Electronic device and its control method, and accessory and its control method

Abstract

The present invention provides an electronic device and a control method thereof, and an accessory and a control method thereof. The accessory can be attached to the electronic device, detached from the electronic device, and communicate with the electronic device. The accessory includes an accessory processing unit configured to make a communication request to the electronic device and send information about factors of the communication request. The accessory processing unit notifies the electronic device, by a first communication method, of information corresponding to a use communication method for communicating information about factors in the first communication method and a second communication method different from the first communication method.

Description

Technical Field

[0001] The present invention relates to an electronic device such as a camera device to which an accessory can be attached. Background Art

[0002] In a camera system in which an accessory can be attached to a camera device (camera), the camera and the accessory exchange data with each other via communication. When controlling such a camera system in response to a user operation on the accessory, high real-time performance data communication is required between the camera and the accessory so as not to miss a photographing opportunity.

[0003] Japanese Patent Application Laid-Open ("JP") 2018-205711 discloses a camera system in which, when an adapter is attached between a camera and an interchangeable lens and changes in optical parameters caused by the adapter are corrected, one-to-many communication among the camera, the interchangeable lens, and the accessory is performed to improve the real-time performance of data communication.

[0004] However, the camera system disclosed in JP 2018-205711 cannot sufficiently improve the real-time performance of data communication in the case of a large amount of data communication and many-to-many communication. Summary of the Invention

[0005] The present invention provides an accessory, a control method of the accessory, an electronic device, and a control method of the electronic device, each of which can provide highly responsive data communication.

[0006] An accessory according to an aspect of the present invention is attachable to an electronic device, detachable from the electronic device, and capable of communicating with the electronic device, and includes an accessory processing unit configured to make a communication request to the electronic device and transmit information on a factor of the communication request. The accessory processing unit notifies the electronic device, by a first communication method, of information corresponding to a use communication method for communicating information on the factor in the first communication method and a second communication method different from the first communication method. The control method of the above accessory also constitutes another aspect of the present invention.

[0007] An electronic device according to another aspect of the present invention is attachable with an accessory, detachable with the accessory, and capable of communicating with the accessory, and includes a first processing unit configured to receive: a communication request from the accessory; and information corresponding to a use communication method for communicating information on a factor of the communication request in a first communication method and a second communication method different from the first communication method. The control method of the above electronic device also constitutes another aspect of the present invention.

[0008] A control method for an accessory, the accessory being attachable to an electronic device, detachable from the electronic device, and capable of communicating with the electronic device, the control method including the steps of: making a communication request to the electronic device; sending information about a factor of the communication request; and notifying, by a first communication method, the electronic device of information corresponding to a communication method used to communicate the information about the factor in the first communication method and a second communication method different from the first communication method.

[0009] A control method for an electronic device, the electronic device being attachable with an accessory, detachable with the accessory, and capable of communicating with the accessory, the control method including the steps of: receiving a communication request from the accessory; and receiving information corresponding to a communication method used to communicate information about a factor of the communication request in a first communication method and a second communication method different from the first communication method.

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

[0011] Figure 1 Illustrate the structure of a camera system (including a camera, a lens unit, and an accessory) in the first embodiment.

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

[0013] Figures 3A to 3D Illustrate a flowchart of the processes to be performed by the camera and the accessory in the first embodiment.

[0014] Figure 4 Illustrate communication data in SPI communication in the first embodiment.

[0015] Figure 5 Illustrate accessory information in the first embodiment.

[0016] Figure 6 Illustrate the processing sequence of the camera system in the first embodiment.

[0017] Figure 7 Illustrate accessory type information in the first embodiment.

[0018] Figure 8 Illustrate factors for generating a communication request in the first embodiment.

[0019] Figure 9A and Figure 9B Illustrate communication intervals in SPI communication in the first embodiment.

[0020] Figure 10 The example shows a flowchart of the startup process to be performed by the camera (camera control circuit A) in the first embodiment.

[0021] Figure 11 The example shows a flowchart of the startup process to be performed by the camera (camera control circuit B) in the first embodiment.

[0022] Figure 12 The example shows a flowchart of the process to be performed by the accessory in the first embodiment.

[0023] Figure 13 It is a flowchart showing the process to be performed when the camera in the first embodiment acquires a communication request signal.

[0024] Figure 14A and Figure 14B The example shows a control example to be performed when the camera in this embodiment acquires a communication request signal.

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

[0026] Figure 16 The example shows the process to be performed by the camera when sending N bytes of data from the camera to the accessory in the first embodiment.

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

[0028] Figure 18A and Figure 18B The example shows the process to be performed by the accessory when communicating N bytes of data between the camera and the accessory in the first embodiment. Detailed implementation mode

[0029] Embodiments of the present invention will now be described with reference to the accompanying drawings.

[0030] First embodiment

[0031] Figure 1Illustrate the electrical structure of a camera system, which includes a camera device (hereinafter referred to as a camera) 100 as an electronic device according to the first embodiment of the present invention and an accessory 200 detachably attached to the camera device. The accessory 200 is, for example, a microphone device or a lighting (strobe / flash) device, and includes various devices attachable to the camera 100. The camera 100 and the accessory 200 are electrically connected via 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 a part of the plurality of contacts TA01 to TA21.

[0032] 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 as a first processing unit and a receiving unit and a camera control circuit B 102 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 A 101 and the camera control circuit B 102 perform various controls and processes according to a computer program.

[0033] The camera control circuit A101 monitors the operation of a switch or the like used for camera operation (not shown) and controls the system power according to the user's operation. The camera control circuit A 101 includes a low-power type 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, the display circuit 127, etc. The camera control circuit B 102 includes a processor that stops operating in the low power consumption mode but operates in the normal operation mode (first power state).

[0034] Although the camera control circuit A 101 and the camera control circuit B 102 include separate processors in this embodiment, the two circuits may be provided in a single processor.

[0035] The system power supply circuit 112 is a circuit that generates the power to be supplied to each circuit in the camera 100, and includes a DC / DC converter circuit, a Low Drop Out (LDO), a charge pump circuit, and the like. The 1.8V voltage generated by the system power supply circuit 112 that receives power from the battery 111 is constantly supplied as the camera microcomputer power supply VMCU_C to the camera control circuit A 101. Several types of voltages generated by the system power supply circuit 112 are supplied as the camera microcomputer power supply VMCU2_C to the camera control circuit B 102 at an arbitrary timing. The camera control circuit A 101 controls the on and off of the power supply to each circuit in the camera 100 by controlling the system power supply circuit 112.

[0036] The optical lens 121 can be attached to and detached from the camera 100. The light from the subject incident through the optical lens 121 is imaged on an image sensor 122 including a CMOS sensor, a CCD sensor, or the like. The optical lens 121 and the camera 100 can be integrated. The subject image formed on the image sensor 122 is encoded into a digital video signal. The image processing circuit 123 performs image processing such as noise reduction processing and white balance processing on the digital video signal to generate image data, and converts the image data into an image file in a format such as JPEG format to record the image data in the recording memory 126. The image processing circuit 123 generates VRAM image data to be displayed on the display circuit 127 from the image data.

[0037] The memory control circuit 124 controls the transmission and reception of the image data and other data generated by the image processing circuit 123 and the like. The volatile memory 125 is a memory such as DDR3 SDRAM that can perform high-speed reading and writing, and is used as a working space for the 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 a CFExpress card that can be attached to and detached 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 changing the amount of light of the backlight of the display circuit 127.

[0038] In this embodiment, each of 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 is a voltage conversion circuit that converts the voltage supplied from the system power supply circuit 112 into a predetermined voltage and generates 3.3V as the accessory power supply VACC. This configuration can convert the voltage into another voltage.

[0039] The accessory power supply circuit A131 is a power supply circuit that includes an LDO, etc., and has low self-power consumption. The accessory power supply circuit B 132 includes a DC / DC converter circuit, etc., and can pass a current larger than that of the accessory power supply circuit A 131. The self-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, and 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 on and off of the voltage output of the accessory power supply circuits A 131 and B 132 according to the operation state of the accessory 200.

[0040] The protection circuit 133 includes a current fuse element, or an electronic fuse circuit that combines multiple switching elements or resistors, an amplifier, and a switching element, etc. When the power supply current value supplied from the accessory power supply circuits A 131 and B 132 to the accessory 200 is higher than 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 in the case where a current of 1 A or more 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 becoming high level. The predetermined value can be different from 1 A.

[0041] 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 the order of contacts TC01 to TC21 from one end to the other end in the arrangement direction.

[0042] TC01 is connected to the ground terminal (GND), and is used not only as a reference potential contact, but also as a contact configured to control the wiring impedance of the differential signals D1N and D1P. TC01 corresponds to the third ground contact.

[0043] The differential signal D1N connected to TC02 and the differential signal D1P connected to TC03 are differential data communication signals that perform 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.

[0044] TC04, which is the first ground contact, is connected to GND and is used as the reference potential contact of the camera 100 and the accessory 200. TC04 is arranged outside of TC05 described below in the contact arrangement direction.

[0045] The accessory power supply VACC generated by the accessory power supply circuits A 131 and B 132 is connected to TC05 which serves as a power supply contact via the protection circuit 133.

[0046] The accessory attachment detection 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 (such as 10 kΩ or the like). 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, and if the signal level (potential) of the accessory attachment detection signal / ACC_DET is a low level (GND potential) which is the activation potential, it is detected that the accessory 200 is attached.

[0047] When the camera 100 is powered on, changing the signal level (potential) of the accessory attachment detection signal / ACC_DET from high level (Hi) to low level (Lo) triggers various transmissions via the contacts between the camera 100 and the accessory 200.

[0048] The camera control circuit 101 supplies power to the accessory 200 via TC05 which serves as a power supply contact in response to detecting the attachment of the accessory 200.

[0049] SCLK connected to TC07 which serves as a communication contact, MOSI connected to TC08, MISO connected to TC09, and Chip Select (CS) connected to TC10 are signals used for communication by the serial peripheral interface (SPI) communication method which is the second communication method (hereinafter referred to as SPI communication), where in the second communication method the camera control circuit B102 becomes the communication master. SCLK is a clock signal, MOSI is a transmission signal, MISO is a reception signal, and CS is a communication selection signal used as a signal for selecting a communication partner. In this embodiment, the SPI communication has a communication clock frequency of 1 MHz, a data length of 8 bits (1 byte), a bit order with MSB first, and a full-duplex communication method.

[0050] In this embodiment, the camera 100 and the accessory 200 support two types of communication protocols of the SPI communication method. The 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 Illustrate the outline of the communication waveform of SPI protocol A. In this figure, CS is active low.

[0051] The camera control circuit B 102 changes CS to low level (activate) at timing A1 and requests SPI communication from the accessory control circuit 201.

