Accessory detachably attachable to electronic device, electronic device, and camera system

Abstract

The present invention provides an accessory that is detachably connected to an electronic device, an electronic device, and a camera system. The accessory is capable of quickly notifying the electronic device of a change in its state. The accessory is detachably connected to the electronic device. A first sending unit sends first information from information stored in the accessory to the electronic device in response to a periodic first communication from a first communication unit of the electronic device. A second sending unit responds to an inquiry through a second communication from a second communication unit of the electronic device. A notification unit notifies the electronic device of a change in the state of the accessory when the electronic device is in a first state or a second state and the state of the accessory changes. In the first state, the first communication stops and the second communication unit is in a standby mode. In the second state, power supply to the first communication unit stops and the second communication unit is in a standby mode.

Description

Technical Field

[0001] The present invention relates to an accessory detachably connected to an electronic device, the electronic device, and a camera system constructed by connecting the accessory to a camera device. Background Art

[0002] Typically, an image pickup device such as a digital camera is configured so that an accessory such as a flash device can be connected. In addition, the image pickup device has a controller that controls communication with the connected flash device through an interface. For example, the controller sends a signal instructing the flash device to emit light. However, in a case where the image pickup device is in a power saving mode and the controller is not operating, data cannot be exchanged between the image pickup device and the flash device. Therefore, even if the state of the flash device changes in this case, the flash device cannot notify the image pickup device of the change in the state of the flash device.

[0003] Japanese Patent 5894397 (a corresponding patent of US Pat. No. 9,438,780) proposes a configuration in which a flash device can activate an image pickup apparatus in a power saving mode.

[0004] However, since the technology disclosed in the above publication determines the state of the image pickup apparatus after the state of the flash device changes, the time period from the change in the state of the flash device until the activation of the image pickup apparatus becomes long.

[0005] Furthermore, in a case where the flash device is detached from the imaging apparatus in the power saving mode and the imaging apparatus is to be in an initial state where the imaging apparatus is not connected to an accessory, the conventional flash device cannot detect this state. Summary of the invention

[0006] The present invention provides an accessory, an electronic device, and a camera system, which can quickly notify the electronic device of the change in the state of the accessory based on the state of the electronic device equipped with the accessory when the state of the accessory changes.

[0007] Therefore, an aspect of the present invention provides an accessory that can be detachably connected to an electronic device, the accessory comprising: a first sending unit configured to send first information among information stored in the accessory to the electronic device in response to a periodic first communication from a first communication unit of the electronic device; a second sending unit configured to respond to an inquiry utilizing a second communication from the second communication unit of the electronic device; and a notification unit configured to notify the electronic device of a change in information stored in the accessory when the electronic device is in one of a first state and a second state and the information stored in the accessory changes, wherein, in the first state, the first communication stops and the second communication unit is in standby mode, and wherein, in the second state, power supply to the first communication unit stops and the second communication unit is in standby mode.

[0008] According to the present invention, in the case where the state of an accessory changes, the electronic device is promptly notified of the state change of the accessory based on the state of the electronic device equipped with the accessory.

[0009] 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

[0010] Figure 1 : is a block diagram schematically showing an imaging system including an imaging apparatus (camera) as an electronic device and accessories according to an embodiment of the present invention.

[0011] Figure 2A and Figure 2B 2 are diagrams schematically showing communication waveforms of the first SPI protocol and the second SPI protocol, respectively.

[0012] Figure 3A and Figure 3B 1 and 2 are flowcharts respectively showing the processing of the second camera controller and the processing of the accessory controller using the first SPI protocol.

[0013] Figure 4A and Figure 4B are flowcharts respectively showing the processing of the second camera controller and the processing of the accessory controller using the second SPI protocol.

[0014] Figure 5 The diagram shows the communication content of an operation execution instruction (command) sent from the camera to the accessory through SPI communication.

[0015] Figure 6 is a diagram showing an example of accessory information.

[0016] Figure 7is a diagram showing a sequence when an accessory is attached to a camera.

[0017] Figure 8 is a diagram showing an example of accessory type information.

[0018] Fig. 9 is a diagram showing an example of factors of the communication request signal / WAKE.

[0019] Fig. 10A It is shown in Figure 6 FIG. 1 is a diagram of an example of the communication interval between communication bytes set at address “0x0D”. Fig. 10B It is shown in Figure 6 FIG. 1 is a diagram of an example of the communication interval between communication bytes set at address “0x0E”.

[0020] Fig.11 is a flowchart showing a first accessory attachment process.

[0021] Fig.12 is a flowchart showing the second accessory attachment process.

[0022] Fig.13 is a flow chart showing an accessory attachment process.

[0023] Fig.14 is a diagram showing the state of a camera recognized by the accessory controller according to the first embodiment of the present invention.

[0024] Fig.15 1 is a flowchart showing a notification process of notifying a camera in a case where a light control correction value of an automatic light control mode of a flash device as an accessory according to a first embodiment of the present invention is changed.

[0025] Fig.16 1 is a flowchart showing a notification process of notifying a camera in a case where the light emission control state of a multi-flash system changes, wherein the sending flash is an accessory according to the second embodiment of the present invention.

[0026] Fig.17A and Fig. 17B is a diagram showing an example of an I2C communication waveform.

[0027] Fig.18 : is a flowchart showing a data transmission process performed when the first camera controller transmits N bytes of data to the accessory controller.

[0028] Fig.19 : is a flowchart showing a data reception process performed when the first camera controller receives N bytes of data from the accessory controller.

[0029] Fig. 20: is a flowchart showing a data transmission / reception process performed in the case where N bytes of data are transmitted and received between the accessory controller and the first camera controller. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

[0031] Figure 1 1 is a block diagram schematically showing an imaging system including an imaging apparatus as an electronic device and an accessory according to an embodiment of the present invention. The imaging system includes a camera 100 as an imaging apparatus and an accessory 200. The accessory 200 is detachable from the camera 100. Figure 1 The electrical structures of the camera 100 and the accessory 200 are shown.

[0032] The camera 100 is provided with a camera-side connector 141 as an attachment portion to which the accessory 200 can be attached. The camera-side connector 141 has contacts TC01 to TC21 as a plurality of terminals. The accessory 200 is provided with an accessory-side connector 211. The accessory-side connector 211 has contacts TA01 to TA21 as a plurality of terminals. The camera 100 and the accessory 200 are electrically connected by bringing the contacts TC01 to TC21 into contact with the contacts TA01 to TA21, respectively. It should be noted that the accessory 200 may have a portion of the contacts TA01 to TA21.

[0033] The camera 100 is supplied with electric power from a battery 111. The battery 111 is detachable from the camera 100. The first camera controller 101 and the second camera controller 102 are each constituted by a microcomputer including a CPU and the like and control the entire camera 100. The first camera controller 101 monitors the operation of a switch (not shown) that controls the camera. The first camera controller 101 operates even when the camera 100 is in a pause state (power saving mode), and controls a system power supply 112 and the like according to an operation of a user. The second camera controller 102 controls an image sensor 122, a display unit 127 and the like, and stops the operation in a pause state. Although the present embodiment describes a case where the first camera controller 101 and the second camera controller 102 are constituted by separate processors, these controllers may be constituted in a single processor.

[0034] The system power supply 112 is composed of a DCDC converter, an LDO (Low Drop Out), a charge pump circuit, and the like, and generates power to be supplied to each section of the camera 100. The battery 111 normally supplies a voltage of 1.8 V generated by the system power supply 112 as a camera microcomputer power supply VMCU_C to the first camera controller 101. In addition, several types of voltages generated by the system power supply 112 are supplied to the second camera controller 102 at an arbitrary timing as a camera microcomputer power supply VMCU2_C. The first camera controller 101 controls the ON / OFF of power supply to each section of the camera 100 by controlling the system power supply 112.

[0035] The image sensor 122 is composed of a CMOS sensor or a CCD sensor, etc. The optical lens 121 is detachably attached to the camera 100. Light from a subject incident via the optical lens 121 forms an image on the image sensor 122. It should be noted that the optical lens 121 can be combined with the camera 100. The subject image formed on the image sensor 122 is encoded into a digital camera signal. The image processing unit 123 generates image data by applying image processing such as noise reduction processing and white balance processing to the digital camera signal. In addition, the image processing unit 123 converts the generated image data into an image file in JPEG format to record the image data in the recording memory 126. In addition, the image processing unit 123 generates VRAM image data displayed on the display unit 127 from the generated image data.

[0036] The memory controller 124 controls transmission and reception of image data and other data generated by the image processing unit 123 and the like. The volatile memory 125 is a memory such as DDR3 SDRAM that enables high-speed reading and writing, and is used as a workspace for image processing performed by the image processing unit 123. The recording memory 126 is a medium such as an SD card or a CFexpress card that can read and write, and is a recording medium that can be attached to the camera 100. The display unit 127 includes a display panel such as an LCD panel or an organic EL display panel arranged on the back of the camera 100. The backlight unit 128 adjusts the brightness of the display unit 127 by changing the light amount of the backlight of the display unit 127.

[0037] The first accessory power supply 131 and the second accessory power supply 132 generate 3.3V accessory power supply VACC as a voltage converter that converts the voltage supplied from the system power supply 112 into a predetermined voltage. It should be noted that the first accessory power supply 131 and the second accessory power supply 132 may convert the supplied voltage into a voltage other than 3.3V.

[0038] The first accessory power supply 131 is a power supply circuit composed of an LDO having a small self-power consumption. The second accessory power supply 132 is composed of a DC / DC converter, and can supply a current larger than the current supplied by the first accessory power supply 131. The self-power consumption of the second accessory power supply 132 is larger than the self-power consumption of the first accessory power supply 131. Therefore, when the load current is small, the first accessory power supply 131 is more efficient than the second accessory power supply 132. When the load current is large, the second accessory power supply 132 is more efficient than the first accessory power supply 131. The first camera controller 101 controls the ON / OFF of each voltage output of the first accessory power supply 131 and the second accessory power supply 132 based on the operation state of the accessory 200.

[0039] The protection unit 133 is composed of a current fuse element, a multi-switch element, or an electronic fuse unit in which a resistor, an amplifier, and a switch element are combined. When the current value of the power supplied from the first accessory power supply 131 or the second accessory power supply 132 to the accessory 200 becomes excessive (abnormal) and exceeds a predetermined value, the protection unit 133 outputs an overcurrent detection signal DET_OVC. The protection unit 133 is, for example, an electronic fuse, and when a current greater than 1A flows, the overcurrent detection signal DET_OVC is notified to the first camera controller 101. A high level of the overcurrent detection signal DET_OVC indicates an overcurrent. It should be noted that the predetermined value may be different from 1A.

[0040] The camera side connector 141 is electrically connected to the accessory 200 through 21 contacts TC01 to TC21 arranged in a row. The contacts TC01 to TC21 are arranged in the order of contacts TC01 to TC21 from one end to the other end of the arrangement direction. The contact TC01 is connected to the ground terminal (GND). The contact TC01 is used as a contact for a reference potential and as a contact for controlling the wiring impedance of the differential signal D1N and the differential signal D1P. The contact TC01 is equivalent to a third ground contact.

[0041] A signal line of a differential signal D1N connected to the contact TC02 and a signal line of a differential signal D1P connected to the contact TC03 are connected to the second camera controller 102. These differential signals D1N and D1P are differential data communication signals for data communication as a mutual pair. The contacts TC02 and TC03, contacts TC07 to TC17, TC19, and TC20 mentioned later are communication contacts.

[0042] The contact TC04 as the first ground contact is connected to GND and serves as a contact for a reference potential of the camera 100 and the accessory 200. The contact TC04 is arranged outside the contact arrangement direction compared with the contact TC05. The accessory power supply VACC generated by the first accessory power supply 131 and the second accessory power supply 132 is connected to the contact TC05 as a power supply contact through the protection unit 133.

[0043] The signal line of the accessory attachment detection signal / ACC_DET is connected to the contact TC06 which is the attachment detection contact. The accessory attachment detection signal / ACC_DET is pulled up to the camera microcomputer power supply VMCU_C through the resistance element Rp134 (for example, 10 kΩ). The first camera controller 101 can detect the attachment of the accessory 200 by reading the signal level of the accessory attachment detection signal / ACC_DET. When the signal level (potential) of the accessory attachment detection signal / ACC_DET is a high level (predetermined potential), it is detected that the accessory 200 is not attached. When the signal level is a low level (GND potential mentioned later), it is detected that the accessory 200 is in an attached state.

[0044] Changing the signal level (potential) of the accessory attachment detection signal / ACC_DET from a high level to a low level when the power of the camera 100 is turned on (ON) becomes a trigger that causes various signals to be transmitted between the camera 100 and the accessory 200 through the contacts.

[0045] Upon detecting that the accessory 200 enters the attached state, the first camera controller 101 supplies power to the accessory 200 through the contact TC05 as a power supply contact.

[0046] The signal line of SCLK (Serial Clock) is connected to contact TC07. The signal line of MOSI (Main Out Secondary In) is connected to contact TC08. The signal line of MISO (Main In Secondary Out) is connected to contact TC09. The signal line of CS (Communication Secondary) is connected to contact TC10. SCLK, MOSI, MISO and CS are signals used by the second camera controller 102, which becomes the communication master, to perform SPI (Serial Peripheral Interface) (registered trademark) communication. In this embodiment, the communication clock frequency of SPI communication should be 1 MHz, its data length should be 8 bits (1 byte), its bit order should be MSB first, and its communication system should be full-duplex.

