Electronic equipment, accessory, control method and system of electronic equipment and accessory, and storage medium

Abstract

The invention provides an electronic device, an accessory, a control method and system thereof, and a storage medium. The accessory includes: a plurality of communication contacts including a first contact; and a control unit for notifying the electronic device of a communication request by changing a signal level of the first contact from a first level to a second level different from the first level, and in response to receiving a request for information indicating a communication factor, transmitting the information indicating the communication factor, wherein a request for information representing a communication factor is received in response to notification of a communication request. In a case where the control unit notifies the electronic device of a communication request via the first contact in response to start of power supply, the control unit performs predetermined communication without receiving a request for information indicating a communication factor or without transmitting the information indicating the communication factor.

Description

[0001] (This application is a divisional application of an application with a filing date of April 21, 2022, application number 202210423089.7, and invention name “Electronic device and accessories and control method, system and storage medium thereof”.) Technical Field

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

[0003] A system including an electronic device and an accessory that can be attached to and detached from the electronic device communicates various commands, notifications, and information via multiple contacts. Japanese Patent Laid-Open (“JP”) 2013-238875 discloses a system in which a camera device, which is an electronic device that detects the attachment of an accessory, notifies the accessory of communication permission through an interrupt signal, and then acquires accessory information from the accessory through communication. In JP 2013-238875, the camera device determines whether to supply power to the accessory from the camera device based on the acquired accessory information (information for identifying the accessory).

[0004] The system disclosed in JP 2013-238875 has a structure in which an electronic device (camera) notifies an accessory of communication permission of accessory information. Various improvements in notification from an accessory to a camera are required. Summary of the invention

[0005] The present invention provides an accessory, an electronic device, a control method, a system, and a storage medium (program), each of which enables the accessory to notify the electronic device.

[0006] An accessory according to one aspect of the present invention is attachable to and detachable from an electronic device. The accessory includes: a plurality of communication contacts, including a first contact; and a control unit configured to control communication with the electronic device via the plurality of communication contacts. The control unit notifies the electronic device of a communication request by changing the signal level of the first contact from a first signal level to a second signal level different from the first signal level, and sends information representing the communication factor in response to receiving a request for information representing the communication factor, wherein the request for information representing the communication factor is received in response to the notification of the communication request. In the case where the control unit notifies the electronic device of the communication request via the first contact in response to the start of power supply, the control unit performs predetermined communication without receiving a request for information representing the communication factor or without sending information representing the communication factor. A system including the above-mentioned accessory and a control method for the above-mentioned accessory also constitute another aspect of the present invention.

[0007] A system comprises: an electronic device; and the above-mentioned accessory, which can be attached to and detached from the electronic device.

[0008] According to another aspect of the present invention, an electronic device is attachable to and detachable from an accessory. The electronic device includes a plurality of communication contacts including a first contact, and a control unit configured to control communication with the accessory via the plurality of communication contacts. The control unit sends a request for information representing a communication factor in response to a notification of a communication request made when the signal level of the first contact changes from a first signal level to a second signal level different from the first signal level, and receives information representing the communication factor in response to the sending of a request for information representing the communication factor. When the control unit is notified of the communication request via the first contact in response to the start of power supply, the control unit performs predetermined communication without sending a request for information representing the communication factor or receiving information representing the communication factor. A system including the above-mentioned electronic device and a control method of the above-mentioned electronic device also constitute another aspect of the present invention.

[0009] A system comprises: the electronic device mentioned above; and an accessory which can be attached to and detached from the electronic device.

[0010] A method for controlling an accessory, wherein the accessory is attachable to and detachable from an electronic device, and the accessory includes multiple communication contacts, the multiple communication contacts including a first contact, the control method comprising the following steps: notifying the electronic device of a communication request by changing the signal level of the first contact from a first signal level to a second signal level different from the first signal level; receiving a request for information representing a communication factor; sending information representing the communication factor; and in a case where, in the notifying step, the electronic device is notified of the communication request via the first contact in response to the start of power supply, performing predetermined communication without performing the receiving step or the sending step.

[0011] A control method for an electronic device, wherein the electronic device can be attached to and detached from an accessory, and the electronic device includes multiple communication contacts, the multiple communication contacts including a first contact, the control method including the following steps: accepting a notification of a communication request made when the signal level of the first contact changes from a first signal level to a second signal level different from the first signal level; sending a request for information representing a communication factor; receiving information representing the communication factor; and, in response to the start of power supply, performing the accepting step via the first contact, performing predetermined communication without performing the sending step or the receiving step.

[0012] A non-transitory computer-readable storage medium stores a program that enables a computer of an accessory to execute the above-mentioned control method. The accessory can be attached to and detached from an electronic device, and the accessory includes multiple communication contacts, including a first contact.

[0013] A non-transitory computer-readable storage medium stores a program that enables a computer of an electronic device to execute the above-mentioned control method. The electronic device can be attached to an accessory and can be detached from the accessory, and the electronic device includes multiple communication contacts, including a first contact.

[0014] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The structure of the camera system (including a camera, a lens unit, and accessories) in the first embodiment is illustrated.

[0016] Figure 2A and Figure 2B The protocol of the SPI communication in the first embodiment is exemplified.

[0017] FIG. 3A to FIG. 3D A flowchart illustrating processing to be performed by the camera and the accessory in the first embodiment is illustrated.

[0018] Figure 4 Communication data in the SPI communication in the first embodiment is exemplified.

[0019] Figure 5 The accessory information in the first embodiment is exemplified.

[0020] Figure 6 The processing sequence of the camera system in the first embodiment is illustrated.

[0021] Figure 7 The accessory type information in the first embodiment is exemplified.

[0022] Figure 8 Factors for generating a communication request in the first embodiment are exemplified.

[0023] Fig.9A and Fig. 9B The communication interval in the SPI communication in the first embodiment is exemplified.

[0024] Fig.10 A flowchart illustrating a startup process to be performed by the camera (camera control circuit A) in the first embodiment is shown.

[0025] Fig.11 A flowchart illustrating a startup process to be performed by the camera (camera control circuit B) in the first embodiment is shown.

[0026] Fig.12 A flowchart illustrating processing to be performed by the accessory in the first embodiment is illustrated.

[0027] Fig.13 The structures of the camera and accessories in the first embodiment are illustrated.

[0028] Fig.14 is a flowchart showing processing to be performed by the camera and accessories in the first embodiment.

[0029] Fig.15 The structures of the camera, the accessory, and the second accessory in the second embodiment are illustrated.

[0030] Fig.16 : is a flowchart showing processing to be performed by the camera, the accessory, and the second accessory in the second embodiment.

[0031] Fig.17 The structures of the camera, accessories, and third accessory in the third embodiment are illustrated.

[0032] Fig.18 : is a flowchart showing processing to be performed by the camera, accessories, and third accessory in the third embodiment.

[0033] Fig.19A and Fig.19B An example of an I2C communication waveform is shown.

[0034] Fig. 20 The following illustrates a process to be performed by the camera in the first embodiment when N-byte data is transmitted from the camera to the accessory.

[0035] Fig.21 The processing to be performed by the camera in the first embodiment when the camera receives N-byte data from the accessory is illustrated.

[0036] Fig.22Aand Fig. 22B The following illustrates processing to be performed by the accessory in the case where N bytes of data are communicated between the camera and the accessory in the first embodiment. DETAILED DESCRIPTION

[0037] Embodiments according to the present invention will now be described with reference to the accompanying drawings.

[0038] First embodiment

[0039] Figure 1 An electrical structure of an imaging system is illustrated, which includes an imaging apparatus (hereinafter referred to as a camera) 100 as an electronic device according to a first embodiment of the present invention and an accessory 200 detachably attached to the imaging apparatus. The accessory 200 is, for example, a microphone device or a lighting (strobe / flash) device, and includes various devices that can be attached to the camera 100. The camera 100 and the accessory 200 are electrically connected via 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, respectively. The accessory 200 may not have a part of the plurality of contacts TA01 to TA21.

[0040] 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 A 101 serving as a first processing unit, a control unit, and a receiving unit and a camera control circuit B 102 serving 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, etc. The camera control circuit A 101 and the camera control circuit B 102 perform various controls and processes according to a computer program.

[0041] The camera control circuit A 101 monitors the operation of switches and the like used for camera operation, not shown, and controls the system power supply according to the operation of the user. The camera control circuit A 101 includes a low-power type processor that can operate even when the camera 100 is in a power saving state, which is a low power consumption state. On the other hand, the camera control circuit B 102 is responsible for controlling the image sensor 122 and 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 state.

[0042] Although the camera control circuit A 101 and the camera control circuit B 102 include separate processors in the present embodiment, these two circuits may be provided in a single processor.

[0043] The system power supply circuit 112 is a circuit that generates 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. A voltage of 1.8 V generated by the system power supply circuit 112 that receives power from the battery 111 is constantly supplied to the camera control circuit A 101 as a camera microcomputer power supply VMCU_C. Several types of voltages generated by the system power supply circuit 112 are supplied to the camera control circuit B 102 at arbitrary timings as a camera microcomputer power supply VMCU2_C. The camera control circuit A 101 controls the on and off of power supply to each circuit in the camera 100 by controlling the system power supply circuit 112.

[0044] The optical lens 121 is attachable to and detachable from the camera 100. Light from a subject incident through the optical lens 121 is imaged on an image sensor 122 including a CMOS sensor or a CCD sensor or the like. The optical lens 121 and the camera 100 may be integrated. The subject image formed on the image sensor 122 is encoded as a digital camera signal. The image processing circuit 123 performs image processing such as noise reduction processing and white balance processing on the digital camera signal to generate image data, and converts the image data into an image file in a JPEG format or the like to record the image data in a recording memory 126. The image processing circuit 123 generates VRAM image data to be displayed on the display circuit 127 from the image data.

[0045] The memory control circuit 124 controls the transmission and reception of image data and other data generated by the image processing circuit 123 and the like. The volatile memory 125 is a memory capable of high-speed reading and writing, such as DDR3 SDRAM, and is used as a workspace for image processing performed by the image processing circuit 123. The recording memory 126 is a readable and writable recording medium such as an SD card or a CFExpress card that is attachable to and detachable from the camera 100 via a connector not shown. The display circuit 127 is a display arranged on the back 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 light amount of the backlight of the display circuit 127.

[0046] In the present embodiment, the accessory power supply circuit A (hereinafter referred to as the accessory power supply circuit A; first power supply unit) 131 and the accessory power supply circuit B (hereinafter referred to as the accessory power supply circuit B; second power supply unit) 132 are each a voltage conversion circuit that converts the voltage supplied from the system power supply circuit 112 into a predetermined voltage and generates 3.3 V as the accessory power supply VACC. This configuration can convert a voltage into another voltage.

[0047] The accessory power supply circuit A131 is a power supply circuit that includes an LDO and the like and has low self-power consumption. The accessory power supply circuit B132 includes a DC / DC converter circuit and the like and can pass a current larger than that of the accessory power supply circuit A131 (or supply a power higher than that of the accessory power supply circuit A131). The self-power consumption of the accessory power supply circuit B132 is larger than the self-power consumption of the accessory power supply circuit A131. Therefore, when the load current is small, the accessory power supply circuit A131 is more efficient than the accessory power supply circuit B132, and when the load current is large, the accessory power supply circuit B132 is more efficient than the accessory power supply circuit A131. The camera control circuit A101 controls the turning on and off of the voltage outputs of the accessory power supply circuits A131 and B132 according to the operating state of the accessory 200.

[0048] The protection circuit 133 includes a current fuse element, or an electronic fuse circuit in which multiple switching elements or resistors, amplifiers, and switching elements are combined, or the like. 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 the present embodiment, the protection circuit 133 is an electronic fuse circuit, and in the case where a current of 1A or more flows, the overcurrent detection signal DET_OVC is notified to the camera control circuit A 101. The overcurrent detection signal DET_OVC indicates an overcurrent by becoming a high level. The predetermined value may be different from 1A.