[0052] At timing A2, which is a predetermined time T_CS after timing A1, the camera control circuit B 102 starts to output SCLK and MOSI. When the accessory control circuit 201 detects the trailing edge of SCLK, the accessory control circuit 201 starts to output MISO.

[0053] The camera control circuit B 102 stops outputting SCLK at timing A3 when it has finished outputting 1 byte of SCLK.

[0054] The camera control circuit B 102 stops outputting SCLK at timing A3 and continues for a predetermined time T_INTERVAL. After T_INTERVAL has elapsed, at timing A4, it restarts outputting SCLK and performs the next 1-byte communication.

[0055] Figure 3A The flowchart in [ ] illustrates the processing to be performed by the camera control circuit B 102 in SPI protocol A. S represents steps.

[0056] In S101, the camera control circuit B 102 stores the value representing the number of bytes to be communicated in the internal variable N. For example, it stores 3 in the case of 3-byte communication.

[0057] In S102, the camera control circuit B 102 changes CS to low level and requests SPI communication.

[0058] In S103, the camera control circuit B 102 performs a waiting process until a predetermined time T_CS has elapsed after CS has been changed to low level. After the predetermined time T_CS has elapsed, the process proceeds to S104.

[0059] In S104, the camera control circuit B 102 controls SCLK output, MOSI data output, and MISO data input, and performs 1-byte data communication.

[0060] In S105, the camera control circuit B 102 confirms whether the internal variable N representing the number of communication bytes is 0. If the internal variable N is 0, the process proceeds to S106, and if the internal variable N is not 0, the process proceeds to S107.

[0061] In S107, the camera control circuit B 102 stores the value obtained by decrementing the value of the internal variable N representing the number of communication bytes by 1 as the new internal variable N.

[0062] In S108, the camera control circuit B 102 performs a waiting process 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 process returns to the process of S104, and the same process is executed again.

[0063] In S106, the camera control circuit B 102 changes CS to high level and ends a series of SPI communications.

[0064] Figure 3B The flowchart in [ ] illustrates the process to be performed by the accessory control circuit 201 in the SPI protocol A.

[0065] In S201, the accessory control circuit 201 confirms whether CS has changed to low level. When CS changes to low level, the process proceeds to S202, and when CS has not changed to low level, the process returns to S211.

[0066] In S202, in response to the input of the SCLK signal, the accessory control circuit 201 performs 1-byte data communication through MOSI data input control and MISO data output control.

[0067] In S203, the accessory control circuit 201 confirms whether CS has changed to high level. When CS changes to high level, it is determined that the SPI communication is completed, and when CS has not changed to high level, the process returns to S202 for the next 1-byte communication.

[0068] 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 the SCLK, and is referred to as the SPI protocol B in the following description. Figure 2B Illustrate the outline of the communication waveform of the SPI protocol B.

[0069] The camera control circuit B 102 changes CS to low level at timing B1 and requests SPI communication from the accessory control circuit 201. The camera control circuit B 102 confirms the potential of MISO together with the communication request. If MISO is at high level, it is determined that the accessory control circuit 201 is in a communicable state, and if MISO is at low level, it is determined that the accessory control circuit 201 is in a non-communicable state.

[0070] 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 to change MISO to high level when the SPI communication is available, and performs control to change MISO to low level when the communication is not available.

[0071] 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 to output SCLK and MOSI. The accessory control circuit 201 starts to output MISO when detecting the trailing edge of SCLK.

[0072] When the output of 1-byte SCLK is completed at timing B4, the camera control circuit B 102 stops outputting SCLK.

[0073] After 1-byte communication, as shown in timings B5 and B6, the accessory control circuit 201 controls to change MISO to a high level when SPI communication is available, and controls to change MISO to a low level when SPI communication is unavailable.

[0074] The camera control circuit B 102 confirms the potential of MISO at timing B7. 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 non-communicable state.

[0075] Figure 3C The flowchart in [ ] illustrates the processing to be performed by the camera control circuit B 102 in SPI protocol B.

[0076] In S111, the camera control circuit B 102 stores the value representing the number of bytes to be communicated in the internal variable N. For example, 3 is stored in the case of 3-byte communication.

[0077] In S112, the camera control circuit B 102 changes CS to a low level and requests SPI communication.

[0078] 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 process proceeds to S114, and if MISO is not yet at a high level, the process returns to S113.

[0079] 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.

[0080] In S115, the camera control circuit B 102 confirms whether all data communication has been completed (whether the internal variable N representing the number of communication bytes is 0). If the internal variable N is 0, the process proceeds to S116, and if the internal variable N is not 0, the process proceeds to S117.

[0081] In S117, the camera control circuit B 102 stores the value obtained by decrementing the value of the internal variable N representing the communication byte count by 1 as the new internal variable N.

[0082] In S118, the camera control circuit B 102 confirms whether MISO changes to a high level. If MISO is at a high level, the process proceeds to S114, and if MISO is not at a high level, the process returns to S118.

[0083] In S116, the camera control circuit B 102 changes CS to a high level and ends a series of SPI communications.

[0084] Figure 3D The flowchart in [ ] illustrates the processing to be performed by the accessory control circuit 201 in SPI protocol B.

[0085] In S211, the accessory control circuit 201 confirms whether CS changes to a low level. If CS changes to a low level, the process proceeds to S212, and if CS does not change to a low level, the process returns to S211.

[0086] 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.

[0087] In S213, the accessory control circuit 201 performs control to change MISO to a high level, and the process proceeds to S215.

[0088] In S214, the accessory control circuit 201 performs control to change MISO to a low level, and the process returns to S212.

[0089] In S215, the accessory control circuit 201 controls MOSI data input and MISO data output in response to the input of the SCLK signal and performs 1-byte data communication.

[0090] In S216, the accessory control circuit 201 confirms 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 process returns to S212 for the next 1-byte communication.

[0091] Figure 4 Illustrates the communication content when notifying an operation execution instruction (command) from the camera 100 to the accessory 200 through SPI communication in this embodiment.

[0092] The camera control circuit B 102 sends the information CMD representing the command number as MOSI data to the accessory control circuit 201 in the first-byte communication. The accessory control circuit 201 sends the value 0xA5 as MISO data, which represents the communicable state information, to the camera control circuit B 102. In the case where the first-byte communication process cannot be executed, the accessory control circuit 201 sends a value other than 0xA5 as MISO data to the camera control circuit B 102.

[0093] The camera control circuit B 102 sends the independent variable MOSI_DATA1 corresponding to the command number CMD to the accessory control circuit 201 in the second-byte communication. Then, from the third byte to the (N - 2)th byte, the independent variables MOSI_DATA2 to MOSI_DATA[N - 3] corresponding to the command number CMD are similarly sent to the accessory control circuit 201.

[0094] The accessory control circuit 201 sends the command number CMD received in the first byte as MISO data to the camera control circuit B 102 in the second-byte communication. This configuration enables the camera control circuit B 102 to determine that the accessory control circuit 201 has correctly received the MOSI data.

[0095] The accessory control circuit 201 sends the return value MISO_DATA1 corresponding to the command number CMD as MISO data to the camera control circuit B 102 in the third-byte communication. Then, from the fourth 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 sent to the camera control circuit B 102.

[0096] It is assumed that the number of independent variables and the number of return values are predetermined for each command number. One or both of the independent variables and the return values can be omitted.

[0097] The camera control circuit B 102 sends the checksum data CheckSum_C as MOSI data to the accessory control circuit 201 in the (N - 1)th byte communication. The checksum data CheckSum_C is a value calculated by the following expression.

[0098] CheckSum_C = EXOR(AND(SUM(CMD, MOSI_DATA1, …, MOSI_DATA[N - 3]), 0xFF), 0xFF)

[0099] The accessory control circuit 201 sends 0x00 as MISO data.

[0100] Next, the camera control circuit B 102 sends 0x00 as the MOSI data to the accessory control circuit 201 in the Nth byte communication.

[0101] The accessory control circuit 201 sends the checksum data CheckSum_A as the 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 is the same as the value of CheckSum_C calculated by the camera control circuit B 102.

[0102] CheckSum_A = EXOR(AND(SUM(0xA5, CMD, MIS0_DATA1,…, MOSI_DATA[N-4]), 0xFF), 0xFF)

[0103] On the other hand, if the value of CheckSum_C received by the camera control circuit B 102 in the (N-1)th byte communication is not the same as the value of CheckSum_C calculated by the camera control circuit B 102, then this value is calculated by the following expression.

[0104] CheckSum_A = AND(SUM(0xA5, CMD, MIS0_DATA1,…, MOSI_DATA[N-4]), 0xFF)

[0105] Figure 1 The shown TC11 as a signal contact (communication request contact) is connected to the communication request signal (second input signal) / WAKE for requesting communication from the accessory 200 to the camera 100 (camera control circuit A101). The communication request signal / WAKE is pulled up to the camera microcomputer power supply VMCU_C via a resistor. The camera control circuit A101 can detect the communication request from the accessory 200 by detecting the change (trailing edge) of the communication request signal / WAKE.

[0106] The SDA connected to TC12 as a communication contact and the SCL connected to TC13 are signals for performing inter-integrated circuit (I2C) communication (hereinafter referred to as I2C communication) as the first communication method, where the camera control circuit A 101 is the communication master device in the first communication method. SDA is the data signal and SCL is the clock signal. SDA and SCL are open-drain communications pulled up by the camera microcomputer power supply VMCU_C and have a communication frequency of 100 kbps in this embodiment.

[0107] In I2C communication, data transmission from the camera 100 and data transmission from the accessory 200 are both carried out via SDA. When comparing SPI communication and I2C communication with each other, the communication speed of I2C communication is lower than that of SPI communication. Since the communication speed of SPI communication is higher than that of I2C communication, it is suitable for information communication with a large amount of data. Therefore, in the communication between the camera 100 and the accessory 200 in this embodiment, information with a large amount of data is communicated by using SPI communication, and information with a small amount of data is communicated by using I2C communication. For example, data is first communicated by using I2C communication, and when based on this data, SPI communication is available or needs to be executed, control can be performed to further execute SPI communication.

[0108] Figure 15A and Figure 15B An example of the I2C communication waveform is illustrated. Figure 15A An example of the waveform is illustrated in the case where the camera transmits N-byte data (DATA[1] to DATA[N]) to the accessory, and Figure 15B An example of the waveform is illustrated in the case where the camera receives N-byte data (DATA[1] to DATA[N]) from the accessory. In Figure 15A and Figure 15B the upper waveform illustrates SCL, and the lower waveform illustrates SDA.

[0109] Below the SDA waveform, the meaning of the signal at each timing and the control circuit for controlling the output level of the SDA signal are illustrated, whether it is the camera control circuit A 101 or the accessory control circuit 201. The communication data includes data in units of 1 byte and 1-bit information indicating a response. The upper part of each figure illustrates the number of bytes of data from the start of communication.