[0047] A signal line of a communication request signal / WAKE used when the accessory 200 requests communication from the first camera controller 101 is connected to the contact TC11. The communication request signal / WAKE is pulled up to the camera microcomputer power supply VMCU_C through a resistor. The first camera controller 101 can receive a communication request from the accessory 200 by detecting a falling edge of the communication request signal / WAKE.

[0048] The signal SDA communicated through the contact TC12 and the signal SCL communicated through the contact TC13 are signals for performing I2C (Inter-Integrated Circuit (registered trademark)) by the first camera controller 101 that becomes the communication host. The signals SDA and SCL are pulled up to the camera microcomputer power supply VMCU_C and realize the open-drain output specification. The communication frequency of this communication should be 100 kbps. In the I2C communication, both data transmission from the camera 100 and data transmission from the accessory 200 are performed via SDA. The communication speed of the I2C communication is lower than the communication speed of the SPI communication. Therefore, the SPI communication is more suitable for communication of information with a large amount of data than the I2C communication. Therefore, the camera 100 and the accessory 200 of the present embodiment use SPI communication to communicate information with a large amount of data, and use I2C communication to communicate information with a small amount of data. For example, the communication can be controlled so that data will be transmitted first using I2C communication, and when SPI communication can be performed based on the data or SPI communication is required, SPI communication is then performed.

[0049] Fig.17A and Fig. 17B is a diagram showing an example of an I2C communication waveform. Fig.17A An example waveform is shown for the case where the camera sends N bytes of actual data (DATA[address] to DATA[address+N]) to the accessory. Fig. 17B An example of the waveform is shown in the case where the camera receives N bytes of actual data (DATA [address] to DATA [address+N]) from the accessory.

[0050] exist Fig.17A and Fig. 17B In each, the upper waveform shows the signal SCL and the lower waveform shows the signal SDA.

[0051] Below the waveform of the signal SDA, the meaning represented by the signal SDA at each timing is shown, and also which of the first camera controller 101 (camera) and the accessory controller 201 (accessory) is controlling the output level of the signal SDA is shown.

[0052] In addition, since the communication data consists of 1-byte data and 1-bit information indicating confirmation (ACK), in order to make the explanation easier to understand, Fig.17A and Fig. 17B In each of the waveforms, the byte order of data from the start of communication is shown above each communication data.

[0053] Because it will use Figures 18 to 20 The details of the communication content are explained in the flowchart of Fig.17A and Fig. 17B To explain the outline.

[0054] exist Fig.17A In the communication of the 1st byte and the 2nd byte in FIG. 1 , the first camera controller 101 transmits address data indicating a storage address on the accessory side where the transmitted data is to be stored to the accessory controller 201. In the communication from the 3rd byte to the (N+2)th byte, the first camera controller 101 transmits N bytes of actual data (DATA[address] to DATA[address+N]) to the accessory controller 201.

[0055] exist Fig. 17B In the communication from the 1st byte to the 2nd byte in , the first camera controller 101 sends address data indicating the storage address of the data to be received to the accessory controller 201. In the communication from the 3rd byte to the (N+3)th byte, the first camera controller 101 receives N bytes of actual data (DATA[ADDRESS] to DATA[ADDRESS+N]) from the accessory controller 201.

[0056] Next, we will explain Figures 18 to 20 Flowchart in .

[0057] Fig.18 1 is a flowchart showing a data transmission process performed by the first camera controller 101 in the case where the first camera controller 101 transmits N bytes of actual data to the accessory controller 201. This process is realized when the CPU in the first camera controller 101 expands and runs a program stored in a ROM (not shown) in the first camera controller 101 into a RAM (not shown) in the first camera controller 101.

[0058] In step S3001, the first camera controller 101 stores the number of bytes of actual data to be transmitted in a variable NC. For example, in the case where 3 bytes of actual data are to be transmitted, the number "3" is stored in the variable NC. In this embodiment, the number "3" should be stored in the variable NC.

[0059] In step S3002, the first camera controller 101 notifies the accessory controller 201 of a start (START) condition by changing SDA to a low level while SCL is at a high level. Thus, the accessory controller 201 is notified of the start of communication.

[0060] In step S3003, the first camera controller 101 sets the upper 7 bits of the address data to secondary address information indicating the secondary address of the accessory controller 201. In this embodiment, the secondary address of the accessory controller 201 should be "1010000" in binary ("0x50" in hexadecimal).

[0061] In step S3004, the first camera controller 101 sets the lower 1 bit of the address data to a flag "0" indicating write (WRITE) communication. Setting "0" to this bit means write communication.

[0062] In step S3005 , the first camera controller 101 transmits the address data (“10100000” in binary and “0xA0” in hexadecimal) set in steps S3003 and S3004 to the accessory controller 201 .

[0063] In step S3006, the first camera controller 101 outputs SCL for one clock after transmitting 1 byte of data, and checks the signal level of SDA. When the signal level of SDA is low, the first camera controller 101 determines that it is a data confirmation (ACK) from the accessory controller 201, and advances the process to step S3007. On the other hand, when the signal level of SDA is high, the first camera controller 101 determines that the accessory controller 201 cannot receive data normally, and advances the process to step S3014.

[0064] In step S3007, the first camera controller 101 sets, as address data, start address information regarding the storage address of actual data transmitted to the accessory controller 201. In the present embodiment, the size of the start address information is 1 byte, and the value shall be "0x00".

[0065] In step S3008, the first camera controller 101 transmits address data to which 1-byte start address information (value "0x00") is set to the accessory controller 201. In step S3009, the first camera controller 101 outputs SCL for one clock after transmitting the address data, and checks the signal level of SDA. In the case where the signal level of SDA is low, the first camera controller 101 determines that it is a data confirmation (ACK) from the accessory controller 201, and advances the processing to step S3010. On the other hand, in the case where the signal level of SDA is high, the first camera controller 101 determines that the accessory controller 201 cannot receive data normally, and advances the processing to step S3014.

[0066] In step S3010, the first camera controller 101 stores "1" in the variable MC. The variable MC is used to count the number of bytes of the actual data transmitted. In step S3011, the first camera controller 101 outputs 1-byte SCL, and transmits 1-byte actual data corresponding to a predetermined address (start address + MC-1) to the accessory controller 201 by changing SDA to a predetermined signal level during the low level of SCL. In this description, since the start address information is "0x00" and the variable MC is "1", the first camera controller 101 transmits 1-byte actual data corresponding to the address "0x00".

[0067] In step S3012, the first camera controller 101 outputs SCL for one clock after transmitting 1 byte of data, and checks the signal level of SDA. When the signal level of SDA is low, the first camera controller 101 determines that it is a data confirmation (ACK) from the accessory controller 201, and advances the process to step S3013. On the other hand, when the signal level of SDA is high, the first camera controller 101 determines that the accessory controller 201 cannot receive data normally, and advances the process to step S3014.

[0068] In step S3013, the first camera controller 101 determines whether the variable MC is equal to the variable NC. When the variable MC is equal to the variable NC, the first camera controller 101 determines that the transmission of all actual data is completed, and advances the process to step S3014. When the variable MC is not equal to the variable NC, the first camera controller 101 determines that unsent actual data still remains, and advances the process to step S3015.

[0069] In step S3015, the first camera controller 101 adds "1" to the variable MC and returns the process to step S3011. After the process returns to step S3011, the first camera controller 101 sequentially increments the address of the actual data to be transmitted and transmits 1 byte of actual data corresponding to each address.

[0070] Thus, the first camera controller 101 transmits N bytes of actual data by repeatedly transmitting 1 byte of actual data until it is determined in the process of step S3013 that the variable MC is equal to the variable NC. When the variable NC is set to "3" as in the embodiment, 3 bytes of actual data can be transmitted.

[0071] In step S3014, the first camera controller 101 notifies the accessory controller 201 of a stop (STOP) condition by changing SDA to a high level while SCL is at a high level. Thus, the accessory controller 201 is notified of the end of communication.

[0072] Fig.19 2 is a flowchart showing a data reception process performed by the first camera controller 101 in the case where the first camera controller 101 receives N bytes of actual data from the accessory controller 201. This process is realized when the CPU in the first camera controller 101 expands and runs a program stored in a ROM (not shown) in the first camera controller 101 into a RAM (not shown) in the first camera controller 101.

[0073] In step S3001, the first camera controller 101 stores the number of bytes of actual data to be received in the variable ND. For example, in the case where 3 bytes of actual data are to be received, the number "3" is stored in the variable ND. In this embodiment, the number "3" should be stored in the variable ND. In steps S3102 to S3106, the first camera controller 101 performs processing similar to steps S3002 to S3006, respectively.

[0074] In step S3107, the first camera controller 101 sets the start address information related to the storage address of the actual data received from the accessory controller 201 as the address data. In the present embodiment, the size of the start address information is 1 byte, and the value should be "0x00". In step S3108, the first camera controller 101 sends the address data to which the start address information (value "0x00") of 1 byte is set to the accessory controller 201.

[0075] In step S3109, the first camera controller 101 outputs SCL for one clock after sending the address data, and checks the signal level of SDA. When the signal level of SDA is low, the first camera controller 101 determines that it is a data confirmation (ACK) from the accessory controller 201, and advances the process to step S3110. On the other hand, when the signal level of SDA is high, the first camera controller 101 determines that the accessory controller 201 cannot receive data normally, and advances the process to step S3122.

[0076] In step S3110, as in step S3102, the first camera controller 101 notifies the accessory controller 201 of the start condition by changing SDA to a low level while SCL is at a high level. In step S3111, the first camera controller 101 sets the upper 7 bits of the address data to the sub-address information indicating the sub-address of the accessory controller 201. In this embodiment, the sub-address of the accessory controller 201 should be "1010000" in the case of binary.

[0077] In step S3112, the first camera controller 101 sets the lower 1 bit of the address data to a flag "1" indicating read (READ) communication. Setting "1" to this bit means read communication.

[0078] In step S3113 , the first camera controller 101 transmits the address data (“10100001” in binary and “0xA1” in hexadecimal) set in steps S3111 and S3112 to the accessory controller 201 .

[0079] In step S3114, the first camera controller 101 outputs SCL for one clock after transmitting 1 byte of data, and checks the signal level of SDA. When the signal level of SDA is low, the first camera controller 101 determines that it is a data confirmation (ACK) from the accessory controller 201, and advances the process to step S3115. On the other hand, when the signal level of SDA is high, the first camera controller 101 determines that the accessory controller 201 cannot receive data normally, and advances the process to step S3014.

[0080] In step S3115, the first camera controller 101 stores "1" in the variable MD. The variable MD is used to count the number of bytes of the received actual data. In step S3116, the first camera controller 101 outputs 1-byte SCL, and reads the signal level of SDA at the timing when SCL changes from low to high. Thus, 1-byte actual data can be received from the accessory controller 201. The received 1-byte actual data can be stored in the volatile memory 125 as data corresponding to the address "0x00" or used for predetermined processing.

[0081] In step S3117, the first camera controller 101 determines whether the actual data of 1 byte is received normally. If the data is received normally, the first camera controller 101 advances the process to step S3118. If the data is not received normally, the first camera controller 101 advances the process to step S3119.

[0082] In step S3118, the first camera controller 101 determines whether the variable MD is equal to the variable ND. When the variable MD is equal to the variable ND, the first camera controller 101 determines that the reception of all actual data is completed, and advances the process to step S3119. When the variable MD is not equal to the variable ND, the first camera controller 101 determines that unsent actual data still remains, and advances the process to step S3120.

[0083] In step S3120, the first camera controller 101 outputs SCL of 1 byte, and transmits a data acknowledgement (ACK) to notify the accessory controller 201 that data communication is continued by controlling SDA to a low level. In step S3121, the first camera controller 101 adds "1" to the variable MD and returns the process to step S3116. After the process returns to step S3116, the first camera controller 101 sequentially increments the address of the actual data to be received, and receives 1 byte of actual data corresponding to each address.

[0084] Thus, the first camera controller 101 receives N bytes of actual data by repeatedly receiving 1 byte of actual data until it is determined that the variable MD is equal to the variable ND in the process of step S3118. When the variable ND is set to "3" as in this embodiment, 3 bytes of actual data can be received.

[0085] In step S3119, the first camera controller 101 outputs 1-byte SCL, and notifies the accessory controller 201 of data communication completion (NACK) by controlling SDA to a high level. In step S3122, the first camera controller 101 notifies the accessory controller 201 of a stop condition by changing SDA to a high level while SCL is at a high level. Thus, the accessory controller 201 is notified of the end of communication.

[0086] Fig. 20 1 is a flowchart showing a data transmission / reception process performed by the accessory controller 201 in the case where N bytes of data are communicated between the first camera controller 101 and the accessory controller 201. The process includes a process in which the accessory controller 201 receives N bytes of actual data from the first camera controller 101 and a process in which the accessory controller 201 transmits N bytes of actual data to the first camera controller 101.

[0087] This process is realized when the CPU in the accessory controller 201 expands and runs a program stored in a ROM (not shown) in the accessory controller 201 to a RAM (not shown) in the accessory controller 201 .

[0088] In step S3201, the accessory controller 201 waits for SDA to change to a low level (occurrence of a start condition) while SCL remains at a high level. Upon detecting the start condition, the accessory controller 201 advances the process to step S3202.

