JP2005150963A - Communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize low power consumption at the time of waiting and operation high speed communication in a communication system comprising a main communication device and a sub-communication device. <P>SOLUTION: A control means in the main communication device performs communication with the sub-communication device through a first communication means when starting communication. When a decision is made that the main communication device can communicate with the sub-communication device, a second communication means in the main communication device is activated to transmit a signal for activating the second communication means in the sub-communication device. Subsequently, communication is performed using the second communication means and the control means in the sub-communication device performs communication through the first communication means. When the signal for activating the second communication means is received from the main communication device, the second communication means is activated. Upon ending communication, the control means in the main communication device transmits an operation stop signal of the second communication means to the sub-communication device using the first or second communication means and stops operation of the second communication means in the main communication device. Upon receiving the operation stop signal of the second communication means, the control means in the sub-communication device stops operation of the second communication means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to wireless communication between a main communication device and a slave transmission device, and power control of a wireless communication means.

Conventionally, in a proposal related to control of communication means in a portable terminal (see Patent Document 1), when a wireless terminal having a high-speed receiving circuit and a low-speed transmitting / receiving circuit and a base station are configured, a wireless terminal enters a high-speed service area The high-speed receiver circuit is turned on, and immediately after the high-speed service ends, the high-speed receiver circuit power supply of the wireless terminal is turned off. It was a patent on control of a high-speed receiving circuit only for a wireless terminal.
JP 2002-135203 A

  However, in the conventional technique, the power supply of the wireless communication means remains ON in the base station itself, and even if this conventional technique is applied to communication between portable terminals, only power control of one of the wireless communication means can be solved. In addition, only power savings can be solved between communication devices, such as a portable computer and a portable printer, and a camera and its accessory lens, both of which are driven by a battery. However, there is a problem that the other battery is insufficient for power saving.

  An object of the present invention is to solve the above problems.

  In order to solve the above-mentioned object, in the first invention of the present invention, the first communication means having low power consumption, the second communication means having a higher communication speed than the first communication means, and the control means are provided. A main communication device that is mainly operated by a user, a first communication unit with low power consumption, a second communication unit having a higher communication speed than the first communication unit, and a control unit. In a communication system consisting of a slave communication device that mainly responds to communication from the master communication device, the control means of the master communication device communicates with the slave communication device using the first communication means at the start of communication. If it is determined that communication with the apparatus is possible, the second communication means of the main communication apparatus is activated and a signal for activating the second communication means of the slave communication apparatus is transmitted, and then communication is performed using the second communication means. The control means of the slave communication device is based on the first communication means. When performing communication and receiving the activation signal of the second communication means from the main communication apparatus, the second communication means is activated, and the control means of the main communication apparatus The first communication unit or the second communication unit is used to transmit an operation stop signal of the second communication unit to the slave communication device, and the operation of the second communication unit of the main communication device is stopped. The control means of the apparatus stops the operation of the second communication means when receiving the second communication means operation stop signal.

  The second invention is characterized in that, in the first invention, the communication is terminated when the main communication device is powered off.

  The third invention is characterized in that, in the first invention, when the communication is terminated, the main communication device is linked to the power saving mode at the time of transition.

  In the fourth invention, the first communication means having low power consumption, the second communication means having a higher communication speed than the first communication means, and the control means are provided, and the user mainly operates. A main communication device, a first communication unit having low power consumption, a second communication unit having a higher communication speed than the first communication unit, and a control unit, and mainly responding to communication from the main communication device In the communication system including the slave communication device, the control unit of the master communication device communicates with the slave communication device using the first communication unit when communication is started, and determines that communication with the slave communication device is possible. The second communication means is activated and a signal for activating the second communication means of the slave communication apparatus is transmitted. Thereafter, communication is performed using the second communication means, and the slave communication apparatus is the first communication means. When the communication signal is received, the control means of the slave communication device is stopped. When a start signal is output to the control means, and the control means communicates with the main communication device using the first communication means while the control means is operating, and the start signal of the second communication means is received from the main communication device, When the second communication means is activated and the control means of the main communication device ends communication with the second communication means, the control means of the main communication device uses the first communication means or the second communication means. An operation stop signal of the second communication means is transmitted to the slave communication device, and the operation of the second communication means of the main communication device is stopped. The control means of the slave communication device sends a second communication means operation stop signal. When receiving, the operation of the second communication means is stopped, and the control means of the main communication device is the first communication means or the second communication at the end of communication in the first communication means. The standby signal of the first communication means is transmitted to the slave communication device using the means At the same time, the operation of the first communication means of the main communication device is stopped, and when the control means of the slave communication device receives the standby signal of the first communication means, the operation of the first communication means is set to the standby state, The control means is also in a standby state in which it is activated by an activation signal from the first communication means.