[0110] Since the details of the communication content will be described below with reference to Figures 16 to 18A and Figure 18B the outline will be described with reference to Figure 15A and Figure 15B the outline will be described.

[0111] In Figure 15A in the first-byte communication and the second-byte communication, the camera control circuit A 101 notifies the accessory control circuit 201 of the storage address information related to the data to be transmitted. In the third-byte communication to the (N + 2)-byte communication, the camera control circuit A 101 transmits N-byte data (DATA[address] to DATA[address + N]) to the accessory control circuit 201.

[0112] In Figure 15BIn the first-byte communication and the second-byte communication, the camera control circuit A 101 notifies the accessory control circuit 201 of the storage address information related to the data to be received. In the third-byte communication to the (N + 3)-byte communication, the camera control circuit A 101 receives N bytes of data (DATA[address] to DATA[address + N]) from the accessory control circuit 201.

[0113] Figure 16 The flowchart in illustrates the processing to be performed by the camera control circuit A 101 when the camera control circuit A 101 transmits N bytes of data to the accessory control circuit 201.

[0114] In S3001, the camera control circuit A 101 stores the value representing the number of bytes to be transmitted in the internal variable N. For example, when transmitting 3 bytes, 3 is stored. In this embodiment, 3 is stored.

[0115] In S3002, the camera control circuit A 101 changes SDA to low level during the period when SCL is at high level (start (START) condition). Thereby, it notifies the accessory control circuit 201 of the start of communication.

[0116] In S3003, the camera control circuit A 101 sets the slave address information representing the slave address of the accessory control circuit 201 to the high 7 bits of the data to be transmitted. In this embodiment, it is assumed that the slave address of the accessory control circuit 201 is 1010000 in binary.

[0117] In S3004, the camera control circuit A 101 sets the information representing the write communication to the low 1 bit of the data to be transmitted. Setting this bit to 0 means write communication.

[0118] In S3005, the camera control circuit A 101 transmits the data set as the data to be transmitted in S3003 and S3004 to the accessory control circuit 201 (10100000 in binary and 0xA0 in hexadecimal).

[0119] In S3006, after the camera control circuit A 101 transmits 1 byte of data, it outputs SCL and maintains it for one clock, and confirms the signal level of SDA. When the signal level of SDA is low, it is determined as the data reception notification (ACK) from the accessory control circuit 201, and the process proceeds to S3007. On the other hand, when the signal level of SDA is high, it is determined that the accessory control circuit 201 has not normally received the data, and the process proceeds to S3014.

[0120] In S3007, the camera control circuit A 101 sets the storage address information (start address information) of the data to be sent to the accessory control circuit 201 into the data to be sent. In this embodiment, the size of the start address information is 1 byte, and the value is 0x00.

[0121] In S3008, the camera control circuit A 101 sends the set 1-byte start address information (value 0x00) to the accessory control circuit 201.

[0122] In S3009, after the camera control circuit A 101 sends 1-byte start address information data, it outputs SCL and maintains it for one clock, and confirms the signal level of SDA. When the signal level of SDA is low, it is determined as the data reception notification (ACK) from the accessory control circuit 201, and the process proceeds to S3010. On the other hand, when 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.

[0123] In S3010, the camera control circuit A 101 stores 1 in the internal variable M. The internal variable M is a variable used to count the number of data to be sent.

[0124] In S3011, the camera control circuit A 101 outputs 1-byte data to the accessory control circuit 201 by outputting 1-byte SCL and changing SDA to the desired signal level during the period when SCL is at a low level. Here, since the start address information is 0x00 and the internal variable M is 1, 1-byte data corresponding to the address 0x00 is sent.

[0125] In S3012, after the camera control circuit A 101 sends 1-byte data, it outputs SCL and maintains it for one clock, and confirms the signal level of SDA. When the signal level of SDA is low, it is determined as the data reception notification (ACK) from the accessory control circuit 201, and the process proceeds to S3013. On the other hand, when 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.

[0126] In S3013, the camera control circuit A 101 confirms whether the internal variable M has the same value as the internal variable N. When the internal variable M has the same value as the internal variable N, it is determined that the transmission of all data is completed, and the process proceeds to S3014. When the internal variable M does not have the same value as the value of the internal variable N, it is determined that there is still data to be sent, and the process proceeds to S3015.

[0127] In S3015, the camera control circuit A 101 increments the internal variable M by 1, and the process returns to S3011.

[0128] Therefore, after the process 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 transmits N-byte data to the accessory control circuit 201 by repeatedly transmitting 1-byte data until the internal variable M and the internal variable N have the same value in the process of S3013. When the internal variable N is set to 3 as in this embodiment, 3-byte data can be transmitted.

[0129] In S3014, the camera control circuit A 101 changes SDA to high level (stop (STOP) condition) while SCL is at high level. Thereby, the communication end is notified to the accessory control circuit 201.

[0130] Figure 17 The flowchart in shows the processing to be performed by the camera control circuit A 101 when the camera control circuit A 101 receives N-byte data from the accessory control circuit 201.

[0131] In S3101, the camera control circuit A 101 stores the numerical value indicating the number of bytes to be received in the internal variable N. For example, when 3-byte data is received, 3 is stored. In this embodiment, 3 is stored.

[0132] In S3102 to S3106, the camera control circuit A 101 performs the same processing as in S3002 to S3006 respectively, and thus the description thereof will be omitted.

[0133] In S3107, the camera control circuit A 101 sets the storage address information (start address information) of the data received from the accessory control circuit 201 to the transmission data. In this embodiment, the size of the start address information is 1 byte, and the value is 0x00.

[0134] In S3108, the camera control circuit A 101 transmits the set 1-byte start address information (value 0x00) to the accessory control circuit 201.

[0135] In S3109, after the camera control circuit A 101 sends 1-byte start address information data, it outputs SCL and maintains it for one clock, and confirms the signal level of SDA. When the signal level of SDA is low, it is determined as the data reception notification (ACK) from the accessory control circuit 201, and the process proceeds to S3110. On the other hand, when 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.

[0136] In S3110, similar to S3102, the camera control circuit A 101 changes SDA to low while SCL is at a high level, and notifies the accessory control circuit 201 of the start condition.

[0137] In S3111, the camera control circuit A 101 sets the slave address information indicating the slave address of the accessory control circuit 201 to the high 7 bits of the data to be transmitted. In this embodiment, it is assumed that the slave address of the accessory control circuit 201 is 1010000 in binary.

[0138] In S3112, the camera control circuit A 101 sets the information indicating read communication to the low 1 bit of the data to be transmitted. Setting this bit to 1 means read communication.

[0139] In S3113, the camera control circuit A 101 sends the data set as the data to be transmitted in S3003 and S3004 (10100001 in binary and 0xA1 in hexadecimal) to the accessory control circuit 201.

[0140] In S3114, after the camera control circuit A 101 sends 1-byte data, it outputs SCL and maintains it for one clock, and confirms the signal level of SDA. When the signal level of SDA is low, it is determined as the data reception notification (ACK) from the accessory control circuit 201, and the process proceeds to S3115. On the other hand, when 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.

[0141] In S3115, the camera control circuit A 101 stores 1 in the internal variable M. The internal variable M is a variable used to count the number of received data.

[0142] In S3116, the camera control circuit A 101 outputs 1 byte of SCL and reads the signal level of SDA at the timing when SCL changes from low level to high level. This configuration enables receiving 1 byte of data from the accessory control circuit 201. The received 1 byte of data can be stored in the volatile memory 125 as the data corresponding to the address 0x00 or used for a predetermined process.

[0143] In S3117, the camera control circuit A 101 determines whether 1 byte of data is normally received. In the case of normal reception, the process proceeds to S3118. In the case of no normal reception, the process proceeds to S3119.

[0144] In S3118, the camera control circuit A 101 confirms whether the internal variable M has the same value as the value of the internal variable N. If the internal variable M has the same value as the value of the internal variable N, it is determined that the reception of all data is completed, and the process proceeds to S3119. If the internal variable M does not have the same value as the value of the internal variable N, it is determined that there is still data to be received, and the process proceeds to S3120.

[0145] 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 of SCL and by performing control for changing SDA to low level.

[0146] In S3121, the camera control circuit A 101 adds 1 to the internal variable M, and the process returns to S3116.

[0147] 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 of data corresponding to each address. In this way, the camera control circuit A 101 receives N bytes of data from the accessory control circuit 201 by repeating the reception of 1 byte of data until the internal variable M and the internal variable N have the same value in the process of S3118. In the case where the internal variable N is set to 3 as in this embodiment, 3 bytes of data can be received.

[0148] In S3119, the camera control circuit A 101 outputs 1 byte of SCL and performs control for changing SDA to high level to notify the accessory control circuit 201 of the completion of data communication (NACK).

[0149] In S3122, the camera control circuit A 101 changes SDA to high level (stop condition) while SCL is at high level. Thereby, the communication end is notified to the accessory control circuit 201.

[0150] Figure 18A and Figure 18B The flowchart in it illustrates the processing to be performed by the accessory control circuit 201 when the camera control circuit A 101 sends 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.

[0151] In S3201, the accessory control circuit 201 waits for SDA to change to low level (start condition) while SCL is at high level. When the accessory control circuit 201 detects the start condition, the process proceeds to S3202.

[0152] In S3202, the accessory control circuit 201 stores 0 in the internal variable M. The internal variable M is a variable used to count the number of transmitted data and the number of received data.

[0153] In S3203, the accessory control circuit 201 receives 1-byte data sent from the camera control circuit A 101.

[0154] In S3204, the accessory control circuit 201 determines whether the high 7-bit data of the 1-byte data received in S3203 is the same as the slave address of the accessory control circuit 201 (0x50 in this embodiment). If the address is the same as the slave address of the accessory control circuit 201, the process proceeds to S3205. If the address is not the same as the slave address of the accessory control circuit 201, the process proceeds to S3221.

[0155] In S3205, the accessory control circuit 201 provides a data reception notification (ACK) to the camera control circuit A 101 by controlling to change SDA to low level for the next SCL clock output after receiving the 1-byte data.

[0156] In S3206, the accessory control circuit 201 determines the type of data for the next 1-byte communication based on the low 1-bit data of the 1-byte data received in S3203. If the low 1-bit data is 0, it is determined that the data for the next 1-byte communication is the start address information from the camera control circuit A 101 to the accessory control circuit 201, and the process proceeds to S3207. If the low 1-bit data is 1, it is determined that the data for the next 1-byte communication is the data sent from the accessory control circuit 201 to the camera control circuit A 101, and the process proceeds to S3209.

[0157] In S3207, the accessory control circuit 201 receives 1-byte data sent from the camera control circuit A 101. The received 1-byte data is information indicating the address of the data to be transmitted and received in subsequent communications. In the present embodiment, as described with reference to Figure 16 and Figure 17 , it is assumed that the start address information is 0x00.