[0089] In step S3202 , the accessory controller 201 stores “0” in the variable ME. The variable ME is used to count the number of bytes of actual data to be transmitted and received. In step S3203 , the accessory controller 201 receives 1-byte address data transmitted from the first camera controller 101 .

[0090] In step S3204, the accessory controller 201 determines whether the upper 7 bits of the address data received in step S3203 are consistent with the sub-address ("0x50" in this embodiment) of the accessory controller 201. If the upper 7 bits are consistent with the sub-address of the accessory controller 201, the accessory controller 201 proceeds to step S3205. If the upper 7 bits are inconsistent with the sub-address of the accessory controller 201, the accessory controller 201 proceeds to step S3221.

[0091] In step S3205, the accessory controller 201 controls SDA to a low level in response to the next SCL clock output after receiving the address data, and transmits a data acknowledgement (ACK) to the first camera controller 101. In step S3206, the accessory controller 201 determines the type of data of the next 1-byte communication based on the data of the lower 1 bit of the address data received in step S3203. In the case where the data of the lower 1 bit is "0" (write), the accessory controller 201 determines that the data of the next 1-byte communication is the start address information from the first camera controller 101 to the accessory controller 201, and then proceeds to step S3207. In the case where the data of the lower 1 bit is "1", the accessory controller 201 determines that the data of the next 1-byte communication is actual data sent from the accessory controller 201 to the first camera controller 101, and then proceeds to step S3209.

[0092] In step S3207, the accessory controller 201 receives 1-byte address data transmitted from the first camera controller 101. The received address data means start address information indicating an address where data transmitted and received by future communication are stored. Fig.18 and Fig.19 As described above, the starting address information should be "0x00".

[0093] In step S3209, the accessory controller 201 sets address information pre-stored by the accessory controller 201 or address information pre-received from the first camera controller 101 as the start address information.

[0094] In step S3208, the accessory controller 201 determines whether the 1-byte data is received normally. In the case where it is determined that the data is received normally, the process proceeds to step S3210. In the case where it is determined that the data is not received normally, the process proceeds to step S3221. In step S3210, the accessory controller 201 sends a data acknowledgement (ACK) to the first camera controller 101 by controlling SDA to a low level in response to the next SCL clock outputting data reception after receiving the 1-byte data.

[0095] In step S3211, the accessory controller 201 determines whether SDA changes to a low level while SCL remains at a high level (whether a start condition is detected). In the case where a start condition is detected, the accessory controller 201 can determine that the 1-byte data subjected to the next communication is the address data to be received by the accessory controller 201 from the first camera controller 101. That is, the accessory controller 201 determines that the 1-byte data subjected to the next communication is the address data indicating the sub-address and the communication type. Then, the processing enters step S3212. In the case where a start condition is not detected, the accessory controller 201 determines that the 1-byte data subjected to the next communication is the actual data to be received by the accessory controller 201 from the first camera controller 101, and then causes the processing to enter step S3216.

[0096] In step S3212, the accessory controller 201 receives the 1-byte address data sent from the first camera controller 101. In step S3213, the accessory controller 201 determines whether the upper 7 bits of the address data received in step S3212 are consistent with the sub-address ("0x50" in the embodiment) of the accessory controller 201. When the upper 7 bits are consistent with the sub-address of the accessory controller 201, the accessory controller 201 advances the processing to step S3214. When the upper 7 bits are inconsistent with the sub-address of the accessory controller 201, the accessory controller 201 advances the processing to step S3221.

[0097] In step S3214, the accessory controller 201 determines the type of data of the next 1-byte communication based on the data of the lower 1 bit of the address data received in step S3203. When the data of the lower 1 bit is "0", the accessory controller 201 advances the process to step S3221. When the data of the lower 1 bit is "1" (read), the accessory controller 201 determines that the data of the next 1-byte communication is actual data sent from the accessory controller 201 to the first camera controller 101, and then advances the process to step S3215.

[0098] In step S3215, the accessory controller 201 transmits a data acknowledgement (ACK) to the first camera controller 101 by controlling SDA to a low level in response to the next SCL clock output after receiving 1 byte of data. In step S3222, the accessory controller 201 transmits the start address information received from the first camera controller 101 in step S3207 to the first camera controller 101, or transmits 1 byte of actual data corresponding to the start address information established in step S3209 to the first camera controller 101.

[0099] In step S3223, the accessory controller 201 adds "1" to the variable ME, and the processing proceeds to step S3224. In step S3224, the accessory controller 201 checks the signal level of SDA after sending 1 byte of actual data. In the case where the signal level of SDA is high, the accessory controller 201 determines that a notification (NACK) indicating that the first camera controller 101 has received all the actual data is shown, and then the processing proceeds to step S3225. On the other hand, in the case where the signal level of SDA is low, the accessory controller 201 determines that the first camera controller 101 still requests the actual data transmission from the accessory controller 201, and then returns the processing to step S3222.

[0100] After the process thus returns to step S3222, the accessory controller 201 sequentially increments the address of the actual data to be transmitted, and transmits 1-byte actual data corresponding to each address. In this way, the accessory controller 201 transmits N-byte actual data to the first camera controller 101 by repeatedly transmitting 1-byte actual data until NACK is received from the first camera controller 101 by the process of step S3224.

[0101] In step S3225, the accessory controller 201 waits for SDA to change to a high level (occurrence of a stop condition) while SCL remains at a high level. Upon detecting the stop condition, the accessory controller 201 ends the communication.

[0102] In step S3216, the accessory controller 201 receives 1-byte actual data. The 1-byte actual data may be stored in a nonvolatile memory (not shown) as data corresponding to the start address information received from the first camera controller 101 in step S3207, or used for predetermined processing.

[0103] In step S3217, the accessory controller 201 adds "1" to the variable ME and causes the process to proceed to step S3218. In step S3218, the accessory controller 201 determines whether the actual data of 1 byte is received normally. In the case where the accessory controller 201 determines that the actual data of 1 byte is received normally, the process proceeds to step S3219. In the case where it is determined that the data is not received normally, the process proceeds to step S3221.

[0104] In step S3219, the accessory controller 201 transmits a data acknowledgement (ACK) to the first camera controller 101 by controlling SDA to a low level in response to the next SCL clock output after receiving 1 byte of data.

[0105] In step S3220, the accessory controller 201 determines whether SDA changes to a high level (whether a start condition is detected) while SCL is maintained at a high level. In the case where a stop condition is detected, the accessory controller 201 ends the communication. On the other hand, in the case where a stop condition is not detected, the accessory controller 201 determines that data will be continuously transmitted from the first camera controller 101 to the accessory controller 201, and returns the process to step S3216.

[0106] After the process thus returns to step S3216, the accessory controller 201 sequentially increments the address of the actual data to be received, and receives 1 byte of actual data corresponding to each address. In this way, the accessory controller 201 receives N bytes of actual data from the first camera controller 201 by repeatedly receiving 1 byte of actual data until a stop condition is received in step S3220.

[0107] The FNC1 signal communicated through the contact TC14, the FNC2 signal communicated through the contact TC15, the FNC3 signal communicated through the contact TC16, and the FNC4 signal communicated through the contact TC17 are functional signals whose functions can be changed corresponding to the type of accessory 200. For example, in the case where the accessory 200 is a microphone device, the signal communicated through the contact TC15 becomes a voice data signal. In addition, in the case where the accessory 200 is a lighting device (flashlight unit), the signal communicated through the contact TC14 becomes a signal giving a light emission timing (flashlight light emission timing signal).

[0108] It should be noted that signals implementing different functions can be communicated through the same contact depending on the type of accessory attached. For example, in the case where accessory 200 is different from a lighting device, a synchronization signal that controls a timing different from the light-emitting timing can be communicated through contact TC14. Contacts TC14 to TC17 are equivalent to functional signal contacts. Communication using at least one of the functional signal contacts is also referred to as functional signal communication. Functional signal communication can be performed in parallel with I2C communication and SPI communication without considering the timing of I2C communication and SPI communication.

[0109] The accessory type is the microphone device, lighting equipment, etc. mentioned above. Accessories that achieve functions for the same purpose, such as lighting equipment with different characteristics, belong to the same type. Accessories such as microphone devices and lighting equipment that achieve functions for different purposes belong to different types. Function signal communication is performed based on information obtained through I2C communication or SPI communication.

[0110] The contact TC18 as the second ground contact is also connected to GND, and like the contact TC04, serves as a contact for the reference potential of the camera 100 and the accessory 200. The signal line of the differential signal D2N connected to the contact TC19 and the signal line of the differential signal D2P connected to the contact TC20 are connected to the second camera controller 102. These differential signals D2N and D2P are differential data communication signals for data communication as a pair with each other. For example, USB communication is available through TC19 and TC20.

[0111] The contact TC21 is connected to GND, and has not only a function as a contact of a reference potential but also a function as a contact for controlling the wiring impedance of the differential signals D2N and D2P. The contact TC21 is equivalent to a fourth ground contact. The contacts TC01, TC04, TC06, TC18, and TC21 are connected to the GND portion of the flexible substrate. The GND portion of the flexible substrate is fixed to a metal member of the camera 100 that maintains the GND level, for example, with screws or the like. The metal member that maintains the GND level may be a bonding member in the accessory shoe portion that is bonded to the accessory 200, or may be a bottom plate (not shown) inside the camera 100.

[0112] In the present embodiment, the attachment detection contact TC06 that sends the accessory attachment detection signal / ACC_DET is arranged between the contact (first clock contact) TC07 that sends the clock signal SCLK (first clock signal) and the contact TC05 that sends the accessory power supply VACC. Generally, noise (clock noise) accompanied by potential fluctuations in the clock signal passes through the contacts adjacent to the contacts of the clock signal, and this may cause malfunctions. In particular, since there are many contacts as in the present embodiment, its influence becomes greater in a configuration where the distance between the contacts is short. Therefore, the attachment detection contact TC06 is arranged between the SCLK contact TC07 and the VACC contact TC05, which reduces the influence of the clock noise on the power supply voltage.

[0113] Although the accessory attachment detection signal / ACC_DET is pulled up before the accessory is attached, it is set to the GND potential after the accessory is attached. On the other hand, since the SCLK contact TC07 does not send a clock signal before the accessory is attached, the potential does not fluctuate. After the accessory is attached, the potential fluctuates because the clock signal is sent.

[0114] 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 is affected by clock noise, the potential of the controller of the camera 100 and the accessory 200 does not easily fluctuate, which prevents malfunction. In addition, this reduces the clock noise that propagates to a position farther than the attachment detection contact TC06. As a result, since there is no need to arrange an additional GND terminal, the influence of clock noise is reduced without increasing the number of contacts.

[0115] In addition, SCL (second clock signal) as a clock signal is also sent to the contact (second clock contact) TC13. Since the frequency of SCLK sent to the SCLK contact TC07 is higher than the frequency of SCL, the clock noise generated from the SCLK contact TC07 is greater than the clock noise generated from the SCL contact TC13. Therefore, compared with the arrangement in which the detection contact TC06 is attached adjacent to the SCL contact TC13, the arrangement in which the detection contact TC06 is attached adjacent to the SCLK contact TC07 is more effective in preventing malfunctions due to clock noise.

[0116] In addition, in addition to the difference in frequency, the SCL sent to the SCL contact TC13 is a clock signal of the I2C communication standard, and the voltage of the signal line is driven and fluctuates according to the open drain connection. On the other hand, the SCLK sent to the SCLK contact TC07 is a clock signal of the SPI communication standard, and the voltage of the signal line is driven and fluctuates by the CMOS output. Therefore, since the edge of the voltage fluctuation of the SCL contact TC13 tends to be gentle, it is difficult to generate clock noise compared with the SCLK contact TC07. Therefore, compared with the arrangement of the attachment detection contact TC06 adjacent to the SCL contact TC13, the arrangement of the attachment detection contact TC06 adjacent to the SCLK contact TC07 is more effective for preventing the failure caused by clock noise.

[0117] In addition, a clock signal can be sent by sending the differential signals D1N and D1P as a pair to the first differential signal contact TC19 and the second differential signal contact TC20. In this case, a clock signal (third clock signal) having a frequency higher than that of SCLK and SCL can be sent. However, since the differential signals D1N and D1P are paired signals, the dissipation of clock noise is smaller than the dissipation of clock noise from the SCLK contact TC07 and the SCL contact TC13 that send single-ended signals. Therefore, compared with the arrangement in which the attached detection contact TC06 is adjacent to the first differential signal contact TC19 and the second differential signal contact TC20, the arrangement in which the attached detection contact TC06 is adjacent to the SCLK contact TC07 is more effective in preventing malfunctions caused by clock noise.

[0118] It should be noted that the contact (first data contact) TC08 arranged adjacent to the SCLK contact TC07 on the opposite side of 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, since MOSI is a data signal of the SPI communication standard that is the same as the clock signal transmitted through the SCLK contact TC07, the fluctuation timing of the potential is synchronized with the clock signal and is not susceptible to clock noise. Therefore, the contact TC08 does not need to be fixed to the GND potential and can be used as a MOSI contact.

[0119] The accessory 200 has a battery 205, and receives power from the battery 205 and also receives power from the camera 100 through the camera-side connector 141 and the accessory-side connector 211. The accessory controller 201 is constituted by a microcomputer including a CPU and the like, and controls the entire accessory 200.

