Accessories, Electronic Devices, and Imaging Systems

Abstract

To provide an accessory that, when the state of the accessory changes, can quickly notify an electronic apparatus of the change in the state of the accessory while considering the state of the electronic apparatus, and provide the electronic apparatus, and an imaging system.SOLUTION: An imaging system comprises a camera 100 and an accessory 200 that is removably connected thereto. The camera 100 includes a camera control unit B102 that periodically acquires, from the accessory 200, information included in the accessory 200 through SPI communication, and a camera control unit A101 that makes an inquiry to the accessory 200 through I2C communication and obtains a response thereto. The accessory 200 includes an accessory control unit 201 that, if the information included in the accessory 200 changes when the currently recognized state of the camera 100 is any one of a camera photometry stopped state and an auto power off state, notifies the camera 100 of the change of the information included in the accessory 200.SELECTED DRAWING: Figure 15

Description

Technical Field

[0001] The present invention relates to an accessory, an electronic device to which the accessory is detachably connected, and an imaging system in which the accessory is connected to an imaging device.

Background Art

[0002] Generally, an imaging device such as a digital camera can connect an accessory such as a flash device. Further, the imaging device has a control unit for performing communication such as transmitting a signal instructing light emission to the flash device in order to control the flash device connected via an interface. However, when the imaging device is in the power saving mode and its control unit is not operating, data cannot be exchanged between the imaging device and the flash device. Therefore, in such a case, even if the state of the flash device changes, the imaging device cannot be notified that the state of the flash device has changed.

[0003] Patent Document 1 proposes a configuration that enables an imaging device in the power saving mode to be activated from a flash device.

Prior Art Documents

Patent Documents

[0004] Japanese Patent No. 5894397

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the prior art disclosed in Patent Document 1, since the state of the imaging device is determined after the state of the flash device has changed, it takes time from when the state of the flash device changes until the imaging device is activated.

[0006] Further, in a conventional flash device, even when it is removed from an imaging device in the power saving mode and the imaging device is in an initial state where it is not connected to an accessory, the flash device cannot detect this.

[0007] Therefore, an object of the present invention is to provide an accessory, an electronic device, and an imaging system that can promptly notify an electronic device of a change in the state of an accessory in view of the state of the electronic device when the state of the accessory changes.

Means for Solving the Problems

[0008] The accessory according to claim 1 of the present invention is an accessory detachably connected to an electronic device, and in response to periodic first communication from a first communication means of the electronic device, information Contained in that the accessory has to the electronic device by a first transmission means for transmitting first information, a second transmission means for responding to an inquiry by second communication from a second communication means of the electronic device, a state recognition means for recognizing the state of the electronic device, and when the state of the electronic device recognized by the state recognition means is either a first state in which the first communication is stopped and the second communication means is in a standby mode, or a second state in which power supply to the first communication means is stopped and the second communication means is in a standby mode, if the information that the accessory has changes, information Is change Information based on what that the accessory has to the electronic device is notified by a notification means. It is characterized by comprising.

[0009] The electronic device according to claim 9 of the present invention is an electronic device to which an accessory is detachably connected, and has a first communication means for periodically acquiring first information of information from the accessory by first communication, and a second communication means for inquiring of the accessory by second communication and acquiring a response therefrom. When the state of the electronic device is either a first state in which the first communication is stopped and the second communication means is in a standby mode, or a second state in which power supply to the first communication means is stopped and the second communication means is in a standby mode, if information Contained in that the accessory has changes and is notified from the accessory, the second communication means Is change Information based on what ​Is the standby mode For release Do characterized in that

[0010] The imaging system according to claim 14 of the present invention is an imaging system including an imaging device and an accessory detachably connected to the imaging device, wherein the imaging device periodically obtains first information of the accessory from the accessory by first communication, and includes first communication means, and second communication means for making an inquiry to the accessory by second communication and obtaining a response therefrom. The accessory includes state recognition means for recognizing the state of the imaging device, and when the state of the imaging device recognized by the state recognition means is either a first state in which the first communication is stopped and the second communication means is in the standby mode, or a second state in which the power supply to the first communication means is stopped and the second communication means is in the standby mode, and when the information held by the accessory changes, the accessory includes notification means for notifying the imaging device of the change in the information held by the accessory. Contained in Is change Information based on what characterized in that it comprises

Advantages of the Invention

[0011] According to the present invention, when the state of the accessory changes, it is possible to promptly notify the electronic device to which the accessory is attached of the change in the state of the accessory in view of the state of the electronic device.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0014] FIG. 1 is a block diagram of an imaging system including an imaging device and an accessory as an electronic device according to an embodiment of the present invention. This imaging system includes a camera 100 as an imaging device and an accessory 200. The accessory 200 is detachable from the camera 100. FIG. 1 shows the electrical configuration of the camera 100 and the accessory 200.

[0015] The camera 100 is provided with a camera-side connection part 141 as a mounting part on which the accessory 200 can be mounted. The camera-side connection part 141 has contacts TC01 to TC21 which are a plurality of terminals. The accessory 200 is provided with an accessory-side connection part 211. The accessory-side connection part 211 has contacts TA01 to TA21 which are a plurality of terminals. The camera 100 and the accessory 200 are electrically connected by the contacts TC01 to TC21 and the contacts TA01 to TA21 coming into one-to-one contact with each other. Note that the accessory 200 may not have some of the plurality of contacts TA01 to TA21.