[0158] On the other hand, in S3209, the accessory control circuit 201 uses the address information pre-stored in the accessory control circuit 201 or the address information notified in advance from the camera control circuit A 101 as the start address information.

[0159] In S3208, when the accessory control circuit 201 determines that the 1-byte data can be normally received, the process proceeds to S3210. When it is determined that the 1-byte data cannot be normally received, the process proceeds to S3221.

[0160] In S3210, the accessory control circuit 201 provides a data reception notification (ACK) to the camera control circuit A 101 by controlling to change SDA to a low level for the next SCL clock output after receiving the 1-byte data.

[0161] In S3211, the accessory control circuit 201 confirms whether SDA changes to a low level (start condition) while SCL is at a high level. When 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 representing the slave device address and communication type to be sent from the camera control circuit A 101 to the accessory control circuit 201. Then, the process proceeds to S3212. When 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 the data information received by the accessory control circuit 201 from the camera control circuit A 101. Then, the process proceeds to S3216.

[0162] In S3212, the accessory control circuit 201 receives 1-byte data sent from the camera control circuit A 101.

[0163] In S3213, the accessory control circuit 201 determines whether the upper 7-bit data of the 1-byte data received in S3212 matches the slave device address (0x50 in the present embodiment) of the accessory control circuit 201. When the upper 7-bit data matches the slave device address of the accessory control circuit 201, the process proceeds to S3214. When the upper 7-bit data does not match the slave device address of the accessory control circuit 201, the process proceeds to S3221.

[0164] In S3214, the accessory control circuit 201 determines the data type to be used for the next one-byte communication based on the lower 1-bit data of the one-byte data received in S3203. If the lower 1-bit data is 0, the process proceeds to S3221. If the lower 1-bit data is 1, it is determined that the data for the next one-byte communication is data to be sent from the accessory control circuit 201 to the camera control circuit A101, and the process proceeds to S3215.

[0165] In S3215, the accessory control circuit 201 provides a data reception notification (ACK) to the camera control circuit A 101 by controlling to change SDA to a low level for the next SCL clock output after receiving the one-byte data.

[0166] In S3222, the accessory control circuit 201 sends one-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.

[0167] In S3223, the accessory control circuit 201 increments the internal variable M by 1, and the process proceeds to S3224.

[0168] In S3224, the accessory control circuit 201 confirms the signal level of SDA after sending one-byte data. If the signal level of SDA is high, the camera control circuit A 101 determines that this is a notification (NACK) of receiving all data, and the process proceeds to S3225. On the other hand, if the signal level of SDA is low, it is determined that the camera control circuit A101 continues to request 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 sent and sends one-byte data corresponding to each address. Thus, by repeatedly sending one-byte data from the camera control circuit A 101 until NACK is notified in the process of S3224, the accessory control circuit 201 sends N-byte data to the camera control circuit A 101.

[0169] 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, the communication is terminated.

[0170] 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 a predetermined process.

[0171] In S3217, the accessory control circuit 201 adds 1 to the internal variable M, and the process proceeds to S3218.

[0172] In S3218, if the accessory control circuit 201 determines that 1-byte data can be normally received, the process proceeds to S3219. If it is determined that 1-byte data cannot be normally received, the process proceeds to S3221.

[0173] In S3219, the accessory control circuit 201 provides a data reception notification (ACK) to the camera control circuit A 101 by controlling to change SDA to a low level for the next SCL clock output after receiving the 1-byte data.

[0174] In S3230, the accessory control circuit 201 confirms whether it has detected 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, the accessory control circuit 201 terminates the communication. On the other hand, when the accessory control circuit 201 does not detect the stop condition, the accessory control circuit 201 determines that data will be continuously transmitted from the camera control circuit A 101 to the accessory control circuit 201. Then, the process returns to S3216.

[0175] 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 repeating the reception of 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 A 101.

[0176] Therefore, the camera connector 141 includes contacts TC12 for data signals by the I2C communication method, and contacts TC13 for clock signals by the I2C communication method arranged on one side of the contacts TC12 for the data signals (adjacent to each other on one side). The camera connector 141 further includes contacts TC11 for a second input signal, contacts TC10 for an input selection signal by the SPI communication method, contacts TC09 for reception by the SPI communication method, contacts TC08 for transmission by SPI communication, contacts TC07 for a clock signal by the SPI communication method, contacts TC06 for a first input signal, and contacts TC05 for an output signal, and these contacts are arranged on the other side of the contacts TC12 for the data signals (arranged in order starting from adjacent positions on the other side).

[0177] The accessory 200 stores accessory information in a non-volatile memory (not shown). The accessory information is information for enabling the camera 100 to identify the type of the accessory 200 and the specifications related to communication and operation (functions) with the accessory 200. Figure 5 Illustrate an example of the accessory information. The accessory information is mapped in the memory space at addresses 0x00 to 0x0F, and the accessory information can be read out from the accessory 200 through I2C communication. The details of the accessory information will be described below. In the I2C communication according to the present embodiment, a checksum value for the read data is added as the final data of the communication.

[0178] Connected to Figure 1 The FNC1 signal connected to TC14 shown as a communication contact, the FNC2 signal connected to TC15, the FNC3 signal connected to TC16, and the FNC4 signal connected to TC17 are function signals whose functions are variable according to the type of the attached accessory 200. For example, when the accessory 200 is a microphone device, the signal communicated via TC15 is a signal related to voice data, and when the accessory 200 is a flash device, the signal communicated via TC14 is a signal notifying the light emission timing.

[0179] Signals for implementing different functions can be communicated via the same contacts according to the type of the attached accessory. For example, when the accessory 200 is an accessory other than a lighting device, a synchronization signal for controlling a timing different from the light emission timing can be communicated via TC14. TC14 to 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 at a timing independent of I2C communication and SPI communication in parallel with I2C communication and SPI communication.

[0180] As used herein, the accessory types mean the above-described microphone devices, lighting devices, etc. Accessories that achieve the same purpose (such as lighting with different performances) belong to the same type of accessories. Accessories that achieve different purposes (such as microphone devices and lighting devices) are different types of accessories. Function signal communication is performed based on information obtained through I2C communication or SPI communication.

[0181] TC18, which is the second ground contact, is also connected to GND and, similar to TC04, is a contact that serves as the 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 which the two perform data communication in pairs and are connected to the camera control circuit B 102. For example, USB communication can be performed via TC19 and TC20.

[0182] TC21 is connected to GND and can be used not only as a reference potential contact but also as a contact configured to control the wiring impedance of the differential signals D2N and D2P. TC21 corresponds to the fourth ground contact. The contacts TC01, TC04, TC06, TC18, and TC21 are connected to the GND portion of, for example, a flexible printed circuit (FPC) board, and the GND portion of the FPC board is fixed to a metal member serving as the GND level of the camera 100 by means such as screws. The metal member serving as the GND level includes, for example, an engagement member that can be engaged with the accessory 200 in the accessory socket portion, and a bottom plate (not shown) inside the camera 100.

[0183] In this embodiment, the attachment detection contact TC06 to which the accessory attachment detection signal / ACC_DET is connected is arranged adjacent to the contact (first clock contact) TC07 that transmits the clock signal SCLK (first clock signal). Generally, noise (clock noise) associated with potential fluctuations of the clock signal is transmitted to a contact adjacent to the contact of the clock signal, which may cause malfunctions. In particular, as in this embodiment, this effect is significant in a configuration having many contacts and a short distance between the contacts. Therefore, by arranging the attachment detection contact TC06 adjacent to the SCLK contact TC07, the influence of clock noise can be suppressed.

[0184] The accessory attachment detection signal / ACC_DET is pulled up before the accessory is attached but is set to the GND potential after the accessory is attached. On the other hand, before the accessory is attached, since the SCLK contact TC07 for transmitting the clock signal does not transmit the clock signal, the potential does not fluctuate. Only after the accessory is attached does the potential fluctuate due to the transmission of the clock signal.

[0185] When the clock signal is sent from the SCLK contact TC07, the attachment detection contact TC06 is at the GND potential. Therefore, even if the attachment detection contact TC06 receives clock noise, the potentials of the control circuits of the camera 100 and the accessory 200 are unlikely to fluctuate, thereby preventing malfunctions. In addition, the clock noise can be suppressed from being sent to a position farther than the accessory detection contact TC06. As a result, it is not necessary to provide a GND terminal, so the influence of the clock noise can be suppressed without increasing the number of contacts.

[0186] The SCL (second clock signal) as the clock signal is also sent to the contact (second clock contact) TC13. However, the SCLK sent to the SCLK contact TC07 has a higher frequency than that of the SCL, 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 next to the SCL contact TC13 is more effective in preventing malfunctions caused by clock noise.

[0187] In addition to the frequency difference, the SCL sent from 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 sent from 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 less likely to generate clock noise. 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.

[0188] The differential signals D1N and D1P can be sent in pairs to the first differential signal contact TC19 and the second differential signal contact TC20 to send the clock signal. In this case, a clock signal (third clock signal) with a higher frequency than that of the SCLK contact TC07 and the SCL contact TC13 can be sent. However, since the differential signals D1N and D1P are paired signals, the clock noise emission is smaller than that of the SCLK contact TC07 and the SCL contact TC13 that send single-ended signals. 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.

[0189] A contact (first data contact) TC08 arranged on the opposite side of the attachment detection contact TC06 adjacent to the SCLK contact TC07 transmits MOSI (first data signal). Since MOSI is a data signal, MOSI seems vulnerable to clock noise. However, MOSI is a data signal of the same SPI communication standard as the clock signal transmitted by the SCLK contact TC07, so the potential fluctuation timing is synchronized with the clock signal and is less likely to be affected by clock noise. Therefore, the contact TC08 does not have to be fixed to the GND potential and can be used as the MOSI contact.

[0190] The accessory 200 has a battery 205 and receives power supply from the battery 205, and also receives power supply from the camera 100 via the camera connector 141 and the accessory connector 211. The accessory control circuit 201, which is the 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 according to a computer program.

[0191] The accessory power supply circuit 202 is a circuit that generates a power supply for supplying power to each circuit in the accessory 200, and includes a DC / DC converter circuit, an LDO, a charge pump circuit, etc. 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 can be different from 1.8V. The control of the accessory power supply circuit 202 can provide on and off control of the power supply to each circuit in the accessory 200.

[0192] The charging circuit 204 is a circuit that charges the battery 205 using the power supplied from the camera 100. When the accessory control circuit 201 can determine that sufficient power has been supplied from the camera 100 for the charging operation, the accessory control circuit 201 controls the charging circuit 204 to charge the battery 205. In this embodiment, the battery 205 is attached to the accessory 200, but the accessory 200 can operate only with the power supply from the camera 100 without the battery 205 attached. In this case, the charging circuit 204 is unnecessary.