  According to a fifth aspect of the invention, when the communication by the second communication means in the fourth aspect of the invention is terminated, the communication device is interlocked when shifting to the power saving mode.

  In a sixth aspect of the present invention, the end of communication by the first communication means in the fourth aspect is interlocked when the main communication device is powered off.

  In a seventh invention, the first communication means and the second communication means in the first and fourth inventions are communication means using radio waves.

  In the eighth invention, the first communication means in the first invention and the fourth first name is a communication means using radio waves, and the second communication means is a communication means using light. It is characterized by.

  In the ninth invention, the first communication means of the slave communication device in the first invention and the fourth invention is supplied with power by a power wave output from the first communication means of the main transmission device. It is characterized by.

  In the tenth invention, the main communication device in the first invention and the fourth invention is a camera, and the slave communication device is a camera accessory that communicates with a camera such as a lens, a flash device, a remote controller, and a printer. It is characterized by being.

  In the eleventh invention, the control means of the slave communication device in the first and fourth inventions stops the second communication means of the slave communication device when the communication from the master communication device is not received for a predetermined time. It is characterized by doing.

  As described above, in the first invention, the second communication means capable of high-speed communication is stopped at the end of communication, and the second communication means is activated after communication with the first communication means at the start of communication. High-speed communication is possible. That is, both power saving during standby and high-speed communication during communication can be achieved in the communication system between the main communication device and the slave communication device.

  In the second invention, it becomes possible to stop the high-speed second communication means in synchronization with the power-off of the main communication device.

  In the third invention, it becomes possible to stop the high-speed second communication means in synchronization with the transition of the power saving mode of the main communication device.

  In the fourth invention, at the end of communication, in addition to stopping the second high-speed communication means, the first communication means having low power consumption and the control means stand by in a standby state with lower power consumption and at the time of communication. High-speed communication.

  In the fifth invention, the stop of the high-speed second communication means in the fourth invention can be synchronized with the power saving mode of the main communication device.

  In the sixth aspect, it is possible to further synchronize the low-consumption first communication unit and the control unit in the fourth aspect with the transition to the power saving standby state and the power supply of the main communication device.

  In the seventh invention, the first and second communication means of the first and fourth inventions are constituted by radio wave communication means, so that the camera as the main communication means and the camera accessory as the slave communication means are provided. Reduction of connection terminals, standby power saving, and high-speed communication during communication are possible.

  In the eighth invention, the first communication means of the first and fourth inventions is constituted by radio wave communication means, and the second communication means is constituted by light communication means, so that the camera as the main communication means, It is possible to reduce the number of connection terminals of the camera accessory that is a slave communication means, and to perform standby power saving and high-speed communication during communication.

  In the ninth invention, it is possible to further reduce the standby power of the first communication means of the slave communication means.

  In the tenth aspect, power saving during standby and high-speed communication during communication are possible between the camera serving as the main communication device and the camera accessory serving as the slave communication device.

  In the eleventh aspect, even when the main communication device is abnormal, it is possible to reduce the current consumption of the slave new device.

(First embodiment)
FIG. 1 is a block diagram showing a configuration according to the first embodiment of the present invention, which will be described in order.

  Reference numeral 1000 denotes a camera corresponding to the main transmission device, reference numeral 1200 denotes a camera accessory such as a lens corresponding to the slave transmission device, and the camera 1000 and the camera accessory 1200 are connected by a connection member 1100.