[0120] The accessory power supply 202 is composed of a DCDC converter, an LDO, or a charge pump, and generates power to be supplied to each part of the accessory 200. The voltage of 1.8 V generated by the accessory power supply 202 is usually supplied to the accessory controller 201 as the accessory microcomputer power supply VMCU_A. It should be noted that the voltage generated by the accessory power supply 202 may be different from 1.8 V. The accessory controller 201 controls the on / off of power supply to each part of the accessory 200 by controlling the accessory power supply 202.

[0121] The charging unit 204 charges the battery 205 using the power supplied from the camera 100. When determining that power sufficient for charging is supplied from the camera 100, the accessory controller 201 controls the charging unit 204 to charge the battery 205. Although the case where the accessory 200 is equipped with the battery 205 is described in the present embodiment, the accessory 200 may operate only with the power supply from the camera 100 without the battery 205. In this case, the charging unit 204 becomes unnecessary.

[0122] The differential communication unit 207 is a circuit for performing differential communication with the camera 100, and can transmit and receive data with the camera 100. The external communication I / F 208 is an I / F (interface) for data communication with an external device (not shown), and can be an Ethernet communication IF, a wireless LAN communication IF, a public network communication IF, or the like.

[0123] The accessory controller 201 transmits data received from the camera 100 to an external device and transmits data received from an external device to the camera by controlling the differential communication unit 207 and the external communication I / F 208. The function unit 206 is a circuit that exhibits one of different functions corresponding to the type of the accessory 200. For example, in the case where the accessory 200 is a flash device, a light emitting unit, a charging unit, and the like exist inside the function unit 206. In addition, in the case where the accessory 200 is a microphone device, a voice codec unit, a microphone, and the like exist inside the function unit 206.

[0124] The external connection terminal 209 is a connector terminal for connecting to an external device, and is exemplified as a USBTYPE-C connector, but is not limited thereto. The connection detection unit 210 detects that an external device is connected to the external connection terminal 209. The accessory controller 201 can detect the connection of the external device to the external connection terminal 209 by receiving an output signal of the connection detection unit 210. The power switch 203 is used to turn on or off the operation of the accessory 200. The accessory controller 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.

[0125] The operation switch 212 is a handler for the user to operate the accessory 200, and is composed of a button, a cross key, a slide switch, a dial switch, a touch sensor, etc. Upon detecting the operation of the operation switch 212, the accessory controller 201 executes predetermined processing corresponding to the operation.

[0126] The accessory-side connector 211 is 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.

[0127] The contact TA01 is connected to GND, and has a function not only as a contact for a reference potential but also as a contact for controlling wiring impedance of the differential signals D1N and D1P. The contact TA01 is equivalent to a third ground contact.

[0128] The differential signal D1N communicated through the contact TA02 and the differential signal D1P communicated through the contact TA03 are data communication signals for data communication as a pair. The contacts TA02 and TA03 are connected to the differential communication unit 207. The contacts TA02, TA03, TA07 to TA17, TA19, and TA20 are communication contacts.

[0129] The contact TA04 as a first ground contact is connected to GND, and is used as a contact for a reference potential of the camera 100 and the accessory 200. The contact TA04 is arranged at an outer position of the contact TA05 in the arrangement direction of the contacts. The contact TA05 as a power supply contact is connected to the accessory power supply 202 and the charging unit 204. The accessory power supply VACC supplied from the camera 100 is also connected to the contact TA05.

[0130] The contact TA06 as the attachment detection contact is directly connected to GND. The contact TC06 enables the camera 100 to detect attachment of the accessory 200 by setting the accessory attachment detection signal / ACC_DET to the GND level (ground potential) which is a low level when the accessory 200 is attached to the camera 100.

[0131] SCLK communicated through the contact TA07, MOSI communicated through the contact TA08, MISO communicated through the contact TA09, and CS communicated through the contact TA10 are signals used for SPI communication in which the accessory controller 201 becomes a communication secondary.

[0132] The communication request signal / WAKE for requesting communication from the camera 100 from the accessory controller 201 is transmitted through the contact TA11. When determining that communication with the camera 100 is necessary, the accessory controller 201 issues a communication request to the camera 100 by outputting a low level of the communication request signal / WAKE.

[0133] In response to detecting the attachment state of the accessory 200, power is supplied from the first camera controller 101 to the accessory 200 through the contact TC5. Then, the accessory controller 201 notifies the first camera controller 101 of the power supply by changing the signal level (potential) of the communication request signal / WAKE from high level to low level.

[0134] The accessory controller 201 notifies the first camera controller 101 that a factor requiring the accessory 200 to communicate with the camera 100 has occurred by changing the signal level (potential) of the communication request signal / WAKE from a high level to a low level without receiving a request from the camera 100. This configuration enables the first camera controller 101 to omit a periodic check operation of checking by polling whether a factor requiring communication by the accessory 200 has occurred. In addition, in the event that a factor requiring communication has occurred, the accessory 200 can notify the camera 100 of such a state in real time.

[0135] SDA communicated through the contact TA12 and SCL communicated through the contact TA13 are signals used for I2C communication in which the accessory controller 201 serves as a communication slave.

[0136] The FNC1 signal communicated through the contact TA14, the FNC2 signal communicated through the contact TA15, the FNC3 signal communicated through the contact TA16, and the FNC4 signal communicated through the contact TA17 are function signals whose functions can be changed corresponding to the type of accessory 200. In the case where the accessory 200 is a microphone device, these function signals are voice data signals. In the case where the accessory 200 is a flash unit, the function signal is a flash light emission timing signal notifying the light emission timing.

[0137] The contact TA18 as the second ground contact is also connected to GND, and like TA04, serves as a contact for the reference potential of the camera 100 and the accessory 200. A signal line of a differential signal D2N connected to the contact TA19 and a signal line of a differential signal D2P connected to the contact TA20 are connected to the external connection terminal 209. These differential signals D2N and D2P are differential data communication signals for performing data communication as a pair with each other.

[0138] The contact TA21 is connected to GND, and has a function not only as a contact of a reference potential but also as a terminal for controlling wiring impedance of the differential signals D2N and D2P. The contact TA21 is equivalent to a fourth ground contact.

[0139] The contacts TA01, TA04, TA06, TA18, and TA21 are connected to the GND portion of the flexible substrate. The GND portion of the flexible substrate is fixed to a metal member that maintains the GND level of the accessory 200, for example, with screws or the like. The metal member that maintains the GND level is a socket mounting leg that engages with the accessory socket portion of the camera 100, or a bottom plate (not shown) inside the accessory 200.

[0140] In this embodiment, the camera 100 and the accessory 200 support two types of communication protocols as SPI communication methods. Among them, the first communication protocol is a method that does not check whether the accessory 200 is in a communication available state before the camera 100 outputs the SCLK signal. This is referred to as the first SPI protocol in this embodiment. The second communication protocol is a method that checks whether the accessory 200 is in a communication available state before the camera 100 outputs the SCLK signal. This is referred to as the second SPI protocol in this embodiment.

[0141] The camera 100 may be equipped with built-in accessories such as a built-in microphone and a built-in flash, etc. The number of built-in accessories is not important.

[0142] Figure 2A is a diagram schematically showing a communication waveform of the first SPI protocol. Figure 2B Schematically shows the communication waveform of the second SPI protocol. Figure 2A and Figure 2BIn this case, the CS signal should be active at a low level.

[0143] like Figure 2A As shown, in the first SPI protocol, the second camera controller 102 issues a request for SPI communication to the accessory controller 201 by changing the CS signal to a low level at timing A1.

[0144] After a predetermined period of time T_CS has passed from the timing A1, the second camera controller 102 starts outputting the SCLK signal and the MOSI signal at the timing A2. Similarly, upon detecting a falling change of the SCLK signal, the accessory controller 201 starts outputting the MISO signal.

[0145] The second camera controller 102 stops SCLK output at timing A3 when 1-byte SCLK output is completed. The second camera controller 102 stops SCLK output until a predetermined period T_INTERVAL has passed from timing A3, and restarts SCLK output for the next 1-byte communication at timing A4 when the predetermined period T_INTERVAL has passed.

[0146] Figure 3A 1 is a flowchart showing the processing of the second camera controller 102 using the first SPI protocol. This processing is realized when the CPU in the second camera controller 102 expands and runs a program stored in a ROM (not shown) in the second camera controller 102 to a RAM (not shown) in the second camera controller 102.

[0147] In step S101, the second camera controller 102 stores the number of bytes of data to be communicated into a variable NA. For example, in the case of communicating 3 bytes of data, the number "3" is stored into the variable NA. In step S102, the second camera controller 102 changes the CS signal to a low level to request SPI communication.

[0148] In step S103, the second camera controller 102 waits until a predetermined period of time T_CS has passed after the CS signal becomes low level. When the predetermined period of time T_CS has passed, the process proceeds to step S104. In step S104, the second camera controller 102 controls the output of SCLK to perform 1-byte data communication, and controls the output of MOSI data and the input of MISO data.

[0149] In step S105, the second camera controller 102 decrements the variable NA by 1. In step S106, the second camera controller 102 determines whether the variable NA is zero. If the variable NA is zero, the second camera controller 102 advances the process to step S107. If the variable NA is not zero, the process advances to step S108.

[0150] In step S108, the second camera controller 102 waits until a predetermined period of time T_INTERVAL has passed after the 1-byte data communication in step S104 is completed. When the predetermined period of time T_INTERVAL has passed, the process returns to step S104. The second camera controller 102 changes the CS signal to a high level in step S107, and ends the process. Figure 3A A series of SPI communications are shown.

[0151] Figure 3B is a flow chart showing the processing of the accessory controller 201 using the first SPI protocol. Figure 3A The processing shown is executed in parallel. The processing is realized when the CPU in the accessory controller 201 expands and runs a program stored in a ROM (not shown) in the accessory controller 201 to a RAM (not shown) in the accessory controller 201.

[0152] In step S201, the accessory controller 201 waits until the CS signal becomes low. When the CS signal becomes low, the process proceeds to step S202. In step S202, the accessory controller 201 performs 1-byte data communication by controlling the input of MOSI data and the output of MISO data in response to the input of the SCLK signal.

[0153] In step S203, the accessory controller 201 determines whether the CS signal is high. If the CS signal is not high, the accessory controller 201 returns the process to step S202 to perform the next 1-byte communication. If the CS signal is high, the accessory controller 201 ends the process. Figure 3B A series of SPI communications are shown.

[0154] Next, the second SPI protocol will be described. Figure 2B As shown, in the second SPI protocol, the second camera controller 102 requests the accessory controller 201 to perform SPI communication by changing the CS signal to a low level at timing B1. The second camera controller 102 checks the potential of the MISO signal in parallel with the communication request. When the MISO signal is at a high level, the second camera controller 102 determines that the accessory controller 201 is communicable. When the MISO signal is at a low level, the second camera controller 102 determines that the accessory controller 201 is not communicable.

[0155] On the other hand, when the falling change of the CS signal is detected in the state where SPI communication is available, the accessory controller 201 controls the MISO signal to a high level. When the falling change is detected in the state where SPI communication is not available, the accessory controller 201 controls the MISO signal to a low level (timing B2).

[0156] When confirming that the MISO signal is at a high level, the second camera controller 102 starts outputting the MISO signal and the SCLK signal at timing B3. Similarly, when detecting a falling change in the SCLK signal, the accessory controller 201 starts outputting the MISO signal.

[0157] When the 1-byte SCLK output is completed, the second camera controller 102 stops the SCLK output at timing B4. After the 1-byte data communication, when the SPI communication is available, the accessory controller 201 controls the MISO signal to a high level. When the SPI communication is not available, the accessory controller 201 controls the MISO signal to a low level (timings B5 and B6).

[0158] The second camera controller 102 checks the potential of the MISO signal at timing B7. If the MISO signal is at a high level, it is determined that the second camera controller 102 is in a state where the accessory controller 201 can communicate, and if the MISO signal is not at a low level, it is determined that the second camera controller 102 is in a state where the accessory controller 201 cannot communicate.

[0159] Figure 4A 1 is a flowchart showing the processing of the second camera controller 102 using the second SPI protocol. This processing is realized when the CPU in the second camera controller 102 expands and runs a program stored in a ROM (not shown) in the second camera controller 102 to a RAM (not shown) in the second camera controller 102.

[0160] In step S111, the second camera controller 102 stores the number of bytes of data to be communicated in the variable NB. For example, in the case of communicating 3 bytes of data, the number "3" is stored in the variable NB. In step S112, the second camera controller 102 changes the CS signal to a low level to request SPI communication. In step S113, the second camera controller 102 waits until the MISO signal becomes a high level. When the MISO signal becomes a high level, the process proceeds to step S114.

[0161] In step S114, the second camera controller 102 controls the output of SCLK to communicate 1-byte data, and controls the output of MOSI data and the input of MISO data. In step S115, the second camera controller 102 decrements the variable NB by 1. In step S116, the second camera controller 102 determines whether the variable NB is zero (whether the communication of all data is completed). When the variable NB is zero, it is determined that the communication of all data is completed.

[0162] If the communication of all data is completed, the second camera controller 102 advances the process to step S117. If the communication of at least a part of the data is not completed, the second camera controller 102 returns the process to step S113. The second camera controller 102 changes the CS signal to a high level in step S117, and ends the process. Figure 4A A series of SPI communications are shown.

[0163] Figure 4B is a flow chart showing the processing of the accessory controller 201 using the second SPI protocol. Figure 4A The processing shown is executed in parallel. The processing is realized when the CPU in the accessory controller 201 expands and runs a program stored in a ROM (not shown) in the accessory controller 201 to a RAM (not shown) in the accessory controller 201.

