Electronic device and control method thereof, and accessory and control method thereof

Abstract

The invention provides an electronic device and a control method thereof, and an accessory and a control method thereof. An electronic device to which an accessory is detachably attached includes a first processing unit capable of communicating with the accessory by a first communication method and a second processing unit capable of communicating with the accessory by a second communication method. The first processing unit receives accessory information from an accessory by a first communication method. The second processing unit communicates with the accessory by a second communication method based on the accessory information. The electronic device has a first power state and a second power state, wherein the power of the second power state is lower than the power of the first power state. The first processing unit communicates with the accessory by a first communication method in a first power state and a second power state. The second processing unit communicates with the accessory by a second communication method in the first power state, and does not communicate with the accessory by the second communication method in the second power state.

Description

[0001] (This application is a divisional application of an application filed on April 22, 2022, with application number 202210429970.8 and entitled “Electronic device, control method thereof, accessory thereof, and control method thereof.”) Technical Field

[0002] The present invention relates to electronic equipment such as a camera device to which accessories can be attached. Background Art

[0003] When an accessory such as a lighting device is attached to an imaging system and the imaging system is powered on, the imaging system typically detects the attachment of the accessory through switch detection or communication detection after the startup is complete, and then obtains necessary information from the accessory. Japanese Patent Application Laid-Open No. 2016-218187 discloses an imaging system that obtains specific information from an accessory having a display function and then instructs the accessory to display the information.

[0004] The camera can start up from a state where it cannot communicate with an accessory, such as a power-off state or a low-power (sleep) state. However, if information cannot be obtained from the accessory until the camera fully starts up, it takes time to acquire the information necessary to control the accessory. In particular, when the camera uses information from the accessory to make control-related decisions, the responsiveness of the camera system is impaired by this time lag. Summary of the Invention

[0005] The present invention provides an electronic device, a control method for the electronic device, an accessory, and a control method for the accessory, each of which can enhance the responsiveness of the accessory when it is attached to a system of the electronic device when it is started.

[0006] According to one aspect of the present invention, an electronic device is provided that is capable of detachably attaching an accessory, and includes: a first processing unit that is capable of communicating with the accessory via a first communication method; and a second processing unit that is capable of communicating with the accessory via a second communication method that is different from the first communication method. The first processing unit receives accessory information for identifying the accessory from the accessory via the first communication method. The second processing unit communicates with the accessory via the second communication method based on the accessory information to control the accessory. The electronic device has a first power state and a second power state, and the power of the second power state is lower than the power of the first power state. The first processing unit communicates with the accessory via the first communication method in the first power state and the second power state. The second processing unit communicates with the accessory via the second communication method in the first power state, and does not communicate with the accessory via the second communication method in the second power state. The control method of the above-mentioned electronic device also constitutes another aspect of the present invention.

[0007] According to another aspect of the present invention, an accessory is detachably attached to an electronic device, the accessory including an accessory processing unit capable of communicating with the electronic device through a first communication method and a second communication method different from the first communication method. The accessory processing unit sends accessory information for identifying the accessory to the electronic device through the first communication method, and after the accessory processing unit sends the accessory information, communicates with the electronic device through the second communication method for controlling the accessory. The accessory processing unit communicates with the electronic device through the first communication method when the electronic device is in a first power state and a second power state, wherein the power of the second power state is lower than the power of the first power state. The accessory processing unit communicates with the electronic device through the second communication method when the electronic device is in the first power state, and does not communicate with the electronic device through the second communication method when the electronic device is in the second power state. The control method of the above-mentioned accessory also constitutes another aspect of the present invention.

[0008] A control method for an electronic device, wherein the electronic device is capable of detachably attaching an accessory, and the electronic device includes a first processing unit and a second processing unit, the control method including the following steps: enabling the first processing unit to receive accessory information for identifying the accessory from the accessory through a first communication method; enabling the second processing unit to communicate with the accessory through a second communication method based on the accessory information for controlling the accessory, wherein the electronic device has a first power state and a second power state, and the power of the second power state is lower than the power of the first power state; enabling the first processing unit to communicate with the accessory through the first communication method in the first power state and the second power state; and enabling the second processing unit to communicate with the accessory through the second communication method in the first power state, and prohibiting the second processing unit from communicating with the accessory through the second communication method in the second power state.

[0009] A method for controlling an accessory that can be detachably attached to an electronic device, the control method comprising the following steps: causing the accessory to send accessory information for identifying the accessory to the electronic device via a first communication method; after the accessory sends the accessory information, causing the accessory to communicate with the electronic device via a second communication method for controlling the accessory; causing the accessory to communicate with the electronic device via the first communication method when the electronic device is in a first power state and a second power state, wherein the power of the second power state is lower than the power of the first power state; and causing the accessory to communicate with the electronic device via the second communication method when the electronic device is in the first power state, and prohibiting the accessory from communicating with the electronic device via the second communication method when the electronic device is in the second power state.

[0010] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The configuration of a camera system (including a camera, a lens unit, and accessories) in the first embodiment is exemplified.

[0012] Figure 2A and Figure 2B The protocol of the SPI communication in the first embodiment is exemplified.

[0013] Figures 3A to 3D A flowchart illustrating processing to be performed by the camera and accessories in the first embodiment is illustrated.

[0014] Figure 4Communication data in the SPI communication in the first embodiment is exemplified.

[0015] Figure 5 The accessory information in the first embodiment is exemplified.

[0016] Figure 6 The processing sequence of the camera system in the first embodiment is exemplified.

[0017] Figure 7 The accessory type information in the first embodiment is exemplified.

[0018] Figure 8 Factors that generate a communication request in the first embodiment are exemplified.

[0019] Figure 9A and Figure 9B The communication interval in the SPI communication in the first embodiment is exemplified.

[0020] Figure 10 A flowchart illustrating startup processing to be performed by the camera (camera control circuit A) in the first embodiment is shown.

[0021] Figure 11 A flowchart illustrating startup processing to be performed by the camera (camera control circuit B) in the first embodiment is shown.

[0022] Figure 12 A flowchart illustrating processing to be performed by the accessory in the first embodiment is shown.

[0023] Figure 13 The startup sequence of the camera system in the first embodiment is illustrated.

[0024] Figure 14A and Figure 14B The startup sequence from the low power consumption mode in the second embodiment is exemplified.

[0025] Figure 15A and Figure 15B Illustrate an example of an I2C communication waveform.

[0026] Figure 16 The following illustrates the processing to be performed by the camera in the first embodiment when N-byte data is transmitted from the camera to the accessory.

[0027] Figure 17 The following illustrates the processing to be performed by the camera in the first embodiment when the camera receives N bytes of data from the accessory.

[0028] Figure 18A and Figure 18B The following illustrates processing to be performed by the accessory in the case where N bytes of data are communicated between the camera and the accessory in the first embodiment.

[0029] Figure 19 The flowchart exemplifies the process when SW1 and SW2 are turned on simultaneously in the third embodiment.

[0030] Figure 20 A flowchart illustrating a process when SW1 and SW2 are simultaneously turned on in a comparative example is shown.

[0031] Figure 21 A flowchart illustrating live view display processing in the fourth embodiment is shown.

[0032] Figure 22 A flowchart illustrating live view display processing in a comparative example is shown. DETAILED DESCRIPTION

[0033] Embodiments according to the present invention will now be described with reference to the accompanying drawings.

[0034] First embodiment

[0035] Figure 1 The electrical structure of an imaging system is illustrated, which includes an imaging device (hereinafter referred to as a camera) 100, which is an electronic device according to a first embodiment of the present invention, and an accessory 200 detachably attached to the imaging device. The accessory 200 is, for example, a microphone device or a lighting (strobe / flash) device, and includes various devices that can be attached to the camera 100. The camera 100 and the accessory 200 are electrically connected via a one-to-one contact between a plurality of contacts (terminals) TC01 to TC21 of a camera connector 141 provided in the camera 100 and a plurality of contacts TA01 to TA21 of an accessory connector 211 provided in the accessory 200. The accessory 200 may not have some of the plurality of contacts TA01 to TA21.

[0036] The camera 100 is powered by a battery 111. The battery 111 is attachable to and detachable from the camera 100. A camera control circuit A101, which serves as a first processing unit and a receiving unit, and a camera control circuit B102, which serves as a second processing unit, in the camera 100 are circuits that control the entire camera 100 and include a processor (microcomputer) such as a CPU. The camera control circuit A101 and the camera control circuit B102 execute various control and processing operations in accordance with computer programs.

[0037] The camera control circuit A 101 monitors the operation of switches (not shown) used for camera operation and controls the system power supply according to user operations. The camera control circuit A 101 includes a low-power processor that can operate even when the camera 100 is in a low-power consumption mode (power saving mode or second power state) as a standby state. On the other hand, the camera control circuit B 102 is responsible for controlling the image sensor 122, display circuit 127, and other components. The camera control circuit B 102 includes a processor that stops operating in the low-power consumption mode but operates in the normal operating mode (first power state).

[0038] Although the camera control circuit A 101 and the camera control circuit B 102 include separate processors in the present embodiment, these two circuits may be provided in a single processor.

[0039] The system power supply circuit 112 generates power to be supplied to various circuits in the camera 100 and includes a DC / DC converter circuit, a low dropout (LDO) circuit, a charge pump circuit, and the like. The 1.8V voltage generated by the system power supply circuit 112, which receives power from the battery 111, is constantly supplied to the camera control circuit A 101 as the camera microcomputer power supply VMCU_C. Several types of voltages generated by the system power supply circuit 112 are supplied to the camera control circuit B 102 at arbitrary timings as the camera microcomputer power supply VMCU2_C. The camera control circuit A 101 controls the on / off switching of power to the various circuits in the camera 100 by controlling the system power supply circuit 112.

[0040] The optical lens 121 is attachable to and detachable from the camera 100. Light from a subject incident through the optical lens 121 forms an image on an image sensor 122, which includes a CMOS sensor or a CCD sensor. The optical lens 121 and the camera 100 may be integrally formed. The subject image formed on the image sensor 122 is encoded into a digital imaging signal. The image processing circuit 123 performs image processing such as noise reduction and white balance processing on the digital imaging signal to generate image data, and converts the image data into an image file in the JPEG format, etc., to record the image data in the recording memory 126. The image processing circuit 123 generates VRAM image data from the image data to be displayed on the display circuit 127.

[0041] The memory control circuit 124 controls the transmission and reception of image data and other data generated by the image processing circuit 123 and the like. The volatile memory 125 is a memory capable of high-speed reading and writing, such as DDR3 SDRAM, and serves as a workspace for image processing performed by the image processing circuit 123. The recording memory 126 is a readable and writable recording medium, such as an SD card or CFExpress card, that is attachable to and detachable from the camera 100 via a connector (not shown). The display circuit 127 is a display arranged on the back surface of the camera 100 and includes an LCD panel, an organic EL display panel, and the like. The backlight circuit 128 adjusts the brightness of the display circuit 127 by varying the amount of light from the backlight of the display circuit 127.

[0042] In this embodiment, the accessory power supply circuit A (hereinafter referred to as the accessory power supply circuit A) 131 and the accessory power supply circuit B (hereinafter referred to as the accessory power supply circuit B) 132 are each a voltage conversion circuit that converts the voltage supplied from the system power supply circuit 112 into a predetermined voltage and generates 3.3 V as the accessory power supply VACC. This configuration can convert a voltage into another voltage.

[0043] The accessory power supply circuit A 131 is a power supply circuit that includes an LDO circuit and has low power consumption. The accessory power supply circuit B 132 includes a DC / DC converter circuit and can pass a current greater than that of the accessory power supply circuit A 131. The power consumption of the accessory power supply circuit B 132 is greater than that of the accessory power supply circuit A 131. Therefore, when the load current is small, the accessory power supply circuit A 131 is more efficient than the accessory power supply circuit B 132, while when the load current is large, the accessory power supply circuit B 132 is more efficient than the accessory power supply circuit A 131. The camera control circuit A 101 controls the voltage output of the accessory power supply circuits A 131 and B 132, turning them on and off according to the operating state of the accessory 200.

[0044] The protection circuit 133 includes a current fuse element, an electronic fuse circuit that combines multiple switching elements or resistors, amplifiers, and switching elements, or the like. When the power supply current value supplied to the accessory 200 from the accessory power supply circuits A 131 and B 132 exceeds a predetermined value and becomes excessive (abnormal), the protection circuit 133 outputs an overcurrent detection signal DET_OVC. In this embodiment, the protection circuit 133 is an electronic fuse circuit, and when a current of 1A or greater flows, it notifies the camera control circuit A 101 of the overcurrent detection signal DET_OVC. The overcurrent detection signal DET_OVC indicates an overcurrent by going high. The predetermined value may be different from 1A.

[0045] The camera connector 141 is a connector for electrically connecting to the accessory 200 via 21 contacts TC01 to TC21 arranged in a row. The contacts TC01 to TC21 are arranged in this order from one end to the other end in the arrangement direction.