  In the configuration of the camera 1000, reference numeral 1001 denotes a battery as a power source, and reference numeral 1002 denotes a power supply unit that boosts the battery voltage, steps down the battery voltage, or connects or disconnects the battery voltage. In FIG. 1, the output of the power supply means is one system, but may be a plurality of outputs. The output of the power supply means and GND are supplied to the camera accessory 1200 via the connection member 1100.

  Reference numeral 1003 denotes a microcomputer (hereinafter referred to as camera microcomputer) which is a camera control means, and reference numeral 1004 denotes a camera operation member.

  Reference numeral 1010 denotes a first communication unit that consumes less power during standby and operation, 1011 denotes an antenna of the first communication unit, and 1012 denotes a communication terminal and a control terminal between the camera microcomputer 1003 and the first communication unit 1010. A group.

  Reference numeral 1020 denotes second communication means capable of performing higher-speed communication than the first communication means 1010, 1021 denotes an antenna of the second communication means 1020, and 1022 denotes a communication terminal and a control terminal group between the camera microcomputer 1003 and the second communication means 1020. It is.

  Reference numeral 1030 denotes other camera operation means such as display means, shutter control means, and photometry means.

  Next, the configuration of the camera accessory 1200 will be described. Reference numeral 1201 denotes a microcomputer (hereinafter referred to as an accessory microcomputer) which is a camera accessory control means, and reference numeral 1210 denotes a first communication means on the accessory side which consumes less power during standby and during operation. First communication means 1010 on the camera side 1021 is an antenna of the first communication means 1210 on the accessory side, and 1212 is a communication terminal and control terminal group between the accessory microcomputer 1201 and the first communication means 1210 on the accessory side.

  Reference numeral 1220 denotes an accessory-side second communication means capable of performing higher-speed communication than the first communication means 1210, and performs wireless communication with the camera-side second communication means 1020. Reference numeral 1221 denotes an accessory-side second communication means 1220 antenna. , 1222 are a communication terminal and control terminal group between the accessory microcomputer 1201 and the second communication means 1220 on the accessory side.

  The power supplied from the camera-side power supply means 1002 via the connection member 1100 is supplied to the accessory microcomputer 1201, the accessory-side first communication means 1210, the accessory-side second communication means 1220, and the accessory-side other operation means (not shown). Supplied.

  The first communication unit 1210 in the slave communication device may receive a power wave supplied from the first communication unit 1010 of the main communication device and use it as a power source.

  Further, although the second communication means uses radio waves for communication, optical communication using a light emitting element and a light receiving element may be used.

  Next, the operation of the camera microcomputer 1003 will be described based on the flowchart of FIG.

When the camera microcomputer 1003 receives a start signal from a power switch (not shown) or the operation means 1004, the start operation is started. (S1000)
In step S1001, an input from the operation unit 1004 is received. In step S1002, it is determined whether communication with the camera accessory 1200 is required in accordance with the operation received in step S1001, and if necessary, the process proceeds to step S1010. If not necessary, the process proceeds to step S1003.

  In step S1003, processing other than communication is performed. S1004 It is determined whether communication with the camera accessory is to be terminated, such as turning off a power switch (not shown), a predetermined time for a non-operation state of the camera, and the like. Otherwise, the process proceeds to S1001.

  In step S1010, the camera microcomputer 1003 detects whether the second communication unit 1020 on the camera side is operating. If the camera microcomputer 1003 is operating, the process proceeds to step S1017. If not, the process proceeds to step S1011.

  In step S <b> 1011, the camera microcomputer 1003 communicates with the camera accessory 1200 using the first communication unit 1010. In step S1012, the first communication unit 1010 determines whether communication with the camera accessory 1200 is possible. If yes, the process proceeds to step S1014. If not, the process proceeds to step S1013.

In S1013, the communication NG state with the camera accessory 1200 is stored, and the process proceeds to S1003.
In step S1014, the second communication unit 1020 on the camera side is activated. In S1015, the first communication means 1010 of the camera is used to perform communication for starting the second communication means 1220 on the camera accessory side.

