JP2013236280A - Sdi apparatus and sdi signal transmission system including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive SDI apparatus which has no risk of damage even if in stopcock connection and can be made compact.SOLUTION: An SDI relay 2 includes a driver 24 for delivering an SDI signal to the outside of the SDI relay 2, a coaxial cable connection terminal 26 for delivering an SDI signal to the outside of the SDI relay 2, an on/off switch SW3 provided between the driver 24 and the coaxial cable connection terminal 26 and switching between passage and interruption or attenuation of an electrical signal, and a transmission path connection control circuit 29 for controlling the on/off switch SW3. After determining that a DC voltage superimposed on the coaxial cable connection terminal 26 has stabilized, the transmission path connection control circuit 29 changes the operation of the on/off switch SW3 from interruption or attenuation of an electrical signal to passage of an electrical signal.

Description

  The present invention relates to an SDI device that processes an SDI (Serial Digital Interface) signal and an SDI signal transmission system including the SDI device.

  Since the SDI signal transmission system transmits an SDI signal that is an uncompressed signal, there is an advantage that there is no signal delay or deterioration due to compression processing and expansion processing. Taking advantage of these advantages, SDI signal transmission systems have been applied to camera systems and the like used in studios in broadcasting stations. However, in recent years, SDI signal transmission systems have begun to be applied to remote monitoring systems equipped with surveillance cameras. Is expanding.

JP 2011-77743 A

  Patent Document 1 discloses an SDI signal transmission system in which DC power is superimposed on an SDI signal transmission line. An SDI signal transmission system that superimposes DC power on an SDI signal transmission line can perform SDI signal transmission and DC power transmission with one signal cable, and is highly convenient because the number of cables is reduced.

  However, in an SDI signal transmission system in which DC power is superimposed on an SDI signal transmission line, when a cable with DC power superimposed is connected to an SDI device, that is, when a stopcock connection is made to the SDI device, A rush voltage is applied to the signal transmission line, and the rush voltage passes through the DC blocking capacitor arranged in the SDI signal transmission line in the SDI device and reaches the SDI signal processing circuit in the SDI device.

  If the SDI signal processing circuit is a receiver that receives an SDI signal sent from the outside of the SDI device, the SDI signal processing circuit is damaged even when the rush voltage reaches because the SDI signal transmission line has high resistance to voltage rise. The fear is low. On the other hand, if the SDI signal processing circuit is a driver for sending an SDI signal to the outside of the SDI device, the SDI signal processing circuit has a low resistance to the voltage rise of the SDI signal transmission line, and the SDI signal processing circuit may be damaged when the rush voltage is reached. is there.

  The SDI signal transmission system disclosed in Patent Document 1 prevents the SDI device from being damaged even when an SDI device that does not support DC power superimposition is mistakenly connected. It does not prevent the corresponding SDI device from being damaged by the rush voltage.

  Therefore, the present inventor examined measures for preventing the SDI device from being damaged by the application of the rush voltage by the stopcock connection. As a first countermeasure, the present inventor provides a buffer amplifier having a high resistance to a voltage increase of the SDI signal transmission line in the subsequent stage of the SDI signal processing circuit (driver) for sending the SDI signal to the outside of the SDI device. As a second countermeasure, a countermeasure was devised in which a high-pass filter that allows a signal of 5 MHz or higher to pass is provided behind the driver.

  However, the first countermeasure has the disadvantage that the number of components and power consumption increase by the buffer amplifier, and the second countermeasure is that the high-pass filter has a signal of 5 MHz or higher (a signal classified as a high-frequency signal). Among them, since it is a high-pass filter that passes a signal of a relatively low frequency), there is a drawback that the size of the high-pass filter becomes large and it is difficult to reduce the size of the SDI device.

  In view of the above situation, an object of the present invention is to provide an inexpensive and small-sized SDI device that does not cause damage even if it is connected to a stopcock, and an SDI signal transmission system including the SDI device.