[0046] TC01 is connected to the ground terminal (GND) and serves not only as a reference potential contact but also as a contact for controlling the wiring impedance of the differential signals D1N and D1P. TC01 corresponds to a third ground contact.

[0047] The differential signal D1N connected to TC02 and the differential signal D1P connected to TC03 are differential data communication signals for data communication in pairs, and are connected to the camera control circuit B 102. TC02, TC03, TC07 to TC10, TC12 to TC17, TC19, and TC20, which will be described below, are communication contacts.

[0048] TC04, which is a first ground contact, is connected to GND and serves as a reference potential contact for the camera 100 and the accessory 200. TC04 is arranged outside TC05 described below in the contact arrangement direction.

[0049] The accessory power (output signal) VACC generated by the accessory power circuits A 131 and B 132 is connected to TC05 as a power contact via the protection circuit 133 .

[0050] The accessory attachment detection signal (first input signal) / ACC_DET is connected to TC06, which serves as an attachment detection contact. The accessory attachment detection signal / ACC_DET is pulled up to the camera microcomputer power supply VMCU_C via a resistor element RP134 (e.g., 10 kΩ). The camera control circuit A 101 can detect whether the accessory 200 is attached by reading the signal level of the accessory attachment detection signal / ACC_DET. If the signal level (potential) of the accessory attachment detection signal / ACC_DET is high (predetermined potential), it is detected that the accessory 200 is not attached. If the signal level (potential) of the accessory attachment detection signal / ACC_DET is low (GND potential), which is an active potential, it is detected that the accessory 200 is attached.

[0051] The signal level (potential) of the accessory attachment detection signal / ACC_DET is changed from a high level (Hi) to a low level (Lo) when the camera 100 is powered on, which triggers various transmissions between the camera 100 and the accessory 200 via the contacts.

[0052] The camera control circuit 101 supplies power to the accessory 200 via TC05 as a power supply contact in response to detecting attachment of the accessory 200 .

[0053] SCLK connected to TC07 (communication contacts), MOSI connected to TC08, MISO connected to TC09, and Chip Select (CS) connected to TC10 are signals used for communication using the Serial Peripheral Interface (SPI) communication method (hereinafter referred to as SPI communication), a second communication method in which the camera control circuit B102 serves as the communication master. SCLK is a clock signal, MOSI is a transmit signal, MISO is a receive signal, and CS is a communication select signal used to select a communication partner. In this embodiment, SPI communication uses a 1 MHz communication clock frequency, an 8-bit (1 byte) data length, an MSB-first bit order, and a full-duplex communication method.

[0054] In this embodiment, the camera 100 and the accessory 200 support two types of communication protocols of the SPI communication method. Communication protocol A is a communication method in which the camera 100 does not confirm whether the accessory 200 is in a communicable state before outputting SCLK, and is referred to as SPI protocol A in the following description. Figure 2A This figure illustrates an overview of the communication waveform for SPI protocol A. In this figure, CS is active low.

[0055] The camera control circuit B 102 changes CS to low level (active) at timing A1 , and requests SPI communication to the accessory control circuit 201 .

[0056] At timing A2 which is a predetermined time T_CS after timing A1, the camera control circuit B 102 starts outputting SCLK and MOSI. When the accessory control circuit 201 detects the trailing edge of SCLK, the accessory control circuit 201 starts outputting MISO.

[0057] The camera control circuit B 102 stops outputting SCLK at timing A3 when outputting 1 byte of SCLK is completed.

[0058] The camera control circuit B 102 stops outputting SCLK for a predetermined time T_INTERVAL at timing A3 , restarts outputting SCLK at timing A4 after T_INTERVAL has elapsed, and performs the next 1-byte communication.

[0059] Figure 3A The flowchart in exemplifies processing to be performed by the camera control circuit B 102 in the SPI protocol A. S represents a step.

[0060] In S101, the camera control circuit B 102 stores a numerical value indicating the number of bytes to be communicated in an internal variable N. For example, 3 is stored in the case of 3-byte communication.

[0061] In S102 , the camera control circuit B 102 changes CS to a low level and requests SPI communication.

[0062] In S103, the camera control circuit B 102 waits until a predetermined time T_CS has elapsed after CS has changed to a low level. After the predetermined time T_CS has elapsed, the flow proceeds to S104.

[0063] In S104 , the camera control circuit B 102 controls the SCLK output, MOSI data output, and MISO data input, and performs 1-byte data communication.

[0064] In S105 , the camera control circuit B 102 confirms whether the internal variable N indicating the number of communication bytes is 0. If the internal variable N is 0, the flow proceeds to S106 , and if the internal variable N is not 0, the flow proceeds to S107 .

[0065] In S107 , the camera control circuit B 102 stores, as a new internal variable N, a value obtained by decrementing the numerical value of the internal variable N indicating the number of communication bytes by 1.

[0066] In S108, the camera control circuit B 102 waits until a predetermined time T_INTERVAL has elapsed after the completion of the 1-byte data communication in S104. Then, after the predetermined time T_INTERVAL has elapsed, the flow returns to the process of S104 and the same process is executed again.

[0067] In S106 , the camera control circuit B 102 changes CS to a high level and ends a series of SPI communications.

[0068] Figure 3B The flowchart in exemplifies the processing to be performed by the accessory control circuit 201 in SPI protocol A.

[0069] In S201 , the accessory control circuit 201 checks whether CS has changed to a low level. If CS has changed to a low level, the flow proceeds to S202 , and if CS has not changed to a low level, the flow returns to S211 .

[0070] In S202 , the accessory control circuit 201 performs 1-byte data communication through MOSI data input control and MISO data output control in response to input of the SCLK signal.

[0071] In S203, the accessory control circuit 201 checks whether CS changes to a high level. If CS changes to a high level, it is determined that the SPI communication is completed, and if CS does not change to a high level, the flow returns to S202 to perform the next 1-byte communication.

[0072] The communication protocol B in the SPI communication method is a communication method in which the camera 100 confirms whether the accessory 200 is in a communicable state before outputting SCLK, and is referred to as SPI protocol B in the following description. Figure 2B An overview of the communication waveform of SPI protocol B is shown below.

[0073] The camera control circuit B 102 changes the CS pin to a low level at timing B1 and requests SPI communication from the accessory control circuit 201. The camera control circuit B 102 checks the potential of MISO along with the communication request. If MISO is at a high level, it is determined that the accessory control circuit 201 is in a communicable state, and if MISO is at a low level, it is determined that the accessory control circuit 201 is in a communicable state.

[0074] On the other hand, when the accessory control circuit 201 detects the trailing edge of CS at timing B2, the accessory control circuit 201 performs control for changing MISO to a high level if SPI communication is available, and performs control for changing MISO to a low level if the communication is not available.

[0075] When the camera control circuit B 102 confirms that MISO is at a high level at timing B3, the camera control circuit B 102 starts outputting SCLK and MOSI. The accessory control circuit 201 starts outputting MISO upon detecting the trailing edge of SCLK.

[0076] When the output of SCLK for one byte is completed at timing B4, the camera control circuit B 102 stops outputting SCLK.

[0077] After 1-byte communication, as shown in timings B5 and B6 , the accessory control circuit 201 performs control for changing MISO to a high level if SPI communication is available, and performs control for changing MISO to a low level if SPI communication is not available.

[0078] The camera control circuit B 102 checks the potential of MISO at timing B7. If MISO is high, it determines that the accessory control circuit 201 is in a communicable state, and if MISO is low, it determines that the accessory control circuit 201 is in a non-communicable state.

[0079] Figure 3CThe flowchart in exemplifies processing to be performed by the camera control circuit B 102 in the SPI protocol B.

[0080] In S111, the camera control circuit B 102 stores a numerical value indicating the number of bytes to be communicated in an internal variable N. For example, 3 is stored in the case of 3-byte communication.

[0081] In S112 , the camera control circuit B 102 changes CS to a low level and requests SPI communication.

[0082] In S113, the camera control circuit B 102 confirms whether MISO has changed to a high level. If MISO is at a high level, the flow proceeds to S114, and if MISO is not at a high level, the flow returns to S113.

[0083] In S114, the camera control circuit B 102 controls the SCLK output, MOSI data output, and MISO data input to perform 1-byte data communication.

[0084] In S115 , the camera control circuit B 102 confirms whether communication of all data has been completed (whether the internal variable N indicating the number of communication bytes is 0). If the internal variable N is 0, the flow proceeds to S116 , and if not, the flow proceeds to S117 .

[0085] In S117 , the camera control circuit B 102 stores, as a new internal variable N, a value obtained by decrementing the numerical value of the internal variable N indicating the number of communication bytes by 1.

[0086] In S118, the camera control circuit B 102 confirms whether MISO has changed to a high level. If MISO is at a high level, the flow proceeds to S114, and if MISO is not at a high level, the flow returns to S118.

[0087] In S116 , the camera control circuit B 102 changes CS to a high level and ends a series of SPI communications.

[0088] Figure 3D The flowchart in exemplifies the processing to be performed by the accessory control circuit 201 in SPI protocol B.

[0089] In S211, the accessory control circuit 201 confirms whether CS changes to a low level. If CS changes to a low level, the flow proceeds to S212, and if CS does not change to a low level, the flow returns to S211.

[0090] In S212, the accessory control circuit 201 confirms whether SPI communication is available. If SPI communication is available, the process proceeds to S213, and if SPI communication is not available, the process proceeds to S214.

[0091] In S213 , the accessory control circuit 201 performs control for changing MISO to a high level, and the flow proceeds to S215 .

[0092] In S214 , the accessory control circuit 201 performs control for changing MISO to the low level, and the flow returns to S212 .

[0093] In S215 , the accessory control circuit 201 controls the MOSI data input and the MISO data output in response to the SCLK signal input, and performs 1-byte data communication.

[0094] In S216, the accessory control circuit 201 checks whether CS changes to a high level. If CS changes to a high level, it is determined that the SPI communication is completed, and if CS does not change to a high level, the flow returns to S212 for the next 1-byte communication.

[0095] Figure 4 The content of communication when an operation execution instruction (command) is notified from the camera 100 to the accessory 200 by SPI communication in this embodiment is exemplified.

[0096] In the first byte communication, the camera control circuit B 102 transmits information CMD indicating a command number as MOSI data to the accessory control circuit 201. The accessory control circuit 201 transmits a value of 0xA5, which indicates a communicable state, as MISO data to the camera control circuit B 102. If the first byte communication process cannot be executed, the accessory control circuit 201 transmits a value other than 0xA5 as MISO data to the camera control circuit B 102.

[0097] The camera control circuit B 102 transmits the argument MOSI_DATA1 corresponding to the command number CMD in the 2nd byte communication to the accessory control circuit 201. Then, from the 3rd byte to the (N-2)th byte, the arguments MOSI_DATA2 to MOSI_DATA[N-3] corresponding to the command number CMD are similarly transmitted to the accessory control circuit 201.

[0098] The accessory control circuit 201 transmits the command number CMD received in the 1st byte as MISO data in the 2nd byte communication to the camera control circuit B 102. This configuration enables the camera control circuit B 102 to determine that the accessory control circuit 201 has correctly received the MOSI data.

[0099] The accessory control circuit 201 transmits the return value MISO_DATA1 corresponding to the command number CMD as MISO data in the 3rd byte communication to the camera control circuit B 102. Then, from the 4th byte to the (N-2)th byte, the return values ​​MISO_DATA2 to MISO_DATA[N-4] corresponding to the command number CMD are similarly transmitted to the camera control circuit B 102.

[0100] It is assumed that the number of arguments and the number of return values ​​are predetermined for each command No. One or both of the arguments and the return value may be omitted.

[0101] The camera control circuit B 102 transmits the checksum data CheckSum_C as MOSI data in the (N-1)th byte communication to the accessory control circuit 201. The checksum data CheckSum_C is a value calculated by the following expression.

[0102] CheckSum_C=EXOR(AND(SUM(CMD,MOSI_DATA1,…,MOSI_DATA[N-3]),0xFF),0xFF)

[0103] The accessory control circuit 201 transmits 0x00 as MISO data.

[0104] Next, the camera control circuit B 102 transmits 0x00 as MOSI data to the accessory control circuit 201 in the N-th byte communication.

[0105] The accessory control circuit 201 transmits the checksum data CheckSum_A as MISO data. The checksum data CheckSum_A is calculated by the following expression when the value of CheckSum_C received by the camera control circuit B 102 in the (N-1)th byte communication and the value of CheckSum_C calculated by the camera control circuit B 102 match each other.

[0106] CheckSum_A=EXOR(AND(SUM(0xA5,CMD,MIS0_DATA1,…,MOSI_DATA[N-4]),0xFF),0xFF)

[0107] On the other hand, if the value of CheckSum_C received by the camera control circuit B 102 and the value of CheckSum_C calculated by the camera control circuit B 102 do not coincide with each other in the (N-1)th byte communication, the value is calculated by the following expression.