[0164] In step S211, the accessory controller 201 waits until the CS signal becomes low. In the case where the CS signal becomes low, the process proceeds to step S212. In step S212, the accessory controller 201 determines whether SPI communication is available. In the case where SPI communication is available, the process proceeds to step S213. In the case where SPI communication is not available, the process proceeds to step S214.

[0165] The accessory controller 201 controls the MISO signal to a high level in step S213, and causes the process to proceed to step S215. The accessory controller 201 controls the MISO signal to a low level in step S214, and causes the process to return to step S212. In step S215, the accessory controller 201 performs 1-byte data communication by controlling the input of MOSI data and the output of MISO data in response to the input of the SCLK signal.

[0166] In step S216, the accessory controller 201 determines whether the CS signal is high. If the CS signal is not high, the accessory controller 201 returns the process to step S202 to perform the next 1-byte communication. If the CS signal is high, the accessory controller 201 ends the process. Figure 4B SPI communication shown.

[0167] Figure 5 1 is a diagram showing the communication content of an operation execution instruction (command) transmitted from the camera 100 to the accessory 200 through SPI communication.

[0168] In the communication of the first byte, the second camera controller 102 transmits information CMD indicating a command number as MOSI data. On the other hand, the accessory controller 201 transmits a value "0xA5" as information indicating that it is in a communication available state as MISO data. If the accessory controller 201 cannot perform the communication process of the first byte, a value other than "0xA5" is transmitted as MISO data.

[0169] In the communication of the 2nd byte, the second camera controller 102 transmits the argument MOSI_DATA1 corresponding to the command number CMD. In the communication of the 3rd byte to the (N-2)th byte, the second camera controller 102 transmits the argument MOSI_DATA2 to MOSI_DATA[N-3] corresponding to the command number CMD in a similar manner.

[0170] On the other hand, in the communication of the second byte, the accessory controller 201 transmits the command number CMD received in the communication of the first byte as MISO data. Thus, the second camera controller 102 can determine that the accessory controller 201 has correctly received the MOSI data.

[0171] In the communication of the 3rd byte, the accessory controller 201 transmits the return value MISO_DATA1 corresponding to the command number CMD as MISO data. In the communication of the 4th byte to the (N-2)th byte, the accessory controller 201 transmits the return values ​​MISO_DATA2 to MISO_DATA[N-4] corresponding to the command number CMD in a similar manner. It should be noted that the number of arguments and the number of return values ​​are predetermined for each command number. In addition, one of the arguments and the return value may be omitted.

[0172] In the communication of the (N-1)th byte, the second camera controller 102 transmits the checksum data "CheckSum_C" as MOSI data. The second camera controller 102 calculates "CheckSum_C" by the following formula 1 based on the data transmitted from the second camera controller 102 to the accessory controller 201. On the other hand, the accessory controller 201 transmits the value "0x00" as MISO data.

[0173] In the communication of the Nth byte, the second camera controller 102 transmits the value "0x00" as the MOSI data. On the other hand, the accessory controller 201 transmits the checksum data "CheckSum_A" as the MISO data.

[0174] "CheckSum_A" is calculated by the following formula 2 or the following formula 3. That is, the accessory controller 201 calculates "CheckSum_A" based on the actually received data. Then, the accessory controller 201 determines whether the received "CheckSum_C" is consistent with the "CheckSum_A" calculated by formula 2 based on the received data. When "CheckSum_C" is consistent with "CheckSum_A", the accessory controller 201 sends the "CheckSum_A" calculated by the following formula 2 to the second camera controller 102.

[0175] On the other hand, when it is determined that “CheckSum_C” and “CheckSum_A” do not match, the accessory controller 201 transmits “CheckSum_A” calculated by the following formula 3 to the second camera controller 102 .

[0176] CheckSum_C=EXOR(AND(SUM(CMD,MOSI_DATA1,...,MOSI_DATA[N-3]),0xFF),0xFF)...Formula 1

[0177] CheckSum_A=EXOR(AND(SUM(0xA5,CMD,MISO_DATA1,...,MOSI_DATA[N-4]),0xFF),0xFF)...Formula 2

[0178] CheckSum_A=AND(SUM(0xA5,CMD,MISO_DATA1,...,MOSI_DATA[N-4]),0xFF)...Formula 3

[0179] Figure 6 is a diagram showing an example of accessory information. The accessory information is stored in a non-volatile memory (not shown) in the accessory 200. The accessory information is used when the camera 100 identifies the type of the accessory 200 and identifies the specifications related to the communication and operation (function) of the accessory 200. The accessory information is mapped to the memory space of addresses "0x00" to "0x0F". The accessory information can be read from the accessory 200 through I2C communication. It should be noted that in the I2C communication in the present embodiment, a checksum value corresponding to the read data should be added as the final data of the communication.

[0180] like Figure 6 As shown, the data in D7 to D0 of address "0x00" is information indicating the accessory type (ACC type). The data in D7 to D0 of address "0x01" is information indicating the identification number of the accessory (ACC identification number). The accessory type is uniquely identified by the accessory type information and the identification number. The data in D7 to D0 of address "0x02" is information indicating the version of the firmware of accessory 200.

[0181] The data in D7 and D6 of the address "0x03" is information indicating whether power supply to the accessory power supply VACC of the accessory 200 is required in a state where the power switch (not shown) of the camera 100 is set to OFF. In the case where this information is "0", power supply is not required. In the case where this information is "1", power supply from the first accessory power supply 131 is required. In the case where this information is "2", power supply from the second accessory power supply 132 is required.

[0182] The data in D5 and D4 of the address "0x03" is information indicating whether power supply to the accessory power supply VACC of the accessory 200 is required when the camera 100 is in the power saving mode (auto-off mode). When the information is "0", power supply is not required. When the information is "1", power supply from the first accessory power supply 131 is required. When the information is "2", power supply from the second accessory power supply 132 is required.

[0183] The data in D3 and D2 of the address "0x03" is information indicating whether the accessory 200 has the battery 205. When the information is "0", this indicates that the accessory 200 does not have the battery 205. When the information is "1", this indicates that the accessory 200 has the battery 205. The data in D1 and D0 of the address "0x03" is information indicating whether the accessory 200 supports the charging function to the battery 205. When the information is "0", this indicates that the accessory 200 does not support the charging function. When the information is "1", this indicates that the accessory 200 supports the charging function.

[0184] The data in D7 to D0 of the address "0x04" is information indicating the required power for the accessory power supply VACC supplied from the camera 100 to the accessory 200. For example, a value obtained by increasing the value of the information by 10 times indicates a current value. In the case where the information is "10", this indicates that the current value is 100 mA. In the case where the information is "100", this indicates that the current value is 1 A. In addition, as a method of reducing the data amount of the information, the information can be associated with an arbitrary current value. For example, the values ​​"0", "1", "3", and "4" of the information respectively indicate required powers of 100 mA, 300 mA, 450 mA, and 600 mA.

[0185] The data in D7 of address "0x05" is information indicating whether accessory 200 is in firmware update mode. When the information is "0", this indicates that accessory 200 is not in firmware update mode. When the information is "1", this indicates that accessory 200 is in firmware update mode. The data in D6 of address "0x05" is information indicating whether accessory 200 has a firmware update function. When the information is "0", this indicates that accessory 200 does not have a firmware update function. When the information is "1", this indicates that accessory 200 has a firmware update function.

[0186] The data in D5 and D4 of the address "0x05" is information indicating whether an operation in a state where the accessory 200 is equipped with an intermediate connection accessory is permitted. In the case where the information is "0", this indicates that the operation is not permitted. In the case where the information is "1", this indicates that the operation is permitted. The data in D3 and D2 of the address "0x05" is information indicating whether the accessory 200 needs to confirm the attachment state of the intermediate connection accessory when the camera 100 is activated. In the case where the information is "0", this indicates that confirmation is not required. In the case where the information is "1", this indicates that confirmation is required.

[0187] The data in D1 and D0 of the address "0x05" is information indicating whether the accessory 200 supports command notification by I2C communication. In the case where the information is "0", this indicates that command notification is not supported. In the case where the information is "0", this indicates that command notification is supported.

[0188] The data in D5 and D4 of the address "0x06" is information indicating a communication method of factors that can notify the camera 100 of a communication request signal / WAKE after the accessory 200 notifies the camera 100 of the communication request signal. In the case where the information is "0", this indicates that I2C communication is available. In the case where the information is "1", this indicates that SPI communication is available. And in the case where the information is "2", this indicates that both I2C communication and SPI communication are available.

[0189] The data in D0, D1, D2, and D3 of address "0x06" are information indicating whether accessory 200 has the functions of FNC1 signal, FNC2 signal, FNC3 signal, and FNC4 signal, respectively. The data in D0 corresponds to the FNC1 signal. The data in D1 corresponds to the FNC2 signal. The data in D2 corresponds to the FNC3 signal. The data in D3 corresponds to the FNC4 signal. In the case where each data value is "0", this indicates that accessory 200 does not have the corresponding function. In the case where each data value is "1", this indicates that accessory 200 has the corresponding function.

[0190] The data in D7 of the address "0x0A" is information indicating whether the accessory 200 issues an activation request to the camera 100 when the accessory 200 notifies the camera of the communication request signal / WAKE. When the information is "0", this indicates that the accessory 200 does not issue an activation request. When the information is "1", this indicates that the accessory 200 issues an activation request.

[0191] The data in D6 to D0 of the address “0x0A” is information indicating the factors of the communication request signal / WAKE sent from the accessory 200 to the camera 100 .

[0192] The data in D1 of address "0x0C" is information indicating the SPI communication protocol supported by accessory 200. When this information is "0", this indicates that accessory 200 supports the first SPI protocol. When this information is "1", this indicates that accessory 200 supports the second SPI protocol.

[0193] The data in D0 of the address "0x0C" is information indicating the control logic of the CS signal in the SPI communication supported by the accessory 200. When the information is "0", it means that the CS signal follows the low active logic. When the information is "1", it means that the CS signal follows the high active logic.

[0194] The data in D7 to D0 of the address "0x0D" is information indicating a time period required as a communication byte interval when the accessory 200 communicates using the first SPI protocol and the data in D7 of the address "0x05" is "0". When the data in D7 of the address "0x05" is "0", as described above, the accessory 200 is not in the firmware update mode.

[0195] The data in D7 to D0 of address 0x0E is information indicating a time period required as a communication byte interval when accessory 200 communicates using the first SPI protocol and the data in D7 of address "0x05" is "1". When the data in D7 of address "0x05" is "1", as described above, accessory 200 is in the firmware update mode.

[0196] Figure 6 The data in D7 to D0 of the address "0x0F" shown is information indicating a checksum.

[0197] Figure 7 1 is a diagram showing a sequence when the accessory 200 is attached to the camera 100. In the following description, communication between the camera 100 and the accessory 200 is schematically described. Details will be mentioned later.

[0198] When the accessory 200 is attached to the camera 100, the accessory attachment detection signal / ACC_DET becomes the GND level (low level), and the first camera controller 101 determines that the accessory 200 is attached. In the case where it is determined that the accessory 200 is attached, the first camera controller 101 sets the power control signal CNT_VACC1 to a high level to turn on the first accessory power supply 131. When the power control signal CNT_VACC1 becomes high, the first accessory power supply 131 outputs the accessory power supply VACC.

[0199] In the accessory 200, upon receiving the accessory power supply VACC, the accessory power supply 202 generates the power supply VMCU_A used by the accessory controller 201. Thus, the accessory controller 201 is activated. The accessory controller 201 initializes each block in the accessory 200 after activation. Thereafter, in the case where communication with the camera 100 is available, the accessory controller 201 sets the communication request signal / WAKE to a low level. In the camera 100, upon detecting that the communication request signal / WAKE becomes a low level, the first camera controller 101 detects that the accessory 200 enters a communicable state.

[0200] The first camera controller 101 requests accessory information from the accessory 200 through I2C communication. In the accessory 200, the accessory controller 201 transmits the accessory information in response to the accessory information request from the camera 100. The accessory controller 201 sets the communication request signal / WAKE to a high level after transmitting the accessory information.

[0201] In the camera 100, the first camera controller 101 analyzes the received accessory information and determines whether the attached accessory 200 is controllable. In addition, the first camera controller 101 turns on the second accessory power source 132. When various settings of the camera 100 are completed, the first camera controller 101 notifies the second camera controller 102 of the accessory information.

[0202] Based on the accessory type information (ACC type information) indicating the type of the accessory, the second camera controller 102 notifies the accessory 200 of a control command through SPI communication in response to the received event, and controls the function signal. The accessory controller 201 responds to the control command from the camera 100 through SPI communication (sends an event), and controls the accessory 200 according to the function signal.

[0203] Figure 8 It is shown in Figure 6 FIG. 1 is a diagram showing an example of accessory type information set in D7 to D0 of address "0x00" in FIG. Figure 8As shown, each number corresponds to the type of accessory. For example, the numbers "0x81", "0x82", "0x83" and "0x84" respectively indicate that the accessories are a flash device, an interface conversion adapter device, a microphone device and a multi-accessory connection adapter device. In this description, the adapter device is an intermediate accessory attached between the camera 100 and an accessory (a flash device or a microphone device, etc.). The interface conversion adapter device converts an interface to provide compatibility between the camera 100 and the accessories having different interfaces. The multi-accessory connection adapter device is used to attach a plurality of accessories to the camera 100.