[0049] 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 order of the contacts TC01 to TC21 from one end to the other end in the arrangement direction.

[0050] TC01 is connected to the ground terminal (GND), and serves not only as a reference potential contact but also as a contact for controlling wiring impedance of the differential signals D1N and D1P. TC01 corresponds to a third ground contact.

[0051] The differential signal D1N connected to TC02 and the differential signal D1P connected to TC03 are differential data communication signals for data communication in pairs, and are connected to the camera control circuit B 102. TC02, TC03, TC07 to TC10, TC12 to TC17, TC19, and TC20 to be described below are communication contacts.

[0052] TC04 as a first ground contact is connected to GND and serves as a reference potential contact for the camera 100 and the accessory 200. TC04 is arranged outside TC05 described below in the contact arrangement direction.

[0053] The accessory power VACC generated by the accessory power circuits A 131 and B 132 is connected to TC05 as a power contact via the protection circuit 133.

[0054] The accessory attachment detection signal / ACC_DET is connected to TC06 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, etc.). The camera control circuit A101 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) as an activation potential, it is detected that the accessory 200 is attached.

[0055] The signal level (potential) of the accessory attachment detection signal / ACC_DET is changed from a high level (Hi) to a low level (Lo) when the camera 100 is powered on, which triggers various transmissions between the camera 100 and the accessory 200 via the contacts.

[0056] The camera control circuit 101 supplies power to the accessory 200 via TC05 as a power supply contact in response to detecting attachment of the accessory 200.

[0057] SCLK connected to TC07 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 a serial peripheral interface (SPI) communication method as a second communication method (hereinafter referred to as SPI communication) in which the camera control circuit B102 becomes a 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 the present embodiment, the SPI communication has a communication clock frequency of 1 MHz, a data length of 8 bits (1 byte) and a bit order of MSB first, and a full-duplex communication method.

[0058] In the present embodiment, the camera 100 and the accessory 200 support two types of communication protocols of the SPI communication method. Communication protocol A is a communication method in which the camera 100 does not confirm whether the accessory 200 is in a communicable state before outputting SCLK, and is referred to as SPI protocol A in the following description. Figure 2A An overview of the communication waveforms illustrating SPI protocol A. In this figure, CS is active low.

[0059] The camera control circuit B 102 changes CS to low level (active) at timing A1 , and requests SPI communication to the accessory control circuit 201 .

[0060] At timing A2 a predetermined time T_CS after timing A1, the camera control circuit B 102 starts outputting SCLK and MOSI. When the accessory control circuit 201 detects the trailing edge of SCLK, the accessory control circuit 201 starts outputting MISO.

[0061] The camera control circuit B 102 stops outputting SCLK at timing A3 when outputting 1-byte SCLK is completed.

[0062] The camera control circuit B 102 stops outputting SCLK for a predetermined time T_INTERVAL at timing A3 , restarts outputting SCLK at timing A4 after T_INTERVAL has elapsed, and performs the next 1-byte communication.

[0063] Figure 3A The flowchart in exemplifies processing to be performed by the camera control circuit B 102 in the SPI protocol A. S represents a step.

[0064] In S101, the camera control circuit B 102 stores a numerical value indicating the number of bytes to be communicated in an internal variable N. For example, 3 is stored in the case of 3-byte communication.

[0065] In S102 , the camera control circuit B 102 changes CS to a low level and requests SPI communication.

[0066] In S103, the camera control circuit B 102 performs a waiting process until a predetermined time T_CS has passed after CS has changed to a low level. After the predetermined time T_CS has passed, the flow proceeds to S104.

[0067] In S104, the camera control circuit B 102 controls the SCLK output, the MOSI data output, and the MISO data input, and performs 1-byte data communication.

[0068] In S105 , the camera control circuit B 102 confirms whether the internal variable N indicating the number of communication bytes is 0. When the internal variable N is 0, the flow proceeds to S106 , and when the internal variable N is not 0, the flow proceeds to S107 .

[0069] In S107 , the camera control circuit B 102 stores, as a new internal variable N, a value obtained by decrementing the numerical value of the internal variable N indicating the number of communication bytes by 1.

[0070] In S108, the camera control circuit B 102 performs a waiting process until a predetermined time T_INTERVAL has passed after the 1-byte data communication in S104 is completed. Then, after the predetermined time T_INTERVAL has passed, the flow returns to the process of S104, and the same process is executed again.

[0071] In S106, the camera control circuit B 102 changes CS to a high level and ends a series of SPI communications.

[0072] Figure 3B The flowchart in exemplifies the processing to be performed by the accessory control circuit 201 in SPI protocol A.

[0073] In S201, the accessory control circuit 201 confirms whether CS changes to a low level. In the case where CS changes to a low level, the flow proceeds to S202, and in the case where CS does not change to a low level, the flow returns to S211.

[0074] In S202, the accessory control circuit 201 performs 1-byte data communication through MOSI data input control and MISO data output control in response to the input of the SCLK signal.

[0075] In S203, the accessory control circuit 201 confirms whether CS changes to high level. If CS changes to high level, it is determined that the SPI communication is completed, and if CS does not change to high level, the flow returns to S202 to perform the next 1-byte communication.

[0076] The communication protocol B in the SPI communication method is a communication method in which the camera 100 confirms whether the accessory 200 is in a communicable state before outputting SCLK, and is referred to as SPI protocol B in the following description. Figure 2B An overview of the communication waveform of SPI protocol B is shown below.

[0077] The camera control circuit B 102 changes CS to low level at timing B1, and requests SPI communication to 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.

[0078] On the other hand, when the accessory control circuit 201 detects the trailing edge of CS at timing B2, the accessory control circuit 201 performs control for changing MISO to high level if SPI communication is available, and performs control for changing MISO to low level if the communication is not available.

[0079] When the camera control circuit B 102 confirms that MISO is at a high level at timing B3, the camera control circuit B 102 starts outputting SCLK and MOSI. The accessory control circuit 201 starts outputting MISO when detecting the trailing edge of SCLK.

[0080] When the output of SCLK for 1 byte is completed at timing B4, the camera control circuit B 102 stops outputting SCLK.

[0081] After 1-byte communication, as shown in timings B5 and B6, the accessory control circuit 201 performs control for changing MISO to a high level if SPI communication is available, and performs control for changing MISO to a low level if SPI communication is not available.

[0082] The camera control circuit B 102 checks 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.

[0083] Figure 3C The flowchart in exemplifies the processing to be performed by the camera control circuit B 102 in the SPI protocol B.

[0084] In S111, the camera control circuit B 102 stores a numerical value indicating the number of bytes to be communicated in an internal variable N. For example, 3 is stored in the case of 3-byte communication.

[0085] In S112, the camera control circuit B 102 changes CS to low level and requests SPI communication.

[0086] In S113, the camera control circuit B 102 confirms whether MISO has changed to a high level. If MISO is at a high level, the flow proceeds to S114, and if MISO has not yet been at a high level, the flow returns to S113.

[0087] 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.

[0088] In S115, the camera control circuit B 102 confirms whether communication of all data is completed (whether the internal variable N indicating the number of communication bytes is 0). If the internal variable N is 0, the flow proceeds to S116, and if the internal variable N is not 0, the flow proceeds to S117.

[0089] In S117, the camera control circuit B 102 stores, as a new internal variable N, a value obtained by decrementing the numerical value of the internal variable N indicating the number of communication bytes by 1.

[0090] In S118, the camera control circuit B 102 confirms whether MISO has changed to a high level. In the case where MISO is at a high level, the flow proceeds to S114, and in the case where MISO is not at a high level, the flow returns to S118.

[0091] In S116, the camera control circuit B 102 changes CS to high level and ends a series of SPI communications.

[0092] Figure 3D The flowchart in exemplifies the processing to be performed by the accessory control circuit 201 in the SPI protocol B.

[0093] In S211, the accessory control circuit 201 confirms whether CS changes to a low level. In the case where CS changes to a low level, the flow proceeds to S212, and in the case where CS does not change to a low level, the flow returns to S211.

[0094] In S212, the accessory control circuit 201 confirms whether SPI communication is available. In the case that SPI communication is available, the process proceeds to S213, and in the case that SPI communication is not available, the process proceeds to S214.

[0095] In S213, the accessory control circuit 201 performs control for changing MISO to a high level, and the flow proceeds to S215.

[0096] In S214, the accessory control circuit 201 performs control for changing MISO to the low level, and the flow returns to S212.

[0097] In S215, the accessory control circuit 201 controls the MOSI data input and the MISO data output in response to the SCLK signal input, and performs 1-byte data communication.

[0098] 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 flow returns to S212 for the next 1-byte communication.

[0099] Figure 4 The content of communication when an operation execution instruction (command) is notified from the camera 100 to the accessory 200 by SPI communication in the present embodiment is exemplified.

[0100] The camera control circuit B 102 transmits information CMD indicating a command number as MOSI data in the 1st byte communication to the accessory control circuit 201. The accessory control circuit 201 transmits a value 0xA5 as information indicating a communicable state as MISO data to the camera control circuit B 102. When the 1st byte communication process cannot be executed, the accessory control circuit 201 transmits a value other than 0xA5 as MISO data to the camera control circuit B 102.

[0101] The camera control circuit B 102 transmits the argument MOSI_DATA1 corresponding to the command number CMD in the 2nd byte communication to the accessory control circuit 201. Then, from the 3rd byte to the (N-2)th byte, the arguments MOSI_DATA2 to MOSI_DATA[N-3] corresponding to the command number CMD are similarly transmitted to the accessory control circuit 201.

[0102] The accessory control circuit 201 transmits the command number CMD received in the 1st byte as MISO data in the 2nd byte communication to the camera control circuit B 102. This configuration enables the camera control circuit B 102 to determine that the accessory control circuit 201 has correctly received the MOSI data.

[0103] The accessory control circuit 201 transmits the return value MISO_DATA1 corresponding to the command number CMD as MISO data in the 3rd byte communication to the camera control circuit B 102. Then, from the 4th byte to the (N-2)th byte, the return values ​​MISO_DATA2 to MISO_DATA[N-4] corresponding to the command number CMD are similarly transmitted to the camera control circuit B 102.

[0104] It is assumed that the number of arguments and the number of return values ​​are predetermined for each command No. One or both of the arguments and the return values ​​may be omitted.

[0105] The camera control circuit B 102 transmits the checksum data CheckSum_C as MOSI data in the (N-1)th byte communication to the accessory control circuit 201. The checksum data CheckSum_C is a value calculated by the following expression.

[0106] CheckSum_C=EXOR(AND(SUM(CMD,MOSI_DATA1,…,MOSI_DATA[N-3]),0xFF),0xFF)

[0107] The accessory control circuit 201 transmits 0x00 as MISO data.

[0108] Next, the camera control circuit B 102 transmits 0x00 as MOSI data to the accessory control circuit 201 in the N-th byte communication.

[0109] The accessory control circuit 201 transmits the checksum data CheckSum_A as MISO data. The checksum data CheckSum_A is calculated by the following expression when the value of CheckSum_C received by the camera control circuit B 102 and the value of CheckSum_C calculated by the camera control circuit B 102 in the (N-1)th byte communication coincide with each other.

[0110] CheckSum_A=EXOR(AND(SUM(0xA5,CMD,MIS0_DATA1,…,MOSI_DATA[N-4]),0xFF),0xFF)

[0111] On the other hand, if the value of CheckSum_C received by the camera control circuit B 102 and the value of CheckSum_C calculated by the camera control circuit B 102 do not coincide with each other in the (N-1)th byte communication, the value is calculated by the following expression.