  In step S1016, the second communication unit 1220 on the camera accessory side WAITs for a start time. In step S1017, high-speed communication is performed with the camera accessory 1200 using the second communication unit 1020 on the camera side. In step S1018, the camera accessory 1200 is processed. The second communication means 1020 determines whether communication is possible. If NG, the process proceeds to S1019, and if OK, the process proceeds to S1003.

  In S1019, the high-speed communication NG state with the camera accessory 1200 is stored, and the process proceeds to S1003.

  In S1030, it is detected whether the second communication means 1020 on the camera side is operating. If it is operating, the process proceeds to S1040, and if it is stopped, the process proceeds to S1031.

  In S1040, a signal for stopping the second communication means 1220 on the camera accessory side is communicated using the first communication means 1010 or the second communication means 1020 on the camera side.

  In step S1041, the second communication unit 1020 on the camera side is stopped and the process proceeds to step S1031.

  In S1031, other operations are stopped, and in S1032, the camera microcomputer 1003 is set to a sleep state.

  The operation flow on the camera side is described above. FIG. 3 shows the operation flow of the accessory microcomputer 1201 on the camera accessory side when communication is performed with the camera accessory 1200 using the first communication unit 1010 being described. The operation flow of the camera accessory when communicating with the camera accessory using the second communication unit 1020 will be described below with reference to FIG.

When the first communication means 1210 of the camera accessory 1200 receives communication from the camera, the accessory microcomputer 1201 generates an interrupt. (S2000 in FIG. 3)
In S2001, the first communication means 1210 on the accessory side is used to send back data such as the status of the camera accessory 1200. In S2002, it is detected whether the communication data received in S2000 is a command to activate the second communication means 1220 on the accessory side. If so, the process proceeds to S2010, and if not, the process proceeds to S2003.

In S2010, the second communication means 1220 on the accessory side is activated and the process proceeds to S2005. In S2003, it is detected whether the communication data received in S2000 is an instruction to stop the second communication means 1220 on the accessory side, and if so, the process proceeds to S2020. If not, the process proceeds to S2004.

  In S2020, the accessory microcomputer 1201 stops the second communication means 1220 on the accessory side and proceeds to S2005. In S2004, other processing is performed, and in S2005, the process returns to the main routine.

  Next, an interrupt process that occurs when the accessory microcomputer 1201 receives communication from the accessory-side second communication means 1220 will be described along a flow starting from S2100 in FIG.

In S2100, an interrupt is started. In S2101, the second communication unit 1220 is used for reply. In S2102, it is detected whether the communication data received in S2100 is a command for stopping the second communication unit 1220. If so, the process proceeds to S2110. Otherwise, go to S2103,
In S2110, the operation of the second communication means 1220 on the accessory side is stopped and the process proceeds to S2104. In S2103, other operations are performed, and the process proceeds to S2104.

  In S2004, the counter for stopping the operation of the accessory-side second communication means 1220 is cleared when communication from the second communication means 1020 on the camera side is not received for a predetermined time or more due to an abnormal operation or the like, and S2105 Proceed to

  In step S2105, the process returns to the main routine.

  Operation of the accessory microcomputer 1201 for stopping the operation of the second communication means 1220 on the accessory side when communication from the second communication means 1020 on the camera side is not received for a predetermined time or more due to an abnormal operation on the camera side or the like Will be described along the flow of FIG.

The accessory microcomputer 1201 generates an interrupt at a predetermined interval. (1300 in FIG. 5)
In S1301, the counter is incremented.

  In S1302, it is determined whether the time when the communication from the second communication unit 1020 on the camera side has not been received is a predetermined time or more. If the time is not less than the predetermined time, the process proceeds to 1310. Otherwise, the process proceeds to S1303.

  In step S1310, the second communication unit 1220 on the accessory side is stopped.

  In S1311, a communication NG signal is transmitted to the camera 1000 as the main communication apparatus using the first communication means 1210 on the accessory side, and the process proceeds to S1303.