  In order to achieve the above object, an SDI device according to the present invention sends a SDI signal processing circuit for sending an SDI signal to the outside of the SDI device and the SDI signal to the outside of the SDI device. An output terminal, a switching means provided between the driver and the output terminal, for switching between passing and blocking or attenuation of an electrical signal, and a control means for controlling the switching means, the control means comprising: After determining that the DC voltage superimposed on the output terminal is stable, the operation of the switching unit is changed from the interruption or attenuation of the electric signal to the passage of the electric signal (first configuration).

  According to such a configuration, it is possible to prevent the rush voltage from reaching the SDI signal processing circuit without adding a buffer amplifier or a high-pass filter, so that the circuit configuration is inexpensive and can be miniaturized. Even if the stopcock is connected, the SDI signal processing circuit can be prevented from being damaged.

  In the SDI device having the first configuration, when the control unit detects that a DC voltage is superimposed on the output terminal, a DC time superimposed on the output terminal when a predetermined time elapses. It is desirable to adopt a configuration for determining that the voltage is stable (second configuration).

  According to such a configuration, it is easy to determine whether or not the DC voltage superimposed on the output terminal is stable.

  In the SDI device having the first or second configuration, for example, the switching unit may be a configuration (third configuration) that is an open / close switch that switches between passing and blocking of an electrical signal. A configuration (fourth configuration) in which the switching unit is a variable resistance element that switches between passage and attenuation of an electrical signal may be employed.

  In the SDI device having any one of the first to fourth configurations, a receiver which is an SDI signal processing circuit for receiving the SDI signal from the outside of the SDI device, and the SDI signal from the outside of the SDI device. An input terminal for receiving, and a switching means different from the switching means, wherein the another switching means is provided between the receiver and the input terminal, and allows passage and blocking or attenuation of an electrical signal. Switching, after the control means determines that the DC voltage superimposed on the output terminal and the input terminal is stable, the operation of the switching means and the other switching means is changed from the interruption or attenuation of the electric signal to the electric signal. It is good also as a structure (5th structure) changed to passage of this.

  According to such a configuration, it is possible to protect against a surge voltage that can be applied to the input terminal.

  In order to achieve the above object, an SDI signal transmission system according to the present invention includes at least one SDI device having any one of the first to fifth configurations, and DC power is provided to at least part of the SDI signal transmission line. Are superposed.

  According to the present invention, it is possible to realize an inexpensive and miniaturized SDI device that does not cause damage even when connected to a stopcock, and an SDI signal transmission system including the SDI device.

It is a figure which shows the structure of the SDI signal transmission system which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the SDI signal transmission system which concerns on 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of an SDI signal transmission system according to the first embodiment of the present invention. The SDI signal transmission system according to the first embodiment of the present invention includes an imaging device 1, an SDI repeater 2, a power supply inserter 3, a power supply device 4, a display monitor 5, coaxial cables 6 to 8, and a power supply. And a cable 9.

  The imaging device 1 converts an imaging signal acquired by imaging into an SDI signal (SD-SDI signal or HD-SDI signal) and outputs it. The SDI signal output from the imaging device 1 is transmitted to the SDI repeater 2 via the coaxial cable 6.

  The SDI repeater 2 is a device that enables long-distance transmission of an SDI signal, corrects the SDI signal received from the coaxial cable 6, outputs the corrected SDI signal to the coaxial cable 7, and generates the SDI signal on the SDI signal transmission line. Compensates for signal attenuation and distortion. The SDI repeater 2 carries the DC power superimposed on the coaxial cable 7 and superimposes it on the coaxial cable 6.

  The power insertion device 3 superimposes the DC power output from the power supply device 4 connected via the power cable 9 on the coaxial cable 7 which is a part of the SDI signal transmission line. Further, the power inserter 3 transmits the SDI signal received from the coaxial cable 7 to the display monitor 5 via the coaxial cable 8. As the configuration of the power supply inserter 3, for example, as shown in FIG. 1, the coaxial cable connection terminal 30 to which the coaxial cable 7 is connected, the coaxial cable connection terminal 31 to which the coaxial cable 8 is connected, and the power cable 9 are connected. Power input terminal 32, a DC blocking capacitor 33 disposed between the coaxial cable connection terminal 30 and the coaxial cable connection terminal 31, a connection point 34 between the coaxial cable connection terminal 30 and the DC blocking capacitor 33, and a power input. A configuration including a high-frequency blocking coil 35 disposed between the terminals 32 and a high-frequency grounding capacitor C4 disposed between a connection point 36 between the power input terminal 32 and the high-frequency blocking coil 35 and the ground potential. it can.