[0112] CheckSum_A=AND(SUM(0xA5,CMD,MIS0_DATA1,…,MOSI_DATA[N-4]),0xFF)

[0113] Figure 1The TC11 shown as a signal contact (communication request contact, first contact) is connected to a communication request signal (second input signal) / WAKE for requesting communication from the accessory 200 to the camera 100 (camera control circuit 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 a communication request from the accessory 200 by detecting a change (trailing edge) of the communication request signal / WAKE.

[0114] SDA connected to TC12 as a communication contact and SCL connected to TC13 are signals for performing inter-integrated circuit (I2C) communication (hereinafter referred to as I2C communication) as a first communication method in which the camera control circuit A101 is a communication master. SDA is a data signal and SCL is a clock signal. SDA and SCL are open drain communication pulled up by the camera microcomputer power supply VMCU_C, and have a communication frequency of 100 kbps in this embodiment.

[0115] In the I2C communication, both data transmission from the camera 100 and data transmission from the accessory 200 are performed via SDA. When SPI communication and I2C communication are compared with each other, the communication speed of I2C communication is lower than that of SPI communication. The communication speed of SPI communication is higher than that of I2C communication, and is therefore suitable for communication of information having a large amount of data. Therefore, in the communication between the camera 100 and the accessory 200 in the present embodiment, information having a large amount of data is communicated by using SPI communication, and information having a small amount of data is communicated by using I2C communication. For example, data is first communicated by using I2C communication, and in a case where SPI communication is available or is required to be performed based on the data, control may be performed to further perform SPI communication.

[0116] Fig.19A and Fig.19B An example of an I2C communication waveform is shown. Fig.19A An example of a waveform is shown in the case where the camera sends N bytes of data (DATA[1] to DATA[N]) to the accessory, and Fig.19B An example of a waveform is shown in the case where the camera receives N bytes of data (DATA[1] to DATA[N]) from the accessory. Fig.19A and Fig.19B , the upper waveform illustrates SCL, and the lower waveform illustrates SDA.

[0117] Below the SDA waveform, the meaning of each timing signal and whether the control circuit for controlling the output level of the SDA signal is the camera control circuit A101 or the accessory control circuit 201 are illustrated. The communication data includes 1-byte unit data 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.

[0118] Since the following will refer to Figures 20 to 22A and Fig. 22B To explain the details of the communication content, reference will be made to Fig.19A and Fig.19B To explain the outline.

[0119] exist Fig.19A In the 1st byte communication and the 2nd byte communication, the camera control circuit A 101 notifies the accessory control circuit 201 of storage address information related to the data to be transmitted. In the 3rd byte communication to the (N+2)th byte communication, the camera control circuit A 101 transmits N-byte data (DATA[address] to DATA[address+N]) to the accessory control circuit 201.

[0120] exist Fig.19B In the 1st byte communication and the 2nd byte communication, the camera control circuit A 101 notifies the accessory control circuit 201 of storage address information related to the data to be received. In the 3rd byte communication to the (N+3)th 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.

[0121] Fig. 20 The flowchart in exemplifies processing to be performed by the camera control circuit A 101 in the case where the camera control circuit A 101 sends N-byte data to the accessory control circuit 201.

[0122] In S3001, the camera control circuit A101 stores a numerical value indicating the number of bytes to be transmitted in an internal variable N. For example, in the case of transmitting 3 bytes, 3 is stored. In the present embodiment, 3 is stored.

[0123] In S3002, the camera control circuit A101 changes SDA to a low level (START condition) while SCL is at a high level. Thus, the accessory control circuit 201 is notified of the start of communication.

[0124] In S3003, the camera control circuit A101 sets slave address information indicating the slave address of the accessory control circuit 201 to the upper 7 bits of the transmission data. In this embodiment, it is assumed that the slave address of the accessory control circuit 201 is 1010000 in binary.

[0125] In S3004, the camera control circuit A101 sets information indicating write communication to the lower 1 bit of the transmission data. Setting this bit to 0 means write communication.

[0126] In S3005, the camera control circuit A101 transmits the data set as transmission data in S3003 and S3004 (10100000 in the case of binary and 0xA0 in the case of hexadecimal) to the accessory control circuit 201.

[0127] In S3006, after sending 1 byte of data, the camera control circuit A101 outputs SCL for one clock and checks the signal level of SDA. When the signal level of SDA is low, it is determined to be a data reception notification (ACK) from the accessory control circuit 201, and the flow proceeds to S3007. On the other hand, 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 flow proceeds to S3014.

[0128] In S3007, the camera control circuit A 101 sets, to the transmission data, storage address information (start address information) of data to be transmitted to the accessory control circuit 201. In the present embodiment, the size of the start address information is 1 byte, and the value is 0x00.

[0129] In S3008 , the camera control circuit A101 sends the set 1-byte start address information (value 0x00) to the accessory control circuit 201 .

[0130] In S3009, after sending the 1-byte start address information data, the camera control circuit A101 outputs SCL for one clock and checks the signal level of SDA. When the signal level of SDA is low, it is determined to be a data reception notification (ACK) from the accessory control circuit 201, and the flow proceeds to 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 flow proceeds to S3014.

[0131] In S3010, the camera control circuit A 101 stores 1 in an internal variable M. The internal variable M is a variable for counting the number of transmission data.

[0132] In S3011, the camera control circuit A101 outputs 1-byte data to the accessory control circuit 201 by outputting 1-byte SCL and by changing SDA to a desired signal level during SCL being at a low level. Here, the start address information is 0x00 and the internal variable M is 1, so 1-byte data corresponding to address 0x00 is transmitted.

[0133] In S3012, after sending 1 byte of data, the camera control circuit A101 outputs SCL for one clock and checks the signal level of SDA. When the signal level of SDA is low, it is determined to be a data reception notification (ACK) from the accessory control circuit 201, and the flow proceeds to S3013. On the other hand, 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 flow proceeds to S3014.

[0134] In S3013, the camera control circuit A101 confirms whether the internal variable M has the same value as the internal variable N. In the case where 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 flow proceeds to S3014. In the case where the internal variable M is not the same value as the internal variable N, it is determined that there is still data to be transmitted, and the flow proceeds to S3015.

[0135] In S3015, the camera control circuit A101 adds 1 to the internal variable M, and the flow returns to S3011.

[0136] Therefore, after the flow returns to S3011, the camera control circuit A101 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 A101 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. In the case where the internal variable N is set to 3 as in the present embodiment, 3-byte data can be transmitted.

[0137] In S3014, the camera control circuit A101 changes SDA to a high level (STOP condition) while SCL is at a high level. This notifies the accessory control circuit 201 of the end of communication.

[0138] Fig.21 The flowchart in exemplifies processing to be performed by the camera control circuit A101 in the case where the camera control circuit A101 receives N-byte data from the accessory control circuit 201.

[0139] In S3101, the camera control circuit A101 stores a numerical value indicating the number of bytes to be received in an internal variable N. For example, when 3-byte data is received, 3 is stored. In the present embodiment, 3 is stored.

[0140] In S3102 to S3106, the camera control circuit A 101 performs the same processing as S3002 to S3006, respectively, and thus description thereof will be omitted.

[0141] In S3107, the camera control circuit A101 sets, to the transmission data, the storage address information (start address information) of the data received from the accessory control circuit 201. In the present embodiment, the size of the start address information is 1 byte, and the value is 0x00.

[0142] In S3108 , the camera control circuit A101 sends the set 1-byte start address information (value 0x00) to the accessory control circuit 201 .

[0143] In S3109, after sending the 1-byte start address information data, the camera control circuit A101 outputs SCL for one clock and checks the signal level of SDA. When the signal level of SDA is low, it is determined to be a data reception notification (ACK) from the accessory control circuit 201, and the flow proceeds to 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 flow proceeds to S3122.

[0144] In S3110 , as in S3102 , the camera control circuit A101 changes SDA to low level while SCL is at high level, and notifies the accessory control circuit 201 of the start condition.

[0145] In S3111, the camera control circuit A101 sets slave address information indicating the slave address of the accessory control circuit 201 to the upper 7 bits of the transmission data. In this embodiment, it is assumed that the slave address of the accessory control circuit 201 is 1010000 in binary.

[0146] In S3112, the camera control circuit A101 sets information indicating read communication to the lower 1 bit of the transmission data. Setting this bit to 1 means read communication.

[0147] In S3113, the camera control circuit A101 transmits the data set as transmission data in S3003 and S3004 (10100001 in the case of binary and 0xA1 in the case of hexadecimal) to the accessory control circuit 201.

[0148] In S3114, after sending 1 byte of data, the camera control circuit A101 outputs SCL for one clock and checks the signal level of SDA. When the signal level of SDA is low, it is determined to be a data reception notification (ACK) from the accessory control circuit 201, and the flow proceeds to 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 flow proceeds to S3122.

[0149] In S3115, the camera control circuit A101 stores 1 in the internal variable M. The internal variable M is a variable for counting the number of received data.

[0150] At S3116, the camera control circuit A101 outputs 1-byte SCL, and reads the signal level of SDA at the timing when SCL changes from a low level to a high level. This configuration enables 1-byte data to be received from the accessory control circuit 201. The received 1-byte data can be stored in the volatile memory 125 as data corresponding to the address 0x00 or used for predetermined processing.

[0151] In S3117, the camera control circuit A101 determines whether the 1-byte data is received normally. If the 1-byte data is received normally, the flow proceeds to S3118. If the 1-byte data is not received normally, the flow proceeds to S3119.

[0152] In S3118, the camera control circuit A101 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 flow proceeds to S3119. If the internal variable M is not the same value as the value of the internal variable N, it is determined that there is still data to be received, and the flow proceeds to S3120.

[0153] 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 SCL of 1 byte and by performing control for changing SDA to the low level.

[0154] In S3121, the camera control circuit A101 adds 1 to the internal variable M, and the flow returns to S3116.

[0155] Therefore, after the flow returns to S3116, the camera control circuit A101 sequentially increments the address of the data to be received, and receives 1-byte data corresponding to each address. In this way, the camera control circuit A101 receives N-byte data from the accessory control circuit 201 by repeatedly receiving 1-byte 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 the present embodiment, 3-byte data can be received.

[0156] In S3119, the camera control circuit A101 outputs SCL of 1 byte, and performs control for changing SDA to a high level to notify the accessory control circuit 201 of the completion of data communication (NACK).

[0157] In S3122, the camera control circuit A101 changes SDA to a high level (stop condition) while SCL is at a high level. This notifies the accessory control circuit 201 of the end of communication.

[0158] Fig.22A and Fig. 22B The flowchart in exemplifies processing to be performed by the accessory control circuit 201 when the camera control circuit A101 sends N-byte data to the accessory control circuit 201 and when the camera control circuit A101 receives N-byte data from the accessory control circuit 201.

[0159] In S3201, the accessory control circuit 201 waits for SDA to change to a low level (a start condition) while SCL is at a high level. When the accessory control circuit 201 detects the start condition, the flow proceeds to S3202.

[0160] In S3202, the accessory control circuit 201 stores 0 in the internal variable M. The internal variable M is a variable for counting the number of transmission data and the number of reception data.

[0161] In S3203, the accessory control circuit 201 receives the 1-byte data transmitted from the camera control circuit A101.

[0162] In S3204, the accessory control circuit 201 determines whether the upper 7 bits of the 1-byte data received in S3203 are consistent with the slave device address (0x50 in this embodiment) of the accessory control circuit 201. If the address is consistent with the slave device address of the accessory control circuit 201, the process proceeds to S3205. If the address is inconsistent with the slave device address of the accessory control circuit 201, the process proceeds to S3221.

[0163] In S3205, the accessory control circuit 201 provides a data reception notification (ACK) to the camera control circuit A101 by performing control for changing SDA to the low level for the next SCL clock output after receiving 1-byte data.

[0164] In S3206, the accessory control circuit 201 determines the type of data used for the next 1-byte communication based on the lower 1-bit data of the 1-byte data received in S3203. When the lower 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 A101 to the accessory control circuit 201, and the flow proceeds to S3207. When the lower 1-bit data is 1, it is determined that the data for the next 1-byte communication is the transmission data from the accessory control circuit 201 to the camera control circuit A101, and the flow proceeds to S3209.