  In step S1303, the interrupt process ends.

  As described above, the high-speed second communication means is stopped at the end of communication, and the high-speed second communication means is started after communication with the low-speed first communication means at the start of communication. High-speed communication can be realized in the power saving state and the communication state when not communicating.

  Further, even if the stop signal of the second communication means is not received due to an abnormality on the camera side or the like, it is possible to stop the second communication means on the accessory side when there is no communication from the second communication means for a predetermined time. Become.

(Second Embodiment)
The configuration of the camera that is the main communication device and the camera accessory that is the slave communication device in the second embodiment is the same as that of the first embodiment of FIG.

  The operation that is the difference will be described below.

  The operation of the camera microcomputer 1003, which is the main communication device, will be described below along the flow of FIG.

When the camera microcomputer 1003 receives a start signal from a power switch (not shown) or the operation means 1004, the start operation is started. (S2000)
In step S2001, the operation unit 1004 is received. In S2002, it is determined whether it is necessary to communicate with the camera accessory 1200 according to the operation received in S2001. If necessary, the process proceeds to S2010, and if not necessary, the process proceeds to S2003.

  In step S2010, the camera microcomputer 1003 detects whether the second communication unit 1020 on the camera side is operating. If it is operating, the process proceeds to step S2040. If not, the process proceeds to step S2011.

  In step S2011, the camera microcomputer 1003 determines whether the first communication unit 1010 on the camera side is activated. If the camera microcomputer 1003 is operating, the process proceeds to step S2020. Otherwise, the process proceeds to step S2012.

  In step S2012, the first communication unit 1010 on the camera side is activated, and in step S2013, an activation signal is transmitted to the first communication unit 1210 on the accessory side using the first communication unit 1010. In S2014, the apparatus waits for the time when the first communication unit 1210 on the accessory side is activated, and proceeds to S2020.

  In step S2020, communication is performed to the camera accessory 1200 using the first communication unit 1010 on the camera side. In S2021, the first communication means 1010 on the camera side determines whether communication with the camera accessory 1200 is possible. If yes, the process proceeds to S2030. If not, the process proceeds to S2022.

In S2022, the communication NG state with the camera accessory 1200 is stored, and the process proceeds to S2003.
In step S2030, the second communication unit 1020 on the camera side is activated. In step S2031, communication is performed to activate the second communication unit 1220 on the accessory side using the first communication unit 1010 on the camera side.

  In S2032, the time waits for the activation of the second communication means 1220 on the accessory side, and the process proceeds to S2040 after the wait.

  In step S2040, high-speed communication is performed with the camera accessory 1200 using the second communication unit 1020 on the camera side. In step S2041, it is determined whether communication is possible between the camera accessory 1200 and the second communication unit 1020 on the camera side. If YES, the process proceeds to 2042, and if OK, the process proceeds to S2003.

  In S2042, the high-speed communication NG state with the camera accessory 1200 is stored, and the process proceeds to S2003.

  In S2003, a warning is displayed if a process other than communication is performed, or if the communication NG state is stored in S2022 or S2042.

  In S2004, it is determined whether or not an operation from the operation unit 1004 is input for a predetermined time. If the operation is not performed for a predetermined time, the process proceeds to S2060. Otherwise, the process proceeds to S2005.

  In S2005, if OFF of a power switch (not shown) is input, the process proceeds to S2050, and if not, the process proceeds to S2001.

  In S2060, it is detected whether the second communication means 1020 on the camera side is operating. If it is operating, the process proceeds to S2063, and if it is stopped, the process proceeds to 2061.

  In S2063, a signal for stopping the second communication unit 1220 on the camera accessory side is communicated using the first communication unit 1010 or the second communication unit 1020 on the camera side.

  In S2064, the second communication means 1020 on the camera side is stopped and the process proceeds to S2061.

  In S2061, other operations are stopped, and in S2062, the camera microcomputer 1003 is set in a power saving state.

