns to step S101. On the other hand, if an initialization command has been received (S109: Yes), initialization processing is performed (S110).

  On the other hand, when the transmission module 2 does not receive the confirmation response command (S102: No), it is determined whether or not a predetermined time has elapsed (S104). And when it determines with predetermined time not having passed (S104: No), it returns to step S102.

  If the transmission module 2 determines that the predetermined time has elapsed (S104: Yes), the transmission module 2 counts up the count value (S105), and determines whether the count value is equal to or greater than the predetermined value (S106). ).

  If the transmission module 2 determines that the count value is not equal to or greater than the predetermined value (S106: No), the process returns to the reception determination of the initialization command (S109).

  If the transmission module 2 determines that the count value is equal to or greater than the predetermined value (S106: Yes), it determines that the error is in the electrical transmission path (S107) and issues an initialization command to the reception module 3. (S108). Then, the process returns to the initialization command reception determination (S109).

  When the reception module 3 does not receive the confirmation command in the above step S201 (S201: No) and the predetermined time has not elapsed (S203: No), the reception module 3 receives the initialization command from the transmission module 2. (S206: No), the process returns to step S201. On the other hand, if an initialization command has been received (S206: Yes), initialization processing is performed (S207).

  On the other hand, if the receiving module 3 determines that the predetermined time has passed (S203: Yes), it is determined that the electric transmission path has an error (S204), and issues an initialization command to the transmitting module 2. (S205). Then, the process returns to the initialization command reception determination (S206).

  Note that the cause of the error in the electrical transmission path is (a) disconnection or breakage of the metal cable 11, (b) poor connection between the metal cable 11 and the differential signal connectors 26, 36, and the like.

(Error detection processing for optical transmission lines)
Next, error detection processing related to the optical transmission line, that is, the optical fiber 10, will be described with reference to the flowchart of FIG.

  First, the receiving module 3 determines whether or not there is an abnormality in the optical transmission line in the optical / electrical converter 32 (S401). Specifically, the amplitude of the R, G, B signal and clock signal amplified by the amplifier circuit is compared with a predetermined threshold value, and if those amplitudes are below the predetermined threshold value, there is an abnormality. It is determined that

  The reason why the amount of light input to the optical / electrical converter 32 is small is that (a) the optical signal does not reach due to disconnection or breakage of the optical fiber 10, (b) the light emitting element of the electrical / optical converter 22 (C) the optical signal does not reach due to poor connection between the optical fiber 10 and the optical connector.

  Next, when the reception module 3 detects an abnormality (S401: Yes), it issues an abnormality detection command to the transmission module 2 (S402) and performs initialization (S403).

  Next, when the transmission module 2 receives the abnormality detection command (S301: Yes), it is determined as an optical transmission line error (S302), and the transmission of the optical signal by the electrical / optical converter 22 is stopped (S303).

  Next, when the transmission module 2 notifies the first or second host computer 4A, 4B that an optical transmission line error has occurred, the display of the first or second host computer 4A, 4B is displayed. For example, an error message is displayed on the section, and the user is inquired about execution of initialization (S305).

  When the user instructs to execute initialization (S305: Yes), the transmission module 2 performs initialization and resumes transmission of the optical signal (S306). On the other hand, when the user has not instructed execution of initialization (S305: No), the transmission module 2 ends in error (S307).

[Second Embodiment]
The image display system according to the second embodiment is different from the image display system 100 according to the first embodiment in that the power mode control unit 38 is provided in the reception module 3 while the power is supplied to the transmission module 2. A mode control unit is provided.

(Configuration of transmission module)
FIG. 7 is a block diagram showing a schematic configuration of the transmission module 2 of the present embodiment. The transmission module 2 is similar in basic configuration and function to the transmission module 2 according to the first embodiment except that it includes a power mode control unit (transmission side control unit) 28.

  The power mode control unit 28 receives an operation state signal from the image display device 5 via the receiving module 3 and the metal cable 11, and also receives a connection state signal from the first host computer 4A via the DVI cable 12A. Then, the power mode control unit 28 determines the power mode based on the operation state signal and the connection state signal, and uses the determination result as the power mode switching signal, and the encoding / decoding control unit 24 and the switch 27. Output to.