[0165] In S3207, the accessory control circuit 201 receives the 1-byte data sent from the camera control circuit A101. The received 1-byte data is information indicating the address of the data to be sent and received in the subsequent communication. Fig. 20 and Fig.21 As described above, it is assumed that the start address information is 0x00.

[0166] 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 A101 for the start address information.

[0167] In S3208, if the accessory control circuit 201 determines that the 1-byte data can be received normally, the flow proceeds to S3210. If it is determined that the 1-byte data cannot be received normally, the flow proceeds to S3221.

[0168] In S3210, the accessory control circuit 201 provides a data reception notification (ACK) to the camera control circuit A101 by performing control for changing SDA to the low level for the next SCL clock output after receiving 1-byte data.

[0169] In S3211, the accessory control circuit 201 confirms whether SDA changes to a low level (start condition) while SCL is at a high level. In the case where the accessory control circuit 201 detects the start condition, the accessory control circuit 201 determines that the 1-byte data to be communicated next is data to be sent from the camera control circuit A101 to the accessory control circuit 201 and indicates the slave device address and communication type. Then, the process proceeds to S3212. In the case where the accessory control circuit 201 does not detect the start condition, the accessory control circuit 201 determines that the 1-byte data to be communicated next is data information received by the accessory control circuit 201 from the camera control circuit A101. Then, the process proceeds to S3216.

[0170] In S3212, the accessory control circuit 201 receives the 1-byte data transmitted from the camera control circuit A 101.

[0171] In S3213, the accessory control circuit 201 determines whether the upper 7 bits of the 1-byte data received in S3212 are consistent with the slave device address (0x50 in this embodiment) of the accessory control circuit 201. If the upper 7 bits are consistent with the slave device address of the accessory control circuit 201, the process proceeds to S3214. If the upper 7 bits are inconsistent with the slave device address of the accessory control circuit 201, the process proceeds to S3221.

[0172] In S3214, the accessory control circuit 201 determines the data type used for the next 1-byte communication based on the lower 1-bit data of the 1-byte data received in S3203. When the lower 1-bit data is 0, the flow proceeds to S3221. When the lower 1-bit data is 1, it is determined that the data for the next 1-byte communication is transmission data from the accessory control circuit 201 to the camera control circuit A101, and the flow proceeds to S3215.

[0173] In S3215, the accessory control circuit 201 provides the camera control circuit A 101 with a data reception notification (ACK) by performing control for changing SDA to the low level for the next SCL clock output after receiving 1-byte data.

[0174] In S3222, the accessory control circuit 201 transmits, to the camera control circuit A 101, 1-byte data corresponding to the start address information received from the camera control circuit A 101 in S3207 or the start address information determined in S3209.

[0175] In S3223, the accessory control circuit 201 adds 1 to the internal variable M, and the flow proceeds to S3224.

[0176] In S3224, the accessory control circuit 201 confirms the signal level of SDA after transmitting 1-byte data. In the case where the signal level of SDA is high, the camera control circuit A101 determines that this is a notification (NACK) that all data has been received, and the process proceeds to S3225. On the other hand, in the case where 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 transmitted, and transmits 1-byte data corresponding to each address. Therefore, by repeatedly transmitting 1-byte data from the camera control circuit A 101 until NACK is notified in the process of S3224, the accessory control circuit 201 transmits N-byte data to the camera control circuit A 101.

[0177] In S3225, the accessory control circuit 201 waits for a stop condition in which SDA changes to a high level while SCL is at a high level. When the accessory control circuit 201 detects the stop condition, communication is terminated.

[0178] 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 A101 in S3207, or uses the 1-byte data for predetermined processing.

[0179] In S3217, the accessory control circuit 201 adds 1 to the internal variable M, and the flow proceeds to S3218.

[0180] In S3218, if the accessory control circuit 201 determines that the 1-byte data can be received normally, the flow goes to S3219. If it is determined that the 1-byte data cannot be received normally, the flow goes to S3221.

[0181] In S3219, the accessory control circuit 201 provides the camera control circuit A101 with a data reception notification (ACK) by performing control for changing SDA to the low level for the next SCL clock output after receiving 1-byte data.

[0182] 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. In the case where the accessory control circuit 201 detects the stop condition, the accessory control circuit 201 terminates the communication. On the other hand, in the case where 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 flow returns to S3216.

[0183] Therefore, after the process returns to S3216, the accessory control circuit 201 sequentially increments the address of the data to be received and receives 1-byte data corresponding to each address. By repeatedly receiving 1-byte data until the stop condition is notified in S3220, the accessory control circuit 201 receives N-byte data from the camera control circuit A101.

[0184] Therefore, the camera connector 141 includes a contact TC12 for a data signal by the I2C communication method, and a contact TC13 for a clock signal by the I2C communication method arranged on one side of the contact TC12 for the data signal (adjacent to each other on one side). The camera connector 141 also includes a contact TC11 for a second input signal, a contact TC10 for an input selection signal by the SPI communication method, a contact TC09 for reception by the SPI communication method, a contact TC08 for transmission by the SPI communication, a contact TC07 for a clock signal by the SPI communication method, a contact TC06 for a first input signal, and a contact TC05 for an output signal, which are arranged on the other side of the contact TC12 for the data signal (arranged in order from positions adjacent to each other on the other side).

[0185] The accessory 200 stores the accessory information in a nonvolatile memory not shown. The accessory information is information for allowing the camera 100 to recognize the type of the accessory 200 and specifications related to communication and operation (function) of the accessory 200. Figure 5 An example of accessory information is illustrated. 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 this embodiment, a checksum value for the read data is added as the final data of the communication.

[0186] Connect to Figure 1The FNC1 signal of TC14, the FNC2 signal connected to TC15, the FNC3 signal connected to TC16, and the FNC4 signal connected to TC17 shown as communication contacts are functional signals whose functions are variable depending on the type of attached accessory 200. For example, in the case where accessory 200 is a microphone device, the signal communicated via TC15 is a signal related to voice data, and in the case where accessory 200 is a flash device, the signal communicated via TC14 is a signal notifying light emission timing.

[0187] Signals for implementing different functions can be communicated via the same contact depending on the type of accessory attached. For example, in the case where accessory 200 is an accessory other than a lighting device, a synchronization signal for controlling a timing different from the light-emitting timing can be communicated via TC14. TC14 to TC17 correspond to functional signal contacts. Communication using at least one of the functional signal contacts will also be referred to as functional signal communication. Functional signal communication can be performed in parallel with I2C communication and SPI communication at a timing independent of I2C communication and SPI communication.

[0188] The accessory type as used herein means the microphone device, lighting device, etc. mentioned above. Accessories that achieve the same purpose (such as lighting with different performances, etc.) belong to the same type of accessories. Accessories that achieve different purposes (such as a microphone device and a lighting device, etc.) are accessories of different types. Functional signal communication is performed based on information acquired through I2C communication or SPI communication. TC18, which is a second ground contact, is also connected to GND, and, similar to TC04, is a contact used as a reference potential for the camera 100 and the accessory 200. The differential signal D2N connected to TC19 and the differential signal D2P connected to TC20 are data communication signals for data communication between the two in pairs, and are connected to the camera control circuit B102. For example, USB communication can be performed via TC19 and TC20.

[0189] TC21 is connected to GND, and can be used not only as a reference potential contact but also as a contact for controlling wiring impedance of differential signals D2N and D2P. TC21 corresponds to a fourth ground contact.

[0190] The contacts TC01, TC04, TC06, TC18, and TC21 are connected to, for example, a GND portion of a flexible printed circuit (FPC) substrate, and the GND portion of the FPC substrate is fixed by screws or the like to a metal member serving as a GND level of the camera 100. The metal member serving as the GND level includes, for example, an engaging member engageable with the accessory 200 in the accessory shoe portion, and a bottom plate, not shown, inside the camera 100.

[0191] In the present embodiment, the attachment detection contact TC06 to which the accessory attachment detection signal / ACC_DET is connected is arranged next to the contact (first clock contact) TC07 that sends the clock signal SCLK (first clock signal). Typically, noise (clock noise) associated with potential fluctuations in the clock signal is sent to the contact adjacent to the contact of the clock signal, which may cause a malfunction. In particular, this effect is significant in a configuration with many contacts and a short distance between the contacts, as in the present embodiment. Therefore, by arranging the attachment detection contact TC06 next to the SCLK contact TC07, the influence of the clock noise can be suppressed.

[0192] 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, the potential does not fluctuate because the SCLK contact TC07 for sending the clock signal does not send the clock signal. Only after the accessory is attached, the potential fluctuates due to the sending of the clock signal.

[0193] When the SCLK contact TC07 sends a clock signal, the attachment detection contact TC06 is at the GND potential. Therefore, even if the attachment detection contact TC06 receives clock noise, the potential of the control circuit of the camera 100 and the accessory 200 is unlikely to fluctuate, thereby preventing malfunction. In addition, it is possible to suppress the clock noise 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.

[0194] SCL (second clock signal) as a 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 the frequency of SCL, and the SCLK contact TC07 generates more clock noise than the SCL contact TC13. Therefore, it is more effective to arrange the attachment detection contact TC06 next to the SCLK contact TC07 rather than next to the SCL contact TC13 in preventing malfunctions caused by clock noise.

[0195] In addition to the difference in frequency, the SCL sent by the SCL contact TC13 is a clock signal of the I2C communication standard, and the voltage fluctuation of the signal line is driven by the open drain connection. On the other hand, the SCLK sent by the SCLK contact TC07 is a clock signal of the SPI communication standard, and the voltage fluctuation of the signal line is driven by the 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 is often smoother, and clock noise is less likely to occur. Therefore, it is more effective to arrange the attachment detection contact TC06 next to the SCLK contact TC07 instead of next to the SCL contact TC13, which is more effective in preventing malfunctions caused by clock noise.

[0196] The differential signals D1N and D1P may be sent in pairs to the first differential signal contact TC19 and the second differential signal contact TC20 to send a clock signal. In this case, a clock signal (third clock signal) having a frequency higher than that of the SCLK contact TC07 and the SCL contact TC13 may be sent. However, the differential signals D1N and D1P are paired signals, so the clock noise emission is smaller than the clock noise emission of the SCLK contact TC07 and the SCL contact TC13 that send a single-ended signal. Therefore, it is more effective to prevent malfunctions caused by clock noise by arranging the attachment detection contact TC06 next to the SCLK contact TC07 instead of next to the first differential signal contact TC19 and the second differential signal contact TC20.

[0197] The contact (first data contact) TC08 arranged next to the SCLK contact TC07 on the opposite side to the attachment detection contact TC06 transmits MOSI (first data signal). Since MOSI is a data signal, MOSI seems to be susceptible to clock noise. However, MOSI is a data signal of the SPI communication standard that is the same 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 a MOSI contact.

[0198] The accessory 200 has a battery 205 and receives power from the battery 205, and also receives power from the camera 100 via the camera connector 141 and the accessory connector 211. The accessory control circuit 201, which is an accessory processing unit in the accessory 200, is a circuit that controls the entire accessory 200, and includes a processor (microcomputer) such as a CPU, etc. The accessory control circuit 201 performs various controls and processes according to a computer program.

[0199] The accessory power supply circuit 202 is a circuit that generates power for supplying power to each circuit in the accessory 200, and includes a DC / DC converter circuit, an LDO, and a charge pump circuit, etc. The 1.8 V voltage generated by the accessory power supply circuit 202 is constantly supplied to the accessory control circuit 201 as the accessory microcomputer power supply VMCU_A. The voltage generated by the accessory power supply circuit 202 may be different from 1.8 V. Control of the accessory power supply circuit 202 can provide on and off control of power supply to each circuit in the accessory 200.