[0108] CheckSum_A=AND(SUM(0xA5,CMD,MIS0_DATA1,…,MOSI_DATA[N-4]),0xFF)

[0109] Figure 1 The signal contact TC11 shown as a communication request contact is connected to a communication request signal (second input signal) / WAKE for requesting communication from the accessory 200 to the camera 100 (camera control circuit A 101). The communication request signal / WAKE is pulled up to the camera microcomputer power supply VMCU_C via a resistor. The camera control circuit A 101 can detect a communication request from the accessory 200 by detecting a change (trailing edge) in the communication request signal / WAKE.

[0110] SDA, connected to TC12 and SCL, connected to TC13, are signals used for inter-integrated circuit (I2C) communication (hereinafter referred to as I2C communication), a first communication method in which the camera control circuit A 101 serves as the communication master. SDA is a data signal, and SCL is a clock signal. SDA and SCL are open-drain signals pulled up by the camera microcomputer power supply VMCU_C, and in this embodiment, have a communication frequency of 100 kbps.

[0111] In I2C communication, both data transmission from the camera 100 and data transmission from the accessory 200 are performed via SDA. When comparing SPI communication and I2C communication, the communication speed of I2C communication is lower than that of SPI communication. SPI communication has a higher communication speed than I2C communication and is therefore suitable for communicating information with large amounts of data. Therefore, in the communication between the camera 100 and the accessory 200 in this embodiment, information with large amounts of data is communicated using SPI communication, and information with small amounts of data is communicated using I2C communication. For example, data may be communicated first using I2C communication, and if SPI communication is available or necessary based on the data, control may be performed to further execute SPI communication.

[0112] Figure 15A and Figure 15B Illustrate an example of an I2C communication waveform. Figure 15A Illustrate a waveform example in the case where the camera sends N bytes of data (DATA[1] to DATA[N]) to the accessory, and Figure 15B An example of a waveform is shown in the case where the camera receives N bytes of data (DATA[1] to DATA[N]) from the accessory. Figure 15A and Figure 15B , the upper waveform illustrates SCL, and the lower waveform illustrates SDA.

[0113] Below the SDA waveform, the meaning of each timing signal is shown, along with the indication of whether the control circuit controlling the SDA signal output level is the camera control circuit A 101 or the accessory control circuit 201. Communication data consists of 1-byte data and 1-bit information indicating a response. The top of each figure shows the number of bytes of data from the start of communication.

[0114] Since the following will refer to Figures 16 to 18A and Figure 18B To explain the details of the communication content, we will refer to Figure 15A and Figure 15B To explain the outline.

[0115] exist Figure 15A In the 1st and 2nd byte communications, the camera control circuit A 101 notifies the accessory control circuit 201 of storage address information related to the data to be transmitted. In the 3rd to (N+2)th byte communications, the camera control circuit A 101 transmits N-byte data (DATA[address] to DATA[address+N]) to the accessory control circuit 201.

[0116] exist Figure 15B In the 1st and 2nd byte communications, the camera control circuit A 101 notifies the accessory control circuit 201 of storage address information related to the data to be received. In the 3rd to (N+3)th byte communications, the camera control circuit A 101 receives N bytes of data (DATA[address] to DATA[address+N]) from the accessory control circuit 201.

[0117] Figure 16 The flowchart in exemplifies processing to be performed by the camera control circuit A 101 in the case where the camera control circuit A 101 transmits N bytes of data to the accessory control circuit 201.

[0118] In S3001, the camera control circuit A 101 stores a numerical value indicating the number of bytes to be transmitted in an internal variable N. For example, in the case of transmitting 3 bytes, 3 is stored. In this embodiment, 3 is stored.

[0119] In S3002, the camera control circuit A 101 changes SDA to a low level while SCL is at a high level (a START condition), thereby notifying the accessory control circuit 201 of the start of communication.

[0120] In S3003, the camera control circuit A 101 sets slave address information indicating the slave address of the accessory control circuit 201 to the upper 7 bits of the transmission data. In this embodiment, it is assumed that the slave address of the accessory control circuit 201 is 1010000 in binary.

[0121] In S3004, the camera control circuit A 101 sets information indicating write communication to the lower 1 bit of the transmission data. Setting this bit to 0 means write communication.

[0122] In S3005 , the camera control circuit A 101 transmits the data set as transmission data in S3003 and S3004 (10100000 in binary and 0xA0 in hexadecimal) to the accessory control circuit 201 .

[0123] In S3006, after transmitting one byte of data, the camera control circuit A 101 outputs SCL for one clock cycle and checks the signal level of SDA. If the signal level of SDA is low, it is determined to be a data reception notification (ACK) from the accessory control circuit 201, and the flow proceeds to S3007. On the other hand, if the signal level of SDA is high, it is determined that the accessory control circuit 201 has not received the data normally, and the flow proceeds to S3014.

[0124] In S3007, the camera control circuit A 101 sets, to the transmission data, storage address information (start address information) of data to be transmitted to the accessory control circuit 201. In the present embodiment, the size of the start address information is 1 byte, and the value is 0x00.

[0125] In S3008 , the camera control circuit A 101 sends the set 1-byte start address information (value 0x00) to the accessory control circuit 201 .

[0126] In S3009, after transmitting the 1-byte start address information data, the camera control circuit A 101 outputs SCL for one clock cycle and checks the signal level of SDA. If the signal level of SDA is low, it is determined that the accessory control circuit 201 has received a data reception notification (ACK), and the process proceeds to S3010. On the other hand, if the signal level of SDA is high, it is determined that the accessory control circuit 201 has not received the data normally, and the process proceeds to S3014.

[0127] In S3010, the camera control circuit A 101 stores 1 in the internal variable M. The internal variable M is a variable for counting the number of transmission data.

[0128] In S3011, the camera control circuit A 101 outputs 1-byte SCL and changes SDA to a desired signal level while SCL is at a low level to output 1-byte data to the accessory control circuit 201. Here, the start address information is 0x00 and the internal variable M is 1, so 1-byte data corresponding to address 0x00 is transmitted.

[0129] In S3012, after transmitting one byte of data, the camera control circuit A 101 outputs SCL for one clock cycle and checks the signal level of SDA. If the signal level of SDA is low, it is determined to be a data reception notification (ACK) from the accessory control circuit 201, and the flow proceeds to S3013. On the other hand, if the signal level of SDA is high, it is determined that the accessory control circuit 201 has not received the data normally, and the flow proceeds to S3014.

[0130] In S3013, the camera control circuit A 101 checks whether the internal variable M has the same value as the internal variable N. If the internal variable M has the same value as the internal variable N, it is determined that all data has been sent, and the flow proceeds to S3014. If the internal variable M is not the same value as the internal variable N, it is determined that there is still data to be sent, and the flow proceeds to S3015.

[0131] In S3015, the camera control circuit A 101 adds 1 to the internal variable M, and the flow returns to S3011.

[0132] Therefore, after the flow returns to S3011, the camera control circuit A 101 sequentially increments the address of the data to be transmitted and transmits 1-byte data corresponding to each address. In this way, the camera control circuit A 101 repeatedly transmits 1-byte data until the internal variables M and N have the same value in the process of S3013, thereby transmitting N bytes of data to the accessory control circuit 201. When the internal variable N is set to 3 as in this embodiment, 3 bytes of data can be transmitted.

[0133] In S3014, the camera control circuit A 101 changes SDA to a high level (STOP condition) while SCL is at a high level, thereby notifying the accessory control circuit 201 of the end of communication.

[0134] Figure 17 The flowchart in exemplifies processing to be performed by the camera control circuit A 101 in a case where the camera control circuit A 101 receives N-byte data from the accessory control circuit 201.

[0135] In S3101, the camera control circuit A 101 stores a numerical value indicating the number of bytes to be received in an internal variable N. For example, when 3-byte data is received, 3 is stored. In this embodiment, 3 is stored.

[0136] In S3102 to S3106, the camera control circuit A 101 performs the same processing as S3002 to S3006, respectively, and thus description thereof will be omitted.

[0137] In S3107, the camera control circuit A 101 sets, to the transmission data, the storage address information (start address information) of the data received from the accessory control circuit 201. In the present embodiment, the size of the start address information is 1 byte, and the value is 0x00.

[0138] In S3108 , the camera control circuit A 101 sends the set 1-byte start address information (value 0x00) to the accessory control circuit 201 .

[0139] In S3109, after transmitting the 1-byte start address information data, the camera control circuit A 101 outputs SCL for one clock and checks the signal level of SDA. If the signal level of SDA is low, it is determined that the accessory control circuit 201 has received a data reception notification (ACK), and the process proceeds to S3110. On the other hand, if the signal level of SDA is high, it is determined that the accessory control circuit 201 has not received the data normally, and the process proceeds to S3122.

[0140] In S3110 , as in S3102 , the camera control circuit A 101 changes SDA to low level while SCL is at high level, and notifies the accessory control circuit 201 of the start condition.

[0141] In S3111, the camera control circuit A 101 sets slave address information indicating the slave address of the accessory control circuit 201 to the upper 7 bits of the transmission data. In this embodiment, it is assumed that the slave address of the accessory control circuit 201 is 1010000 in binary.

[0142] In S3112, the camera control circuit A 101 sets information indicating read communication to the lower 1 bit of the transmission data. Setting this bit to 1 means read communication.

[0143] In S3113 , the camera control circuit A 101 transmits the data set as transmission data in S3003 and S3004 (10100001 in binary and 0xA1 in hexadecimal) to the accessory control circuit 201 .

[0144] In S3114, after transmitting one byte of data, the camera control circuit A 101 outputs SCL for one clock cycle and checks the signal level of SDA. If the signal level of SDA is low, it is determined to be a data reception notification (ACK) from the accessory control circuit 201, and the process proceeds to S3115. On the other hand, if the signal level of SDA is high, it is determined that the accessory control circuit 201 has not received the data normally, and the process proceeds to S3122.

[0145] In S3115, the camera control circuit A 101 stores 1 in the internal variable M. The internal variable M is a variable for counting the number of received data.

[0146] At S3116, the camera control circuit A 101 outputs 1-byte SCL and reads the signal level of SDA at the timing when SCL changes from low level to high level. This configuration enables reception of 1-byte data from the accessory control circuit 201. The received 1-byte data can be stored in the volatile memory 125 as data corresponding to address 0x00 or used for predetermined processing.

[0147] In S3117, the camera control circuit A 101 determines whether the 1-byte data has been received normally. If the data has been received normally, the flow proceeds to S3118. If the data has not been received normally, the flow proceeds to S3119.

[0148] In S3118, the camera control circuit A 101 checks whether the internal variable M has the same value as the internal variable N. If the internal variable M has the same value as the internal variable N, it is determined that reception of all data has been completed, and the flow proceeds to S3119. If the internal variable M does not have the same value as the internal variable N, it is determined that there is still data to be received, and the flow proceeds to S3120.

[0149] In S3120, the camera control circuit A 101 provides a data reception notification (ACK) to the accessory control circuit 201, and notifies the accessory control circuit 201 of continuous data communication by outputting 1-byte SCL and by performing control for changing SDA to the low level.

[0150] In S3121, the camera control circuit A 101 adds 1 to the internal variable M, and the flow returns to S3116.

[0151] Therefore, after the process returns to S3116, the camera control circuit A 101 sequentially increments the address of the data to be received and receives 1-byte data corresponding to each address. In this way, the camera control circuit A 101 receives N-byte data from the accessory control circuit 201 by repeatedly receiving 1-byte data until the internal variables M and N have the same value in the process of S3118. When the internal variable N is set to 3 as in this embodiment, 3-byte data can be received.

[0152] In S3119, the camera control circuit A 101 outputs SCL of 1 byte, and performs control for changing SDA to the high level to notify the accessory control circuit 201 of data communication completion (NACK).

[0153] In S3122, the camera control circuit A 101 changes SDA to a high level (stop condition) while SCL is at a high level, thereby notifying the accessory control circuit 201 of the end of communication.

[0154] Figure 18A and Figure 18B The flowchart in exemplifies processing to be performed by the accessory control circuit 201 when the camera control circuit A 101 transmits N-byte data to the accessory control circuit 201 and when the camera control circuit A 101 receives N-byte data from the accessory control circuit 201.

[0155] In S3201, the accessory control circuit 201 waits for SDA to change to a low level (a start condition) while SCL is at a high level. When the accessory control circuit 201 detects the start condition, the flow proceeds to S3202.

[0156] In S3202, the accessory control circuit 201 stores 0 in the internal variable M. The internal variable M is a variable for counting the number of transmission data and the number of reception data.

[0157] In S3203, the accessory control circuit 201 receives the 1-byte data transmitted from the camera control circuit A 101.

[0158] In S3204, the accessory control circuit 201 determines whether the upper 7 bits of the 1-byte data received in S3203 match the slave device address (0x50 in this embodiment) of the accessory control circuit 201. If the address matches the slave device address of the accessory control circuit 201, the process proceeds to S3205. If the address does not match the slave device address of the accessory control circuit 201, the process proceeds to S3221.

[0159] In S3205, the accessory control circuit 201 provides a data reception notification (ACK) to the camera control circuit A 101 by performing control for changing SDA to the low level for the next SCL clock output after receiving 1 byte of data.