[0204] Fig. 9 It is shown in Figure 6 FIG. 1 is a diagram of an example of factors of the communication request signal / WAKE set in D6 to D0 of address “0x0A” in FIG. Fig. 9 An example is shown in the case where the accessory 200 is a microphone device. For example, the factor number "0x00" indicates that the menu call switch (SW) in the operation switch 212 is pressed. In addition, the factor number "0x01" indicates that the accessory 200 has completed the output control of the audio signal. In addition, the factor number "0x02" indicates that the accessory 200 has completed the mute processing of the audio signal. In this way, the camera 100 can be notified of information related to the generation factor of the communication request signal / WAKE.

[0205] Fig. 10A It is shown in Figure 6 FIG. 1 is a diagram of an example of a communication interval between communication bytes set at address “0x0D” in FIG. Fig. 10B It is shown in Figure 6 FIG. 1 is a diagram of an example of the communication interval between communication bytes set at address “0x0E” in FIG.

[0206] Fig.11 is a flowchart showing a first accessory attachment process performed by the camera 100. The flowchart shows a process using the first camera controller 101 that is performed until the accessory 200 is attached to the camera 100 and the function of the accessory 200 becomes available. The first accessory attachment process is implemented when the CPU in the first camera controller 101 expands and runs a program stored in a ROM (not shown) in the first camera controller 101 to a RAM (not shown) in the first camera controller 101. This process is started when the main power of the camera 100 is turned on or when the camera 100 is restored from an automatic off mode (power saving mode).

[0207] In step S401, the first camera controller 101 monitors the signal level of the accessory attachment detection signal / ACC_DET, and waits until the signal level becomes low. That is, the first camera controller 101 waits until the accessory 200 is attached. In the case where the signal level of the accessory attachment detection signal / ACC_DET is high, it is determined that the accessory 200 is not attached. In the case where the signal level is low, it is determined that the accessory 200 is attached, and the first camera controller 101 advances the process to step S402.

[0208] In step S402, the first camera controller 101 controls the power control signal CNT_VACC1 to a high level (Hi) to turn on the first accessory power supply 131. Then, the process proceeds to step S403. When the power control signal CNT_VACC1 becomes high, the first accessory power supply 131 outputs the accessory power supply VACC.

[0209] In step S403, the first camera controller 101 monitors the signal level of the overcurrent detection signal DET_OVC and determines whether the signal level is low. In the case where the signal level is low, the first camera controller 101 can determine that the overcurrent is not flowing, so the process proceeds to step S404. On the other hand, in the case where the signal level is high, the first camera controller 101 can determine that the overcurrent is flowing. In this case, the first camera controller 101 ends Fig.11 The process shown in FIG. 14 and causes the process to enter error handling.

[0210] In step S404, the first camera controller 101 monitors the signal level of the communication request signal / WAKE as a notification signal from the accessory 200, and waits until the signal level becomes low (that is, until the initialization of the accessory 200 is completed). When the above-mentioned signal level becomes low, since the first camera controller 101 can determine that the initialization of the accessory 200 is completed, the process proceeds to step S405.

[0211] If the signal level of the communication request signal / WAKE does not become low during the predetermined period in step S404, the process may enter error processing (not shown). In the error processing, the first camera controller 101 notifies the user that the attached accessory 200 cannot be effectively used by displaying a message or voice.

[0212] In step S405, the first camera controller 101 performs I2C communication with the accessory 200 as initial communication, and reads Figure 6That is, the first camera controller 101 requests the accessory information from the accessory 200. In the accessory 200, the accessory controller 201 transmits the accessory information to the camera 100 in response to the accessory information request from the camera 100. The camera 100 receives the accessory information.

[0213] In step S406, the first camera controller 101 determines whether the attached accessory 200 is a device compatible with the camera 100 based on the accessory information obtained in step S405. In the case where it is determined that the attached accessory 200 is a compatible accessory, the first camera controller 101 advances the processing to step S407. In the case where it is determined that the attached accessory 200 is an incompatible accessory, the first camera controller 101 ends the processing. Fig.11 The process shown and causes the process to enter an error process (not shown). In the error process, the first camera controller 101 notifies the user that the attached accessory 200 is an incompatible accessory by displaying a message or voice.

[0214] In step S407, the first camera controller 101 controls the power control signal CNT_VACC2 to a high level to turn on the output of the second accessory power supply 132. Then, the process proceeds to step S408. In a case where the power control signal CNT_VACC2 becomes high, the second accessory power supply 132 outputs the accessory power supply VACC. In the present embodiment, in a case where both the power control signal CNT_VACC1 and the power control signal CNT_VACC2 are controlled to a high level, the second accessory power supply 132 should output the accessory power supply VACC.

[0215] In step S408, the first camera controller 101 notifies the second camera controller 102 of the accessory information read in step S405, and the process is completed. Fig.11 Processing shown.

[0216] Fig.12 1 is a flowchart showing a second accessory attachment process performed by the camera 100. The flowchart shows a process performed by the second camera controller 102 until the accessory 200 is attached to the camera 100 and the function of the accessory 200 becomes available. The second accessory attachment process is implemented when the CPU in the second camera controller 102 expands and runs a program stored in a ROM (not shown) in the second camera controller 102 to a RAM (not shown) in the second camera controller 102. Fig.11 ) starts, the process begins.

[0217] In step S501, the second camera controller 102 waits until accessory information is provided from the first camera controller 101. Fig.11 Upon receiving the accessory information, the second camera controller 102 sets the function signals (FNC1 to FNC4) based on the provided accessory information in step S502.

[0218] For example, if the accessory 200 is determined to be a microphone device based on the accessory information, the second camera controller 102 sets the FNC1 signal to be used as the audio data clock signal. Similarly, the second camera controller 102 sets the FNC2 signal and the FNC3 signal to be used as the audio data channel signal and the voice data signal, respectively.

[0219] Furthermore, for another example, in the case where the accessory 200 is a flash device, the second camera controller 102 sets the FNC4 signal to be used as a flash firing synchronization signal (flash firing timing signal). Function signals that do not require control of the accessory 200 may be set so as not to cause malfunctions in the operations of the camera 100 and the accessory 200.

[0220] In step S503, the second camera controller 102 sets the control logic of the CS signal in the SPI communication based on the accessory information supplied from the first camera controller 101. In step S504, the second camera controller 102 waits until an event occurs (is detected) for the accessory 200. When an event occurs, the process proceeds to step S505.

[0221] In step S505, the second camera controller 102 determines whether the event detected in step S504 requires SPI communication with the accessory 200. If the detected event requires SPI communication, the second camera controller 102 advances the process to step S506. If the detected event does not require SPI communication, the process advances to step S507.

[0222] In step S506, the second camera controller 102 controls SPI communication with the accessory 200. For example, in the case where the accessory 200 is a microphone device, instruction communication for turning ON / OFF the microphone operation, instruction communication for switching the sound collection directivity of the microphone, instruction communication for switching the equalizer function of the microphone, etc. are performed as SPI communication. In addition, in the case where the accessory 200 is a flash device, communication for reading setting information related to the flash, communication for notifying the flash of the setting information, etc. are performed as the above-mentioned SPI communication. After step S506, the second camera controller 102 returns the process to step S504.

[0223] In step S507, the second camera controller 102 determines whether the detected event requires control of the accessory 200 using a function signal. If the detected event requires control using a function signal, the second camera controller 102 advances the process to step S508. If the detected event does not require control using a function signal, the process advances to step S509.

[0224] In step S508, the second camera controller 102 controls the accessory 200 based on the function signal. For example, when the accessory 200 is a microphone device, the function signal is used to control the output of the audio data clock signal of FNC1, the output of the audio data channel signal of FNC2, and the input of the audio data signal of FNC3. Thus, the camera 100 can obtain voice data from the accessory 200. Furthermore, when the accessory 200 is a flash device, the flash light emission synchronization signal of FNC4 can be controlled at a predetermined timing. Thus, the flash light can be notified of the emission instruction. After step S508, the second camera controller 102 returns the process to step S504.

[0225] In step S509, the second camera controller 102 executes "other control" corresponding to the event detected in step S504. In the case where the detected event requires I2C communication, the second camera controller 102 controls I2C communication to the accessory 200 in other control. In addition, the second camera controller 102 performs in-camera control according to the detected event in other control. In the case where the accessory 200 is a microphone device, for example, start / end control of recording voice data into the recording memory 126 and control of equalizer processing of voice data are performed as in-camera control performed in step S509. In addition, in the case where the accessory 200 is a flash device, photometry control of obtaining the light amount of light emitted by the flash accumulated by the image sensor 122 and calculation control of the flash light emission amount indication value are performed as in-camera control. After step S509, the second camera controller 102 returns the process to step S504.

[0226] exist Fig.11 and Fig.12 In the illustrated process, the camera-side connector 141, the first camera controller 101, and the second camera controller 102 implement the function of the communication unit in the present invention. In addition, the first camera controller 101 implements the functions of the acquisition unit, the determination unit, and the controller in the present invention.

[0227] Fig.131 is a flowchart showing a second accessory attachment process performed by the accessory 200. The flowchart shows a process using the accessory controller 201 that is performed until the accessory 200 is attached to the camera 100 and the function of the accessory 200 becomes available. The process is realized when the CPU in the accessory controller 201 expands and runs a program stored in a ROM (not shown) in the accessory controller 201 to a RAM (not shown) in the accessory controller 201. The process starts when the accessory 200 is attached to the camera 100.

[0228] In step S601, the accessory controller 201 waits until the accessory power VACC from the camera 100 is turned on. When the accessory power VACC is turned on, the process proceeds to step S602. In addition to this method, in the case where the accessory 200 has the battery 205, the accessory controller 201 can monitor the voltage of the accessory power VACC and can detect the turning on of the accessory power VACC. If the accessory 200 does not have the battery 205, power is supplied to the accessory controller 201, and since the accessory controller 201 itself starts the operation, it can be determined that the accessory power VACC is turned on.

[0229] In step S602, the accessory controller 201 performs initial setting. The initial setting includes setting of the operating frequency of the microcomputer, initialization of the input / output control port of the microcomputer, initialization of the timer function of the microcomputer, initialization of the interrupt function of the microcomputer, etc. In step S603, the accessory controller 201 notifies the camera 100 that the initial setting is completed (communication becomes available) by controlling the communication request signal / WAKE to a low level.

[0230] In step S604, the accessory controller 201 responds to the I2C communication as the initial communication from the camera 100, and transmits 15 bytes of accessory information ( Figure 6 ). In step S605, the accessory controller 201 controls the communication request signal / WAKE to a high level. In step S606, the accessory controller 201 waits until an event occurs (is detected). In the event that an event occurs, the process proceeds to step S607. Therefore, in the first communication after the information indicating that communication becomes available is notified and before starting an event-based operation, the accessory information is sent.

[0231] In step S607, the accessory controller 201 determines whether the event detected in step S606 requires SPI communication with the camera 100. If the detected event requires SPI communication, the accessory controller 201 proceeds to step S608. If the detected event does not require SPI communication, the process proceeds to step S609.

[0232] In step S608, the accessory controller 201 controls the SPI communication with the camera 100. In the case where the communication request signal / WAKE is low when controlling the SPI communication, the accessory controller 201 sets the communication request signal / WAKE to high after the SPI communication.

[0233] In the case where the accessory 200 is a microphone device, for example, in step S608, instruction communication for turning on / off the microphone operation from the camera 100 is performed as SPI communication control. In addition, instruction communication for switching the sound collection directivity of the microphone, instruction communication for switching the equalizer function of the microphone, etc. are performed as SPI communication. In addition, in the case where the accessory 200 is a flash device, communication for reading setting information related to the flash, communication for notifying the flash of the setting information, etc. are performed as SPI communication control. After step S608, the accessory controller 201 returns the process to step S606.

[0234] In step S609, the accessory controller 201 determines whether the detected event requires I2C communication with the camera 100. If the detected event requires I2C communication, the accessory controller 201 advances the process to step S610. If the detected event does not require I2C communication, the process advances to step S611.

[0235] In step S610, the accessory controller 201 controls the I2C communication with the camera 100. In the case where the communication request signal / WAKE is low when controlling the I2C communication, the accessory controller 201 sets the communication request signal / WAKE to high after the I2C communication. For example, in step S610, communication for reading a communication request factor in response to the communication request signal / WAKE notified by the accessory controller 201 to the camera 100 is performed as the I2C communication control. After step S610, the accessory controller 201 returns the process to step S606.

[0236] In step S611, the accessory controller 201 determines whether the event detected in step S606 uses a function signal. In the case where the detected event requires control using a function signal, the accessory controller 201 advances the process to step S612. In the case where the detected event does not require control using a function signal, the process advances to step S613.

[0237] In step S612, the accessory controller 201 uses the function signal to control the camera 100. In the case where the accessory 200 is a microphone device, the following control is employed as the control using the function signal performed in step S612.

[0238] For example, reception control of the audio data clock signal of FNC1 and the audio data channel signal of FNC2 output from the camera 100, and output control of the audio data of FNC2 synchronized with these signals are performed as control using the function signal. On the other hand, in the case where the accessory 200 is a flash device, flash emission control by controlling the received flash emission synchronization signal of FNC4 is performed as control using the function signal in step S612. After step S612, the accessory controller 201 returns the process to step S606.