  FIG. 8 is a block diagram showing a schematic configuration of the receiving module 3 of the present embodiment. The receiving module 3 has the same basic configuration and function as the receiving module 3 according to the first embodiment, except that the power mode control unit 38 is not provided.

(Operation of Second Embodiment)
Next, the operation of the image display system according to the present embodiment will be described with reference to the flowchart of FIG. First, as in the first embodiment, when the image display device 5 receives a control signal for switching the operation state and switches its own operation state, the image display device 5 outputs an operation state signal indicating the switched operation state. It transmits to the receiving module 3 via the status signal cable 15 (S10).

  Next, the encoding / decoding control unit 34 of the reception module 3 encodes the operation state signal into a packet, and transmits the packet to the transmission module 2 (S11). The first host computer 4A transmits a connection status signal to the transmission module 2 (S12).

  Next, when receiving the operation state signal by decoding the packet, the encoding / decoding control unit 24 of the transmission module 2 sends the connection state signal to the power mode control unit 28 together with the operation state signal.

  Next, the power mode control unit 28 determines the power mode based on the operation state signal and the connection state signal sent from the encoding / decoding control unit 24 (S20). Specifically, when the operation state signal indicates the normal state and the connection state signal indicates that it is connected, it is determined that the power mode is switched to the normal power mode, and the operation state signal indicates the standby state. Or, when the connection state signal indicates that it is not connected, it is determined that the power mode is switched to the power saving mode.

  The power mode control unit 28 outputs a power mode switching signal to the encoding / decoding control unit 24 and the switch 27 based on the determination result.

  Then, the encoding / decoding control unit 24 to which the power mode switching signal is input transmits a packet obtained by encoding the power mode switching signal to the receiving module 3 (S21).

  Next, when receiving the power mode switching signal by the packet, the encoding / decoding control unit 34 of the receiving module 3 outputs the power mode switching signal to the switch 37.

  Then, the switch 37 switches on / off of the power supplied to the optical / electrical converter 32 according to the power mode switching signal (S31).

  In addition, the switch 27 to which the power mode switching signal is input also switches on / off the power supplied to the electrical / optical converter 22 in accordance with the power mode switching signal (S30).

[Third Embodiment]
In the image display system according to the third embodiment, in the image display system according to the second embodiment, the transmission module 2 controls the power mode based on the operation state signal from the image display device 5. On the other hand, the transmission module 2 controls the power mode based on the control signal transmitted from the second host computer 4B.

(Configuration of transmission module)
FIG. 10 is a block diagram illustrating a schematic configuration of the transmission module 2 according to the present embodiment. Compared with the transmission module 2 according to the second embodiment, the transmission module 2 has the same basic configuration and function except that the power mode control unit 28 includes a state storage unit 280.

  The power mode control unit 28 includes a state storage unit 280 that stores an operation state indicated by a control signal (instruction signal) transmitted from the second host computer 4B as operation state information. Further, the power mode control unit 28 determines the power mode based on the operation state information, and outputs the determination result to the encoding / decoding control unit 24 and the switch 27 as a power mode switching signal.

  FIG. 11 is a block diagram showing a schematic configuration of the receiving module 3 of the present embodiment. The receiving module 3 is the same in basic configuration and function as the receiving module 3 according to the second embodiment except that the receiving module 3 does not include the state signal connector 30D.

(Operation of the third embodiment)
Next, the operation of the image display system according to the present embodiment will be described with reference to the flowchart of FIG. First, for example, the second host computer 4B receives an operation from the user and transmits a control signal to the transmission module 2 via the control cable 14A (S13).

  Next, when the control signal from the second host computer 4B is input, the encoding / decoding control unit 24 of the transmission module 2 encodes the packet and transmits the packet to the reception module 3 via the metal cable 11. (S14).

  Next, the encoding / decoding control unit 34 of the receiving module 3 decodes the packet transmitted from the transmitting module 2 and transmits a control signal to the image display device 5 (S15).