[0160] In S3206, the accessory control circuit 201 determines the type of data to be used for the next 1-byte communication based on the lower-order bit of the 1-byte data received in S3203. If the lower-order bit is 0, the data to be communicated in the next 1-byte communication is determined to be start address information from the camera control circuit A 101 to the accessory control circuit 201, and the flow proceeds to S3207. If the lower-order bit is 1, the data to be communicated in the next 1-byte communication is determined to be transmission data from the accessory control circuit 201 to the camera control circuit A 101, and the flow proceeds to S3209.

[0161] In S3207, the accessory control circuit 201 receives 1-byte data transmitted from the camera control circuit A 101. The received 1-byte data is information indicating the address where data to be transmitted and received in subsequent communication is stored. Figure 16 and Figure 17 As described above, it is assumed that the start address information is 0x00.

[0162] On the other hand, in S3209, the accessory control circuit 201 uses address information stored in advance in the accessory control circuit 201 or address information notified in advance from the camera control circuit A 101 for the start address information.

[0163] In S3208, if the accessory control circuit 201 determines that the 1-byte data can be received normally, the flow proceeds to S3210. If it determines that the 1-byte data cannot be received normally, the flow proceeds to S3221.

[0164] In S3210, the accessory control circuit 201 provides a data reception notification (ACK) to the camera control circuit A 101 by performing control for changing SDA to the low level for the next SCL clock output after receiving 1 byte of data.

[0165] In S3211, the accessory control circuit 201 checks whether SDA has changed to a low level while SCL is at a high level (a start condition). If the accessory control circuit 201 detects the start condition, the accessory control circuit 201 determines that the next 1-byte data to be communicated is data indicating the slave device address and communication type, to be transmitted from the camera control circuit A 101 to the accessory control circuit 201. The flow then proceeds to S3212. If the accessory control circuit 201 does not detect the start condition, the accessory control circuit 201 determines that the next 1-byte data to be communicated is data information received by the accessory control circuit 201 from the camera control circuit A 101. The flow then proceeds to S3216.

[0166] In S3212, the accessory control circuit 201 receives the 1-byte data transmitted from the camera control circuit A 101.

[0167] In S3213, the accessory control circuit 201 determines whether the upper 7 bits of the 1-byte data received in S3212 match the slave address of the accessory control circuit 201 (0x50 in this embodiment). If the upper 7 bits match the slave address of the accessory control circuit 201, the process proceeds to S3214. If the upper 7 bits do not match the slave address of the accessory control circuit 201, the process proceeds to S3221.

[0168] In S3214, the accessory control circuit 201 determines the data type used for the next 1-byte communication based on the lower-order bit of the 1-byte data received in S3203. If the lower-order bit is 0, the flow proceeds to S3221. If the lower-order bit is 1, it is determined that the next 1-byte communication data is transmission data from the accessory control circuit 201 to the camera control circuit A101, and the flow proceeds to S3215.

[0169] In S3215, the accessory control circuit 201 provides a data reception notification (ACK) to the camera control circuit A 101 by performing control for changing SDA to the low level for the next SCL clock output after receiving 1 byte of data.

[0170] In S3222, the accessory control circuit 201 transmits 1-byte data corresponding to the start address information received from the camera control circuit A 101 in S3207 or the start address information determined in S3209 to the camera control circuit A 101.

[0171] In S3223, the accessory control circuit 201 adds 1 to the internal variable M, and the flow proceeds to S3224.

[0172] In S3224, after transmitting 1 byte of data, the accessory control circuit 201 checks the signal level of SDA. If the signal level of SDA is high, the camera control circuit A 101 determines that this is a notification (NACK) that all data has been received, and the process proceeds to S3225. On the other hand, if the signal level of SDA is low, the camera control circuit A 101 is determined to continue requesting data transmission from the accessory control circuit 201, and the process returns to S3222. Therefore, after the process returns to S3222, the accessory control circuit 201 sequentially increments the address of the data to be transmitted and transmits 1 byte of data corresponding to each address. Thus, by repeatedly transmitting 1 byte of data from the camera control circuit A 101 until a NACK is received in the process of S3224, the accessory control circuit 201 transmits N bytes of data to the camera control circuit A 101.

[0173] In S3225, the accessory control circuit 201 waits for a stop condition in which SDA changes to a high level while SCL is at a high level. When the accessory control circuit 201 detects the stop condition, communication is terminated.

[0174] On the other hand, in S3216, the accessory control circuit 201 receives 1-byte data and stores the 1-byte data in a non-volatile memory not shown as data corresponding to the start address information received from the camera control circuit A 101 in S3207, or uses the 1-byte data for predetermined processing.

[0175] In S3217, the accessory control circuit 201 adds 1 to the internal variable M, and the flow proceeds to S3218.

[0176] In S3218, if the accessory control circuit 201 determines that the 1-byte data can be received normally, the process proceeds to S3219. If it determines that the 1-byte data cannot be received normally, the process proceeds to S3221.

[0177] In S3219, the accessory control circuit 201 provides a data reception notification (ACK) to the camera control circuit A 101 by performing control for changing SDA to the low level for the next SCL clock output after receiving 1 byte of data.

[0178] In S3230, the accessory control circuit 201 checks whether it has detected a stop condition, in which SDA changes to a high level while SCL is at a high level. If the accessory control circuit 201 detects a stop condition, the accessory control circuit 201 terminates communication. On the other hand, if the accessory control circuit 201 does not detect a stop condition, the accessory control circuit 201 determines that data will continue to be transmitted from the camera control circuit A 101 to the accessory control circuit 201. The flow then returns to S3216.

[0179] Therefore, after the process returns to S3216, the accessory control circuit 201 sequentially increments the address of the data to be received and receives 1-byte data corresponding to each address. By repeatedly receiving 1-byte data until the stop condition is notified in S3220, the accessory control circuit 201 receives N bytes of data from the camera control circuit A101.

[0180] Thus, the camera connector 141 includes a contact TC12 for a data signal using the I2C communication method, and a contact TC13 for a clock signal using the I2C communication method, which is arranged on one side of the contact TC12 for the data signal (adjacent to each other on one side). The camera connector 141 also includes a contact TC11 for a second input signal, a contact TC10 for an input selection signal using the SPI communication method, a contact TC09 for reception using the SPI communication method, a contact TC08 for transmission using the SPI communication method, a contact TC07 for a clock signal using the SPI communication method, a contact TC06 for a first input signal, and a contact TC05 for an output signal, which are arranged on the other side of the contact TC12 for the data signal (arranged in order from adjacent positions on the other side).

[0181] The accessory 200 stores accessory information in a nonvolatile memory not shown. The accessory information is information for allowing the camera 100 to recognize the type of the accessory 200 and specifications related to communication and operation (function) of the accessory 200. Figure 5 An example of accessory information is shown. The accessory information is mapped in the memory space at addresses 0x00 to 0x0F and can be read from the accessory 200 via I2C communication. The details of the accessory information will be described below. In the I2C communication according to this embodiment, a checksum value for the read data is added as the final data of the communication.

[0182] Connect to Figure 1The FNC1 signal of TC14, the FNC2 signal connected to TC15, the FNC3 signal connected to TC16, and the FNC4 signal connected to TC17 shown as communication contacts are functional signals whose functions vary depending on the type of attached accessory 200. For example, if accessory 200 is a microphone device, the signal communicated via TC15 is a signal related to voice data, and if accessory 200 is a flash device, the signal communicated via TC14 is a signal notifying light emission timing.

[0183] Depending on the type of accessory attached, signals implementing different functions can be communicated via the same contacts. For example, if accessory 200 is other than a lighting device, a synchronization signal for controlling a timing different from the lighting timing can be communicated via TC14. TC14 through TC17 correspond to function signal contacts. Communication using at least one of the function signal contacts will also be referred to as function signal communication. Function signal communication can be performed in parallel with I2C and SPI communications at a timing independent of I2C and SPI communications.

[0184] The accessory type as used herein means the above-mentioned microphone device, lighting device, etc. Accessories that achieve the same purpose (such as lighting with different performance, etc.) belong to the same type of accessories. Accessories that achieve different purposes (such as a microphone device and a lighting device, etc.) are different types of accessories. Functional signal communication is performed based on information acquired through I2C communication or SPI communication. TC18, which serves as a second ground contact, is also connected to GND, and similar to TC04, is a contact serving as a reference potential for the camera 100 and the accessory 200. The differential signal D2N connected to TC19 and the differential signal D2P connected to TC20 are data communication signals for data communication between the two in pairs, and are connected to the camera control circuit B102. For example, USB communication can be performed via TC19 and TC20.

[0185] TC21 is connected to GND and serves not only as a reference potential contact but also as a contact for controlling the wiring impedance of differential signals D2N and D2P. TC21 corresponds to the fourth ground contact. Contacts TC01, TC04, TC06, TC18, and TC21 are connected to, for example, the GND portion of a flexible printed circuit (FPC) substrate. The GND portion of the FPC substrate is secured to a metal member serving as the GND level for the camera 100 using screws or the like. The metal member serving as the GND level includes, for example, a coupling member that can couple with the accessory 200 in the accessory shoe portion, and a base plate (not shown) within the camera 100.

[0186] In this embodiment, the attachment detection contact TC06 to which the accessory attachment detection signal / ACC_DET is connected is arranged in close proximity to the contact (first clock contact) TC07 that transmits the clock signal SCLK (first clock signal). Typically, noise (clock noise) associated with potential fluctuations in the clock signal is transmitted to contacts adjacent to the contacts of the clock signal, which can cause malfunctions. This effect is particularly significant in configurations with many contacts and short distances between them, as in this embodiment. Therefore, by arranging the attachment detection contact TC06 in close proximity to the SCLK contact TC07, the influence of clock noise can be suppressed.

[0187] The accessory attachment detection signal / ACC_DET is pulled up before an accessory is attached, but is set to GND potential after the accessory is attached. On the other hand, before the accessory is attached, the SCLK contact TC07 for transmitting a clock signal does not transmit a clock signal, so the potential does not fluctuate. Only after the accessory is attached does the potential fluctuate due to the transmission of a clock signal.

[0188] While the SCLK contact TC07 is transmitting a clock signal, the attachment detection contact TC06 is at GND potential. Therefore, even if the attachment detection contact TC06 receives clock noise, the potential of the control circuits of the camera 100 and accessory 200 is unlikely to fluctuate, thereby preventing malfunctions. Furthermore, clock noise can be prevented from being transmitted to locations farther than the accessory detection contact TC06. Consequently, there is no need to provide a GND terminal, thus suppressing the effects of clock noise without increasing the number of contacts.

[0189] The clock signal SCL (second clock signal) is also transmitted to the contact (second clock contact) TC13. However, the SCLK signal transmitted to the SCLK contact TC07 has a higher frequency than the SCL signal, and the SCLK contact TC07 generates more clock noise than the SCL contact TC13. Therefore, arranging the attachment detection contact TC06 next to the SCLK contact TC07 rather than the SCL contact TC13 is more effective in preventing malfunctions caused by clock noise.

[0190] In addition to the frequency difference, the SCL signal sent by the SCL contact TC13 is a clock signal of the I2C communication standard, and the voltage fluctuation of the signal line is driven by an open-drain connection. On the other hand, the SCLK signal sent by the SCLK contact TC07 is a clock signal of the SPI communication standard, and the voltage fluctuation of the signal line is driven by a CMOS output. Therefore, compared with the edge of the voltage fluctuation of the SCLK contact TC07, the edge of the voltage fluctuation of the SCL contact TC13 tends to be smoother, and clock noise is less likely to occur. Therefore, arranging the attachment detection contact TC06 next to the SCLK contact TC07 rather than next to the SCL contact TC13 is more effective in preventing malfunctions caused by clock noise.

[0191] Differential signals D1N and D1P can be sent as a pair to the first differential signal contact TC19 and the second differential signal contact TC20 to transmit a clock signal. In this case, a clock signal (third clock signal) having a higher frequency than that of the SCLK contact TC07 and the SCL contact TC13 can be transmitted. However, since the differential signals D1N and D1P are paired signals, clock noise emission is smaller than that of the SCLK contact TC07 and the SCL contact TC13 transmitting a single-ended signal. Therefore, it is more effective to prevent malfunctions caused by clock noise by arranging the attachment detection contact TC06 next to the SCLK contact TC07 rather than next to the first differential signal contact TC19 and the second differential signal contact TC20.

[0192] Contact (first data contact) TC08, located next to SCLK contact TC07 on the opposite side of attachment detection contact TC06, transmits MOSI (first data signal). Since MOSI is a data signal, it would appear to be susceptible to clock noise. However, MOSI is a data signal of the SPI communication standard, identical to the clock signal transmitted by SCLK contact TC07. Therefore, the timing of potential fluctuations is synchronized with the clock signal and is less likely to be affected by clock noise. Therefore, contact TC08 does not need to be fixed to the GND potential and can be used as a MOSI contact.