[0239] In step S613, the accessory controller 201 determines whether the event detected in step S606 is provided to the camera 100 in response to the communication request signal / WAKE. In the case where the detected event needs to be notified to the camera in response to the communication request signal / WAKE, the accessory controller 201 advances the process to step S614. In the case where the detected event does not need to be notified to the camera in response to the communication request signal / WAKE, the accessory controller 201 advances the process to step S615.

[0240] In step S614, the accessory controller 201 stores the communication request factor number for the camera 100 corresponding to the event detected in step S606 into a volatile memory (not shown) of the accessory 200, and controls the communication request signal / WAKE to be low. Fig. 9 As described above, the communication request factor number is a unique number assigned to each content of the factor. After step S614, the accessory controller 201 returns the process to step S606.

[0241] In step S615, the accessory controller 201 performs accessory control according to the event detected in step S606. For example, if the accessory 200 has a battery 205, the battery remaining amount detection control is performed as the accessory control in step S615. In addition, the detection control of the operation switch 212 is also performed as the accessory control. After step S615, the accessory controller 201 returns the process to step S606.

[0242] It should be noted that when the main power of the camera 100 is turned off, when the mode of the camera 100 is shifted to the automatic off mode, and when the accessory 200 is detached from the camera 100, Fig.13 The shown processing ends.

[0243] As mentioned above, when executing Fig.11 , Fig.12 and Fig.13 Following the illustrated process, camera 100 becomes available to control accessory 200, and accessory 200 becomes available to operate.

[0244] Hereinafter, the operation of the camera 100 as the image pickup apparatus according to the first embodiment of the present invention will be described.

[0245] Fig.14 2 is a diagram showing the state of the camera 100 recognized by the accessory controller 201 (state recognition unit).

[0246] Upon detecting that the accessory 200 is attached to the camera 100, the accessory controller 201 proceeds to step S141, and recognizes that the camera 100 transitions from the initial state to the connected state. In the present embodiment, upon receiving a predetermined signal from the accessory power supply 202, the accessory controller 201 detects that the accessory 200 is attached to the camera 100. Specifically, in the case where the accessory 200 is attached, the camera 100 outputs the accessory power supply VACC to the contact TC05 of the camera-side connector 141. In the accessory 200, the accessory power supply VACC is supplied to the accessory power supply 202 through the contact TA05 of the accessory-side connector 211. In the case where the accessory power supply VACC is supplied, the accessory power supply 202 starts outputting a predetermined signal to the accessory controller 201. In the case where the predetermined signal is received from the accessory power supply 202, the accessory controller 201 detects that the accessory 200 is attached to the camera 100. On the other hand, in the case where the accessory 200 is detached from the camera 100, the supply of the accessory power supply VACC to the accessory power supply 202 is stopped, and the accessory power supply 202 stops supplying the predetermined signal to the accessory controller 201. When the transmission of a predetermined signal from the accessory power supply 202 stops, the accessory controller 201 detects that the accessory 200 is detached from the camera 100 .

[0247] Attachment and detachment of the accessory 200 to and from the camera 100 may be detected by methods other than outputting a predetermined signal from the accessory power supply 202. These may be determined from the signals FNC1 to FNC4 received via the function unit 206, for example.

[0248] In the case of receiving the initial communication from the camera 100 currently identified as being in the connected state, the accessory controller 201 proceeds to step S142 and recognizes that the camera 100 transitions to the metering pause state. The initial communication from the camera 100 uses SPI communication (first communication) and I2C communication (second communication) which are different in the granularity of the information transmitted. As described above, the SPI communication uses the SCLK signal, the MOSI signal, and the MISO signal respectively output from the contacts TC07, TC08, and TC09 of the camera-side connector 141. In addition, the I2C communication uses the SDA signal and the SCL signal respectively output from the contacts TC12 and TC13 of the camera-side connector 141.

[0249] Upon receiving the light metering in progress notification from the camera 100 currently recognized as being in the light metering paused state, the accessory controller 201 proceeds to step S143 and recognizes that the camera 100 shifts to the light metering in progress state.

[0250] Upon receiving the automatic power-off notification from the camera 100 currently recognized as being in the metering pause state, the accessory controller 201 proceeds to step S144 and recognizes that the camera 100 shifts to the automatic power-off state.

[0251] Furthermore, in the case of receiving a power-off notification from the camera 100 currently recognized as being in the metering pause state, the accessory controller 201 proceeds to step S145 and recognizes that the camera 100 transitions to the power-off state. Similarly, in the case of receiving a power-off notification from the camera 100 currently recognized as being in the automatic power-off state, the accessory controller 201 proceeds to step S145 and recognizes that the camera 100 transitions to the power-off state.

[0252] Upon receiving the light metering off notification from the camera 100 currently recognized as being in the light metering in progress state, the accessory controller 201 proceeds to step S142 , and recognizes that the camera 100 shifts to the light metering paused state.

[0253] Upon receiving the activation notification from the camera 100 currently recognized as being in the automatic power-off state, the accessory controller 201 proceeds to step S142 , and recognizes that the camera 100 shifts to the light-metering pause state.

[0254] Upon receiving the activation notification from the camera 100 currently recognized as being in the power-off state, the accessory controller 201 proceeds to step S142 , and recognizes that the camera 100 shifts to the light-metering pause state.

[0255] Upon detecting that the accessory 200 is currently identified as being Fig.14 When the camera 100 in any state shown is detached, the accessory controller 201 (detachment detection unit) recognizes that the state of the camera 100 returns to the initial state. As described above, in this embodiment, when the transmission of a predetermined signal from the accessory power supply 202 stops, the accessory controller 201 detects that the accessory 200 is detached from the camera 100.

[0256] When the camera 100 is in the light metering in progress state, the second camera controller 102 (first communication unit) obtains information stored in the accessory 200 by periodically performing SPI communication with the accessory 200, and displays the obtained information on the display unit 127 as accessory related information. In addition, on the display unit 127, the subject image formed on the image sensor 122 is displayed as a through image together with the accessory related information. In addition, imaging parameters such as shutter speed, aperture, and ISO used when capturing an image are also displayed on the display unit 127. Specifically, in the case where the accessory 200 is a flash device, the following imaging parameters are displayed on the display unit 127. For example, in the case where information indicating that the accessory 200 is in a light emission available state is obtained through SPI communication, imaging parameters for flash emission are displayed on the display unit 127. On the other hand, in the case where information indicating that the accessory 200 is in a light emission unavailable state is obtained through SPI communication, imaging parameters for flash non-emission are displayed on the display unit 127. In this embodiment, the light-emitting available state means that the charging unit has completed charging the light-emitting unit in the functional unit 206 and the light-emitting unit can emit light. In addition, the light-emitting unavailable state means that the charging unit has not charged the light-emitting unit to a predetermined charging level and the light-emitting unit cannot emit light.

[0257] When the camera 100 is in the light metering pause state (first state), the second camera controller 102 stops the SPI communication with the accessory 200 , but continues to display the through image and the imaging parameters on the display unit 127 .

[0258] When the camera 100 is in the automatic power off state (second state), power supply from the system power supply 112 to the second camera controller 102 is stopped. Therefore, the second camera controller 102 not only stops SPI communication with the accessory 200, but also stops displaying the through image and imaging parameters on the display unit 127.

[0259] In addition, when the camera 100 is in the metering pause state or the automatic power off state, power is supplied to the first camera controller 101 and the first camera controller 101 is in the standby mode. When the camera 100 is activated due to the operation of a switch (not shown) connected to the first camera controller 101, or when the signal state of the communication request signal / WAKE of the contact TC11 of the camera-side connector 141 changes, the standby mode is released.

[0260] When the camera 100 is in the power-off state, the power supply from the system power supply 112 to the second camera controller 102 is stopped. On the other hand, power is supplied to the first camera controller 101, and the first camera controller 101 stops communicating with the accessory 200 but is in the standby mode. Therefore, only when the power switch among the switches for camera operation (not shown) connected to the first camera controller 101 is operated, the standby mode of the first camera controller 101 is released.

[0261] Fig.15 1 is a flowchart showing a notification process for notifying the camera 100 when a light control correction value of an automatic light control mode of a flash device as the accessory 200 is changed.

[0262] In step S1501, the accessory controller 201 checks whether the light control correction value of the accessory 200 has changed. In the case where the light control correction value has changed ("Yes" in step S1501), the process proceeds to step S1502. Otherwise, the process returns to step S1501, and the change of the light control correction value is checked again. For example, the light control correction value of the accessory 200 can be changed by the user's operation of the operation switch 212.

[0263] In step S1502, the accessory controller 201 checks whether the camera 100 is currently recognized as being in Fig.14 In the case where the camera 100 is not in the light metering in progress state ("No" in step S1502), the processing proceeds to step S1503. Otherwise, the processing returns to step S1501, and the change of the light control correction value is checked again. As described above, in the case where the camera 100 is in the light metering in progress state, the second camera controller 102 periodically obtains information such as the light control correction value stored in the accessory 200 through SPI communication with the accessory 200. In addition, the light control correction value of the accessory 200 obtained periodically is displayed on the display unit 127 of the camera 100 as accessory-related information.

[0264] In step S1503, the accessory controller 201 checks whether the camera 100 is currently recognized as being in Fig.14 The metering pause state shown in step S142 of FIG. 140 is in the metering pause state. If the camera 100 is in the metering pause state (YES in step S1503), the process proceeds to step S1510. Otherwise, the process proceeds to step S1504.

[0265] In step S1504, the accessory controller 201 checks whether the camera 100 is currently recognized as being in Fig.14The automatic power-off state shown in step S144 of FIG. 140 . If the camera 100 is in the automatic power-off state (YES in step S1504 ), the process proceeds to step S1505 . Otherwise, the process returns to step S1501 , and the change in the light control correction value is checked again.

[0266] In step S1505, the accessory controller 201 checks whether the light control correction value is changed from a value other than "0" (second value) to "0" (first value). In the case where the light control correction value is changed from a value other than "0" to "0", the process proceeds to step S1511. Otherwise, the process proceeds to step S1506.

[0267] In step S1506, the accessory controller 201 checks whether the light control correction value has changed from "0" to a value other than "0". In the case where the light control correction value has changed from "0" to a value other than "0", the process proceeds to step S1511. Otherwise, the process returns to step S1501, and the change in the light control correction value is checked again.

[0268] In step S1510, the accessory controller 201 (notification unit) notifies the camera 100 of the change in the state of the accessory 200, and ends the processing. In this step, the accessory controller 201 notifies the camera 100 of the change in the state of the accessory 200 by controlling the potential of the contact TA11 of the accessory-side connector 211 to change the signal state of the communication request signal / WAKE of the contact TC11 of the camera-side connector 141. In the case where the accessory controller 201 notifies the camera 100 of the change in the state of the accessory 200, the first camera controller 101 releases the standby mode. Thereafter, the first camera controller 101 accesses the address 0x0A of the nonvolatile memory of the accessory 200 through I2C communication, and inquires about the factor of the communication request signal / WAKE. In response to the inquiry, the accessory controller 201 transmits response data in which "0" requesting the activation of the camera 100 is set as data in D7, and a value indicating the change in the light control correction value is set as data in D6 to D0. Upon receiving the start request in the response data, the second camera controller 102 starts the suspended SPI communication with the accessory 200. In response to the SPI communication started by the second camera controller 102, the accessory controller 201 (first transmission unit) transmits information (detailed information) such as the light control correction value stored in the accessory 200 to the camera 100. In the case where the above detailed information is transmitted from the accessory controller 201, the second camera controller 102 displays the detailed information on the display unit 127.

[0269] The accessory controller 201 (notification unit) notifies the camera 100 of the change in the state of the accessory 200 in step S1511, and ends the processing. In the case where the accessory controller 201 notifies the camera 100 of the change in the state of the accessory 200, the first camera controller 101 (second communication unit) releases the standby mode. Thereafter, the first camera controller 101 accesses the address 0x0A of the nonvolatile memory of the accessory 200 through I2C communication, and inquires about the factor of the communication request signal / WAKE. In response to the inquiry, the accessory controller 201 transmits response data in which "1" not requesting the activation of the camera 100 is set as data in D7, and a value indicating a change in the light control correction value is set as data in D6 to D0. That is, as a result of the above notification from the accessory controller 201 to the camera 100 in step S1511, simplified information indicating a change in the light control correction value is transmitted from the accessory controller 201 (second transmission unit) to the camera 100.

[0270] According to this processing, even if the camera 100 is in the metering pause state, since the light control correction value (detailed information) of the accessory 200 is displayed on the display unit 127, the user can know the light control correction value. In the present embodiment, the detailed information indicating the value of the control parameter related to the accessory means the first information, and the simplified information indicating whether the accessory 200 satisfies the predetermined condition means the second information. For example, the value of the control parameter includes the light control correction value, the manual light emission amount, the bounce angle, the zoom position of the optical lens 121, and the like. For example, the predetermined condition includes a change in the set light control correction value, a change in the set manual light emission amount, a change in the bounce angle, a light emission available state, and a change between the light emission available state and the light emission unavailable state, and the like.

[0271] Furthermore, even if the camera 100 is in the automatic power-off state, the first camera controller 101 can know whether the light control correction value (simplified information) is set for the accessory 200. Therefore, for example, in a case where the light control correction value can be set from the camera 100 in a manner excluding the light control correction value of the accessory 200, the first camera controller 101 can immediately determine whether the light control correction value can be set from the camera 100. For example, in a case where information that the light control correction value is set for the accessory 200 is obtained as simplified information, the first camera controller 101 determines that the light control correction value cannot be set from the camera 100.