[0200] The charging circuit (powered unit) 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 is supplied from the camera 100 for a charging operation, the accessory control circuit 201 controls the charging circuit 204 to charge the battery 205. In the present embodiment, the battery 205 is attached to the accessory 200, but the accessory 200 may operate only by supplying power from the camera 100 to the accessory power source unit (powered unit) 202 without attaching the battery 205. In this case, the charging circuit 204 is unnecessary.

[0201] 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 transmit data received from the camera 100 to the external device, and transmit data received from the external device to the camera 100.

[0202] Function circuit 206 is a circuit having different functions depending on the type of accessory 200. When accessory 200 is a flash device, function circuit 206 is, for example, a lighting circuit or a charging circuit. When accessory 200 is a microphone device, accessory 200 is a voice codec circuit or a microphone circuit.

[0203] 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 an output signal of the connection detection circuit 210.

[0204] The power switch 203 is a switch operable by a user to turn on and off the power (ie, operation) of the accessory 200. The accessory control circuit 201 can detect the on position and the off position by reading the signal level of the terminal to which the power switch 203 is connected.

[0205] The operation switch 212 is a switch that can be operated by the user to give various instructions to the accessory 200 and make various settings, and includes a button, a cross key, a slide switch, a dial switch, a touch sensor, etc. When the operation switch 212 is operated, the accessory control circuit 201 detects the operation and performs predetermined processing according to the operation.

[0206] The accessory connector 211 is a connector electrically connectable to the camera 100 via 21 contacts TA01 to TA21 arranged in a row. The contacts TA01 to TA21 are arranged in order of the contacts TA01 to TA21 from one end to the other end in the arrangement direction.

[0207] TA01 is connected to GND, and serves not only as a reference potential contact but also as a contact for controlling wiring impedance of differential signals D1N and D1P. TA01 corresponds to a third ground contact.

[0208] The differential signal D1N connected to TA02 and the differential signal D1P connected to TA03 are data communication signals for data communication between the two in pairs, and are connected to the differential communication circuit 207. TA02, TA03, TA07 to TA10, TA12 to TA17, TA19, and TA20 described below are communication contacts.

[0209] TA04 as a first ground contact is connected to GND, and serves as a reference potential contact for the camera 100 and the accessory 200. TA04 is arranged outside TA05 described below in the arrangement direction of the contacts.

[0210] The accessory power supply circuit 202 and the charging circuit 204 are connected to TA05 as a power supply contact, and the accessory power supply VACC supplied from the camera 100 is connected to TA05 .

[0211] TA06 as an attachment detection contact is directly connected to GND. When the accessory 200 is attached to the camera 100, the accessory control circuit 201 sets the above-mentioned accessory attachment detection signal / ACC_DET to a low level (GND potential) as an activation potential. Thus, the camera 100 can detect the attachment of the accessory 200.

[0212] SCLK connected to TA07 as a communication contact, MOSI connected to TA08, MISO connected to TA09, and CS connected to TA10 are signals for the accessory control circuit 201 to use as a communication slave to perform SPI communication.

[0213] A communication request signal / WAKE for requesting communication from the accessory control circuit 201 to the camera 100 is connected to TA11 which is a signal contact (communication request contact, first contact). When the accessory control circuit 201 determines that communication with the camera 100 is necessary, 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.

[0214] When power is supplied from the camera control circuit 101 to the accessory 200 via TC5 in response to detecting attachment of the accessory 200, the accessory control circuit 201 notifies the camera control circuit 101 that power has been received by changing the signal level of the communication request signal / WAKE (by changing the potential of the communication request signal / WAKE) from a high level to a low level.

[0215] Even if there is no request from the camera, the accessory control circuit 201 can notify that there is a factor causing the accessory 200 to communicate with the camera 100 by changing the signal level (potential) of the communication request signal / WAKE from a high level to a low level. With this configuration, the camera control circuit 101 can omit an operation of periodically checking whether the accessory 200 has a factor requiring communication by polling. When the communication requiring factor occurs, the accessory 200 can communicate with the camera 100 in real time.

[0216] SDA connected to TA12 as a communication contact and SCL connected to TA13 are signals for the accessory control circuit 201 to perform I2C communication as a communication slave.

[0217] Therefore, the accessory connector 211 includes a contact TA12 for a data signal by the I2C communication method, and a contact TA13 for a clock signal by the I2C communication method arranged on one side of the contact TA12 for the data signal (adjacent to the contact TA12 for the data signal on one side). The accessory connector 211 also includes 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 on the other side of the contact TA12 for the data signal (in order from a position adjacent to the contact TA12 for the data signal on the other side).

[0218] The FNC1 signal connected to TA14 as a communication contact (function signal contact), the FNC2 signal connected to TA15, the FNC3 signal connected to TA16, and the FNC4 signal connected to TA17 are function signals whose functions are variable depending on the type of accessory 200. For example, in the case where accessory 200 is a microphone device, these signals may be signals related to voice data, and in the case where accessory 200 is a flash device, these signals may be signals for notifying light emission timing.

[0219] 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 between the two in pairs, and are connected to the external connection terminal 209.

[0220] TA21 is connected to GND, and can be used not only as a reference potential contact but also as a terminal for controlling wiring impedance of differential signals D2N and D2P. TA21 corresponds to a fourth ground contact.

[0221] The contacts TA01, TA04, TA06, TA18, and TA21 are connected to, for example, a GND portion of an FPC substrate, and the GND portion of the FPC substrate is fixed to a metal member serving as a GND level of the accessory 200 with screws not shown. The metal member serving as the GND level includes, for example, a socket attachment leg engageable with the accessory socket portion of the camera 100, a bottom plate not shown inside the accessory 200, and the like.

[0222] Figure 6A processing sequence to be performed when the accessory 200 is attached to the camera 100 is illustrated. An overview of each of the processing of the camera 100 (camera control circuits A101 and B102) and the accessory 200 (accessory control circuit 201) will now be described, and details will be described below.

[0223] When the accessory 200 is attached to the camera 100, the accessory attachment detection signal / ACC_DET becomes at a low level. Thus, the camera control circuit A101 determines that the accessory 200 is attached to the camera 100. The camera control circuit A101, which determines that the accessory 200 is attached, sets the power control signal CNT_VACC1 to a high level to turn on the output of the accessory power circuit A131. When the power control signal CNT_VACC1 becomes at a high level, the accessory power circuit A131 outputs the accessory power VACC.

[0224] The accessory power supply circuit 202 that has received VACC generates a power supply VMCU_A for the accessory control circuit 201. Thus, the accessory control circuit 201 is activated. The activated accessory control circuit 201 initializes each block in the accessory 200. Thereafter, when the accessory control circuit 201 is ready to communicate with the camera 100, the accessory control circuit 201 sets the communication request signal / WAKE to a low level.

[0225] When the communication request signal / WAKE becomes at a low level, the camera control circuit A101 detects that the accessory 200 is in a communicable state. The camera control circuit A101 requests the accessory 200 to communicate accessory information through I2C communication. The accessory control circuit 201, which has received the communication request for the accessory information, sends the accessory information to the camera control circuit A101. The accessory control circuit 201, which has sent the accessory information, sets the communication request signal / WAKE to a high level.

[0226] The camera control circuit A101 determines whether the attached accessory is controllable based on the received accessory information. The camera control circuit A101 turns on the accessory power circuit B 132. Then, the camera control circuit A101 performs various settings of the camera 100, and upon completion of these settings, the camera control circuit A101 notifies the camera control circuit B 102 of the accessory information.

[0227] The camera control circuit B 102 notifies the accessory 200 of a control command (accessory control communication) or performs control corresponding to a function signal (function signal control) through SPI communication based on the notified accessory information. That is, the camera control circuit B 102 controls the accessory 200 through SPI communication.

[0228] The accessory control circuit 201 responds to a control command from the camera 100 through SPI communication, and operates according to a function signal.

[0229] Now we will explain Figure 5 The data of D7-D0 at address 0x00 is information indicating the type of the accessory (hereinafter referred to as accessory type information). Figure 7 Examples of accessory type information are illustrated. For example, 0x81 represents a flash device, 0x82 represents an interface conversion adapter device, 0x83 represents a microphone device, and 0x84 represents a multi-accessory connection adapter device for attaching multiple accessory devices to the camera 100.

[0230] The adapter device is an intermediate accessory attached between the camera 100 and an accessory such as a flash device and a microphone device. The interface conversion adapter device is an adapter device that converts interfaces to provide compatibility between the camera 100 and the accessory in a case where the interface of the camera 100 and the interface of the accessory are different. The multi-accessory connection adapter device is an adapter device to which a plurality of accessories can be attached.

[0231] Figure 5 The data D7-D0 at address 0x01 in is information indicating the model (type) of the accessory 200 (hereinafter referred to as accessory type information). The type and model of the accessory can be identified by the above-mentioned accessory type information and this information.

[0232] The data D7 to D0 at the address 0x02 is information indicating the firmware version of the accessory 200 .

[0233] The data D7-D6 at the address 0x03 is specification information (hereinafter referred to as power-off power supply required / unrequired information) indicating whether to request the supply of (electric power) to the accessory power source VACC of the accessory 200 in the power-off state (first power saving state) in which the power switch (not shown) of the camera 100 is turned off. When the information is 0, power supply is not requested. When the information is 1, power supply is requested by the accessory power supply circuit A 131. When the information is 2, power supply is requested by the accessory power supply circuit B 132.

[0234] The D5-D4 data at the address 0x03 is specification information (hereinafter referred to as automatic power-off power supply required / unrequired information) indicating whether to request the accessory power source VACC to the accessory 200 when the camera 100 is in a power saving state (hereinafter referred to as automatic power-off state; second power saving state) by the automatic power-off function. The camera 100 has an automatic power-off function to save power, and the automatic power-off function automatically turns off the power when a non-operating state in which no operation is performed continues for a predetermined time. In the case where this information is 0, this means that power supply is not required. In the case where this information is 1, this means that there is power supply requested by the accessory power supply circuit A 131. In the case where this information is 2, this means that there is power supply requested by the accessory power supply circuit B 132.

[0235] The D3-D2 data at address 0x03 is specification information (hereinafter referred to as charging support information) indicating whether the accessory 200 has a battery 205. If this information is 0, it means that the accessory 200 does not have a battery, and if this information is 1, it means that the accessory 200 has a battery.

[0236] The D1-D0 data at address 0x03 is specification information (hereinafter referred to as charging support 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.

[0237] The D7-D0 data at address 0x04 is specification information indicating the required power of the accessory power supply VACC supplied from the camera 100 to the accessory 200. For example, a value obtained by multiplying the information by 10 indicates a current value. In the case where the information is 10, this means 100 mA, and in the case where the information is 100, this means 1 A. In order to reduce the amount of information of the information, the information may be simply associated with the current value. For example, in the case where the information is 0, this may mean 100 mA, in the case where the information is 1, this may mean 300 mA, in the case where the information is 3, this may mean 450 mA, and in the case where the information is 4, this may mean 600 mA.

[0238] The D7 data at address 0x05 is specification information indicating whether the accessory 200 is in the firmware update mode. When the information is 0, it means that the accessory 200 is not in the firmware update mode, and when the information is 1, it means that the accessory 200 is in the firmware update mode.

[0239] The D6 data at address 0x05 is specification information indicating whether the accessory 200 has a firmware update function. When this information is 0, it means that the accessory 200 does not have a firmware update function. When this information is 1, it means that the accessory 200 has a firmware update function.

[0240] The D5-D4 data at address 0x05 is specification information indicating whether the operation of the accessory 200 attached to the intermediate (connection) accessory is permitted. If the information is 0, it means that the operation is not permitted, and if the information is 1, it means that the operation is permitted.

[0241] The D3-D2 data at address 0x05 is specification information indicating whether the accessory 200 requires the camera 100 to confirm the attachment of the intermediate accessory when the camera 100 is activated. If this information is 0, it means that confirmation is unnecessary, and if this information is 1, it means that confirmation is necessary.