[0193] The accessory 200 has a battery 205 and receives power from the battery 205, and also receives power from the camera 100 via the camera connector 141 and the accessory connector 211. The accessory control circuit 201, which is an accessory processing unit in the accessory 200, is a circuit that controls the entire accessory 200 and includes a processor (microcomputer) such as a CPU. The accessory control circuit 201 performs various controls and processes in accordance with a computer program.

[0194] The accessory power supply circuit 202 generates power for supplying various circuits in the accessory 200 and includes a DC / DC converter circuit, an LDO, a charge pump circuit, and the like. The 1.8V voltage generated by the accessory power supply circuit 202 is constantly supplied to the accessory control circuit 201 as the accessory microcomputer power supply VMCU_A. The voltage generated by the accessory power supply circuit 202 may be different from 1.8V. Control of the accessory power supply circuit 202 allows for on / off control of the power supply to various circuits in the accessory 200.

[0195] The charging circuit 204 is a circuit that charges the battery 205 using power supplied from the camera 100. When the accessory control circuit 201 can determine that sufficient power is supplied from the camera 100 for a charging operation, the accessory control circuit 201 controls the charging circuit 204 to charge the battery 205. In the present embodiment, the battery 205 is attached to the accessory 200, but the accessory 200 can operate only with power supplied from the camera 100 without the battery 205 attached. In this case, the charging circuit 204 is unnecessary.

[0196] The differential communication circuit 207 is a circuit for performing differential communication with the camera 100, and can communicate data with the camera 100. The external communication IF circuit 208 is an IF circuit for performing data communication with an external device (not shown), such as an Ethernet communication IF, a wireless LAN communication IF, and a public network communication IF. The accessory control circuit 201 controls the differential communication circuit 207 and the external communication IF circuit 208 to transmit data received from the camera 100 to the external device, and to transmit data received from the external device to the camera 100.

[0197] Functional circuit 206 has different functions depending on the type of accessory 200. If accessory 200 is a flash device, functional circuit 206 may be, for example, a lighting circuit or a charging circuit. If accessory 200 is a microphone device, functional circuit 206 may be, for example, a voice codec circuit or a microphone circuit.

[0198] The external connection terminal 209 is a connector terminal for connecting to an external device and, in this embodiment, is a USB Type-C connector. The connection detection circuit 210 is a circuit for detecting that an external device has been connected to the external connection terminal 209. The accessory control circuit 201 can detect the connection of an external device to the external connection terminal 209 by receiving an output signal from the connection detection circuit 210.

[0199] The power switch 203 is a switch operable by a user to turn on and off the power (ie, operation) of the accessory 200. The accessory control circuit 201 can detect the on position and the off position by reading the signal level of the terminal to which the power switch 203 is connected.

[0200] The operation switch 212 is a switch that can be operated by the user to give various instructions to the accessory 200 and perform various settings, and includes a button, a cross key, a slide switch, a dial switch, a touch sensor, etc. When the operation switch 212 is operated, the accessory control circuit 201 detects the operation and executes predetermined processing according to the operation.

[0201] The accessory connector 211 is a connector electrically connectable to the camera 100 via 21 contacts TA01 to TA21 arranged in a row. The contacts TA01 to TA21 are arranged in order of the contacts TA01 to TA21 from one end to the other end in the arrangement direction.

[0202] TA01 is connected to GND and serves not only as a reference potential contact but also as a contact for controlling wiring impedance of differential signals D1N and D1P. TA01 corresponds to a third ground contact.

[0203] The differential signal D1N connected to TA02 and the differential signal D1P connected to TA03 are data communication signals for data communication between the two in pairs, and are connected to the differential communication circuit 207. TA02, TA03, TA07 to TA10, TA12 to TA17, TA19, and TA20 described below are communication contacts.

[0204] TA04, which is a first ground contact, is connected to GND and serves as a reference potential contact for the camera 100 and the accessory 200. TA04 is arranged outside TA05 described below in the arrangement direction of the contacts.

[0205] The accessory power supply circuit 202 and the charging circuit 204 are connected to TA05 as a power supply contact, and the accessory power supply VACC supplied from the camera 100 is connected to TA05 .

[0206] TA06, which serves as an attachment detection contact, is directly connected to GND. When the accessory 200 is attached to the camera 100, the accessory control circuit 201 sets the accessory attachment detection signal / ACC_DET to a low level (GND potential) as an activation potential. This allows the camera 100 to detect the attachment of the accessory 200.

[0207] SCLK connected to TA07 as a communication contact, MOSI connected to TA08, MISO connected to TA09, and CS connected to TA10 are signals for the accessory control circuit 201 to perform SPI communication as a communication slave.

[0208] A communication request signal / WAKE for requesting communication from the accessory control circuit 201 to the camera 100 is connected to TA11, which is a signal contact (communication request contact). When the accessory control circuit 201 determines that communication with the camera 100 is necessary, the accessory control circuit 201 changes the communication request signal / WAKE from a high level to a low level to request communication from the camera 100.

[0209] When power is supplied from the camera control circuit 101 to the accessory 200 via TC5 in response to detecting attachment of the accessory 200, the accessory control circuit 201 notifies the camera control circuit 101 that power has been received by changing the signal level of the communication request signal / WAKE (by changing the potential of the communication request signal / WAKE) from a high level to a low level.

[0210] Even if there is no request from the camera, the accessory control circuit 201 can notify the presence of a factor causing the accessory 200 to communicate with the camera 100 by changing the signal level (potential) of the communication request signal / WAKE from a high level to a low level. With this configuration, the camera control circuit 101 can omit the operation of periodically checking whether the accessory 200 has a factor requiring communication through polling. When a communication requiring factor occurs, the accessory 200 can communicate with the camera 100 in real time.

[0211] SDA connected to TA12 as a communication contact and SCL connected to TA13 are signals for the accessory control circuit 201 to perform I2C communication as a communication slave.

[0212] Therefore, the accessory connector 211 includes a contact TA12 for a data signal using the I2C communication method, and a contact TA13 for a clock signal using the I2C communication method, which is arranged on one side of the contact TA12 for the data signal (adjacent to the contact TA12 for the data signal on one side). The accessory connector 211 also includes, on the other side of the contact TA12 for the data signal (in order from the position adjacent to the contact TA12 for the data signal on the other side), a contact TA11 for a second input signal, a contact TA10 for an input select signal using the SPI communication method, a contact TA09 for transmission using the SPI communication method, a contact TA08 for reception using the SPI communication method, a contact TA07 for a clock signal using the SPI communication method, a contact TA06 for a first input signal, and a contact TA06 for an output signal.

[0213] The FNC1 signal connected to TA14 as a communication contact (function signal contact), the FNC2 signal connected to TA15, the FNC3 signal connected to TA16, and the FNC4 signal connected to TA17 are function signals whose functions are variable depending on the type of accessory 200. For example, in the case where the accessory 200 is a microphone device, these signals may be signals related to voice data, and in the case where the accessory 200 is a flash device, these signals may be signals for notifying light emission timing.

[0214] TA18, serving as a second ground contact, is also connected to GND and, similar to TA04, serves as a reference potential contact for the camera 100 and the accessory 200. A differential signal D2N connected to TA19 and a differential signal D2P connected to TA20 are data communication signals for data communication between the two in pairs, and are connected to an external connection terminal 209.

[0215] TA21 is connected to GND and can be used not only as a reference potential contact but also as a terminal for controlling the wiring impedance of the differential signals D2N and D2P. TA21 corresponds to a fourth ground contact.

[0216] The contacts TA01, TA04, TA06, TA18, and TA21 are connected to, for example, a GND portion of an FPC board, and the GND portion of the FPC board is fixed with unillustrated screws to a metal member serving as a GND level for the accessory 200. The metal member serving as the GND level includes, for example, a shoe attachment leg engageable with the accessory shoe portion of the camera 100, a bottom plate (unillustrated) inside the accessory 200, and the like.

[0217] Figure 6A processing sequence to be performed when the accessory 200 is attached to the camera 100 is illustrated. An overview of each of the processing of the camera 100 (camera control circuits A 101 and B 102) and the accessory 200 (accessory control circuit 201) will now be described, and details will be described below.

[0218] When the accessory 200 is attached to the camera 100, the accessory attachment detection signal / ACC_DET becomes low. Consequently, the camera control circuit A 101 determines that the accessory 200 is attached to the camera 100. Having determined that the accessory 200 is attached, the camera control circuit A 101 sets the power control signal CNT_VACC1 to high to turn on the output of the accessory power circuit A 131. When the power control signal CNT_VACC1 becomes high, the accessory power circuit A 131 outputs the accessory power VACC.

[0219] Upon receiving VACC, the accessory power supply circuit 202 generates power supply VMCU_A for the accessory control circuit 201. This activates the accessory control circuit 201. The activated accessory control circuit 201 initializes each block in the accessory 200. Thereafter, when the accessory control circuit 201 is ready to communicate with the camera 100, the accessory control circuit 201 sets the communication request signal / WAKE to a low level.

[0220] When the communication request signal / WAKE is at a low level, the camera control circuit A 101 detects that the accessory 200 is in a communicable state. The camera control circuit A 101 requests the accessory 200 to communicate accessory information via I2C communication. Upon receiving the accessory information request, the accessory control circuit 201 transmits the accessory information to the camera control circuit A 101. Having transmitted the accessory information, the accessory control circuit 201 sets the communication request signal / WAKE to a high level.

[0221] The camera control circuit A 101 determines whether the attached accessory is controllable based on the received accessory information. The camera control circuit A 101 turns on the accessory power circuit B 132. The camera control circuit A 101 then performs various settings for the camera 100 and, upon completing these settings, notifies the camera control circuit B 102 of the accessory information.

[0222] The camera control circuit B 102 notifies the accessory 200 of a control command (accessory control communication) or performs control corresponding to a function signal (function signal control) based on the notified accessory information via SPI communication.

[0223] The accessory control circuit 201 responds to control commands from the camera 100 through SPI communication, and operates according to function signals.

[0224] Now we will explain Figure 5 The data of D7-D0 at address 0x00 is information indicating the type of the accessory (hereinafter referred to as accessory type information). Figure 7 Examples of accessory type information are shown below. For example, 0x81 indicates a flash device, 0x82 indicates an interface conversion adapter device, 0x83 indicates a microphone device, and 0x84 indicates a multi-accessory connection adapter device for attaching multiple accessory devices to the camera 100.

[0225] An adapter device is an intermediate accessory that is attached between the camera 100 and accessories such as a flash unit and a microphone unit. When the interface of the camera 100 and the interface of the accessory differ, the adapter device converts the interfaces to improve compatibility between the camera 100 and the accessory. A multi-accessory connection adapter device is an adapter device to which multiple accessories can be attached.

[0226] Figure 5 The data D7-D0 at address 0x01 in the is information indicating the model (type) of the accessory 200. The type and model of the accessory can be identified by the above-mentioned accessory type information and this information.

[0227] The data D7 to D0 at address 0x02 is information indicating the firmware version of the accessory 200 .

[0228] Data D7-D6 at address 0x03 is specification information indicating whether or not the accessory power supply VACC is requested to the accessory 200 when the power switch (not shown) of the camera 100 is off. If this information is 0, no power supply is requested. If this information is 1, the accessory power supply circuit A 131 requests power supply. If this information is 2, the accessory power supply circuit B 132 requests power supply.

[0229] The data D5-D4 at address 0x03 is specification information (hereinafter referred to as auto-power-off power supply required / unrequired information) indicating whether the accessory power source VACC is requested from the accessory 200 when the camera 100 is in a power saving state (hereinafter referred to as the auto-power-off state) due to the auto-power-off function. The camera 100 has an auto-power-off function to save power. This auto-power-off function automatically shuts off power when a non-operating state without any operation continues for a predetermined period of time. If this information is 0, it means that power supply is not required. If this information is 1, it means that power supply is requested by the accessory power supply circuit A 131. If this information is 2, it means that power supply is requested by the accessory power supply circuit B 132.

[0230] The D3-D2 data at address 0x03 is specification information indicating whether the accessory 200 has the battery 205. When this information is 0, it means that the accessory 200 does not have a battery, and when this information is 1, it means that the accessory 200 has a battery.

[0231] The D1-D0 data at address 0x03 is specification information indicating whether the accessory 200 has a charging function for the battery 205. If this information is 0, it means that the accessory 200 does not have a charging function, and if this information is 1, it means that the accessory 200 has a charging function.

[0232] The D7-D0 data at address 0x04 is information indicating the specifications of the power required by the accessory power supply VACC supplied from the camera 100 to the accessory 200. For example, the value obtained by multiplying this information by 10 represents the current value. If this information is 10, it means 100 mA, and if it is 100, it means 1 A. To reduce the amount of information, this information can be simply associated with the current value. For example, if this information is 0, it can mean 100 mA, if it is 1, it can mean 300 mA, if it is 3, it can mean 450 mA, and if it is 4, it can mean 600 mA.