  The power supply device 4 is a power supply device that outputs DC power. Examples of the configuration of the power supply device 4 include a configuration including a power conversion circuit that converts commercial AC power into DC power.

  The display monitor 5 displays an image based on the transmitted SDI signal.

  The imaging device 1 is an SDI device that outputs an SDI signal to the outside of the device, and the SDI repeater 2 is an SDI device that receives an SDI signal supplied from the outside of the device and outputs the SDI signal to the outside of the device. The display monitor 5 is an SDI device that receives an SDI signal supplied from the outside of the device.

  Next, the configuration of the imaging device 1 which is an example of the SDI device according to the present invention will be described with reference to FIG. The imaging device 1 includes an imaging unit 10 that executes imaging and outputs an imaging signal, a signal conversion unit 11 that converts an imaging signal output from the imaging unit 10 into an SDI signal, a driver 12, an open / close switch SW1, A DC blocking capacitor 13, a coaxial cable connection terminal 14 to which the coaxial cable 6 is connected, a high frequency blocking coil 15, a transmission line connection control circuit 16, and a high frequency grounding capacitor C1 are provided. The driver 12 is an example of a “driver” described in the claims, the coaxial cable connection terminal 14 is an example of an “output terminal” described in the claims, and the open / close switch SW1 is described in the claims. The transmission line connection control circuit 16 is an example of “control means” described in the claims. Further, the “electric signal” described in the claims includes not only an SDI signal but also a noise signal such as a rush voltage and a surge voltage. The open / close switch SW1 cuts off the “electric signal” when in the open state and allows the “electric signal” to pass through when in the closed state. The same applies to open / close switches SW2 and SW3 described later. Although not shown in FIG. 1, a matching circuit that matches the output impedance of the imaging device 1 with the impedance (75Ω) of the coaxial cable 6 is provided after the opening / closing switch SW1, and the DC blocking capacitor 13 is the matching circuit. Should be included.

  The output terminal of the imaging unit 10 is connected to the input terminal of the signal conversion unit 11, and the output terminal of the signal conversion unit 11 is connected to the input terminal of the driver 12. The output terminal of the driver 12 is connected to one end of the DC blocking capacitor 13 via the open / close switch SW1, and the other end of the DC blocking capacitor 13 is connected to one end of the high frequency blocking coil 15 and the coaxial cable connection terminal 14. . The other end of the high frequency blocking coil 15 is connected to the imaging unit 10 and the transmission path connection control circuit 16 via a DC power carrier line. The connection point between the high-frequency blocking coil 15 and the DC power carrier line is connected to the ground potential via the high-frequency grounding capacitor C1. The imaging unit 10 uses DC power supplied from the DC power carrier line as a power source.

  The transmission path connection control circuit 16 determines whether or not the DC voltage superimposed on the coaxial cable connection terminal 14 is stable. The transmission path connection control circuit 16 is a control circuit having a timer function, and detects the voltage of the DC power carrier line between the high frequency blocking coil 15 and the imaging unit 10, so that the coaxial cable connection terminal 14 is connected. It is detected whether or not a DC voltage is superimposed, and when a predetermined time has elapsed after detecting that a DC voltage is superimposed on the coaxial cable connection terminal 14, the DC voltage is superimposed on the coaxial cable connection terminal 14. It is determined that the DC voltage is stable, the open / close switch SW1 is switched from the open state to the closed state, and then the open / close switch SW1 is maintained in the closed state until the superimposition of the DC voltage on the coaxial cable connection terminal 14 stops. The predetermined time may be set longer than the expected time from when the DC voltage is superimposed on the coaxial cable connection terminal 14 until the rush voltage is settled. For example, the predetermined time may be set to an arbitrary value on the order of ms.