  In S2050, using the first communication unit 1010 or the second communication unit 1020 on the camera side, the transition communication to the standby state of the first communication unit 1210 on the camera accessory side and the stop communication of the second communication unit 1220 are performed. Do. In step S2051, the first communication unit 1010 and the second communication unit 1020 on the camera side are stopped. In step S2053, other operations of the camera 1000 are stopped. In step S2053, the camera microcomputer 1003 is stopped.

  Next, the operation of the camera accessory 1200 will be described.

  First, the operation when the accessory microcomputer 1201 receives the activation signal of the first communication means 1210 on the accessory side from the standby state from the first communication means 1010 on the camera side in S2013 of FIG. 6 is performed according to the flow of FIG. explain.

  In S2500, the first communication unit 1210 starts the operation and causes the accessory microcomputer 1201 to generate an activation interrupt.

  In step S2501, the operation of the accessory microcomputer 1201 is started.

  In step S2501, the interrupt process ends.

  As described above, it is possible to return from the stop state of the accessory microcomputer 1201 and the standby state of the first communication means 1210 on the accessory side.

  The subsequent communication operation between the camera 1000 and the camera accessory 1200 using the first communication means 1210 on the camera accessory side will be described along the flow of FIG.

  When communication is received from the first communication means 1010 on the camera side, communication interruption is started (S2100). In S2101, the first communication means 1210 on the accessory side sends a reply to the camera 1000.

  In S2102, if the command received from the camera 1000 is an activation signal for the second communication means 1220 on the accessory side, the process proceeds to S2110; otherwise, the process proceeds to S2103.

  In S2110, the second communication unit 1220 on the accessory side is activated and the process proceeds to S2106.

  In S2103, if the command received from the camera 1000 is a stop signal for the second communication means 1220 on the accessory side, the process proceeds to S2120; otherwise, the process proceeds to S2104.

  In S2120, the second communication means 1220 on the accessory side is stopped and the process proceeds to S2106.

  In S2104, if the command received from the camera 1000 is a signal for shifting to the standby state of the first communication means 1210 on the accessory side, the process proceeds to S2130; otherwise, the process proceeds to S2105.

  In S2130, the first communication unit 1210 on the accessory side is set in a standby state, and the process proceeds to S2131.

  In step S 2131, the operation of the camera accessory control unit 1203 is stopped and the camera accessory control unit 1203 is activated when interrupted by the activation signal from the first communication unit 1210 on the accessory side.

  In S2105, other operations of the camera accessory 1200 are performed, and the process proceeds to S2106.

  In step S2106, the communication interrupt process ends.

  Note that the interrupt processing by the second communication means 1220 on the accessory side is the same as the operation of the flow of FIG.

  As described above, when the power is OFF, the second communication unit 1220 on the accessory side and the accessory microcomputer 1201 stop operating, and the first communication unit 1210 on the accessory side is also in a standby state. It is possible to achieve a power saving state.

It is a block diagram showing the structure of the main communication apparatus in the 1st and 2nd embodiment of this invention, and a following new apparatus. It is a flowchart showing operation | movement of the camera which is a main communication apparatus in the 1st Embodiment of this invention. It is a flowchart showing the communication interruption operation | movement of the camera accessory which is a slave communication apparatus in the 1st Embodiment of this invention. It is a flowchart showing the communication interruption operation | movement of the camera accessory which is a slave communication apparatus in the 1st Embodiment of this invention. It is a flowchart showing the timer interruption operation | movement of the camera accessory which is a slave communication apparatus in the 1st Embodiment of this invention. It is a flowchart showing operation | movement of the camera which is a main communication apparatus in the 2nd Embodiment of this invention. It is a flowchart showing the communication interruption operation | movement of the camera accessory which is a slave communication apparatus in the 2nd Embodiment of this invention. It is a flowchart showing the starting interruption operation | movement of the camera accessory which is a slave communication apparatus in the 2nd Embodiment of this invention.