[0233] The D7 data at address 0x05 is specification information indicating whether the accessory 200 is in firmware update mode. If this information is 0, it means that the accessory 200 is not in firmware update mode, and if this information is 1, it means that the accessory 200 is in firmware update mode.

[0234] The D6 data at address 0x05 is specification information indicating whether the accessory 200 has a firmware update function. If this information is 0, it means that the accessory 200 does not have a firmware update function. If this information is 1, it means that the accessory 200 has a firmware update function.

[0235] The D5-D4 data at address 0x05 is specification information indicating whether the operation of the accessory 200 attached to the intermediate (connection) accessory is permitted. If this information is 0, it means that the operation is not permitted, and if this information is 1, it means that the operation is permitted.

[0236] The D3-D2 data at address 0x05 is specification information indicating whether the accessory 200 requires the camera 100 to confirm the connection of the intermediate accessory when the camera 100 is activated. If this information is 0, it means that confirmation is unnecessary, and if this information is 1, it means that confirmation is necessary.

[0237] The D1-D0 data at address 0x05 is specification information indicating whether the accessory 200 supports command notification via I2C communication. If this information is 0, it means command notification is not supported, and if this information is 1, it means command notification is supported.

[0238] The data D5-D4 at address 0x06 is specification information indicating the communication request factor acquisition method (the communication method used: hereinafter referred to as the factor acquisition method), which is a communication method that can be used to notify the camera 100 of the generation factor of the communication request after the accessory 200 notifies the camera 100 of the communication request signal / WAKE. If this information is 0, it means that the I2C communication method is the factor acquisition method. If this information is 1, it means that the SPI communication method is the factor acquisition method. If this information is 2, it means that both the I2C communication method and the SPI communication method are the factor acquisition methods.

[0239] The D3-D0 data at address 0x06 is specification information indicating whether accessory 200 has the functions corresponding to the FNC1 signal (function signal 1), the FNC2 signal (function signal 2), the FNC3 signal (function signal 3), and the FNC4 signal (function signal 4). D0 data corresponds to the FNC1 signal, D1 data corresponds to the FNC2 signal, D2 data corresponds to the FNC3 signal, and D3 data corresponds to the FNC4 signal. If this value is 0, it means that accessory 200 does not have the function. If this value is 1, accessory 200 has the function.

[0240] The D7 data at address 0x0A is specification information indicating whether the accessory 200 requests activation of the camera 100 when notifying the camera 100 of the communication request signal / WAKE. If this information is 0, activation is requested, and if it is 1, activation is not requested.

[0241] The data D6-D0 at the address 0x0A is information indicating a generation factor of the communication request signal / WAKE that the accessory 200 notifies the camera 100 of.

[0242] Figure 8 An example of a factor for generating a communication request signal / WAKE (hereinafter also referred to as a communication request factor) is illustrated. Here, an example is shown in the case where the accessory 200 is a microphone device. For example, factor number 0x00 is a number indicating that the menu call switch in the operation switch 212 has been operated (pressed). Factor number 0x01 is a number indicating that the accessory 200 has completed output control of the audio signal. Factor number 0x02 is a number indicating that the accessory 200 has completed mute processing (unmuting) of the audio signal. As described above, in this embodiment, information related to the communication request factor (number) used as information related to the generation factor of the communication request signal / WAKE can be notified (sent) from the accessory 200 to the camera 100 as accessory information.

[0243] exist Figure 5 In the example, the D1 data at address 0x0C represents the specification information of the SPI communication protocol supported by accessory 200, and when the information is 0, it means that accessory 200 supports SPI protocol A, and when the information is 1, it means that accessory 200 supports SPI protocol B.

[0244] The D0 data at address 0x0C is specification information indicating the CS control logic of the SPI communication supported by the accessory 200. When this information is 0, it means that CS is low active logic, and when this information is 1, it means that CS is high active logic.

[0245] The D7-D0 data at address 0x0D is specification information indicating the time required as a communication byte interval when the accessory 200 communicates according to SPI protocol A and the D7 data at address 0x05 is 0 or the accessory 200 is not in firmware update mode.

[0246] The D7-D0 data at address 0x0E is specification information indicating the time required as a communication byte interval when the accessory 200 communicates according to SPI protocol A and the D7 data at address 0x05 is 1 or the accessory 200 is in firmware update mode.

[0247] Figure 9A and Figure 9B The time (communication interval) of the communication byte interval corresponding to the data (0 to 7) at addresses 0x0D and 0x0E is illustrated. Figure 9A illustrates the communication interval for data at address 0x0D, and Figure 9B The communication interval for data at address 0x0E is illustrated.

[0248] exist Figure 5 , the data at address 0x0F is data indicating a checksum value of the sum of the values ​​at addresses 0x00 to 0x0E.

[0249] Figure 10 The startup process to be executed by the camera control circuit A 101 until the accessory 200 is attached to the camera 100 and the function of the accessory 200 is enabled is illustrated.

[0250] In S401, the camera control circuit A 101 monitors the signal level of the accessory attachment detection signal (first input signal) / ACC_DET and determines (detects) whether the accessory 200 is attached. If the signal level of the accessory attachment detection signal / ACC_DET is high, the camera control circuit A 101 determines that the accessory 200 is not attached, and the process returns to S401. Therefore, the camera control circuit A 101 again determines whether the accessory 200 is attached. If the signal level is low, the camera control circuit A 101 determines that the accessory 200 is attached, and the process proceeds to S402.

[0251] In S402, the camera control circuit A 101 controls the power control signal CNT_VACC1 to a high level to turn on the output of the accessory power circuit A 131. The flow then proceeds to S403. While the power control signal CNT_VACC1 is at a high level, the accessory power circuit A 131 outputs the accessory power (output signal) VACC.

[0252] In S403, the camera control circuit A 101 monitors the signal level of the overcurrent detection signal DET_OVC and determines whether an overcurrent is flowing. If the signal level of DET_OVC is low, the camera control circuit A 101 determines that no overcurrent is flowing, and the process proceeds to S404. If the signal level is high, the camera control circuit A 101 determines that an overcurrent is flowing, and the process proceeds to S405 for error processing.

[0253] In S404, the camera control circuit A 101 monitors the signal level of the communication request signal (second input signal) / WAKE, which is a notification signal from the accessory 200, and determines whether initialization of the accessory 200 is complete. If the signal level of the communication request signal / WAKE is low (active), the camera control circuit A 101 determines that initialization is complete, and the flow proceeds to S406. If the signal level is high, the camera control circuit A 101 determines that initialization is not yet complete, and the flow returns to S404, so that the camera control circuit A 101 again determines whether initialization is complete.

[0254] In S406, the camera control circuit A 101 performs I2C communication as initial communication with the accessory 200 and reads out 15 bytes of accessory information.

[0255] In S407, the camera control circuit A 101 determines, based on the accessory information read out in S406, whether the attached accessory 200 is a compatible device (compatible accessory) with the camera 100. If the camera control circuit A 101 determines that the attached accessory 200 is a compatible accessory, the flow proceeds to S408, and if the camera control circuit A 101 determines that the attached accessory 200 is not a compatible accessory, the flow proceeds to S409 to perform error processing.

[0256] In S408, the camera control circuit A 101 controls the power supply control signal CNT_VACC2 to a high level, thereby turning on the output of the accessory power supply circuit B 132. The flow then proceeds to S410. When the power supply control signal CNT_VACC2 is at a high level, the accessory power supply circuit B 132 outputs the accessory power supply VACC. In this embodiment, when both the power supply control signals CNT_VACC1 and CNT_VACC2 are at a high level, the output from the accessory power supply circuit B 132 is supplied to the accessory power supply VACC.

[0257] In S410, the camera control circuit A 101 notifies the camera control circuit B 102 of the accessory information read out in S406. Thus, the activation process of the camera 100 in response to the attachment of the accessory 200 is completed.

[0258] Figure 11 The flowchart in exemplifies activation processing to be performed by the camera control circuit B 102 until the accessory 200 is attached to the camera 100 and the function of the accessory 200 is activated.

[0259] In S501, the camera control circuit B 102 determines whether accessory information has been notified from the camera control circuit A 101. If accessory information has not been notified, the flow returns to S501, and the camera control circuit B 102 again determines whether accessory information has been notified. If accessory information has been notified, the flow proceeds to S502.

[0260] In S502, the camera control circuit B 102 sets function signals FNC1 to FNC4 based on the accessory information received from the camera control circuit A 101. For example, if the accessory 200 is a microphone device, FNC1 is set to function as the voice data clock signal BCLK, FNC2 is set to function as the voice data channel signal LRCLK, and FNC3 is set to function as the voice data signal SDAT. As another example, if the accessory 200 is a flash device, FNC4 is set to function as the flash emission synchronization signal XOUT. Function signals not required for controlling the accessory 200 are set to function as signals that do not interfere with the operation of the camera 100 or the accessory 200.

[0261] In S503 , the camera control circuit B 102 sets the CS control logic in the SPI communication based on the accessory information notified from the camera control circuit A 101 .

[0262] In S504, the camera control circuit B 102 determines whether a predetermined event has occurred for the accessory 200. If the event has not occurred, the flow returns to S504, and the camera control circuit B 102 determines again whether the event has occurred. If the event has occurred, the flow proceeds to S505.

[0263] In S505, the camera control circuit B 102 determines whether the event determined in S504 is an event requiring SPI communication with the accessory 200. If the event requires SPI communication, the flow proceeds to S506, otherwise the flow proceeds to S507.

[0264] In S507, the camera control circuit B 102 determines whether the event determined in S504 requires control of the accessory 200 using a function signal. If the event requires control using a function signal, the process proceeds to S508, otherwise the process proceeds to S509.

[0265] In S506, the camera control circuit B 102 performs SPI communication with the accessory 200. If the accessory 200 is a microphone device, the SPI communication performed here includes, for example, communication for instructing to turn on microphone operation, communication for instructing to turn off microphone operation, communication for instructing to switch the microphone's sound collection directionality, and communication for instructing to switch the microphone's equalizer function. If the accessory 200 is a flash device, the SPI communication includes communication for reading out setting information related to the flash device and communication for notifying the flash device of the setting information. Upon completion of the SPI communication in S506, the flow returns to S504, and the camera control circuit B 102 again determines whether an event has occurred.

[0266] In S508, the camera control circuit B 102 uses the function signal to control the accessory 200. For example, if the accessory 200 is a microphone device, the camera control circuit B 102 outputs the audio data clock signal BCLK of FNC1 and the audio data channel signal LRCLK of FNC2, and receives the audio data signal SDAT of FNC3. This allows the camera 100 to acquire voice data from the microphone device. If the accessory 200 is a flash device, the camera control circuit B 102 outputs the flash emission synchronization signal XOUT of FNC4 at a predetermined timing. This allows the camera 100 to instruct the flash device to fire. When control using the function signal is completed in this manner, the process returns to S504, and the camera control circuit B 102 again determines whether an event has occurred.

[0267] In S509, the camera control circuit B 102 performs predetermined in-camera control based on the event determined in S504. If the accessory 200 is a microphone device, the in-camera control includes, for example, control for starting or ending the recording of voice data in the recording memory 126, and control for performing equalizer processing on the voice data. If the accessory 200 is a flash device, the in-camera control includes, for example, photometry control for accumulating and acquiring light emitted by the flash device using the image sensor 122, and control for calculating an indication value of the flash device's light emission amount. When the in-camera control is thus completed, the flow returns to S504, and the camera control circuit B 102 again determines whether an event has occurred.

[0268] Through the above-described start-up processing by the camera control circuit A 101 and the activation processing by the camera control circuit B 102 , the accessory 200 attached to the camera 100 can be controlled.

[0269] Figure 12The flowchart in exemplifies processing to be executed by the accessory control circuit 201 from when the accessory 200 is attached to the camera 100 until when various functional operations of the accessory 200 are enabled.

[0270] In S601, the accessory control circuit 201 waits for the accessory power supply VACC from the camera 100 to be turned on. If the accessory 200 does not have the battery 205, the turning on of the accessory power supply VACC can be detected when power is supplied to the accessory control circuit 201 and the operation of the accessory control circuit 201 itself begins. If the accessory 200 has the battery 205, the accessory control circuit 201 can monitor the voltage value of the accessory power supply VACC to detect that the accessory power supply VACC has been turned on.

[0271] In S602, the accessory control circuit 201 performs predetermined initial settings. For example, the accessory control circuit 201 sets the operating frequency of the microcomputer, the input / output control port of the microcomputer, the initialization of the timer function of the microcomputer, and the initialization of the interrupt function of the microcomputer.

[0272] When the initial setting in S602 is completed, the accessory control circuit 201 controls the communication request signal / WAKE to a low level in S603 , thereby notifying the camera 100 of the completion of the initial setting.

[0273] In S604, the accessory control circuit 201 responds to the I2C communication from the camera 100 and sends 15 bytes of accessory information to the camera 100 as initial communication. The accessory information includes Figure 5 Various information displayed.

[0274] When the initial communication in S604 is completed, the accessory control circuit 201 controls the communication request signal / WAKE to a high level in S605.