  Since the rush voltage is generated by the stopcock connection of the coaxial cables 6 and 7, and the DC voltage superimposed on the coaxial cable connection terminal 14 is not stable, the open / close switch SW1 is in the open state. Reaching the driver 12 can be prevented. After the DC voltage superimposed on the coaxial cable connection terminal 14 is stabilized, the open / close switch SW1 is closed, so that the SDI signal is transferred from the coaxial cable connection terminal 14 to the coaxial cable 6 using the driver 12. Can be output.

  Since the imaging device 1 having the above configuration prevents the rush voltage only by adding the open / close switch SW1 and the transmission line connection control circuit 16 that performs simple control, the rush voltage is inexpensive and can be downsized. Is blocking. In other words, the imaging device 1 having the above configuration is an SDI device that is inexpensive and can be downsized without risk of damage even if it is connected to a stopcock.

  Next, a configuration of an SDI repeater 2 as another example of the SDI device according to the present invention will be described with reference to FIG. The SDI repeater 2 includes a coaxial cable connection terminal 20 to which the coaxial cable 6 is connected, a DC blocking capacitor 21, an open / close switch SW2, and a receiver having an equalizer function that compensates for attenuation of an SDI signal caused by transmission through the cable. 22, a reclocker 23 having a reclocking function that compensates for distortion of an SDI signal caused by transmission through a cable, a driver 24, a switch SW3, a DC blocking capacitor 25, and a coaxial cable 7 to which a coaxial cable 7 is connected. A cable connection terminal 26, high frequency blocking coils 27 and 28, a transmission line connection control circuit 29, and high frequency grounding capacitors C2 and C3 are provided. The driver 24 is an example of a “driver” described in the claims, the coaxial cable connection terminal 26 is an example of an “output terminal” described in the claims, and the open / close switch SW3 is described in the claims. The transmission line connection control circuit 29 is an example of the “control means” recited in the claims, and the coaxial cable connection terminal 20 is the “input terminal” recited in the claims. The open / close switch SW2 is an example of “another switching unit” recited in the claims. Although not shown in FIG. 1, a matching circuit for matching the output impedance of the SDI repeater 2 with the impedance (75Ω) of the coaxial cable 7 is provided at the subsequent stage of the opening / closing switch SW3. It may be included in the circuit.

  The coaxial cable connection terminal 20 is connected to one end of the high frequency blocking coil 28 and one end of the DC blocking capacitor 21. The other end of the high frequency blocking coil 28 is connected to the coaxial cable connection terminal 26 via a DC power carrier line and a high frequency blocking coil 27. A transmission path connection control circuit 29 is connected to the DC power carrier line. The connection point between the high frequency blocking coil 28 and the DC power carrier line is connected to the ground potential via the high frequency grounding capacitor C2, and the connection point between the high frequency blocking coil 27 and the DC power carrier line is connected to the high frequency grounding capacitor C3. To the ground potential.

  The other end of the DC blocking capacitor 21 is connected to the input terminal of the receiver 22 via the open / close switch SW2, the output terminal of the receiver 22 is connected to the input terminal of the reclocker 23, and the output terminal of the reclocker 23 is connected to the driver 24. Connected to the input terminal.

  The output terminal of the driver 24 is connected to the coaxial cable connection terminal 26 via the open / close switch SW3 and further via the DC blocking capacitor 25.

  The SDI repeater 2 having the above-described configuration converts the DC power superimposed on the coaxial cable 7 into the coaxial cable connection terminal 26, the high frequency blocking coil 27, the DC power carrier line, the high frequency blocking coil 28, and the coaxial cable connecting terminal 20. And is superimposed on the coaxial cable 6.

  The SDI repeater 2 configured as described above compensates for attenuation of the SDI signal received from the coaxial cable 6 at the coaxial cable connection terminal 20 by the receiver 22 when the open / close switches SW2 and SW3 are in the closed state. After the distortion is compensated at 23, the signal is output from the coaxial cable connection terminal 26 to the coaxial cable 7 using the driver 24.