  Then, when receiving the control signal, the image display device 5 switches the operation state based on the control signal (S16).

  Also, the encoding / decoding control unit 24 of the transmission module 2 sends the received control signal to the power mode control unit 28, and the power mode control unit 28 uses the operation state indicated by the control signal as the operation state information. It memorize | stores in the memory | storage part 280 (S17).

  Next, the power mode control unit 28 determines the power mode based on the operation state information (S20).

  Next, the power mode control unit 28 outputs a power mode switching signal to the encoding / decoding control unit 24 and the switch 27 based on the determination result. Then, the encoding / decoding control unit 24 to which the power mode switching signal is input encodes the power mode switching signal into a packet, and transmits the packet to the receiving module 3 (S21).

  Next, when receiving the power mode switching signal by decoding the packet, the encoding / decoding control unit 34 of the receiving module 3 outputs the power mode switching signal to the switch 37. Then, the switch 37 switches on / off of the power supplied to the optical / electrical converter 32 according to the power mode switching signal (S31).

  In addition, the switch 27 to which the power mode switching signal is input also switches on / off the power supplied to the electrical / optical converter 22 in accordance with the power mode switching signal (S30).

[Fourth Embodiment]
The image display system according to the fourth embodiment is different from the image display system according to the first embodiment in that the receiving module 3 does not include the state signal connector 30D.

  FIG. 13 is a block diagram showing a schematic configuration of the receiving module 3 of the present embodiment. The receiving module 3 does not include the state signal connector 30D, but includes a power mode control unit 38 that controls the power mode based on the HPD signal input from the DVI connector 30A as the operation state signal. Other basic configurations and functions are the same as those in the first embodiment.

  The power mode control unit 38 uses an HPD signal instead of the operation state signal. In this case, the display control circuit of the image display device 5 outputs its own operation state to the HPD signal. Control. In addition to the HPD signal, a DDC 5V signal may be used, or an HPD signal and a DDC 5V signal may be used in combination. Further, the display control circuit outputs a control signal indicating the operation state to the RS232C connector 30C, and the power mode control unit 38 controls the power mode based on the control signal input from the RS232C connector 30C. Good.

[Other embodiments]
In addition, this invention is not limited to said each embodiment, A various deformation | transformation implementation is possible within the range which does not change the summary. For example, in each of the above embodiments, the power mode control unit is provided in one of the transmission module or the reception module, but the power mode control unit may be provided in both the transmission module or the reception module. In addition, the constituent elements of the above-described embodiments can be arbitrarily combined without departing from the scope of the invention.

1 is an overall view showing an example of an image display system according to a first embodiment of the present invention. It is a block diagram which shows schematic structure of a transmission module. It is a block diagram which shows schematic structure of a receiving module. It is a flowchart which shows an example of the operation | movement at the time of the signal transmission apparatus of 1st Embodiment controlling supply electric power. It is a flowchart which shows an example of the operation | movement at the time of a signal transmission apparatus detecting an error in an electric transmission line. It is a flowchart which shows an example of the operation | movement at the time of a signal transmission apparatus detecting an error in an optical transmission line. It is a block diagram which shows schematic structure of the transmission module of 2nd Embodiment. It is a block diagram which shows schematic structure of the receiving module of 2nd Embodiment. It is a flowchart which shows an example of the operation | movement at the time of the signal transmission apparatus of 2nd Embodiment controlling supplied electric power. It is a block diagram which shows schematic structure of the transmission module of 3rd Embodiment. It is a block diagram which shows schematic structure of the receiving module of 3rd Embodiment. It is a flowchart which shows an example of the operation | movement at the time of the signal transmission apparatus of 3rd Embodiment controlling supplied power. It is a block diagram which shows schematic structure of the receiving module of 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Signal transmission apparatus, 2 ... Transmission module, 3 ... Reception module, 4A, 4B ... Host computer, 5 ... Image display apparatus, 5a ... Display part, 6A, 6B ... External power supply device, 10 ... Optical fiber, 11 ... Metal Cable, 12A, 12B ... DVI cable, 13A, 13B ... Audio cable, 14A, 14B ... Control cable, 15 ... Status signal cable, 20A ... DVI connector, 20B ... Audio connector, 20C ... RS232C connector, 21 ... Power supply unit, 22 ... electric / optical converter, 23A ... display signal I / F, 23B ... audio signal I / F, 23C ... control signal I / F, 24 ... encoding / decoding controller, 25 ... differential signal I / F section, 26 ... differential signal connector, 27 ... switch, 28 ... power mode control section, 30A ... DVI connector, 30B ... audio connector, 3 C ... RS232C connector, 30D ... Status signal connector, 31 ... Power supply unit, 32 ... Optical / electrical conversion unit, 33A ... Display signal I / F unit, 33B ... Audio signal I / F unit, 33C ... Control signal I / F unit 34 ... Encoding / decoding control unit, 35 ... Differential signal I / F unit, 36 ... Differential signal connector, 37 ... Switch, 38 ... Power mode control unit, 100 ... Image display system, 270 ... Power supply side Terminals 271: Conversion unit side terminals, 280 ... State storage unit, 380 ... Power supply unit side terminals, 381 ... Conversion unit side terminals