[0193] The differential communication circuit 207 is a circuit for 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 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 send the data received from the camera 100 to the external device and send the data received from the external device to the camera 100.

[0194] The function circuit 206 is a circuit that has different functions according to the type of the accessory 200. When the accessory 200 is a flash device, the function circuit 206 is, for example, a light-emitting circuit or a charging circuit. When the accessory 200 is a microphone device, the accessory 200 is a voice codec circuit or a microphone circuit.

[0195] The external connection terminal 209 is a connector terminal for connection to an external device and is a USB TYPE-C connector in this embodiment. 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 the external device to the external connection terminal 209 by receiving the output signal of the connection detection circuit 210.

[0196] The power switch 203 is a switch that can be operated by the user to turn on and off the power of the accessory 200 (i.e., the operation). 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.

[0197] 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 buttons, cross keys, slide switches, dial switches, and touch sensors. When the operation switch 212 is operated, the accessory control circuit 201 detects the operation and executes a predetermined process according to the operation.

[0198] The accessory connector 211 is a connector that can be electrically connected to the camera 100 via 21 contacts TA01 to TA21 arranged in a row. The contacts TA01 to TA21 are arranged in the order of contacts TA01 to TA21 from one end to the other end in the arrangement direction.

[0199] TA01 is connected to GND and is used not only as a reference potential contact but also as a contact configured to control the wiring impedance of the differential signals D1N and D1P. TA01 corresponds to the third ground contact.

[0200] The differential signal D1N connected to TA02 and the differential signal D1P connected to TA03 are data communication signals for the two to perform data communication 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.

[0201] TA04, which is the first ground contact, is connected to GND and serves as the reference potential contact for the camera 100 and the accessory 200. TA04 is arranged outside TA05 described below along the arrangement direction of the contacts.

[0202] The accessory power supply circuit 202 and the charging circuit 204 are connected to TA05, which is a power supply contact, and the accessory power supply VACC supplied from the camera 100 is connected to TA05.

[0203] TA06, which is 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 above-mentioned accessory attachment detection signal / ACC_DET to a low level (GND potential) as the activation potential. Thus, the camera 100 can detect the attachment of the accessory 200.

[0204] SCLK connected to TA07, which is 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 be used as a communication slave device for SPI communication.

[0205] The 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 required, the accessory control circuit 201 requests communication from the camera 100 by changing the communication request signal / WAKE from a high level to a low level.

[0206] When power is supplied to the accessory 200 from the camera control circuit 101 via TC5 in response to detecting the attachment of the accessory 200, the accessory control circuit 201 notifies the camera control circuit 101 of receiving the power supply by changing the signal level (by changing the potential) of the communication request signal / WAKE from a high level to a low level.

[0207] Even when there is no request from the camera, the accessory control circuit 201 can notify the existence of a factor that enables the accessory 200 to communicate with the camera 100 by changing the signal level (potential) of the communication request signal / WAKE from high level to low level. With this configuration, the camera control circuit 101 can omit the operation of periodically checking by polling whether the accessory 200 has a factor that requires communication. When a communication required factor occurs, the accessory 200 can communicate with the camera 100 in real time.

[0208] SDA connected to TA12 as a communication contact and SCL connected to TA13 are signals for the accessory control circuit 201 to be used as a communication slave device for I2C communication.

[0209] Therefore, the accessory connector 211 includes a contact TA12 for data signals by the I2C communication method, and a contact TA13 for clock signals by the I2C communication method arranged on one side of the contact TA12 for data signals (adjacent to the contact TA12 for data signals on one side). The accessory connector 211 also includes a contact TA11 for a second input signal, a contact TA10 for an input selection signal by the SPI communication method, a contact TA09 for transmission by the SPI communication method, a contact TA08 for reception by the SPI communication method, a contact TA07 for a clock signal by the SPI communication method, a contact TA06 for a first input signal, and a contact TA06 for an output signal in sequence from a position adjacent to the contact TA12 for data signals on the other side (on the other side).

[0210] 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 according to the type of the accessory 200. For example, when the accessory 200 is a microphone device, these signals can be signals related to voice data, and when the accessory 200 is a flash device, these signals can be signals for notifying the light emission timing.

[0211] TA18 as a second ground contact is also connected to GND and, similar to TA04, is a reference potential contact for the camera 100 and the accessory 200. The differential signal D2N connected to TA19 and the differential signal D2P connected to TA20 are data communication signals for data communication in pairs and are connected to the external connection terminal 209.

[0212] 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 differential signals D2N and D2P. TA21 corresponds to the fourth ground contact.

[0213] Contacts TA01, TA04, TA06, TA18, and TA21 are connected to the GND portion of, for example, an FPC substrate, and the GND portion of the FPC substrate is fixed to a metal member serving as the GND level of the accessory 200 using a screw (not shown). The metal member serving as the GND level includes, for example, socket attachment legs that can be engaged with the accessory socket portion of the camera 100, and a bottom plate (not shown) inside the accessory 200.

[0214] Figure 6 An example of the processing sequence to be performed when the accessory 200 is attached to the camera 100 is illustrated. Now, an overview of the processing of each of the camera 100 (camera control circuits A 101 and B 102) and the accessory 200 (accessory control circuit 201) will be described, and the details will be described below.

[0215] When the accessory 200 is attached to the camera 100, the accessory attachment detection signal / ACC_DET becomes low. Thereby, the camera control circuit A 101 determines that the accessory 200 is attached to the camera 100. The camera control circuit A 101 that determines that the accessory 200 has been attached sets the power control signal CNT_VACC1 to high level to turn on the output of the accessory power supply circuit A 131. When the power control signal CNT_VACC1 becomes high, the accessory power supply circuit A 131 outputs the accessory power VACC.

[0216] The accessory power supply circuit 202 that has received VACC generates the power VMCU_A used by the accessory control circuit 201. Thereby, the accessory control circuit 201 is started. The started accessory control circuit 201 initializes each block in the accessory 200. After that, 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 low level.

[0217] When the communication request signal / WAKE becomes low, 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 through I2C communication. The accessory control circuit 201 that has received the accessory information request sends the accessory information to the camera control circuit A 101. The accessory control circuit 201 that has sent the accessory information sets the communication request signal / WAKE to high level.

[0218] 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 supply circuit B 132. Then, the camera control circuit A 101 performs various settings of the camera 100, and when these settings are completed, the camera control circuit A 101 notifies the camera control circuit B 102 of the accessory information.

[0219] Based on the notified accessory information, the camera control circuit B 102 notifies a control command (accessory control communication) to the accessory 200 through SPI communication or performs control corresponding to a function signal (function signal control). That is, the camera control circuit B 102 controls the accessory 200 through SPI communication.

[0220] The accessory control circuit 201 responds to the control command from the camera 100 through SPI communication and operates according to the function signal.

[0221] Now, the Figure 5 shown accessory information will be described. The D7 - D0 data at address 0x00 is information indicating the type of the accessory (hereinafter referred to as accessory type information). Figure 7 Examples of the accessory type information are illustrated. 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.

[0222] The adapter device is an intermediate accessory attached between the camera 100 and accessories such as a flash device and a microphone device. The interface conversion adapter device is an adapter device that converts the interface to provide compatibility between the camera 100 and the accessory when the interfaces of the camera 100 and the accessory are different. The multi - accessory connection adapter device is an adapter device to which multiple accessories can be attached.

[0223] Figure 5 The D7 - D0 data at address 0x01 in [[ ]] 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.

[0224] The D7 - D0 data at address 0x02 is information indicating the firmware version of the accessory 200.

[0225] The D7-D6 data at address 0x03 is specification information indicating whether to request the supply of accessory power VACC to the accessory 200 when the power switch (not shown) of the camera 100 is turned off. When this information is 0, power supply is not requested. When this information is 1, the accessory power supply circuit A 131 requests power supply. When this information is 2, the accessory power supply circuit B 132 requests power supply.

[0226] The D5-D4 data at address 0x03 is specification information (hereinafter referred to as auto power-off power supply required / not required information) indicating whether to request the supply of accessory power VACC to the accessory 200 when the camera 100 is in the power saving state (hereinafter referred to as the auto power-off state) through the auto power-off function. The camera 100 has an auto power-off function to save power, and this auto power-off function automatically cuts off the power when the non-operation state without operation continues for a predetermined time. When this information is 0, it means that power supply is not required. When this information is 1, it means that there is a power supply requested by the accessory power supply circuit A131. When this information is 2, it means that there is a power supply requested by the accessory power supply circuit B 132.

[0227] The D3-D2 data at address 0x03 is specification information indicating whether the accessory 200 has a 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.

[0228] The D1-D0 data at address 0x03 is specification information indicating whether the accessory 200 has a charging function for the battery 205. When this information is 0, it means that the accessory 200 does not have a charging function, and when this information is 1, it means that the accessory 200 has a charging function.

[0229] The D7-D0 data at address 0x04 is specification information indicating the required power of the accessory power 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. When this information is 10, it means 100 mA, and when this information is 100, it means 1 A. To reduce the amount of information of this information, this information can be simply associated with the current value. For example, when this information is 0, it can mean 100 mA, when this information is 1, it can mean 300 mA, when this information is 3, it can mean 450 mA, and when this information is 4, it can mean 600 mA.

[0230] The D7 data at address 0x05 is specification information indicating whether the accessory 200 is in the firmware update mode. When this information is 0, it means that the accessory 200 is not in the firmware update mode, and when this information is 1, it means that the accessory 200 is in the firmware update mode.

[0231] The D6 data at address 0x05 is specification information indicating whether the accessory 200 has the firmware update function. When this information is 0, it means that the accessory 200 does not have the firmware update function. When this information is 1, it means that the accessory 200 has the firmware update function.

[0232] 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. When this information is 0, it means that the operation is not permitted, and when this information is 1, it means that the operation is permitted.

[0233] The D3-D2 data at address 0x05 is specification information indicating whether the accessory 200 needs the camera 100 to confirm the connection of the intermediate accessory when the camera 100 is started. When this information is 0, it means that the confirmation is unnecessary, and when this information is 1, it means that the confirmation is necessary.

[0234] The D1-D0 data at address 0x05 is specification information indicating whether the accessory 200 supports command notification via I2C communication. When this information is 0, it means that command notification is not supported, and when this information is 1, it means that command notification is supported.

[0235] The D5-D4 data 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) of the following communication method, which 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. When this information is 0, it means that the I2C communication method is the factor acquisition method. When this information is 1, it means that the SPI communication method is the factor acquisition method. When this information is 2, it means that both the I2C communication method and the SPI communication method are the factor acquisition methods.