  The transmission path connection control circuit 29 determines whether or not the DC voltage superimposed on the coaxial cable connection terminals 20 and 26 is stable. The transmission path connection control circuit 29 is a control circuit having a timer function, and detects the voltage of the DC power carrier line between the high-frequency blocking coil 27 and the high-frequency blocking coil 28, so that the coaxial cable connection terminal It is detected whether a DC voltage is superimposed on 20 and 26, and when a predetermined time elapses after it is detected that a DC voltage is superimposed on the coaxial cable connection terminals 20 and 26, the coaxial cable connection is detected. It is determined that the DC voltage superimposed on the terminals 20 and 26 is stable, the open / close switches SW2 and SW3 are switched from the open state to the closed state, and thereafter, until the DC voltage superimposition on the coaxial cable connection terminals 20 and 26 stops. The open / close switches SW2 and SW3 are kept closed. The predetermined time may be set longer than the expected time from when the DC voltage is superimposed on the coaxial cable connection terminals 20 and 26 until the rush voltage is settled, and may be set to an arbitrary value on the order of ms, for example.

  During the period when the rush voltage is generated by the stopcock connection of the coaxial cable 7 and the DC voltage superimposed on the coaxial cable connection terminals 20 and 26 is not stable, the open / close switches SW2 and SW3 are in the open state. It is possible to prevent the voltage from reaching the receiver 22 and the rush voltage from reaching the driver 24. After the DC voltage superimposed on the coaxial cable connection terminals 20 and 26 is stabilized, the open / close switches SW2 and SW3 are closed, so that the SDI signal is sent from the coaxial cable connection terminal 26 using the driver 24. It can output to the coaxial cable 7.

  The SDI repeater 2 having the above configuration prevents the rush voltage only by adding the open / close switch SW3 and the transmission line connection control circuit 29 that performs simple control. The voltage is blocked. That is, the SDI repeater 2 having the above configuration is an SDI device that is inexpensive and can be reduced in size without risk of breakage even when connected to a stopcock. Further, the SDI repeater 2 configured as described above also protects against a surge voltage that can be applied to the coaxial cable connection terminal 20 by adding the open / close switch SW2.

  Next, an SDI signal transmission system according to a second embodiment of the present invention will be described with reference to FIG. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The SDI signal transmission system according to the second embodiment of the present invention is different from the SDI signal transmission system according to the first embodiment of the present invention in that variable resistance elements VR1 to VR3 are used instead of the on-off switches SW1 to SW3. The transmission line connection control circuits 16 'and 29' are used in place of the transmission line connection control circuits 16 and 29. The variable resistance elements VR <b> 1 to VR <b> 3 are also examples of “switching means” recited in the claims, like the open / close switches SW <b> 1 to SW <b> 3. The variable resistance elements VR1 to VR3 attenuate the “electric signal” when the resistance value is large and allow the “electric signal” to pass when the resistance value is small.

  The transmission path connection control circuit 16 ′ determines whether or not the DC voltage superimposed on the coaxial cable connection terminal 14 is stable. The transmission path connection control circuit 16 ′ is a control circuit having a timer function, and detects the voltage of the DC power carrier line between the high frequency blocking coil 15 and the imaging unit 10, whereby the coaxial cable connection terminal 14. Whether or not a DC voltage is superimposed on the coaxial cable connection terminal 14 is detected when a predetermined time elapses after it is detected that the DC voltage is superimposed on the coaxial cable connection terminal 14. It is determined that the DC voltage is stable, the variable resistance element VR1 is switched from a state in which the resistance value is large to a state in which the resistance value is small, and then the variable resistance element VR1 until the superposition of the DC voltage on the coaxial cable connection terminal 14 is interrupted. The resistance value of is kept small. Note that switching from a state in which the resistance value of the variable resistance element VR1 is large to a state in which the resistance value is small may be performed gradually or may be performed at once. The predetermined time may be set longer than the expected time from when the DC voltage is superimposed on the coaxial cable connection terminal 14 until the rush voltage is settled. For example, the predetermined time may be set to an arbitrary value on the order of ms.

  Since the rush voltage is generated by the stopcock connection of the coaxial cables 6 and 7, and the DC voltage superimposed on the coaxial cable connection terminal 14 is not stable, the variable resistance element VR1 is in a state of high resistance. The rush voltage can be prevented from reaching the driver 12. Then, after the DC voltage superimposed on the coaxial cable connection terminal 14 is stabilized, the variable resistance element VR1 is in a state of low resistance, so that the SDI signal is sent from the coaxial cable connection terminal 14 using the driver 12. The signal can be output to the coaxial cable 6.