Claims (8)

An optical transmission unit that converts an image electrical signal input from a host device into an image optical signal and transmits the image optical signal via an optical transmission path;
An optical receiver that receives the image optical signal transmitted from the optical transmitter via the optical transmission path, converts the received image optical signal into an electrical image signal, and outputs the image electrical signal to a display device;
A signal transmission device comprising: a control unit that controls power supplied to at least one of the optical transmission unit and the optical reception unit based on an operation state signal indicating an operation state of the display device. The control unit is a reception side control unit provided in the optical reception unit,
The receiving-side control unit controls power supplied to the optical receiving unit based on the operation state signal, and transmits a power control signal for controlling the supplied power to the optical transmitting unit via an electric transmission path. And
The signal transmission device according to claim 1, wherein the optical transmission unit includes a transmission-side control unit that controls power supplied to the optical transmission unit based on the power control signal. The control unit is a transmission side control unit provided in the optical transmission unit,
The transmission-side control unit controls power supplied to the optical transmission unit based on the operation state signal, and transmits a power control signal for controlling the supply power to the optical reception unit via an electric transmission path. And
The signal transmission device according to claim 1, wherein the optical reception unit includes a reception-side control unit that controls supply power to the optical reception unit based on the power control signal. The optical transmission unit receives a connection state signal indicating a connection state between the upper level device and the optical transmission unit from the higher level device;
The signal transmission device according to claim 1, wherein the control unit controls the supplied power based on the connection state signal and the operation state signal. Furthermore, an optical transmission path for transmitting an image optical signal between the optical transmitter and the optical receiver;
5. The signal transmission device according to claim 1, further comprising: an electric transmission path that transmits a power control signal for controlling the supplied power by the control unit between the optical transmission unit and the optical reception unit. 6. . An optical transmission unit that converts an image electrical signal input from a host device into an image optical signal and transmits the image optical signal via an optical transmission path;
An optical receiver that receives the image optical signal transmitted from the optical transmitter via the optical transmission path, converts the received image optical signal into an electrical image signal, and outputs the image electrical signal to a display device;
A control unit that controls power supplied to at least one of the optical transmission unit and the optical reception unit based on an instruction signal that instructs switching of an operation state of the display device transmitted from the host device to the display device; A signal transmission device comprising: An electrical / optical converter that converts an electrical image signal input from the host device into an optical image signal;
A transmission unit for transmitting the image optical signal converted by the electrical / optical conversion unit via an optical transmission line;
A signal transmission device comprising: a control unit that controls power supplied to the electrical / optical conversion unit based on an operation state signal indicating an operation state of the display device. A receiving unit that receives an image light signal input via an optical transmission path;
An optical / electrical converter that converts the image optical signal received by the receiver into an electrical image signal and outputs the electrical signal to a display device;
A signal receiving device comprising: a control unit that controls power supplied to the optical / electrical conversion unit based on an operation state signal indicating an operation state of the display device.

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