[0275] In S606, the accessory control circuit 201 determines whether a predetermined event has occurred. If no event has occurred, the process returns to S606, and the accessory control circuit 201 determines again whether an event has occurred, and if an event has occurred, the process proceeds to S607.

[0276] In S607, the accessory control circuit 201 determines whether the event determined in S606 is an event requiring SPI communication with the camera 100. If the event requires SPI communication, the flow proceeds to S608, otherwise the flow proceeds to S609.

[0277] In S609, the accessory control circuit 201 determines whether the event determined in S606 is an event requiring I2C communication with the camera 100. If the event requires I2C communication, the flow proceeds to S610, otherwise the flow proceeds to S611.

[0278] In S611, the accessory control circuit 201 determines whether the event determined in S606 is an event that requires control using a function signal. If the event requires control using a function signal, the process proceeds to S612, otherwise the process proceeds to S613.

[0279] In S613, the accessory control circuit 201 determines whether the event determined in S606 is an event that needs to be notified to the camera 100 via the communication request signal / WAKE. If the event needs to be notified to the camera 100 via the communication request signal / WAKE, the flow proceeds to S614; otherwise, the flow proceeds to S615.

[0280] In S608, the accessory control circuit 201 performs SPI communication with the camera 100. If the communication request signal / WAKE is at a low level when the accessory control circuit 201 performs SPI communication, the accessory control circuit 201 performs control to change the communication request signal / WAKE to a high level after the SPI communication. If the accessory 200 is a microphone device, the SPI communication performed here includes, for example, communication of instructions from the camera 100 to turn on microphone operation, communication of instructions to turn off microphone operation, and communication of instructions to switch the microphone's sound collection directionality. This SPI communication also includes communication of instructions to switch the microphone's equalizer function. If the accessory 200 is a flash device, the SPI communication includes communication for reading out setting information related to the flash device and communication for notifying the flash device of the setting information. Upon completion of the predetermined SPI communication in S608, the process returns to S606, and the accessory control circuit 201 again determines whether an event has occurred.

[0281] In S610, the accessory control circuit 201 performs I2C communication with the camera 100. If the communication request signal / WAKE is at a low level during the I2C communication, control is performed to change the communication request signal / WAKE to a high level after the I2C communication. The I2C communication performed here includes, for example, communication to read the communication request factor of the communication request signal / WAKE that the accessory control circuit 201 has notified the camera 100. When the I2C communication in S610 is completed, the flow returns to S606, and the accessory control circuit 201 again determines whether an event has occurred.

[0282] In S612, the accessory control circuit 201 uses the function signal to control the camera 100. If the accessory 200 is a microphone device, the control performed here includes, for example, receiving and controlling the audio data clock signal BCLK of FNC1 and the audio data channel signal LRCLK of FNC2 output from the camera 100. This control also includes controlling the output of the voice data signal SDAT of FNC3 synchronized with these signals. If the accessory 200 is a flash device, this control includes receiving and controlling the flash emission synchronization signal XOUT of FNC4 and controlling the corresponding flash emission. Upon completion of the control using the function signal in S612, the process returns to S606, and the accessory control circuit 201 again determines whether an event has occurred.

[0283] In S614, the accessory control circuit 201 stores the communication request factor number to the camera 100 in response to the event determined in S606 in a volatile memory not shown in the accessory 200, and performs control for changing the communication request signal / WAKE to a low level. Figure 8 As shown, the communication request factor number is a unique number assigned to each factor content. When the low level control of the communication request signal / WAKE in S614 is completed, the flow returns to S606, and the accessory control circuit 201 determines again whether an event has occurred.

[0284] In S615, the accessory control circuit 201 performs in-accessory control based on the event determined in S606. If the accessory 200 includes a battery 205, the in-accessory control performed here includes control for detecting the remaining battery charge and control for detecting operation of the operating switch 212. When the in-accessory control in S615 is completed, the process returns to S606, and the accessory control circuit 201 again determines whether an event has occurred.

[0285] Through the above-described processing using the accessory control circuit 201 , after the accessory 200 is attached to the camera 100 , the accessory 200 can perform various functional operations.

[0286] Figure 13 Example Figure 6 In the processing sequence shown, the processing to be performed by the camera control circuits A 101 and B 102 when the accessory 200 is attached to the camera 100 before the camera 100 is powered on will be omitted. Figure 6 The processing is the same as the description of the processing.

[0287] In parallel with the accessory detection process using the accessory detection signal / ACC_DET, the camera control circuit A 101 supplies the camera microcomputer power supply VMCU2_C to the camera control circuit B, and powers on the camera control circuit B 102. Upon powering on, the camera control circuit B 102 performs its own initialization process and, upon completion of this initialization process, notifies the camera control circuit A 101 of the completion of preparation.

[0288] The camera control circuit 101A that has received the preparation completion notification notifies the camera control circuit B 102 of the accessory information acquired from the accessory 200 .

[0289] Through the above-described processing, the camera control circuit A 101 can execute the detection process of the attachment of the accessory 200 to the camera 100 and the activation process of the camera control circuit B 102 in parallel. Therefore, the activation time of the accessory 200 (i.e., the imaging system) can be shortened. In other words, the responsiveness at the time of activation can be improved.

[0290] Second embodiment

[0291] A second embodiment according to the present invention will be described. Figure 14A and Figure 14B Example Figure 6 In the processing sequence shown, the processing performed by the camera control circuits A 101 and B 102 when the accessory 200 is attached to the camera 100 in a state where the camera 100 is in a low power consumption mode (sleep mode) will be omitted. Figure 6 The processing is the same as the description in the .

[0292] exist Figure 14A In the case where the attachment of the accessory 200 is detected in the low power consumption mode, the camera control circuit A 101 does not send a Figure 13 The camera control circuit B 102 shown is not powered, but rather outputs power used by accessories and obtains accessory information.

[0293] exist Figure 14B In the case of switching the low power consumption mode to the normal operation mode in response to input detection, the camera control circuit A 101 supplies power to the camera control circuit B 102. When the initialization process is completed, the camera control circuit B 102 notifies the camera control circuit A 101 of the completion of preparation.

[0294] The camera control circuit A 101 that has received the preparation completion notification notifies the camera control circuit B 102 that Figure 14A Accessory information obtained from .

[0295] The camera control circuit B 102 which has received the accessory information performs control switching of the accessory based on the accessory information, and performs accessory control communication and function signal control on the accessory 200 .

[0296] By doing so, the camera 100 can omit the accessory detection process when starting up from the low power consumption mode, thereby shortening the startup time of the accessory 200 (ie, the imaging system).

[0297] Third embodiment

[0298] A third embodiment of the present invention will now be described. The camera 100 includes a shutter button (not shown), a first shutter switch (hereinafter referred to as SW1), and a second shutter switch (hereinafter referred to as SW2), which is turned on by operating the shutter button. SW1 is turned on by half-pressing the shutter button and instructs the start of imaging preparations such as automatic exposure control and focus control. SW2 is turned on by fully pressing the shutter button and instructs still image capture.

[0299] Normally, after SW1 is turned on and the image capture preparation operation is completed, SW2 is turned on. However, the shutter button can be pressed fully at once so that SW2 is immediately turned on when SW1 is turned on. In this embodiment, the state in which the shutter button is pressed fully at once and SW1 and SW2 are turned on almost simultaneously will be referred to as the simultaneous turning on of SW1 and SW2.

[0300] Figure 19 The flowchart in exemplifies processing to be executed by the camera control circuit B102 when SW1 and SW2 are turned on simultaneously.

[0301] First, at S701, the camera control circuit B 102 Figure 13 or Figure 14A and Figure 14B The communication exchange shown receives accessory information from camera control circuit A 101.

[0302] Next, in S702, the camera control circuit B 102 determines whether SW2 is on (ie, SW1 and SW2 are simultaneously on), and if SW2 is on, the flow advances to step S703.

[0303] In S703, the camera control circuit B 102 refers to the accessory information acquired in S701 and determines whether the accessory 200 is a flash device. If the accessory 200 is a flash device, the flow proceeds to S704, and if the accessory 200 is not a flash device, the flow proceeds to S707.

[0304] In S704, the camera control circuit B 102 performs SPI communication required for flash photography with the accessory 200. Through this SPI communication, charging completion information indicating whether charging of the accessory 200 is completed can also be obtained.

[0305] Next, in S705, the camera control circuit B 102 refers to the charging completion information obtained in S704 and determines whether charging of the accessory 200 is completed. If charging is completed, the flow proceeds to S706, and if charging is not completed, the flow proceeds to S707.

[0306] In S706, the camera control circuit B 102 permits flash imaging, and the flow proceeds to the next S708. If the automatic exposure control and focus control have not yet been completed, the camera control circuit B 102 does not permit flash imaging and waits for completion of these two controls.

[0307] In S708, the camera control circuit B 102 performs light amount control on the accessory 200, and determines the flash emission amount during imaging.

[0308] After that, the flow proceeds to S709, where the camera control circuit B 102 causes the flash to emit light at the flash light emission amount determined in S708, and performs main imaging.

[0309] On the other hand, in S707, the camera control circuit B 102 permits non-flash (non-light emission) imaging, and the flow proceeds to S710. If the automatic exposure control or the focus control has not yet been completed, the camera control circuit B 102 waits for completion of both controls without permitting non-flash imaging.

[0310] After that, the flow proceeds to S710, and the camera control circuit B 102 performs main imaging without causing the accessory 200 to emit flash light. Then, this processing is terminated.

[0311] Figure 20 The flowchart in FIG. 1 illustrates operations to be performed by the camera control circuit B 102 when SW1 and SW2 are turned on simultaneously. Figure 19 The processing shown is different from the processing according to the comparative example.

[0312] In S801, the camera control circuit B 102 performs the Figure 19 When the accessory information corresponding to S701 in step 100 is received, it is determined whether SW2 is on (SW1 and SW2 are on at the same time). If SW2 is on, the flow proceeds to step S802, and the camera control circuit B 102 turns on the same as the Figure 19 The SPI communication with the accessory 200 is performed in the same manner as the S704 in FIG.

[0313] Next, in S803, the camera control circuit B 102 determines whether the accessory 200 is a fully charged flash device based on the information obtained through the SPI communication in S802. If the accessory 200 is a fully charged flash device, the flow proceeds to S804; otherwise, the flow proceeds to S805. S804 to S808 are respectively Figure 19 S706 to S710 in are the same.

[0314] exist Figure 20 In the processing of , the camera control circuit B 102 does not previously acquire the accessory information from the accessory 200. Therefore, when SW2 is turned on (S801), SPI communication with the accessory 200 is always performed (S802).

[0315] However, in the case where the accessory 200 is not a flash device, SPI communication is not required for image capture control. Unnecessary SPI communication increases the time lag until image capture is permitted. Figure 19 As shown, acquiring accessory information in advance in S701 enables permitting image capture without SPI communication ( S704 ) when accessories other than the flash device are attached, thereby reducing time lag.

[0316] Fourth embodiment

[0317] A fourth embodiment of the present invention will now be described. The camera 100 uses the display circuit 127 to perform live view display. Typically, the brightness of the live view image is adjusted to be the same as the brightness of the captured image. However, when a flash device is attached as accessory 200, the brightness of the captured image obtained by flash photography is unknown before the image is captured. Therefore, the brightness of the live view image is adjusted as follows.

[0318] For example, assume that the user manually sets the camera 100 to F4, a shutter speed of 1 / 60s, and ISO 100 for a subject whose image is properly exposed using F4, a shutter speed of 1 / 60s, and ISO 400. In this case, since the exposure of the captured image is two stops underexposed, the brightness of the live view image can be set to be two stops underexposed. However, if the attached accessory 200 is a fully charged flash device, the brightness setting of the live view image is changed. This is because the flash light may cause the underexposure to be inappropriate.

[0319] Figure 21 The flowchart in exemplifies live view display processing to be executed by the camera control circuit B 102 when the camera 100 is activated.

[0320] First, in S901, the camera control circuit B 102 Figure 13 or Figure 14A and Figure 14B The communication exchange shown receives accessory information from camera control circuit A 101.

[0321] Next, in S902, the camera control circuit B 102 determines whether there is an instruction for live view (LV) display. If there is such an instruction, the flow proceeds to S903, and if there is no instruction, the camera control circuit B 102 repeats the determination in this step.

[0322] In S903, the camera control circuit B 102 refers to the accessory information acquired in S901 and determines whether the accessory 200 is a flash device. If the accessory 200 is a flash device, the flow proceeds to S904, and if the accessory 200 is not a flash device, the flow proceeds to S907.

[0323] In S904, the camera control circuit B 102 performs SPI communication with the accessory 200 to obtain charging completion information.

[0324] Next, in S905, the camera control circuit B 102 refers to the charging completion information obtained in S904 and determines whether charging of the accessory 200 is completed. If charging is completed, the flow proceeds to S906, and if charging is not completed, the flow proceeds to S907.