  The imaging device 1 having the configuration shown in FIG. 2 prevents the rush voltage only by adding the variable resistance element VR1 and the transmission line connection control circuit 16 ′ that performs simple control, so that it is inexpensive and can be downsized. Rush voltage is blocked by the circuit configuration. That is, the imaging device 1 having the configuration shown in FIG. 2 is an SDI device that is inexpensive and can be reduced in size without risk of breakage even when connected to a stopcock, like the imaging device 1 having the configuration shown in FIG.

  The transmission path connection control circuit 29 ′ determines whether or not the DC voltage superimposed on the coaxial cable connection terminals 20 and 26 is stable. The transmission path connection control circuit 29 ′ is a control circuit having a timer function, and detects the voltage of the DC power carrier line between the high frequency blocking coil 27 and the high frequency blocking coil 28, thereby connecting the coaxial cable. It is detected whether or not a DC voltage is superimposed on the terminals 20 and 26, and when a predetermined time elapses after it is detected that the DC voltage is superimposed on the coaxial cable connection terminals 20 and 26, the coaxial cable It is determined that the DC voltage superimposed on the connection terminals 20 and 26 is stable, the variable resistance elements VR2 and VR3 are switched from a state where the resistance value is large to a state where the resistance value is small, and then the connection to the coaxial cable connection terminals 20 and 26 is performed. Until the superposition of the DC voltage is interrupted, the resistance values of the variable resistance elements VR2 and VR3 are kept small. The predetermined time may be set longer than the expected time from when the DC voltage is superimposed on the coaxial cable connection terminals 20 and 26 until the rush voltage is settled, and may be set to an arbitrary value on the order of ms, for example.

  During the period when the rush voltage is generated by the stopcock connection of the coaxial cable 7 and the DC voltage superimposed on the coaxial cable connection terminals 20 and 26 is not stable, the variable resistance elements VR2 and VR3 are set in a state where the resistance value is large. Therefore, it is possible to prevent the surge voltage from reaching the receiver 22 and the rush voltage from reaching the driver 24. After the DC voltage superimposed on the coaxial cable connection terminals 20 and 26 is stabilized, the resistance values of the variable resistance elements VR2 and VR3 are set to be small, so that the SDI signal is transmitted to the coaxial cable using the driver 24. The signal can be output from the connection terminal 26 to the coaxial cable 7.

  The SDI repeater 2 having the configuration shown in FIG. 2 is inexpensive and downsized because the rush voltage is blocked only by adding the variable resistance elements VR2 and VR3 and the transmission line connection control circuit 29 ′ that performs simple control. The rush voltage is blocked by the circuit configuration that can. That is, the SDI repeater 2 having the configuration shown in FIG. 2 is an SDI device that is inexpensive and can be reduced in size without risk of damage even when connected to a stopcock, like the SDI repeater 2 having the configuration shown in FIG. . Further, the SDI repeater 2 configured as shown in FIG. 2 also protects against a surge voltage that can be applied to the coaxial cable connection terminal 20 by adding the variable resistance element VR2.

  In the first and second embodiments described above, it is detected whether a DC voltage is superimposed on the coaxial cable connection terminal, and it is detected that the DC voltage is superimposed on the coaxial cable connection terminal. It is determined that the DC voltage superimposed on the coaxial cable connection terminal is stable when a predetermined time has elapsed since then, but other determination methods may be used. For example, one end of the switch is connected to a connection point between the open / close switch or the variable resistance element and the DC element capacitor, the other end of the switch is connected to one end of the load, and the other end of the load is connected to the ground potential. When the switch is closed, the voltage at the connection point between the open / close switch or variable resistance element and the DC element capacitor is detected to detect whether or not the DC voltage is superimposed on the coaxial cable connection terminal. When it is detected that the connection voltage between the open / close switch or variable resistance element and the DC element capacitor is within a predetermined range after detecting that the DC voltage is superimposed, it is superimposed on the coaxial cable connection terminal. The determined DC voltage may be determined to be stable, and the switch may be opened.