[0242] The D1-D0 data at address 0x05 is specification information indicating whether the accessory 200 supports command notification by I2C communication. In the case where the information is 0, this means that command notification is not supported, and in the case where the information is 1, this means that command notification is supported.

[0243] The D5-D4 data at address 0x06 is specification information indicating a communication request factor acquisition method (communication method used: hereinafter referred to as factor acquisition method) as a communication method that can be used to notify the camera 100 of the generation factor of the communication request after the accessory 200 notifies the camera 100 of the communication request signal / WAKE. In the case where this information is 0, it means that the I2C communication method is the factor acquisition method. In the case where this information is 1, it means that the SPI communication method is the factor acquisition method. In the case where this information is 2, it means that the I2C communication method and the SPI communication method are each the factor acquisition method.

[0244] 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), the FNC2 signal (function signal 2), the FNC3 signal (function signal 3), and the 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. In the case where the value is 0, this means that the accessory 200 does not have the function. In the case where the value is 1, the accessory 200 has the function.

[0245] The D7 data at address 0x0A is specification information indicating whether the accessory 200 requests activation of the camera 100 when the accessory 200 notifies the camera 100 of the communication request signal / WAKE. If the information is 0, this means activation is requested, and if the information is 1, this means activation is not requested.

[0246] The data D6-D0 at the address 0x0A is information indicating a generation factor of the communication request signal / WAKE which the accessory 200 notifies the camera 100 of.

[0247] Figure 8 An example of a factor for generating a communication request signal / WAKE (hereinafter also referred to as a communication request factor) is illustrated. Here, an example is illustrated in the case where the accessory 200 is a microphone device. For example, factor number 0x00 is a number indicating that the menu call switch in the operation switch 212 has been operated (pressed). Factor number 0x01 is a number indicating that the accessory 200 has completed the output control of the audio signal. Factor number 0x02 is a number indicating that the accessory 200 has completed the mute processing (unmuting) of the audio signal. As described above, in the present embodiment, information related to the communication request factor (number) used as information related to the generation factor of the communication request signal / WAKE can be notified (sent) from the accessory 200 to the camera 100 as accessory information.

[0248] exist Figure 5 In the example, the D1 data at address 0x0C is the specification information of the SPI communication protocol supported by accessory 200, and when the information is 0, it means that accessory 200 supports SPI protocol A, and when the information is 1, it means that accessory 200 supports SPI protocol B.

[0249] The D0 data at address 0x0C is specification information indicating the CS control logic of the SPI communication supported by the accessory 200. In the case where the information is 0, it means that the CS is a low active logic, and in the case where the information is 1, it means that the CS is a high active logic.

[0250] The D7-D0 data at address 0x0D is specification information indicating the time required as a communication byte interval when accessory 200 communicates according to SPI protocol A and the D7 data at address 0x05 is 0 or accessory 200 is not in the firmware update mode.

[0251] The D7-D0 data at address 0x0E is specification information indicating the time required as a communication byte interval when the accessory 200 communicates according to SPI protocol A and the D7 data at address 0x05 is 1 or the accessory 200 is in the firmware update mode.

[0252] Fig.9A and Fig. 9B The time (communication interval) of the communication byte interval corresponding to the data (0 to 7) at the addresses 0x0D and 0x0E is illustrated. Fig.9A illustrates the communication interval for data at address 0x0D, and Fig. 9B The communication interval for data at address 0x0E is illustrated.

[0253] exist Figure 5 , the data at address 0x0F is data indicating a checksum value of the sum of the values ​​at addresses 0x00 to 0x0E.

[0254] Fig.10 The startup process to be performed by the camera control circuit A 101 until the accessory 200 is attached to the camera 100 and the function of the accessory 200 is enabled is illustrated.

[0255] In S401, the camera control circuit A101 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 A101 determines that the accessory 200 is not attached, and the flow 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 A101 determines that the accessory 200 is attached, and the flow proceeds to S402.

[0256] In S402, the camera control circuit A101 performs control for changing the power control signal CNT_VACC1 to a high level to turn on the output of the accessory power circuit A 131. Then, the flow proceeds to S403. When the power control signal CNT_VACC1 is at a high level, the accessory power circuit A 131 outputs the accessory power VACC.

[0257] In S403, the camera control circuit A101 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 A101 determines that no overcurrent is flowing, and the process proceeds to S404, and if the signal level is high, the camera control circuit A101 determines that an overcurrent is flowing, and the process proceeds to S405 for error processing.

[0258] In S404, the camera control circuit A 101 monitors the signal level of the communication request signal / WAKE as a notification signal from the accessory 200, and determines whether the initialization of the accessory 200 is completed. If the signal level of the communication request signal / WAKE is low (active), the camera control circuit A 101 determines that the initialization is completed, and the flow proceeds to S406. If the signal level is high, the camera control circuit A 101 determines that the initialization has not been completed, and the flow returns to S404 so that the camera control circuit A 101 determines again whether the initialization is completed.

[0259] In S406, the camera control circuit A 101 performs I2C communication with the accessory 200 as initial communication, and reads out 15 bytes of accessory information. Then, the flow proceeds to S407.

[0260] In S407, the camera control circuit A 101 determines, based on the accessory information read out in S406, whether the attached accessory 200 is a compatible device (compatible accessory) with the camera 100. In a case where the camera control circuit A 101 determines that the attached accessory 200 is a compatible accessory, the flow proceeds to S408, and in a case where the camera control circuit A 101 determines that the attached accessory 200 is not a compatible accessory, the flow proceeds to S409 for error processing.

[0261] In S408, the camera control circuit A101 performs control for changing the power control signal CNT_VACC2 to a high level to turn on the output of the accessory power circuit B 132. Then, the flow proceeds to S410. When the power control signal CNT_VACC2 is at a high level, the accessory power circuit B 132 outputs the accessory power VACC. In the present embodiment, when both the power control signals CNT_VACC1 and CNT_VACC2 are at a high level, the output from the accessory power circuit B 132 is supplied to the accessory power VACC.

[0262] In S410, the camera control circuit A 101 notifies the camera control circuit B 102 of the accessory information read out in S406. Thus, the activation process of the camera 100 in response to the attachment of the accessory 200 is completed.

[0263] Fig.11 The flowchart in exemplifies activation processing to be performed by the camera control circuit B 102 until the accessory 200 is attached to the camera 100 and the function of the accessory 200 is activated.

[0264] In S501, the camera control circuit B 102 determines whether the accessory information has been notified from the camera control circuit A 101. If the accessory information has not been notified, the flow 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 flow proceeds to S502.

[0265] 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, in the case where 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, in the case where 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 signal that does not require the 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.

[0266] 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 .

[0267] 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 flow returns to S504, and the camera control circuit B 102 determines again whether the event has occurred. If the event has occurred, the flow proceeds to S505.

[0268] In S505, the camera control circuit B 102 determines whether the event determined in S504 is an event requiring SPI communication with the accessory 200. If the event requires SPI communication, the flow proceeds to S506, otherwise the flow proceeds to S507.

[0269] 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 a function signal. If the event requires control using a function signal, the flow proceeds to S508, otherwise the flow proceeds to S509.

[0270] In S506, the camera control circuit B 102 performs SPI communication with the accessory 200. In the case where 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. In the case where 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. When the SPI communication in S506 is completed, the flow returns to S504, and the camera control circuit B 102 determines again whether an event has occurred.

[0271] In S508, the camera control circuit B 102 controls the accessory 200 using the function signal. For example, in the case where 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 accepts the audio data signal SDAT of FNC3. Thus, the camera 100 can acquire voice data from the microphone device. In the case where 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. Thus, the camera 100 can instruct the flash device to emit light. When the control using the function signal is completed in this way, the flow returns to S504, and the camera control circuit B 102 determines again whether an event has occurred.

[0272] In S509, the camera control circuit B 102 performs predetermined in-camera control according to the event determined in S504. In the case where the accessory 200 is a microphone device, the in-camera control includes, for example, control for starting or ending recording of voice data in the recording memory 126, and control for performing equalizer processing on the voice data, etc. In the case where the accessory 200 is a flash device, the in-camera control includes photometry control for accumulating and acquiring light emitted by the flash device using the image sensor 122, and control for calculating an indication value of the amount of light emitted by the flash device, etc. When the in-camera control is thus completed, the flow returns to S504, and the camera control circuit B 102 determines again whether an event has occurred.

[0273] Through the above-described start-up processing by the camera control circuit A 101 and the enablement processing by the camera control circuit B 102 , the accessory 200 attached to the camera 100 can be controlled.

[0274] Fig.12The flowchart in exemplifies processing to be executed by the accessory control circuit 201 from when the accessory 200 is attached to the camera 100 until when various functional operations of the accessory 200 are enabled.

[0275] In S601, the accessory control circuit 201 waits for the accessory power VACC from the camera 100 to be turned on. In the case where the accessory 200 does not have the battery 205, the turning on of the accessory power VACC may be detected when power is supplied to the accessory control circuit 201 and the operation of the accessory control circuit 201 itself starts. In the case where the accessory 200 has the battery 205, the accessory control circuit 201 may monitor the voltage value of the accessory power VACC to detect that the accessory power VACC is turned on.

[0276] In S602, the accessory control circuit 201 performs predetermined initial settings. For example, the accessory control circuit 201 sets the operating frequency of the microcomputer, the input / output control port of the microcomputer, the initialization of the timer function of the microcomputer, and the initialization of the interrupt function of the microcomputer.

[0277] When the initial setting in S602 is completed, the accessory control circuit 201 performs control for changing the communication request signal / WAKE to a low level in S603. Thus, the camera 100 is notified of the completion of the initial setting.

[0278] In S604, the accessory control circuit 201 responds to the I2C communication from the camera 100 and sends 15 bytes of accessory information to the camera 100 as initial communication. The accessory information includes Figure 5 Various information displayed.

[0279] When the initial communication of S604 is completed, the accessory control circuit 201 controls the communication request signal / WAKE to a high level in S605.

[0280] In S606, the accessory control circuit 201 determines whether a predetermined event has occurred. If no event has occurred, the flow returns to S606, and the accessory control circuit 201 determines again whether an event has occurred, and if an event has occurred, the flow proceeds to S607.

[0281] In S607, the accessory control circuit 201 determines whether the event determined in S606 is an event requiring SPI communication with the camera 100. If the event requires SPI communication, the flow proceeds to S608, otherwise the flow proceeds to S609.

[0282] In S609, the accessory control circuit 201 determines whether the event determined in S606 is an event requiring I2C communication with the camera 100. If the event requires I2C communication, the flow proceeds to S610, otherwise the flow proceeds to S611.

[0283] 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.

[0284] In S613, the accessory control circuit 201 determines whether the event determined in S606 is an event that needs to be notified to the camera 100 via the communication request signal / WAKE. If the event needs to be notified to the camera 100 via the communication request signal / WAKE, the flow proceeds to S614, otherwise the flow proceeds to S615.

[0285] In S608, the accessory control circuit 201 performs SPI communication with the camera 100. In the case where the communication request signal / WAKE is at a low level when the accessory control circuit 201 performs SPI communication, the accessory control circuit 201 performs control for changing the communication request signal / WAKE to a high level after the SPI communication. In the case where 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 from the camera 100, communication of an instruction to turn off the microphone operation, and communication of an instruction to switch the sound collection directivity of the microphone. The SPI communication also includes communication of an instruction to switch the equalizer function of the microphone. In the case where the accessory 200 is a flash device, the SPI communication includes communication for reading out setting information related to the flash device, communication for notifying the flash device of the setting information, and the like. When the predetermined SPI communication in S608 is completed, the flow returns to S606, and the accessory control circuit 201 determines again whether an event has occurred.