[0236] The D3 - D0 data at address 0x06 is specification information indicating whether the accessory 200 has functions corresponding to the FNC1 signal (function signal 1), FNC2 signal (function signal 2), FNC3 signal (function signal 3), and FNC4 signal (function signal 4). The D0 data corresponds to the FNC1 signal, the D1 data corresponds to the FNC2 signal, the D2 data corresponds to the FNC3 signal, and the D3 data corresponds to the FNC4 signal. When the value is 0, it means the accessory 200 does not have this function. When the value is 1, the accessory 200 has this function.

[0237] The D7 data at address 0x0A is specification information indicating whether the accessory 200 requests the camera 100 to start when the accessory 200 notifies the camera 100 of a communication request signal / WAKE. When this information is 0, it means a start request, and when this information is 1, it means no start request.

[0238] The D6 - D0 data at address 0x0A is information indicating the generation factor of the communication request signal / WAKE notified by the accessory 200 to the camera 100.

[0239] Figure 8 Examples of factors (hereinafter also referred to as communication request factors) for generating the communication request signal / WAKE are illustrated. Here, examples in the case where the accessory 200 is a microphone device are illustrated. For example, the factor number 0x00 is the number indicating that the menu call switch in the operation switch 212 has been operated (pressed). The factor number 0x01 is the number indicating that the accessory 200 has completed the output control of the audio signal. The factor number 0x02 is the number indicating that the accessory 200 has completed the mute (unmute) process of the audio signal. As described above, in this embodiment, information related to the communication request factor (number), which is 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.

[0240] In Figure 5 the D1 data at address 0x0C is specification information indicating the SPI communication protocol supported by the accessory 200. When this information is 0, it means the accessory 200 supports SPI protocol A, and when this information is 1, it means the accessory 200 supports SPI protocol B.

[0241] 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 CS is low - active logic, and when this information is 1, it means CS is high - active logic.

[0242] The data of D7 - D0 at address 0x0D is specification information representing the time required as a communication byte interval in the case where 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 the firmware update mode.

[0243] The data of D7 - D0 at address 0x0E is specification information representing the time required as a communication byte interval in the case where the accessory 200 communicates according to SPI protocol A and the D7 data at address 0x05 is 1, or the accessory 200 is in the firmware update mode.

[0244] Figure 9A and Figure 9B Illustrate the time (communication interval) of the communication byte interval corresponding to the data (0 to 7) at addresses 0x0D and 0x0E. Figure 9A Illustrate the communication interval for the data at address 0x0D, and Figure 9B Illustrate the communication interval for the data at address 0x0E.

[0245] In Figure 5 the data at address 0x0F is data of a checksum value representing the sum of the values at addresses 0x00 to 0x0E.

[0246] Figure 10 Illustrate the startup process that the camera control circuit A 101 has to execute until the accessory 200 is attached to the camera 100 and the functions of the accessory 200 are enabled.

[0247] In S401, the camera control circuit A 101 monitors the signal level of the accessory attachment detection 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 A101 determines again 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.

[0248] In S402, the camera control circuit A 101 performs control to change the power control signal CNT_VACC1 to a high level to turn on the output of the accessory power supply circuit A 131. Then, the process proceeds to S403. When the power control signal CNT_VACC1 is at a high level, the accessory power supply circuit A 131 outputs the accessory power VACC.

[0249] 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 handling.

[0250] In S404, the camera control circuit A 101 monitors the signal level of the communication request signal / WAKE, which is a notification signal from the accessory 200, and determines whether the 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 the initialization is complete, and the process proceeds to S406. If the signal level is high, the camera control circuit A 101 determines that the initialization is not yet complete, and the process returns to S404 so that the camera control circuit A 101 determines again whether the initialization is complete.

[0251] In S406, the camera control circuit A 101 performs I2C communication with the accessory 200 as initial communication and reads 15 bytes of accessory information. Then, the process proceeds to S407.

[0252] In S407, the camera control circuit A 101 determines whether the attached accessory 200 is a compatible device (compatible accessory) with the camera 100 based on the accessory information read in S406. If the camera control circuit A 101 determines that the attached accessory 200 is a compatible accessory, the process proceeds to S408. If the camera control circuit A 101 determines that the attached accessory 200 is not a compatible accessory, the process proceeds to S409 for error handling.

[0253] In S408, the camera control circuit A 101 performs control to change the power control signal CNT_VACC2 to a high level to turn on the output of the accessory power supply circuit B 132. Then, the process proceeds to S410. When the power control signal CNT_VACC2 is at a high level, the accessory power supply circuit B 132 outputs the accessory power VACC. In this embodiment, when both the power 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 VACC.

[0254] In S410, the camera control circuit A 101 notifies the camera control circuit B 102 of the accessory information read in S406. Thus, the startup process of the camera 100 in response to the attachment of the accessory 200 is completed.

[0255] Figure 11 The flowchart in Figure 11 illustrates the enabling process to be performed by the camera control circuit B 102 until the accessory 200 is attached to the camera 100 and the functions of the accessory 200 are enabled.

[0256] In S501, the camera control circuit B 102 determines whether accessory information has been notified from the camera control circuit A 101. If the accessory information has not been notified, the process returns to S501, and the camera control circuit B 102 determines again whether the accessory information has been notified. If the accessory information has been notified, the process proceeds to S502.

[0257] In S502, the camera control circuit B 102 sets the function signals FNC1 to FNC4 based on the accessory information notified from the camera control circuit A 101. For example, when it is notified that the accessory 200 is a microphone device, FNC1 is set to be used as the voice data clock signal BCLK, FNC2 is set to be used as the voice data channel signal LRCLK, and FNC3 is set to be used as the voice data signal SDAT. As another example, when it is notified that the accessory 200 is a flash device, FNC4 is set to be used as the flash emission synchronization signal XOUT. For the function signals that do not require control of the accessory 200, a predetermined setting is made so as not to interfere with the operations of the camera 100 and the accessory 200.

[0258] 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.

[0259] In S504, the camera control circuit B 102 determines whether a predetermined event for the accessory 200 has occurred. If the event has not occurred, the process returns to S504, and the camera control circuit B 102 determines again whether the event has occurred. If the event has occurred, the process proceeds to S505.

[0260] In S505, the camera control circuit B 102 determines whether the event determined in S504 is an event that requires SPI communication with the accessory 200. If the event requires SPI communication, the process proceeds to S506; otherwise, the process proceeds to S507.

[0261] In S507, the camera control circuit B 102 determines whether the event determined in S504 is an event that requires control of the accessory 200 using the function signals. If the event requires control using the function signals, the process proceeds to S508; otherwise, the process proceeds to S509.

[0262] In S506, the camera control circuit B 102 performs SPI communication with the accessory 200. When the accessory 200 is a microphone device, the SPI communication performed here includes, for example, communication of an instruction to turn on the microphone operation, communication of an instruction to turn off the microphone operation, communication of an instruction to switch the sound collection directivity of the microphone, and communication of an instruction to switch the equalizer function of the microphone, etc. When 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, etc. When the SPI communication in S506 is completed, the process returns to S504, and the camera control circuit B 102 determines again whether an event has occurred.

[0263] In S508, the camera control circuit B 102 controls the accessory 200 using function signals. For example, when 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. Thereby, the camera 100 can acquire voice data from the microphone device. When 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. Thereby, the camera 100 can instruct the flash device to emit light. When the control using the function signal is completed in this way, the process returns to S504, and the camera control circuit B 102 determines again whether an event has occurred.

[0264] In S509, the camera control circuit B 102 performs predetermined in-camera control according to the event determined in S504. When 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, etc. When the accessory 200 is a flash device, the in-camera control includes photometric control for using the image sensor 122 to accumulate and acquire the light emitted by the flash device and control for calculating an indication value of the light emission amount of the flash device, etc. When the in-camera control is completed in this way, the process returns to S504, and the camera control circuit B 102 determines again whether an event has occurred.

[0265] Through the above-mentioned startup process using the camera control circuit A 101 and the enabling process using the camera control circuit B 102, the accessory 200 attached to the camera 100 can be controlled.

[0266] Figure 12The flowchart in illustrates the processing to be performed by the accessory control circuit 201 from when the accessory 200 is attached to the camera 100 until various functional operations of the accessory 200 are enabled.

[0267] In S601, the accessory control circuit 201 waits for the accessory power supply VACC from the camera 100 to be turned on. When 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 starts. When 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 the turning on of the accessory power supply VACC.

[0268] In S602, the accessory control circuit 201 performs predetermined initial settings. For example, the accessory control circuit 201 sets the operation frequency of the microcomputer, the input / output control ports of the microcomputer, the initialization of the timer function of the microcomputer, and the initialization of the interrupt function of the microcomputer.

[0269] When the initial settings in S602 are completed, in S603, the accessory control circuit 201 performs control to change the communication request signal / WAKE to a low level. Thereby, the camera 100 is notified that the initial settings are completed.

[0270] In S604, the accessory control circuit 201 responds to the I2C communication from the camera 100 and sends 15-byte accessory information to the camera 100 as the initial communication. The accessory information includes Figure 5 the various information shown.

[0271] When the initial communication in S604 is completed, in S605, the accessory control circuit 201 controls the communication request signal / WAKE to a high level.

[0272] 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.

[0273] In S607, the accessory control circuit 201 determines whether the event determined in S606 is an event that requires SPI communication with the camera 100. If the event requires SPI communication, the process proceeds to S608, otherwise the process proceeds to S609.

[0274] In S609, the accessory control circuit 201 determines whether the event determined in S606 is an event that requires I2C communication with the camera 100. If the event requires I2C communication, the process proceeds to S610; otherwise, the process proceeds to S611.

[0275] 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.

[0276] In S613, the accessory control circuit 201 determines whether the event determined in S606 is an event that requires notification to the camera 100 via a communication request signal / WAKE. If the event requires notification to the camera 100 via a communication request signal / WAKE, the process proceeds to S614; otherwise, the process proceeds to S615.

[0277] In S608, the accessory control circuit 201 performs SPI communication with the camera 100. When the communication request signal / WAKE is at a low level during the execution of SPI communication by the accessory control circuit 201, the accessory control circuit 201 performs control to change the communication request signal / WAKE to a high level after the SPI communication. When the accessory 200 is a microphone device, the SPI communication performed here includes, for example, communication for an instruction to turn on the microphone operation from the camera 100, communication for an instruction to turn off the microphone operation, and communication for an instruction to switch the sound collection directionality of the microphone. The SPI communication also includes communication for an instruction to switch the equalizer function of the microphone. When the accessory 200 is a flash device, the SPI communication includes communication for reading setting information related to the flash device and communication for notifying the flash device of the setting information. When the predetermined SPI communication in S608 is completed, the process returns to S606, and the accessory control circuit 201 determines again whether an event has occurred.

[0278] In S610, the accessory control circuit 201 performs I2C communication with the camera 100. When the communication request signal / WAKE is at a low level during the execution of 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 for reading the communication request factor (number) 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 process returns to S606, and the accessory control circuit 201 determines again whether an event has occurred.