Explanation of symbols

1000 camera 1003 camera microcomputer 1010 first communication means on camera side 1011 antenna on first communication means on camera side 1020 second communication means on camera side 1021 antenna on second communication means on camera side 1100 camera and camera accessory Connection unit 1200 Camera accessory 1201 Accessory microcomputer 1210 First communication means on the accessory side 1211 Antenna of the first communication means on the accessory side 1220 Second communication means on the accessory side 1221 Antenna of the second communication means on the accessory side

Claims (11)

A first communication unit having low power consumption, a second communication unit having a communication speed higher than that of the first communication unit, and a control unit; a first communication unit having low power consumption; In a communication system comprising a second communication unit having a higher communication speed than the communication unit and a control unit, and comprising a slave communication device responding to communication from the main communication device, the control unit of the main communication device starts communication Sometimes the first communication means is used to communicate with the slave communication apparatus, and when it is determined that communication with the slave communication apparatus is possible, the second communication means of the master communication apparatus is activated and the second communication means of the slave communication apparatus is activated. A signal to be activated is transmitted, and then communication is performed using the second communication means. The control means of the slave communication apparatus communicates with the first communication means and the second communication means from the main communication apparatus. When receiving the activation signal, the second communication means And the control means of the main communication apparatus uses the first communication means or the second communication means to send the slave communication apparatus an operation stop signal for the second communication means when the communication ends. Is transmitted, and the operation of the second communication means of the main communication device is stopped, and when the control means of the slave communication device receives the second communication means operation stop signal, the operation of the second communication means is stopped. A communication system characterized by the above.   The communication system according to claim 1, wherein the end of communication is linked when the main communication device is powered off.   2. The communication system according to claim 1, wherein the end of communication is interlocked when shifting to the power saving mode of the main communication device. A first communication unit having low power consumption, a second communication unit having a communication speed higher than that of the first communication unit, and a control unit; a first communication unit having low power consumption; In a communication system comprising a second communication unit having a higher communication speed than the communication unit and a control unit, and comprising a slave communication device responding to communication from the main communication device, the control unit of the main communication device starts communication Sometimes the first communication means is used to communicate with the slave communication apparatus, and when it is determined that communication with the slave communication apparatus is possible, the second communication means of the master communication apparatus is activated and the second communication means of the slave communication apparatus is activated. A signal to be activated is transmitted, and thereafter, communication is performed using the second communication means. When the first communication means receives the communication signal, the slave communication apparatus receives the communication signal when the control means of the slave communication apparatus is stopped. When the control means is in operation Communicating with the main communication device using the first communication means and receiving the activation signal of the second communication means from the main communication device, the second communication means is activated to control the main communication device When the communication with the second communication means ends, the control means of the main communication device transmits an operation stop signal of the second communication means to the slave communication device using the first communication means or the second communication means. In addition, the operation of the second communication means of the main communication device is stopped, and when the control means of the slave communication device receives the second communication means operation stop signal, the operation of the second communication means is stopped, When the communication device control means ends communication with the first communication means, the master communication device control means uses the first communication means or the second communication means to send the standby signal to the slave communication device. And stop the operation of the first communication means of the main communication device When the control unit of the slave communication device receives the standby signal of the first communication unit, the control unit sets the operation of the first communication unit to the standby state, and the control unit is also activated by the start signal from the first communication unit. A communication system characterized by being in a standby state.   5. The communication system according to claim 4, wherein the end of communication in the second communication unit is interlocked when shifting to the power saving mode of the main communication device.   5. The communication system according to claim 4, wherein the end of communication by the first communication means is interlocked when the main communication device is powered off.   5. The communication system according to claim 1, wherein the first communication means and the second communication means are communication means using radio waves.   5. The communication system according to claim 1, wherein the first communication unit is a communication unit using radio waves, and the second communication unit is a communication unit using light.   5. The communication system according to claim 1, wherein the first communication means of the slave communication apparatus is supplied with power by a power wave output from the first communication means of the main transmission apparatus.   5. The communication system according to claim 1, wherein the main communication device is a camera, and the slave communication device is a camera accessory that communicates with a camera such as a lens, a flash device, a remote controller, and a printer.   5. The communication system according to claim 1, wherein the control unit of the slave communication device stops the second communication unit of the slave communication device when the communication from the master communication device is not received for a predetermined time. .

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