[0286] In S610, the accessory control circuit 201 performs I2C communication with the camera 100. In the case where the communication request signal / WAKE is at a low level when the I2C communication is performed, control for changing the communication request signal / WAKE to a high level is performed after the I2C communication. The I2C communication performed here includes, for example, communication for reading out a 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 flow returns to S606, and the accessory control circuit 201 determines again whether an event has occurred.

[0287] In S612, the accessory control circuit 201 controls the camera 100 using the function signal. In the case where 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. The control also includes output control of the voice data signal SDAT of FNC3 synchronized with these signals. In the case where 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 the function signal in S612 is completed, the flow returns to S606, and the accessory control circuit 201 determines again whether an event has occurred.

[0288] In S614, the accessory control circuit 201 stores the communication request factor number to the camera 100 in response to the event determined in S606 in a volatile memory not shown in the accessory 200, and performs control for changing the communication request signal / WAKE to a low level. Figure 8 As shown, the communication request factor number is a unique number assigned to each factor content. When the low level control of the communication request signal / WAKE in S614 is completed, the flow returns to S606, and the accessory control circuit 201 determines again whether an event has occurred.

[0289] In S615, the accessory control circuit 201 performs accessory control according to the event determined in S606. In the case where the accessory 200 includes the battery 205, the accessory control performed here includes control for detecting the remaining battery power, control for detecting the operation of the operation switch 212, etc. When the accessory control in S615 is completed, the flow returns to S606, and the accessory control circuit 201 determines again whether an event has occurred.

[0290] Through the above-described processing using the accessory control circuit 201 , after the accessory 200 is attached to the camera 100 , the accessory 200 can perform various functional operations.

[0291] Reference now Fig.13 and Fig.14 , a description will be given of a usage example of a communication request signal between the camera 100 and the accessory 200 in the present embodiment. Fig.13 Example Figure 1 The camera control circuits A 101 and B 102, the accessory control circuit 201 and the accessory power supply circuit 202 are shown. Fig.13 Example Figure 1Among the contacts shown, an accessory detection line 1000 including contacts TC06 and TA06 for an accessory attachment detection signal / ACC_DET, a power line 1001 including contacts TC05 and TA05 for an accessory power supply VACC, a communication request line 1002 including contacts TC11 and TA11 for a communication request signal / WAKE, a first communication line 1003 including contacts TC12, TA12, TC13 and TA13 for I2C communication, and a second communication line 1004 including contacts TC07 to TC10 and TA07 to TA10 for SPI communication.

[0292] Fig.14 The following illustrates a processing sequence to be performed when the accessory 200 is attached to the camera 100. This sequence is different from the above-described one in terms of the method of using the communication request signal. Figure 6 This will simplify the sequence of Figure 6 Instructions for supplying power to accessories are shown.

[0293] When the accessory 200 is attached to the camera 100 in S701 , the accessory attachment detection signal / ACC_DET in the accessory detection line 1000 becomes a low level. Thus, the camera control circuit A101 determines that the accessory 200 has been attached to the camera 100 .

[0294] The camera control circuit A101 which determines that the accessory 200 is attached performs control to output the accessory power VACC to the power line 1001 in S702 .

[0295] In S703 , when the accessory 200 receives the accessory power VACC, the accessory control circuit 201 starts up. The started accessory control circuit 201 initializes each block in the accessory 200 .

[0296] Thereafter, in S704, when the above-mentioned initialization is completed, preparation for communication with the camera 100 is completed, and communication becomes available, the accessory control circuit 201 sets the communication request signal / WAKE in the communication request line 1002 to a low level for assertion (activation), thereby notifying the camera 100 of communication permission.

[0297] The timing of notifying the camera 100 of communication permission from the accessory 200 is not limited to the time after the accessory power VACC is supplied in S702. For example, as long as the accessory 200 has a built-in battery and is ready for communication when it is attached to the camera 100, communication permission may be notified when the accessory 200 is attached.

[0298] Next, in S705 , the camera control circuit A101 having received the notification of communication permission from the accessory 200 , requests the accessory 200 to communicate accessory information by I 2 C communication via the first communication line 1003 .

[0299] Next, in S706, the accessory control circuit 201 that has received the communication request for the accessory information transmits the accessory information to the camera control circuit A101 via the first communication line 1003. However, the accessory information communicated through I2C may not be communicated between the camera control circuit A101 and the accessory control circuit 201. For example, in a case where the accessory control circuit 201 does not have a function of storing the accessory information and the accessory information is stored in a separate storage device, the accessory information may be communicated between the camera control circuit A101 and the storage device.

[0300] Next, in S707, the camera control circuit A101 determines whether the attached accessory 200 is controllable and a factor acquisition method when acquiring a communication request factor from the accessory 200 based on the received accessory information. The camera control circuit A101 performs various settings on the camera 100. After the camera control circuit A101 completes these settings, the camera control circuit A101 notifies the camera control circuit B 102 of the accessory information.

[0301] On the other hand, the accessory control circuit 201 that has transmitted the accessory information (or confirmed that the accessory information has been transmitted from the storage device) sets the communication request signal / WAKE in the communication request line 1002 to a high level for negation (deactivation) in S708. Thus, the camera 100 transitions to a state of waiting for a communication request from the accessory 200.

[0302] The timing for negating the communication request signal / WAKE is not limited to the time after the accessory information is transmitted in S705. For example, when SPI communication is required between the camera 100 and the accessory 200 to communicate the accessory information, the communication request signal / WAKE may be negated after SPI communication following I2C communication.

[0303] Next, in S709, the accessory control circuit 201 sets the communication request signal / WAKE in the communication request line 1002 to low level to assert, thereby performing an event requiring SPI communication with the camera 100 via the second communication line 1004, and notifies the camera of the communication request.

[0304] Next, in S710, the camera control circuit B 102 requests the accessory 200 for a communication request factor from the accessory 200 in response to the notified communication request. As described above, the communication request factor is included in the accessory information, and the camera control circuit B 102 determines whether to make an acquisition request for the communication request factor by I2C communication or by SPI communication based on the accessory information. In this specification, it is determined to be made by SPI communication.

[0305] In S711, the accessory control circuit 201 transmits the communication request factor to the camera 100 through the SPI communication in response to the acquisition request for the communication request factor. In a case where the camera control circuit B 102 determines in S710 that the acquisition request for the communication request factor is to be made through the I2C communication, the accessory control circuit 201 transmits the communication request factor to the camera 100 through the I2C communication.

[0306] In the above Fig.14 In the sequence of FIG. 1 , assertion of the initial communication request signal / WAKE in the communication request line 1002 (the first time) after the accessory 200 is attached to the camera 100 and communication is available is used for notification of communication permission from the accessory 200 to the camera 100. The camera 100 having received the notification of communication permission acquires the accessory information from the accessory 200. Thereafter, assertion of the communication request signal / WAKE in the communication request line 1002 for the second time and thereafter after an event requiring communication with the camera 100 occurs in the accessory 200 is used for notification of a communication request from the accessory 200 to the camera 100. The camera 100 having received the notification of the communication request acquires the communication request factor from the accessory 200.

[0307] Thus, in the present embodiment, the accessory 200 can transmit accessory information to the camera 100 by notifying the camera 100 of communication permission after the accessory 200 is attached to the camera 100. The communication request signal / WAKE connected to one (same) communication request line 1002 provided between the camera 100 and the accessory 200 can be used to notify the camera 100 of communication permission and a subsequent communication request from the accessory 200. Thus, the accessory 200 can notify the camera 100 of communication permission and a communication request while making the number of contacts of the camera 100 and the accessory 200 smaller than in the case where the notification of communication permission and the notification of communication request are performed via different contacts.

[0308] Second embodiment

[0309] Reference now Fig.15 and Fig.16 , a second embodiment according to the present invention will be described. The second embodiment will discuss a method of using a communication request signal in the case where another accessory (hereinafter referred to as a second accessory) 300 is attached to an accessory (hereinafter referred to as a first accessory) 200 attached to a camera 100. This embodiment assumes that the first accessory 200 is an intermediate accessory, and the second accessory 300 is a flash device or the like connected to the camera 100 via the intermediate accessory.

[0310] Fig.15 The camera control circuits A101 and B102, the accessory control circuit 201, and the accessory power supply circuit 202 are shown with Figure 1These circuits are identical in Fig.15 In the embodiment, the accessory detection line 1000, the power line 1001, the communication request line 1002, the first communication line 1003 and the second communication line 1004 are connected to Fig.13 These lines in are the same. Fig.15 Also shown is a communication request line 1005 provided between the accessory connector 213 provided in the first accessory 200 and the accessory connector 302 provided in the second accessory 300, and a third communication line (SPI / I2C). The accessory control circuit (hereinafter referred to as the first accessory control circuit) 201 in the first accessory 200 and the accessory control circuit (hereinafter referred to as the second accessory control circuit) 301 in the second accessory 300 can perform at least one of I2C communication and SPI communication via (one or more) third communication lines.

[0311] In the present embodiment, the first accessory 200 performs initial communication with the camera 100 through I2C communication, and then transmits the communication content through SPI communication to the second accessory 300 through SPI communication. The first accessory 200 transmits the communication content through SPI communication from the second accessory 300 to the camera 100. The first accessory 200 also transmits a communication request signal from the second accessory 300 to the camera 100. The communication between the first accessory 200 and the second accessory 300 is controlled by the second accessory control circuit 301.

[0312] Fig.16 A processing sequence to be performed when the first accessory 200 and the second accessory 300 are attached to the camera 100 is illustrated.

[0313] In S801 , when the first accessory 200 is attached to the camera 100 , the accessory attachment detection signal / ACC_DET in the accessory detection line 1000 becomes at a low level. Thus, the camera control circuit A101 determines that the first accessory 200 and the second accessory 300 are attached to the camera 100 .

[0314] The camera control circuit A101 which determines that the first accessory 200 is attached performs control in S802 to output the accessory power VACC to the power line 1001. Thereby, the first accessory control circuit 201 is activated. It is assumed that the main power of the second accessory 300 is turned on.

[0315] Next, in S803, when preparation for communication with the camera 100 is completed and communication becomes available, the first accessory control circuit 201 sets the communication request signal / WAKE in the communication request line 1002 to low level to assert, thereby notifying the camera 100 of communication permission.

[0316] The timing of notifying the camera 100 of communication permission from the first accessory 200 is not limited to the time after the accessory power VACC is supplied in S802. For example, if the first accessory 200 has a built-in battery and is ready for communication when it is attached to the camera 100, communication permission may be notified when the first accessory 200 is attached.

[0317] Next, in S804 , the camera control circuit A101 having received the notification of communication permission from the first accessory 200 , requests the first accessory 200 to communicate accessory information by I2C communication via the first communication line 1003 .

[0318] Next, in S805, the first accessory control circuit 201 that has received the communication request for the accessory information transmits the accessory information to the camera control circuit A101 via the first communication line 1003. However, the accessory information by I2C communication may not be communicated between the camera control circuit A101 and the accessory control circuit 201. For example, in a case where the first accessory control circuit 201 does not have a function of storing the accessory information and the accessory information is stored in a separate storage device, the accessory information may be communicated between the camera control circuit A101 and the storage device.

[0319] Next, in S806, the camera control circuit A101 determines whether the attached first accessory 200 is controllable and a factor acquisition method for acquiring a communication request factor from the first accessory 200 based on the received accessory information. The camera control circuit A101 performs various settings on the camera 100. When these settings are completed, the camera control circuit A101 notifies the camera control circuit B 102 of the accessory information.

[0320] Next, in S807 , the camera control circuit B 102 performs initial communication (predetermined communication) with the first accessory control circuit 201 by SPI communication via the second communication line 1004 to connect with the second accessory 300 .

[0321] In S808, the first accessory control circuit 201 responds to the initial communication in S807 to the camera control circuit B 102 through SPI communication.

[0322] Next, in S809 , the first accessory control circuit 201 sets the communication request signal / WAKE in the communication request line 1002 to a high level for negation. Thus, the first accessory 200 transitions to a state of waiting for a communication request from the second accessory 300 .