[0279] In S612, the accessory control circuit 201 controls the camera 100 using function signals. When the accessory 200 is a microphone device, the control performed here includes, for example, reception control of 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 output control of the voice data signal SDAT of FNC3 synchronized with these signals. When the accessory 200 is a flash device, the control includes reception control of the flash emission synchronization signal XOUT of FNC4 and corresponding flash emission control. When the control using function signals in S612 is completed, the process returns to S606, and the accessory control circuit 201 determines again whether an event has occurred.

[0280] In S614, the accessory control circuit 201 stores the communication request factor number for the camera 100 in response to the event determined in S606 in a non-illustrated volatile memory of the accessory 200, and performs control to change the communication request signal / WAKE to a low level. As Figure 8 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 process returns to S606, and the accessory control circuit 201 determines again whether an event has occurred.

[0281] In S615, the accessory control circuit 201 performs in-accessory control according to the event determined in S606. When the accessory 200 includes a battery 205, the in-accessory control performed here includes control for detecting the remaining battery power and control for detecting the operation of the operation switch 212, etc. When the in-accessory control in S615 is completed, the process returns to S606, and the accessory control circuit 201 determines again whether an event has occurred.

[0282] Through the above 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.

[0283] Figure 13 The illustrated flowchart illustrates the process in which when the camera 100 receives a communication request signal from the accessory 200, the camera control circuit A 101 notifies the camera control circuit B 102 of the occurrence of an event (communication request event) that requires accessory information and communication.

[0284] In S701, the camera control circuit A 101 monitors the signal level of the communication request signal / WAKE from the accessory 200 and determines whether a communication request from the accessory 200 has occurred. If the communication request signal / WAKE from the accessory 200 is at a low level, the camera control circuit A 101 determines that a communication request has occurred, and the process proceeds to S702. If the communication request signal / WAKE is at a high level, the camera control circuit A 101 determines that no communication request has occurred. Then, the process returns to S701, and the camera control circuit A 101 makes this determination again.

[0285] In S702, the camera control circuit A 101 determines whether Figure 10 the factor acquisition method in the accessory information obtained by I2C communication in S406 of

[0286] is the I2C communication method. If the factor acquisition method is the I2C communication method, the process proceeds to S703; otherwise, the process proceeds to S704.

[0287] In S704, the camera control circuit A 101 determines whether the factor acquisition method of the accessory information obtained by I2C communication in S406 is both the I2C communication method and the SPI communication method. If the factor acquisition method is these two communication methods, the process proceeds to S706; otherwise, the process proceeds to S707.

[0288] In S705, the camera control circuit A 101 notifies the camera control circuit B 102 of the accessory information obtained in S406 and notifies the accessory 200 that an event requiring I2C communication (I2C communication request event) has occurred. The accessory information at this time is the accessory information having the communication request factor obtained by updating the communication request factor read in S703.

[0289] In S706, the camera control circuit A 101 determines whether to perform I2C communication and SPI communication simultaneously (in parallel). If I2C communication and SPI communication are to be performed simultaneously, the process proceeds to S708; if I2C communication and SPI communication are not performed simultaneously, the process proceeds to S709.

[0290] In this embodiment, when I2C communication and SPI communication are to be performed simultaneously, 1 is assigned to the D0 data at address 0x0D, which is a reserved area for accessory information, and 0 is assigned when I2C communication and SPI communication are not performed simultaneously. However, information regarding whether I2C communication and SPI communication are to be performed simultaneously can be assigned to another reserved area. In addition, information regarding whether I2C communication and SPI communication can be performed simultaneously can be acquired from the accessory 200 in advance via SPI communication, and this information can be obtained from the camera control circuit B 102.

[0291] In S708, the camera control circuit A 101 notifies the camera control circuit B 102 of the accessory information read in S406, and notifies the accessory 200 of the occurrence of an event that requires SPI communication (SPI communication request event). In response, the camera control circuit B 102 performs SPI communication with the accessory 200 and reads the communication request factor to be acquired via SPI communication from the D6 - D0 data at address 0x0A.

[0292] In S710, the camera control circuit A 101 performs I2C communication with the accessory 200 and reads the communication request factor to be acquired via I2C communication from the D6 - D0 data at address 0x0A. Then, the process proceeds to S711.

[0293] In S711, the camera control circuit A 101 notifies the camera control circuit B 102 of the accessory information read in S406, and notifies the accessory 200 of the occurrence of an event that requires I2C communication. The accessory information at this time is the accessory information having the communication request factor obtained by updating the communication request factor read in S710.

[0294] The SPI communication performed by the camera control circuit B 102 in response to the notification of the SPI communication request event in S708 and the I2C communication performed by the camera control circuit A 101 in S710 are performed in parallel with no significant time difference. More specifically, the time for performing SPI communication and the time for performing I2C communication at least partially overlap each other. If another communication among I2C communication and SPI communication starts before a predetermined time has elapsed after one of the I2C communication and SPI communication is completed, the two communications can be considered to be performed in parallel when the predetermined time is short.

[0295] In S709, the camera control circuit A 101 performs I2C communication with the accessory 200 and reads the communication request factor, which is the D6 - D0 data at address 0x0A. Then, the process proceeds to S712.

[0296] In S712, the camera control circuit A 101 notifies the camera control circuit B 102 of the accessory information read in S406, and notifies the camera control circuit B 102 that an event (I2C / SPI communication request event) that requires both I2C and SPI communications from the accessory 200 has occurred. The accessory information at this time is accessory information having a communication request factor obtained by updating the communication request factor read in S709.

[0297] In S707, the camera control circuit A 101 determines whether the factor acquisition method in the accessory information acquired by I2C communication in S406 is the SPI communication method. When the factor acquisition method is the SPI communication method, the process proceeds to S713, and when the factor acquisition method is not the SPI communication method, the process proceeds to S714 for error handling.

[0298] In S713, the camera control circuit A 101 notifies the camera control circuit B 102 of the accessory information read in S406, and notifies the accessory 200 that an event requiring SPI communication has occurred.

[0299] Now, an example of controlling the camera 100 by a communication request from the accessory 200 will be described.

[0300] Example of controlling the camera 100 using I2C communication

[0301] Now, the menu display control of the camera 100 using I2C communication when the accessory 200 is a microphone device will be described.

[0302] Processing on the accessory 200 side

[0303] In Figure 12 In S604 of, the accessory control circuit 201 sends 15-byte accessory information to the camera control circuit A101 as a response to the I2C communication from the camera control circuit A 101. Now, it is assumed that the factor acquisition method in the accessory information is set to the I2C communication method.

[0304] When the user presses the menu call switch of the operation switch 212 in the accessory 200, the accessory control circuit 201 detects the operation and generates a menu call event for the camera 100. Thereby, the accessory control circuit 201 determines in S606 that a menu call event has occurred, and the process proceeds to S613 through S607, S609, and S611.

[0305] In S613, the accessory control circuit 201 determines that the event determined to have occurred in S606 is an event to be notified to the camera 100 using the communication request signal / WAKE, and in S614, controls to change the communication request signal / WAKE to a low level. As data of a communication request factor to be notified to the camera 100 through I2C communication, Figure 8 the data shown in

[0306] indicating "press the menu call SW" is stored. Then, the process returns to S606, and the accessory control circuit 201 determines again whether an event has occurred. When I2C communication from the camera control circuit A 101 occurs, the process proceeds in the order of S607, S609, and S610, and the accessory control circuit 201 notifies the communication request factor to the camera control circuit B 102 through I2C communication.

[0307] Processing on the camera 100 side

[0308] In Figure 11 S504, when the camera control circuit B 102 is notified by the camera control circuit A101 in Figure 13 S705 of an event that requires accessory information and I2C communication, it determines that an event has occurred. Thus, the process enters S509 through S505 and S507.

[0309] In S509, the camera control circuit B 102 causes the display circuit 127 to display a menu for the microphone device as shown in Figure 14A as an in-camera control in response to the event of "press the menu call SW" determined to have occurred in S504.

[0310] Therefore, the camera control circuit B 102 can complete the control of menu display control only by performing I2C communication with the accessory 200 without performing SPI communication. Therefore, the time required for SPI communication can be reduced, and a camera system with high real-time data communication performance can be realized.

[0311] Example of controlling the camera 100 using SPI communication

[0312] Now, the menu display control of the camera 100 using SPI communication in the case where the accessory 200 is a flash device will be described.

[0313] Processing on the accessory 200 side

[0314] In Figure 12In S604, the accessory control circuit 201 sends 15-byte accessory information to the camera control circuit A 101 in response to I2C communication from the camera control circuit A 101. Now assume that the factor acquisition method in the accessory information is set to the SPI communication method.

[0315] When the user presses the menu call switch of the operation switch 212 in the accessory 200, the accessory control circuit 201 detects this operation and generates a menu call event for the camera 100. Thus, the accessory control circuit 201 determines in S606 that a menu call event has occurred, and the process enters S613 through S607, S609, and S611.

[0316] In S613, the accessory control circuit 201 determines that the event determined to have occurred in S606 is an event for notifying the camera 100 using the communication request signal / WAKE, and performs control to change the communication request signal / WAKE to a low level in S614. As data for the communication request factor to be notified to the camera 100 through SPI communication, Figure 8 the data shown representing "press the menu call SW" is stored.

[0317] Next, the process returns to S606, and the accessory control circuit 201 determines again whether an event has occurred. When SPI communication from the camera control circuit B 102 occurs, the process enters S608 from S607, and the accessory control circuit 201 notifies the communication request factor to the camera control circuit B 102 through SPI communication.

[0318] Processing on the camera 100 side

[0319] In Figure 11 S504, when in Figure 13 S705 the camera control circuit A 101 notifies the camera control circuit B102 of the accessory information and the occurrence of an event that requires SPI communication, the camera control circuit B 102 determines that an event has occurred.

[0320] Thus, the camera control circuit B 102 acquires the communication request factor from the accessory control circuit 201 through SPI communication in S506 and acquires the flash information required for menu display. Then, the event of "press the menu call SW" is set, and the SPI communication terminates.

[0321] Next, the process returns to S504, and the camera control circuit B 102 determines again whether an event has occurred. The camera control circuit B 102 determines that the event of "press the menu call SW" has occurred, and the process enters S509 through S505 and S507.

[0322] In S509, the camera control circuit B 102 causes the display circuit 127 to display the following Figure 14B The menu used by the flash device is shown as the in-camera control in response to the event of “pressing the menu call SW” determined in S504.

[0323] Therefore, in the case where there is a large amount of necessary information such as a menu display for a flash device, the camera control circuit B 102 performs SPI communication. Therefore, compared with the case where a large amount of data is communicated only by I2C communication having a communication speed lower than that of SPI communication, an image pickup system with higher real-time performance can be realized.