[0325] In S906, the camera control circuit B 102 sets the brightness of the live view image to brightness corresponding to appropriate exposure (such as F4, 1 / 60S, and ISO 400), and causes the display circuit 127 to display the live view image.

[0326] On the other hand, in S907, the camera control circuit B 102 sets the brightness of the live view image to the brightness corresponding to the imaging exposure (such as F4, 1 / 60s and ISO 100), and causes the display circuit 127 to display the live view image. Then, the flow proceeds to S908.

[0327] In S908, the camera control circuit B 102 determines whether the light metering timer is counting. If the light metering timer is counting, the flow proceeds to S909. If the light metering timer is not counting, the camera control circuit B 102 repeats the determination in this step. The light metering timer is a timer that starts counting when SW1 is turned on and counts for a specified time.

[0328] The processes related to the live view display while the light metering timer is counting (S909 to S913) are the same as the processes related to the live view display before the light metering timer starts counting (S903 to S907). Therefore, unless there is a change in the status of the accessory 200 (such as the charging status), the brightness of the live view image before and after the light metering timer starts counting becomes the same.

[0329] Figure 22 The flowchart in FIG. 1 illustrates the operations to be performed by the camera control circuit B 102 when the camera 100 is started. Figure 21 The processing shown is different from the live view display processing as a comparative example.

[0330] In S1001, the camera control circuit B 102 does not need to communicate with Figure 21 In the case of receiving the accessory information corresponding to S901 in the embodiment, it is determined whether there is an instruction for live view (LV) display. If there is such an instruction, the flow proceeds to S1002, and if there is no instruction, the determination in this step is repeated.

[0331] In S1002 , the camera control circuit B 102 sets the brightness of the live view image to the brightness corresponding to the imaging exposure, and causes the display circuit 127 to display the live view image.

[0332] Next, in S1003, the camera control circuit B 102 determines whether the light metering timer is counting. If the light metering timer is counting, the flow proceeds to S1004, and if the light metering timer is not counting, the camera control circuit B 102 repeats the determination in this step.

[0333] In S1004, the camera control circuit B 102 performs SPI communication to obtain information about the accessory 200, which is a flash device. Power consumption can be reduced by SPI communication only when the light metering timer is counting.

[0334] Next, in S1005, the camera control circuit B 102 determines whether the accessory 200 is a fully charged flash device based on the information obtained through the SPI communication in S1004. If the accessory 200 is a fully charged flash device, the flow proceeds to S1006; otherwise, the flow proceeds to S1007.

[0335] In S1006, the camera control circuit B 102 sets the brightness of the live view image to the brightness corresponding to the appropriate exposure, and causes the display circuit 127 to display the live view image. Then, this process is terminated.

[0336] On the other hand, in S1007, the camera control circuit B 102 sets the brightness of the live view image to the brightness corresponding to the imaging exposure, and causes the display circuit 127 to display the live view image. Then, this processing is terminated.

[0337] exist Figure 22 In the illustrated process, the camera control circuit B 102 cannot obtain accessory information in advance. Therefore, the camera control circuit B 102 temporarily displays the live view image at a brightness corresponding to the imaging exposure in S1002. Then, if the flash unit is fully charged, the camera control circuit B 102 switches the brightness of the live view display to a brightness corresponding to the appropriate exposure (S1006). As a result, the brightness of the live view display changes.

[0338] On the other hand, Figure 21 In the illustrated process, the camera control circuit B 102 can acquire accessory information in advance in S901, and thus can perform control to adjust the brightness of the live view display to a brightness corresponding to the accessory 200 from the start of the live view display (S906, S907). Therefore, the brightness of the live view display does not change.

[0339] In the above-described respective embodiments, the first communication method is the I2C communication method and the second communication method is the SPI communication method, but the first communication method and the second communication method may be communication methods other than the I2C communication method and the SPI communication method.

[0340] In each of the above-described embodiments, the electronic device is an imaging device, but the electronic device according to the present invention may include various electronic devices other than an imaging device.

[0341] In the various embodiments described above, the accessory 200 is directly attached to the camera 100, but another attachment form may be used. For example, the camera 100 and a main accessory corresponding to the accessory 200 may communicate with each other via the main accessory and an intermediate accessory (such as an adapter device to which the camera 100 is attached). In this case, the intermediate accessory may perform communication control similar to at least a portion of the communication control performed by the accessory 200 and the communication control performed by the camera 100 described in the above embodiments. The intermediate accessory may serve as an information transmission path so that the accessory outputs information corresponding to information input from the camera 100 to the main accessory, and the main accessory outputs information corresponding to the input information to the camera 100. Therefore, accessories according to embodiments of the present invention include various accessories such as a microphone device, a lighting device, and an adapter device. In addition, the adapter device may also be included in the electronic device.

[0342] The above-described embodiments can each provide an electronic device, a control method of an electronic device, an accessory, and a control method of an accessory, each of which can enhance responsiveness at startup in a system in which an accessory is attached to the electronic device.

[0343] Other embodiments

[0344] The embodiments of the present invention can also be implemented by the following method, that is, the software (program) that performs the functions of the above-mentioned embodiments is supplied to a system or device through a network or various storage media, and the computer or central processing unit (CPU) or microprocessing unit (MPU) of the system or device reads and executes the program.

[0345] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications, equivalent structures and functions.

Claims

1. An electronic device to which accessories can be detachably attached, the electronic device comprising: an accessory shoe portion, wherein the accessory is attachable to the accessory shoe portion; a first processing unit capable of communicating with the accessory via a first communication method; as well as a second processing unit capable of communicating with the accessory via a second communication method different from the first communication method, The electronic device has a first power state and a second power state, the power of the second power state is lower than the power of the first power state, and the first power state and the second power state are each a state in which communication with the accessory is possible. wherein the first processing unit communicates with the accessory using the first communication method in the first power state and the second power state; wherein the second processing unit communicates with the accessory using the second communication method in the first power state, and does not send information to or receive information from the accessory using the second communication method in the second power state; and The contact point used for communication using the first communication method is different from the contact point used for communication using the second communication method.

2. The electronic device according to claim 1, wherein The first processing unit includes a processor that operates with lower power than a processor constituting the second processing unit.

3. The electronic device according to claim 1, wherein The first processing unit and the second processing unit are provided in a single processor.

4. The electronic device according to claim 2, wherein: A communication speed of the first communication method is lower than a communication speed of the second communication method.

5. The electronic device according to claim 1, wherein the first processing unit operates in the first power state and the second power state, and The second processing unit does not operate in the second power state, and operates in the first power state.

6. The electronic device according to claim 1, wherein: Before the second processing unit is ready to communicate with the accessory through the second communication method, the first processing unit receives accessory information for identifying the accessory from the accessory using the first communication method in response to detecting that the accessory is attached to the electronic device.

7. The electronic device according to claim 1, wherein: When the electronic device is started, the first processing unit is started before the second processing unit, so that the detection of the attachment of the accessory and the startup of the second processing unit are performed in parallel, and the accessory information for identifying the accessory is notified to the started second processing unit.

8. The electronic device according to claim 6, wherein: The accessory information includes information about the type of the accessory and information about specifications of communication and operation of the accessory.

9. The electronic device according to claim 1, wherein: The first processing unit outputs an output signal to the accessory by detecting a first input signal activated by the accessory in response to the accessory being attached to the electronic device, and communicates with the accessory through the first communication method in response to detecting a second input signal activated by the accessory having received the output signal.

10. The electronic device according to claim 1, wherein The first communication method is an I2C communication method, and the second communication method is an SPI communication method.

11. The electronic device according to claim 10, characterized in that the first processing unit outputting an output signal to the accessory by detecting a first input signal activated by the accessory in response to the accessory being attached to the electronic device, and communicating with the accessory through the first communication method in response to detecting a second input signal activated by the accessory having received the output signal, wherein the electronic device comprises a plurality of contacts arranged in a row, the plurality of contacts being capable of being electrically connected to a plurality of contacts arranged in a row in the accessory, and The multiple contacts of the electronic device include: a contact for a data signal by the I2C communication method, and a contact for a clock signal by the I2C communication method arranged on one side of the contact for the data signal; and The following contacts are arranged on the other side of the contact for the data signal: a contact for the second input signal, a contact for an input selection signal by the SPI communication method, a contact for reception by the SPI communication method, a contact for transmission by the SPI communication method, a contact for a clock signal by the SPI communication method, a contact for the first input signal, and a contact for the output signal.

12. The electronic device according to claim 1, wherein The second processing unit determines whether to communicate with the accessory through the second communication method when a predetermined operation is performed on the electronic device.

13. The electronic device according to claim 1, wherein The second processing unit determines whether to communicate with the accessory through the second communication method after performing the predetermined operation based on the accessory information for identifying the accessory acquired before performing the predetermined operation on the electronic device.

14. The electronic device according to claim 1, wherein The electronic device is a camera device, and the accessory is a lighting device or a microphone device.

15. The electronic device according to any one of claims 1 to 14, characterized in that: A contact point used for communication by the first communication method and a contact point used for communication by the second communication method are different from a contact point used for detection of attachment of the accessory to the electronic device.

16. An accessory that is detachably attached to an accessory shoe portion of an electronic device, the accessory comprising: an accessory processing unit capable of communicating with the electronic device through a first communication method and a second communication method different from the first communication method, The accessory processing unit communicates with the electronic device through the first communication method when the electronic device is in a first power state and a second power state, wherein the power of the second power state is lower than the power of the first power state, and the first power state and the second power state are each a state in which communication with the accessory is possible. wherein the accessory processing unit communicates with the electronic device through the second communication method when the electronic device is in the first power state, and does not send information to or receive information from the electronic device through the second communication method when the electronic device is in the second power state; and The contact point used for communication using the first communication method is different from the contact point used for communication using the second communication method.

17. The accessory according to claim 16, characterized in that A communication speed of the first communication method is lower than a communication speed of the second communication method.

18. The accessory according to claim 16, characterized in that The accessory processing unit transmits accessory information for identifying the accessory to the electronic device through the first communication method before communication through the second communication method is ready.

19. The accessory according to claim 18, characterized in that The accessory information includes information about the type of the accessory and information about specifications of communication and operation of the accessory.

20. The accessory according to claim 16, wherein The accessory processing unit activates a first input signal input to the electronic device in response to the accessory being attached to the electronic device, activates a second input signal input to the electronic device in response to receiving an output signal output from the electronic device that has detected the first input signal, and communicates with the electronic device that has detected the second input signal through the first communication method.

21. The accessory according to claim 16, wherein The first communication method is an I2C communication method, and the second communication method is an SPI communication method.

22. The accessory according to claim 21, characterized in that the accessory processing unit activating a first input signal input to the electronic device in response to the accessory being attached to the electronic device, activating a second input signal input to the electronic device in response to receiving an output signal output from the electronic device that detected the first input signal, and communicating with the electronic device that detected the second input signal through the first communication method, The accessory includes a plurality of contacts arranged in a row, and the plurality of contacts can be electrically connected to a plurality of contacts arranged in a row in the electronic device. The multiple contacts of the accessory include: a contact for a data signal by the I2C communication method, and a contact for a clock signal by the I2C communication method arranged on one side of the contact for the data signal; and The following contacts are arranged on the other side of the contact for the data signal: a contact for the second input signal, a contact for an input selection signal by the SPI communication method, a contact for transmission by the SPI communication method, a contact for reception by the SPI communication method, a contact for a clock signal by the SPI communication method, a contact for the first input signal, and a contact for the output signal.

23. The accessory according to claim 16, characterized in that The accessory is a lighting device or a microphone device, and the electronic device is a camera device.

24. An accessory according to any one of claims 16 to 23, characterized in that A contact point used for communication by the first communication method and a contact point used for communication by the second communication method are different from a contact point used for detection of attachment of the accessory to the electronic device.

25. A method for controlling an electronic device to which an accessory is detachably attached, the electronic device having a first power state and a second power state, the second power state having lower power than the first power state, the first power state and the second power state each being a state capable of communicating with the accessory, the electronic device comprising an accessory shoe portion to which the accessory is attachable, a first processing unit, and a second processing unit, the method comprising the following steps: enabling the first processing unit to communicate with the accessory using a first communication method in the first power state and the second power state; as well as enabling the second processing unit to communicate with the accessory using a second communication method in the first power state, and prohibiting the second processing unit from sending information to or receiving information from the accessory using the second communication method in the second power state, It is characterized in that the contact point used for communication by the first communication method is different from the contact point used for communication by the second communication method.

26. A method for controlling an accessory, the accessory being detachably attached to an accessory shoe portion of an electronic device, the method comprising the following steps: enabling the accessory to communicate with the electronic device using a first communication method when the electronic device is in a first power state and a second power state, wherein the second power state has lower power than the first power state, the first power state and the second power state each being a state capable of communicating with the accessory; as well as enabling the accessory to communicate with the electronic device using a second communication method when the electronic device is in the first power state, and prohibiting the accessory from sending information to or receiving information from the electronic device using the second communication method when the electronic device is in the second power state, It is characterized in that the contact point used for communication by the first communication method is different from the contact point used for communication by the second communication method.

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