  In the first embodiment described above, both the imaging device 1 and the SDI device 2 are the SDI devices according to the present invention, but only one of them may be the SDI device according to the present invention. For example, the imaging device 1 may be configured by removing the open / close switch SW1 and the transmission line connection control circuit 16 from the configuration shown in FIG. 1, and the SDI repeater 2 may be left in the configuration shown in FIG. 1 may be maintained as shown in FIG. 1, and the SDI repeater 2 may be configured by removing the on / off switches SW2 and SW3 and the transmission line connection control circuit 29 from the configuration shown in FIG.

  In the second embodiment described above, both the imaging device 1 and the SDI device 2 are SDI devices according to the present invention, but only one of them may be an SDI device according to the present invention. For example, the imaging device 1 may be configured by removing the variable resistance element VR1 and the transmission path connection control circuit 16 ′ from the configuration illustrated in FIG. 2, and the SDI repeater 2 may be configured as illustrated in FIG. The imaging device 1 may be configured as shown in FIG. 2, and the SDI repeater 2 may be configured by removing the variable resistance elements VR2 and VR3 and the transmission line connection control circuit 29 ′ from the configuration shown in FIG.

  In the first and second embodiments described above, the imaging device 1 is a DC power superimposition type imaging device, but the imaging device and the power separator may be separate devices. For example, the DC blocking capacitor 13 and the high frequency blocking coil 15 in the imaging device 1 shown in FIGS. 1 and 2 may be separated from the imaging device as a power supply separator.

  In the form in which the imaging device and the power separator are separate devices, the SDI signal transmission line and the DC power carrier line are separated inside the imaging device, but when the stopcock connection is made, the rush voltage is separated from the power source. Therefore, the present invention is sufficiently meaningful to be applied to an imaging device that is not a DC power superimposition type imaging device.

DESCRIPTION OF SYMBOLS 1 Imaging equipment 2 SDI repeater 3 Power supply insertion device 4 Power supply device 5 Display monitor 6-8 Coaxial cable 9 Power supply cable 10 Imaging part 11 Signal conversion part 12, 24 Driver 13, 21, 25, 33 DC blocking capacitor 14, 20 , 26, 30, 31 Coaxial cable connection terminals 15, 27, 28, 35 High frequency blocking coils 16, 16 ', 29, 29' Transmission path connection control circuit 22 Receiver 23 Reclocker 32 Power input terminals 34, 36 Connection point C1 ~ C4 High frequency grounding capacitor SW1 ~ SW3 Open / close switch VR1 ~ VR3 Variable resistance element

Claims (6)

An SDI device that processes SDI signals,
A driver that is an SDI signal processing circuit for sending the SDI signal to the outside of the SDI device;
An output terminal for sending the SDI signal to the outside of the SDI device;
Switching means provided between the driver and the output terminal, for switching between passage and blocking or attenuation of an electrical signal;
Control means for controlling the switching means,
An SDI device characterized in that after the control means determines that the DC voltage superimposed on the output terminal is stable, the operation of the switching means is changed from interruption or attenuation of the electric signal to passage of the electric signal. .   The control means determines that the DC voltage superimposed on the output terminal is stable when a predetermined time elapses after detecting that the DC voltage is superimposed on the output terminal. The SDI device according to claim 1.   3. The SDI device according to claim 1, wherein the switching unit is an open / close switch that switches between passing and blocking of an electric signal. 4.   The SDI device according to claim 1, wherein the switching unit is a variable resistance element that switches between passage and attenuation of an electric signal. A receiver which is an SDI signal processing circuit for receiving the SDI signal from the outside of the SDI device;
An input terminal for receiving the SDI signal from outside the SDI device;
Provided between the receiver and the input terminal, comprising a switching means different from the switching means for switching between passing and blocking or attenuation of electrical signals,
After the control means determines that the DC voltage superimposed on the output terminal and the input terminal is stable, the operation of the switching means and the other switching means is changed from interruption or attenuation of the electric signal to passage of the electric signal. The SDI device according to claim 1, wherein the SDI device is changed.   An SDI signal transmission system comprising at least one SDI device according to any one of claims 1 to 5, wherein DC power is superimposed on at least a part of an SDI signal transmission line.

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