[0324] Control Example of Camera 100 Using Both I2C and SPI Communications

[0325] Menu display control and flash bounce control of the camera 100 using both I2C communication and SPI communication in a case where the accessory 200 is a flash device will now be described.

[0326] Processing of accessory 200

[0327] exist Figure 12 In S604 of FIG. 2 , the accessory control circuit 201 transmits 15 bytes of accessory information to the camera control circuit A 101 as a response to the I2C communication from the camera control circuit A 101. It is now assumed that the factor acquisition method in the accessory information is set to both the I2C and SPI communication methods.

[0328] When the user presses the auto bounce switch and the menu call switch of the operation switch 212 in the accessory 200, the accessory control circuit 201 detects these operations, and generates an event of “auto bounce drive” and an event of “menu call SW pressed” for the camera 100. Thus, the accessory control circuit 201 determines in S606 that the event of “auto bounce drive” has occurred, and the flow proceeds to S615 through S607, S609, S611, and S613.

[0329] In S615, the accessory control circuit 201 performs automatic reflective drive control in response to the "automatic reflective drive" event as in-accessory control.

[0330] Next, the process returns to S606, and the accessory control circuit 201 determines that an event of "pressing the menu call SW" has occurred. Then, after the process passes through S607, S609, and S611 in sequence, the accessory control circuit 201 determines in S613 that the event determined to have occurred in S606 is an event for notifying the camera 100 using the communication request signal / WAKE, and the accessory control circuit 201 performs control to change the communication request signal / WAKE to a low level in S614. In addition, the accessory control circuit 201 stores the data ("automatic reflection drive") (first information) in Figure 8 at the address 0x03 as data of a communication request factor to be notified to the camera 100 through I2C communication. In this embodiment, "automatic reflection drive" is assigned as a communication request factor to the data at the address 0x03 in the reserved area. The accessory control circuit 201 stores the data ("pressing the menu call SW") (second information) as data of a communication request factor to be notified to the camera 100 through SPI communication.

[0331] The process returns to S606, and the accessory control circuit 201 determines the occurrence of an event. When I2C communication from the camera control circuit A 101 occurs, the process proceeds in the order of S607, S609, and S610 to notify the communication request factor to the camera control circuit B 102 through I2C communication. When SPI communication from the camera control circuit B 102 occurs, the process enters S608 from S607, and the accessory control circuit 201 notifies the communication request factor to the camera control circuit B 102 through SPI communication.

[0332] Although I2C communication and SPI communication are performed in this order in this example, the order can be reversed or simultaneous.

[0333] Processing on the camera 100 side

[0334] In Figure 11 at S504, the camera control circuit B 102 determines that an event has occurred based on Figure 13 the notification of accessory information from the camera control circuit A 101 in S705 and the occurrence of events of I2C communication and SPI communication. First, to handle the event of I2C communication, the process enters S509 through S505 to S507.

[0335] In S509, the camera control circuit B 102 calculates the optimal automatic reflection angle and generates an automatic reflection drive request event as an in-camera control according to the event of "automatic reflection drive" determined to have occurred in S504.

[0336] Next, the process returns to S504, and the camera control circuit B 102 processes the event of SPI communication. In S506, communication request factors are obtained through SPI communication, flash information required for menu display is also obtained, the event of "menu call SW pressed" is set, and SPI communication is terminated.

[0337] Next, the process returns to S504 again, and the camera control circuit B 102 detects the event of "menu call SW pressed", and the process enters S509 through S505 to S507. In S509, the camera control circuit B 102 causes the display circuit 127 to display the menu for the flash device as shown Figure 14B below, as the in-camera control in response to the event of "menu call SW pressed" detected in S504.

[0338] Therefore, since the camera control circuit B 102 controls the events obtained through I2C communication and SPI communication simultaneously, a imaging system with high real-time data communication performance can be realized.

[0339] Since the control when I2C communication and SPI communication are not performed simultaneously is realized through the combination of the above controls, its description will be omitted.

[0340] In each of the above 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 can be communication methods other than the I2C communication method and the SPI communication method.

[0341] In each of the above embodiments, the accessory is compatible with both the first communication method and the second communication method. However, the accessory is compatible with the first communication method but may not be compatible with the second communication method. As long as such an accessory sends information corresponding to the communication method used to communicate information related to the accessory request factor, the accessory can also reduce the number of inquiries from the camera to the accessory and perform highly responsive data communication.

[0342] In each of the above embodiments, the electronic device is an imaging device, but the electronic device according to the present invention can include various electronic devices other than the imaging device.

[0343] In each of the above-described embodiments, the accessory 200 is directly attached to the camera 100, but another attachment form may also be used. For example, the camera 100 and the 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 part of the communication control performed by the accessory 200 and the communication control performed by the camera 100 in the above-described embodiments. The intermediate accessory may serve as an information transmission path such that the accessory outputs information corresponding to the 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, the accessories according to the 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 an electronic device.

[0344] Each of the above-described embodiments may be an accessory, a control method of the accessory, an electronic device, and a control method of the electronic device, each of which can provide highly responsive data communication between the accessory and the electronic device.

[0345] Other embodiments

[0346] Embodiments of the present invention can also be implemented by a method in which software (program) that executes the functions of the above-described embodiments is provided to a system or device via a network or various storage media, and a computer or a central processing unit (CPU) or a microprocessing unit (MPU) of the system or device reads and executes the program.

[0347] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims is to be accorded the broadest interpretation so as to encompass all such modifications, equivalent structures, and functions.

Claims

1. An accessory that can be attached to an electronic device, can be detached from the electronic device, and can communicate with the electronic device via a first communication method and a second communication method different from the first communication method. The accessory includes an accessory processing unit configured to, in response to the accessory being attached to the electronic device, notify the electronic device via the first communication method of a factor acquisition method among the first communication method and the second communication method, where the factor acquisition method is used to communicate information about factors of a communication request from the accessory to the electronic device, and where the information is about factors of a communication request associated with an event that enables the accessory to communicate with the electronic device; and then make a communication request to the electronic device; and then in response to the communication request, use the factor acquisition method notified to the electronic device to send the information about the factors of the communication request to the electronic device.

2. The accessory according to claim 1, further comprising: contacts configured to send information via the first communication method; and contacts different from the contacts configured to send information via the first communication method and configured to send information via the second communication method.

3. The accessory according to claim 2, further comprising contacts different from each of the contacts configured to send information via the first communication method and the contacts configured to send information via the second communication method and configured to make the communication request.

4. The fitting according to claim 1, characterized in that, The communication speed of the first communication method is lower than the communication speed of the second communication method.

5. The accessory according to claim 1, characterized in that, The first communication method is an I2C communication method, and the second communication method is an SPI communication method.

6. The fitting according to claim 1, characterized in that, The factor acquisition method is one of the first communication method and the second communication method.

7. The accessory according to claim 1, wherein, The factor acquisition method is both the first communication method and the second communication method.

8. The fitting according to claim 7, characterized in that, The information about the factors includes first information and second information, wherein the accessory processing unit sends the first information to the electronic device via the first communication method and sends the second information via the second communication method.

9. The fitting according to claim 8, characterized in that, The accessory processing unit performs in parallel: sending the first information via the first communication method and sending the second information via the second communication method.

10. The fitting according to claim 1, characterized in that, The accessory processing unit makes the communication request by changing the level of a signal to be input to the electronic device.

11. The fitting according to any one of claims 1 to 10, characterized in that, The accessory can be attached to an accessory socket portion of the electronic device.

12. An electronic device to which an accessory can be attached, can be detached from the electronic device, and can communicate with the electronic device via a first communication method and a second communication method different from the first communication method. The electronic device includes a first processing unit configured to: In response to the accessory being attached to the electronic device, receive, via the first communication method, a factor acquisition method among the first communication method and the second communication method, where the factor acquisition method is used to communicate information about factors of a communication request from the accessory to the electronic device, and where the information is about factors of a communication request associated with an event that enables communication between the accessory and the electronic device; then receive the communication request from the accessory; then In response to the communication request, use the factor acquisition method notified to the electronic device to receive, from the accessory, information corresponding to the factor acquisition method for communicating information about the factors of the communication request.

13. The electronic device according to claim 12, characterized in that, Further includes a second processing unit capable of communicating with the accessory via the second communication method, wherein the first processing unit receives notification of the factor acquisition method from the accessory via the first communication method, and wherein, among the first processing unit and the second processing unit, the processing unit capable of communicating via the notified factor acquisition method receives information about the factors from the accessory via the factor acquisition method.

14. The electronic device according to claim 13, characterized in that, The first processing unit notifies the second processing unit of the factor acquisition method notified from the accessory.

15. The electronic device according to claim 13, wherein The communication speed of the first communication method is lower than the communication speed of the second communication method.

16. The electronic device according to claim 13, wherein The first communication method is an I2C communication method, and the second communication method is an SPI communication method.

17. The electronic device according to claim 13, wherein The factor acquisition method is both the first communication method and the second communication method, wherein the information about the factors includes first information and second information, and wherein the first processing unit receives the first information via the first communication method, and the second processing unit receives the second information via the second communication method.

18. The electronic device according to claim 17, wherein The first processing unit and the second processing unit perform in parallel: sending the first information via the first communication method and sending the second information via the second communication method.

19. The electronic device according to claim 12, characterized in that, As a result of a change in the level of a signal input from the accessory, the first processing unit receives the communication request.

20. The electronic device according to any one of claims 12 to 19, further comprising an accessory socket portion capable of being attached to and detached from the accessory.

21. A control method for an accessory capable of being attached to an electronic device, capable of being detached from the electronic device, and capable of communicating with the electronic device via a first communication method and via a second communication method different from the first communication method, the control method comprising the following steps: In response to the accessory being attached to the electronic device, notify the electronic device of the factor acquisition method among the first communication method and the second communication method through the first communication method, where the factor acquisition method is used to communicate information about factors of a communication request from the accessory to the electronic device, and where the information is about factors of a communication request associated with an event that enables communication between the accessory and the electronic device; then make a communication request to the electronic device; then In response to the communication request, use the factor acquisition method notified to the electronic device to send the information about the factors of the communication request to the electronic device.

22. A control method for an electronic device, where an accessory can be attached to the electronic device, can be detached from the electronic device, and can communicate with the electronic device through a first communication method and through a second communication method different from the first communication method, the control method comprising the following steps: In response to the accessory being attached to the electronic device, receive from the accessory the factor acquisition method among the first communication method and the second communication method through the first communication method, where the factor acquisition method is used to communicate information about factors of a communication request from the accessory to the electronic device, and where the information is about factors of a communication request associated with an event that enables communication between the accessory and the electronic device; then receive the communication request from the accessory; then In response to the communication request, use the factor acquisition method notified to the electronic device to receive from the accessory information corresponding to the factor acquisition method for communicating information about the factors of the communication request.

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