[0323] Next, in S810, the second accessory control circuit 301 sets the communication request signal / WAKE in the communication request line 1005 to low level to assert, thereby performing an event requiring SPI communication with the camera 100 through the first accessory 200, and notifies the communication request.

[0324] Next, in S811 , the first accessory control circuit 201 sets the communication request signal / WAKE in the communication request line 1002 to a low level to assert, thereby notifying the camera 100 of the communication request from the second accessory 300 .

[0325] Then, in S812, the camera control circuit B 102 requests the first accessory 200 for a communication request factor from the second accessory 300 in response to the notified communication request. The camera control circuit B 102 determines whether to request the acquisition of the communication request factor by I2C communication or by SPI communication based on the accessory information received in S805. In this specification, it is determined that the acquisition request is made by SPI communication.

[0326] Next, in S813, the first accessory control circuit 201 transmits the acquisition request for the communication request factor received from the camera 100 to the second accessory 300. At this time, the first accessory control circuit 201 converts the signal level (voltage level) of the acquisition request for the communication request factor received from the camera 100 into a level suitable for communication with the second accessory 300.

[0327] Then, in S814, the second accessory control circuit 301 sends the communication request factor to the first accessory 200 through the SPI communication in response to the acquisition request for the communication request factor.

[0328] Next, in S815, the first accessory control circuit 201 transmits the communication request factor received from the second accessory 300 to the camera 100. At this time, the first accessory control circuit 201 converts the signal level of the communication request factor received from the second accessory 300 into a level suitable for communication with the camera 100.

[0329] In the present embodiment described above, assertion of the initial communication request signal / WAKE in the communication request line 1002 (for the first time) after the first accessory 200 is attached to the camera 100 and communication is available is used for notification of communication permission from the accessory 200 to the camera 100. The camera 100 having received the notification of communication permission acquires accessory information from the first accessory 200. Thereafter, assertion of the communication request signal / WAKE in the communication request line 1002 for the second and subsequent times after an event requiring communication with the camera 100 occurs in the second accessory 300 is used for notification of a communication request from the second accessory 300 to the camera 100. The camera 100 having received the notification of the communication request acquires a communication request factor from the second accessory 300 via the first accessory 200.

[0330] Thus, in the present embodiment, the first accessory 200 can transmit accessory information to the camera 100 by notifying the camera 100 of communication permission after the first accessory 200 is attached to the camera 100. The communication request signal / WAKE connected to one (same) communication request line 1002 provided between the camera 100 and the first accessory 200 can be used to notify the camera 100 of communication permission from the first accessory 200, and to notify the camera 100 of communication request from the second accessory 300. Thus, the accessory 200 can notify the camera 100 of communication permission and communication request, while making the number of contacts of the camera 100 and the accessory 200 smaller than in the case where the notification of communication permission and the notification of communication request are performed via different contacts.

[0331] Third embodiment

[0332] Reference now Fig.17 and Fig.18 , a third embodiment according to the present invention will be described. The third embodiment will describe a method of using a communication request signal in the case where another accessory (hereinafter referred to as a third accessory) 400 is attached to an accessory (hereinafter referred to as a first accessory) 200 attached to a camera 100. This embodiment assumes that the third accessory 400 is a smartphone or a tablet terminal, and the first accessory 200 is a holder that holds the smartphone or tablet terminal. In this embodiment, the communication request signal / WAKE in the communication request line 1002 is used only to notify communication permission.

[0333] Fig.17 The camera control circuits A101 and B102, the first accessory control circuit 201, and the accessory power supply circuit 202 are shown with Fig.15 These circuits are identical in Fig.17 In the embodiment, the accessory detection line 1000, the power line 1001, the communication request line 1002 and the first communication line 1003 are connected to Fig.15 These lines are the same in Fig.17The fourth communication line 1006 includes Figure 1 The fourth communication line 1006 is connected to the accessory control circuit (hereinafter referred to as the third accessory control circuit) 401 in the third accessory 400 via the accessory connector 215 provided in the first accessory 200 and the accessory connector 402 provided in the third accessory 400.

[0334] The third accessory control circuit 401 determines whether the camera 100 is communicable via the fourth communication line 1006 , and if it is determined that the camera 100 is communicable, the third accessory control circuit 401 communicates with the camera 100 .

[0335] Fig.18 A processing sequence to be performed when the first accessory 200 and the third accessory 400 are attached to the camera 100 is illustrated.

[0336] S901 to S906 are the same as those in the second embodiment ( Fig.16 ) corresponds to S801 to S806.

[0337] In S907 , the third accessory control circuit 401 functions as a host, and communicates with the camera 100 through the fourth communication line 1006 .

[0338] Next, in S908, the camera control circuit B 102 responds to the communication received in S907 to the third accessory 400 via the fourth communication line 1006. In S904 to S908, the first accessory control circuit 201 maintains assertion of the communication request signal / WAKE in the communication request line 1002.

[0339] In the present embodiment described above, assertion of the initial communication request signal / WAKE in the communication request line 1002 after the first accessory 200 is attached to the camera 100 and communication is available is used for notification of communication permission from the first accessory 200 to the camera 100. The camera 100, which has received the notification of communication permission, acquires accessory information from the first accessory 200. Thereafter, the first accessory 200 allows communication between the camera 100 and the third accessory 400 by continuing to maintain assertion of the communication request signal / WAKE.

[0340] Therefore, in the present embodiment, the communication request signal / WAKE connected to one (same) communication request line 1002 provided between the camera 100 and the accessory 200 can be used to notify the camera 100 of communication permission from the first accessory 200 and to notify communication permission between the third accessory 400 and the camera 100. Therefore, the accessory 200 can notify the camera 100 of communication permission while making the number of contacts of the camera 100 and the accessory 200 smaller than in the case where these notifications of communication permission are performed via different contacts.

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

[0342] The above-described embodiments each can provide an accessory, an electronic device, a control method, a system, and a storage medium (program), each of which enables an accessory to notify an electronic device.

[0343] Other embodiments

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

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

Claims

1. An accessory that can be attached to and detached from an electronic device, the accessory comprising: a plurality of communication contacts including a first contact; a control unit configured to control communication with the electronic device via the plurality of communication contacts, It is characterized in that when the control unit changes the signal level of the first contact from the second signal level to the first signal level corresponding to the start of power supply, the control unit performs predetermined communication, wherein the predetermined communication is different from the communication performed when the signal level of the first contact is changed from the second signal level to the first signal level corresponding to a factor different from the start of power supply.

2. The accessory according to claim 1, characterized in that The predetermined communication includes receiving a request for attribute information related to the accessory, and sending the attribute information related to the accessory.

3. The accessory according to claim 2, characterized in that: The attribute information related to the accessory includes information related to a communication method for receiving a request for information representing a communication factor and for sending the information representing the communication factor.

4. The accessory according to claim 2, characterized in that: In response to notification of a communication request notified via the first contact in response to start of power supply, the control unit performs reception of a request for attribute information related to the accessory and transmission of attribute information related to the accessory through I2C communication.

5. The accessory according to claim 3, characterized in that: In a case where the information about the communication method indicates the first information, the control unit performs reception of a request for information indicating the communication factor and transmission of the information indicating the communication factor through I2C communication.

6. The accessory according to claim 5, characterized in that In synchronization with a clock signal received via a second contact in the I2C communication, the control unit receives a request for information indicating the communication factor via a third contact and transmits the information indicating the communication factor.

7. The accessory according to claim 5, characterized in that In a case where the information about the communication method indicates second information, the control unit performs reception of a request for information indicating the communication factor and transmission of the information indicating the communication factor through SPI communication.

8. The accessory according to claim 6, characterized in that Power supply starts in response to a change in the signal level of the fourth contact.

9. The accessory according to claim 8, characterized in that Power supply starts in response to the electronic device being powered on or the accessory being attached to the electronic device.

10. The accessory according to claim 1, characterized in that When the control unit notifies the electronic device of a communication request via the first contact for the first time after power supply starts, the control unit performs the predetermined communication without receiving a request for information indicating a communication factor or without sending the information indicating the communication factor.

11. A system comprising: Electronic equipment; as well as The accessory according to any one of claims 1 to 10, which is attachable to and detachable from the electronic device.

12. An electronic device that is attachable to and detachable from an accessory, the electronic device comprising: a plurality of communication contacts including a first contact; as well as a control unit configured to control communication with the accessory via the plurality of communication contacts, It is characterized in that when the control unit changes the signal level of the first contact from the second signal level to the first signal level corresponding to the start of power supply, the control unit performs predetermined communication, wherein the predetermined communication is different from the communication performed when the signal level of the first contact is changed from the second signal level to the first signal level corresponding to a factor different from the start of power supply.

13. The electronic device according to claim 12, characterized in that: The predetermined communication includes sending a request for attribute information related to the accessory, and receiving attribute information related to the accessory.

14. The electronic device according to claim 13, characterized in that: The attribute information related to the accessory includes information related to a communication method for sending a request for information representing a communication factor and for receiving the information representing the communication factor.

15. The electronic device according to claim 13, characterized in that: The control unit performs transmission of a request for attribute information related to the accessory and reception of attribute information related to the accessory through I2C communication in response to notification of a communication request notified via the first contact in response to start of power supply.

16. The electronic device according to claim 14, characterized in that: In a case where the information about the communication method indicates first information, the control unit performs transmission of a request for information indicating the communication factor and reception of the information indicating the communication factor through I2C communication.

17. The electronic device according to claim 16, characterized in that: In synchronization with a clock signal received via a second contact in the I2C communication, the control unit transmits a request for information indicating the communication factor via a third contact and receives the information indicating the communication factor.

18. The electronic device according to claim 16, characterized in that: In a case where the information related to the communication method indicates second information, the control unit performs transmission of a request for information indicating the communication factor and reception of the information indicating the communication factor through SPI communication.

19. The electronic device according to claim 17, characterized in that: Power supply starts in response to a change in the signal level of the fourth contact.

20. The electronic device according to claim 19, characterized in that: Power supply starts in response to the electronic device being powered on or the accessory being attached to the electronic device.

21. The electronic device according to claim 12, characterized in that: When the control unit is notified of a communication request via the first contact for the first time after power supply starts, the control unit performs the predetermined communication without sending a request for information indicating a communication factor or without receiving the information indicating the communication factor.

22. A system comprising: The electronic device according to any one of claims 12 to 21; as well as An accessory that can be attached to and detached from the electronic device.

23. A method for controlling an accessory, wherein the accessory is attachable to and detachable from an electronic device, and the accessory comprises a plurality of communication contacts, wherein the plurality of communication contacts comprises a first contact, the method comprising the following steps: When the signal level of the first contact is changed from the second signal level to the first signal level corresponding to the start of power supply, predetermined communication is performed, wherein the predetermined communication is different from the communication performed when the signal level of the first contact is changed from the second signal level to the first signal level corresponding to a factor different from the start of power supply.

24. A control method of an electronic device, wherein the electronic device is attachable to and detachable from an accessory, and the electronic device comprises a plurality of communication contacts, wherein the plurality of communication contacts comprises a first contact, the control method comprising the following steps: When the signal level of the first contact is changed from the second signal level to the first signal level corresponding to the start of power supply, predetermined communication is performed, wherein the predetermined communication is different from the communication performed when the signal level of the first contact is changed from the second signal level to the first signal level corresponding to a factor different from the start of power supply.

25. A non-transitory computer-readable storage medium storing a program that enables a computer of an accessory to execute the control method according to claim 23, wherein the accessory can be attached to and detached from an electronic device, and the accessory includes multiple communication contacts, including a first contact.

26. A non-transitory computer-readable storage medium storing a program that enables a computer of an electronic device to execute the control method according to claim 24, wherein the electronic device can be attached to and detached from an accessory, and the electronic device includes multiple communication contacts, including a first contact.

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