[0272] Furthermore, when the camera is in the automatic power-off state, only when the light control correction value of the accessory 200 changes from "0" to a value other than "0" or from a value other than "0" to "0", the accessory controller 201 notifies the camera 100 of the change in the state of the accessory 200. Thus, the frequency of communication between the camera 100 and the accessory 200 can be reduced.

[0273] In addition, when the accessory controller 201 detects that the accessory 200 is detached from the camera 100 after determining that the camera 100 is currently recognized as being in the metering pause state ("Yes" in step S1503), the accessory controller 201 ends the processing at this time. Similarly, when the accessory controller 201 detects detachment after determining that the camera is currently recognized as being in the automatic power-off state ("Yes" in step S1504), the accessory controller 201 ends the processing at this time.

[0274] Hereinafter, the operation of the camera 100 as the image pickup apparatus according to the second embodiment of the present invention will be described. It should be noted that the same structures in this embodiment as those in the first embodiment are denoted by the same reference numerals, and repeated description is omitted.

[0275] Fig.16 1 is a flowchart showing a notification process of notifying the camera 100 in a case where a sender flash is a multi-flash system of the accessory 200 in which a light emission control state changes.

[0276] In addition, the multi-flash system is formed by wirelessly controlling a plurality of receiver flashes using the accessory 200 as a transmitter flash. In addition, like the accessory 200, each receiver flash is equipped with a functional unit including a light emitting unit and a charging unit.

[0277] The light emission control state of the accessory 200 changes to a light emission enabled state when the charging unit completes charging of the light emission unit, and changes to a light emission disabled state when charging is not completed. Similarly, the light emission control state of each receiving flash light changes to a light emission enabled state when the charging unit completes charging of the light emission unit in its functional unit, and changes to a light emission disabled state when charging is not completed. The accessory controller 201 obtains the light emission control state of each receiving flash light through wireless communication.

[0278] Furthermore, when the sending flash and all the receiving flashes are in the light-emitting state, the accessory controller 201 determines that the multi-flash system is in the light-emitting state (first value). On the other hand, when any one of the sending flash and all the receiving flashes is in the light-emitting unavailable state, the accessory controller 201 determines that the multi-flash system is in the light-emitting unavailable state (second value).

[0279] In step S1601, the accessory controller 201 checks whether any of the emission control states of the sender flash (accessory 200) and the receiver flash has changed. In the case where the emission control state of any of these flashes has changed ("Yes" in step S1601), the process proceeds to step S1602. Otherwise, the process returns to step S1601, and the change of the emission control state of each flash is checked again.

[0280] In step S1602, the accessory controller 201 checks whether the camera 100 is currently recognized as being in Fig.14 The metering-in-progress state shown in step S143 of . In a case where the camera 100 is not in the metering-in-progress state ("No" in step S1602), the processing proceeds to step S1603. Otherwise, the processing returns to step S1601, and the change in the emission control state of each flash is checked again. As described above, in a case where the camera 100 is in the metering-in-progress state, the second camera controller 102 periodically obtains the emission control state of the sending flash and the emission control state of the receiving flash from the accessory 200 as the sending flash through SPI communication with the accessory 200. In addition, the camera 100 displays the emission control states of the sending flash and the receiving flash that are periodically obtained on the display unit 127.

[0281] In step S1603, the accessory controller 201 checks whether the camera 100 is currently recognized as being in Fig.14 The metering pause state shown in step S142 of FIG. 140 is in the metering pause state. If the camera 100 is in the metering pause state (YES in step S1603), the process proceeds to step S1610. Otherwise, the process proceeds to step S1604.

[0282] In step S1604, the accessory controller 201 checks whether the camera 100 is currently recognized as being in Fig.14 The automatic power-off state shown in step S144 of FIG. 140. If the camera 100 is in the automatic power-off state (YES in step S1604), the process proceeds to step S1605. Otherwise, the process returns to step S1601, and the change of the light emission control state of each flash is checked again.

[0283] In step S1605, the accessory controller 201 checks whether the emission control state of the multi-flash system has changed. In the case where the emission control state has changed ("Yes" in step S1605), the process proceeds to step S1611. Otherwise, the process returns to step S1601, and the change in the emission control state of each flash is checked again.

[0284] The accessory controller 201 notifies the camera 100 of the change in the state of the accessory 200 in step S1610, and ends the process. In this step, the accessory controller 201 notifies the camera 100 of the change in the state of the accessory 200 by controlling the potential of the contact TA11 of the accessory-side connector 211 to change the signal state of the communication request signal / WAKE of the contact TC11 of the camera-side connector 141. When the accessory controller 201 notifies the camera 100 of the change in the state of the accessory 200, the first camera controller 101 cancels the standby mode.

[0285] After that, the first camera controller 101 accesses the address 0x0A of the nonvolatile memory of the accessory 200 through I2C communication, and inquires about the factor of the communication request signal / WAKE. In response to the inquiry, the accessory controller 201 sends response data in which "0" requesting activation of the camera 100 is set as data in D7, and a value indicating a change in the light emission available state of the multi-flash system is set as data in D6 to D0.

[0286] Upon receiving the start request in the response data, the second camera controller 102 starts the suspended SPI communication with the accessory 200. In response to the SPI communication started by the second camera controller 102, the accessory controller 201 transmits the emission control states of the sender flash and the receiver flash to the camera 100 as detailed information stored in the accessory 200. In the case where the above detailed information is transmitted from the accessory controller 201, the second camera controller 102 displays the detailed information on the display unit 127.

[0287] The accessory controller 201 (notification unit) notifies the camera 100 of the change in the state of the accessory 200 in step S1611, and ends the processing. In the case where the accessory controller 201 notifies the camera 100 of the change in the state of the accessory 200, the first camera controller 101 releases the standby mode. Thereafter, the first camera controller 101 accesses the address 0x0A of the nonvolatile memory of the accessory 200 through I2C communication, and inquires about the factor of the communication request signal / WAKE. In response to the inquiry, the accessory controller 201 transmits response data in which "1" not requesting the activation of the camera 100 is set as data in D7, and values ​​indicating a change in the light emission available state of the multi-flash system are set as data in D6 to D0. That is, as a result of the above notification from the accessory controller 201 to the camera 100 in step S1611, simplified information indicating a change in the light emission available state of the multi-flash system is transmitted from the accessory controller 201 (second transmission unit) to the camera 100.

[0288] According to this processing, even if the camera 100 is in the metering paused state, since the emission control states (detailed information) of the transmission-side flash and the reception-side flash are displayed on the display unit 127 , the user can know these emission control states.

[0289] Furthermore, even if the camera 100 is in the automatic power-off state, the user can know the light emission control state since the light emission control state (simplified information) of the multi-flash system is displayed on the display unit 127. Therefore, for example, in the case where the user immediately starts an image capturing operation using the camera 100 in the automatic power-off state, the user can judge whether flash image capturing using the multi-flash system is available at this time, which can shorten the time period until the image capturing operation.

[0290] Furthermore, when the camera 100 is in the automatic power off state, the accessory controller 201 notifies the camera 100 of the change in the state of the accessory 200 only when the light emission available state of the multi-flash system changes. Thus, the communication frequency between the camera 100 and the accessory 200 can be reduced.

[0291] In addition, in the case where the accessory controller 201 detects that the accessory 200 is detached from the camera 100 after determining that the camera 100 is currently recognized as being in the metering pause state ("Yes" in step S1603), the accessory controller 201 ends the processing at this time. Similarly, in the case where the accessory controller 201 detects detachment after determining that the camera is currently recognized as being in the automatic power-off state ("Yes" in step S1604), the accessory controller 201 ends the processing at this time.

[0292] Although a structure in which the accessory 200 is directly attached to the camera 100 is described in the above embodiment, another structure may be adopted. For example, a main accessory corresponding to the accessory 200 may communicate with the camera 100 via an intermediate accessory such as an adapter device equipped with the camera 100. With this structure, at least a part of the communication control performed by the accessory 200 and the communication control performed by the camera 100 described in the above embodiment may be performed by the intermediate accessory. Alternatively, the intermediate accessory may be used as an information transmission path that outputs information corresponding to information input from the camera to the main accessory and outputs information corresponding to information input from the main accessory to the camera 100. As described above, the accessories defined in the present invention include a microphone device, a lighting device, an adapter device, or the like. In addition, the adapter device may also be included in the electronic device.

[0293] Other embodiments

[0294] 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.

[0295] 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.

[0296] This application claims the benefit of Japanese Patent Application No. 2021-077483, filed on Apr. 30, 2021, which is hereby incorporated by reference herein in its entirety.

Claims

1. An accessory that can be detachably connected to an electronic device, the accessory comprising: a first sending unit configured to send first information among the information stored in the accessory to the electronic device in response to a periodic first communication from a first communication unit of the electronic device, wherein the first information indicates a value of a control parameter related to the accessory; a second transmitting unit configured to respond to an inquiry using a second communication from a second communication unit of the electronic device; as well as a notification unit configured to notify the electronic device of a change in the information stored in the accessory when the electronic device is in one of the first state and the second state and the information stored in the accessory changes, wherein, in the first state, the first communication is stopped and the second communication unit is in a standby mode, and Here, in the second state, power supply to the first communication unit is stopped, and the second communication unit is in a standby mode.

2. The accessory according to claim 1, wherein: The notification unit releases the standby mode of the second communication unit by notification, and In which, when the standby mode of the second communication unit of the electronic device in the second state is released, the second sending unit sends second information different from the first information among the information stored in the accessory as a response to an inquiry related to the notification from the second communication unit, wherein the second information shows whether the accessory meets a predetermined condition.

3. The accessory according to claim 1, wherein: The notification unit releases the standby mode of the second communication unit by notification, and When the standby mode of the second communication unit of the electronic device in the first state is released, the second sending unit starts the first communication by sending a startup request of the electronic device as a response to an inquiry related to the notification from the second communication unit.

4. The accessory according to any one of claims 1 to 3, further comprising a state recognition unit, wherein the state recognition unit is configured to recognize a state of the electronic device, in, The notification unit notifies the electronic device of the change in the information stored in the accessory when the electronic device is recognized by the state recognition unit as being in one of the first state and the second state and the information stored in the accessory is changed.

5. The accessory according to claim 4, further comprising a disassembly detection unit configured to detect disassembly of the accessory from the electronic device. in, After the state recognition unit recognizes that the electronic device is in one of the first state and the second state, when the disassembly detection unit detects the disassembly, the processing by the notification unit is terminated.

6. The accessory according to any one of claims 1 to 3, wherein: When the electronic device is in the third state in which the first sending unit periodically sends the information stored in the accessory and the information stored in the accessory changes, the first sending unit sends the information stored in the accessory to the electronic device without using the notification unit to notify.

7. The accessory according to any one of claims 1 to 3, wherein: The information sent by the first sending unit and the information sent by the second sending unit are different in granularity.

8. The accessory according to any one of claims 1 to 3, wherein: When the electronic device is in the second state and when the information stored in the accessory that can be the first value has not changed from the first value to another value and has not changed from another value to the first value, notification using the notification unit is not performed even if the information stored in the accessory changes.

9. The accessory according to any one of claims 1 to 3, wherein: The standby mode is a mode in which power is supplied to the second communication unit and the second communication unit does not communicate with the accessory.

10. An electronic device capable of being detachably connected to an accessory, the electronic device comprising: a first communication unit configured to obtain, from the accessory through periodic first communication, first information among the information stored in the accessory, wherein the first information indicates a value of a control parameter related to the accessory; as well as a second communication unit configured to query the accessory through a second communication and obtain a response, wherein, when the electronic device is in one of the first state and the second state and the accessory notifies a change in information stored in the accessory, the standby mode of the second communication unit is released, wherein, in the first state, the first communication is stopped, and the second communication unit is in the standby mode, and Here, in the second state, power supply to the first communication unit is stopped, and the second communication unit is in the standby mode.

11. The electronic device according to claim 10, wherein: When the standby mode of the second communication unit of the electronic device in the second state is released, the second communication unit sends an inquiry about notification to the accessory through the second communication, and obtains information stored in the accessory as a response to the inquiry.

12. The electronic device according to claim 10, wherein: In a case where the standby mode of the second communication unit of the electronic device in the first state is released, the second communication unit sends an inquiry about notification to the accessory through the second communication, and obtains a start-up request of the electronic device from the accessory as a response to the inquiry, and Wherein, when the first communication is started in response to the start request, the first communication unit obtains the first information from the accessory. 13 . The electronic device according to claim 12 , further comprising a display unit configured to display detailed information obtained after starting the first communication.

14. The electronic device according to any one of claims 10 to 13, wherein: The standby mode is a mode in which power is supplied to the second communication unit and the second communication unit does not communicate with the accessory.

15. A camera system, comprising: Camera equipment, comprising: a first communication unit configured to obtain first information among the information stored in the accessory from the accessory through periodic first communication, wherein the first information indicates a value of a control parameter related to the accessory, and A second communication unit configured to query the accessory through a second communication and obtain a response; and An accessory, which can be detachably connected to the camera device, comprising: a notification unit configured to notify the camera of a change in the information stored in the accessory when the camera is in one of the first state and the second state and the information stored in the accessory changes, wherein, in the first state, the first communication is stopped and the second communication unit is in a standby mode, and Here, in the second state, power supply to the first communication unit is stopped, and the second communication unit is in the standby mode.

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