[0016] The camera 100 is supplied with power from the battery 111. The battery 111 is detachable from the camera 100. The camera control unit A101 and the camera control unit B102 are each composed of a microcomputer incorporating a CPU or the like, and control the entire camera 100. The camera control unit A101 monitors the operation of switches (not shown) for camera operations. The camera control unit A101 operates even when the camera 100 is in a standby state (low power consumption mode), and controls the system power supply according to the user's operation. The camera control unit B102 is responsible for controlling the imaging sensor 122, the display unit 127, etc., and stops operating in the standby state. In this embodiment, the case where the camera control unit A101 and the camera control unit B102 are configured by separate processors is described, but they may be provided within a single processor.

[0017] The system power supply unit 112 is composed of a DCDC converter, an LDO (Low Drop Out), a charge pump circuit, etc., and generates the power to be supplied to each part of the camera 100. A voltage of 1.8V generated by the system power supply unit 112 is constantly supplied as the camera microcomputer power supply VMCU_C from the battery 111 to the camera control unit A101. Also, several types of voltages generated by the system power supply unit 112 are supplied as the camera microcomputer power supply VMCU2_C to the camera control unit B102 at an arbitrary timing. The camera control unit A101 controls the on / off of the power supply to each part of the camera 100 by controlling the system power supply unit 112.

[0018] The imaging sensor 122 is composed of a CMOS sensor, a CCD sensor, or the like. The optical lens 121 of the camera 100 is detachable. The light from the subject incident through the attached optical lens 121 forms an image on the imaging sensor 122. Note that the optical lens 121 and the camera 100 may be integrally configured. The subject image formed on the imaging sensor 122 is encoded into a digital imaging signal. The image processing unit 123 performs image processing such as noise reduction processing and white balance processing on the digital imaging signal to generate image data. Further, the image processing unit 123 converts the generated image data into an image file in a format such as JPEG in order to record it in the recording memory 126. Also, the image processing unit 123 generates VRAM image data for display on the display unit 127 from the generated image data.

[0019] The memory control unit 124 controls the 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 a 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 readable and writable medium such as an SD card or a CFexpress card, and is a recording medium detachable from the camera 100. The display unit 127 includes a display disposed on the back surface of the camera 100, and this display is composed of an LCD panel, an organic EL display panel, or the like. 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.

[0020] The accessory power supply unit A131 and the accessory power supply unit B132 are voltage conversion units that convert the voltage supplied from the system power supply unit 112 into a predetermined voltage to generate an accessory power supply VACC of 3.3V. Note that the accessory power supply unit A131 and the accessory power supply unit B132 may be configured to convert to other voltages.

[0021] The accessory power supply unit A131 is a power supply circuit with low self-consumption power, composed of an LDO or the like. The accessory power supply unit B132 is composed of a DC / DC converter or the like and can supply a larger current than the accessory power supply unit A131. Note that the self-consumption power of the accessory power supply unit B132 is larger than that of the accessory power supply unit A131. Therefore, when the load current is small, the accessory power supply unit A131 is more efficient than the accessory power supply unit B132, and when the load current is large, the accessory power supply unit B132 is more efficient than the accessory power supply unit A131. The camera control unit A101 controls the on / off of the voltage outputs of the accessory power supply unit A131 and the accessory power supply unit B132 according to the operating state of the accessory 200.

[0022] The protection unit 133 is composed of a current fuse element, a polyswitch element, or an electronic fuse unit formed by combining a resistor, an amplifier, and a switch element. The protection unit 133 outputs an overcurrent detection signal DET_OVC when the power supply current value supplied from the accessory power supply unit A131 or the accessory power supply unit B132 to the accessory 200 exceeds a predetermined value and becomes excessive (abnormal). The protection unit 133 is an electronic fuse as an example and notifies the camera control unit A101 with the overcurrent detection signal DET_OVC when a current of 1 A or more flows. The overcurrent detection signal DET_OVC indicates an overcurrent by a high level. Note that the configuration may be different from 1 A for the predetermined value.

[0023] The camera-side connection part 141 is a connector for making an electrical connection with the accessory 200 via 21 contacts TC01 to TC21 arranged in a row. The contacts TC01 to TC21 are arranged in this order from one end to the other end in the arrangement direction. The contact TC01 is connected to the ground (GND) and serves not only as a reference potential contact but also as a contact for controlling the wiring impedance of the differential signal D1N and the differential signal D1P. The contact TC01 corresponds to the third ground contact.

[0024] The differential signal D1N connected to the contact TC02 and the differential signal D1P connected to the contact TC03 are differential data communication signals that pair with each other to perform data communication, and are connected to the camera control unit B102. The contacts TC02, TC03, and the contacts TC07 to TC17, TC19, and TC20 described later are communication contacts.

[0025] The contact TC04 as the first ground contact is connected to GND and serves as the reference potential contact between the camera 100 and the accessory 200. The contact TC04 is arranged outside the contact TC05 in the contact arrangement direction. The accessory power supply VACC generated by the accessory power supply units A131 and B132 is connected to the contact TC05 as the power supply contact via the protection unit 133.

[0026] The accessory mounting detection signal / ACC_DET is connected to the contact TC06 as the mounting detection contact. The accessory mounting detection signal / ACC_DET is pulled up to the camera microcomputer power supply VMCU_C via a resistance element Rp134 (for example, 10 kΩ). The camera control unit A101 can detect the presence or absence of the accessory 200 by reading the signal level of the accessory mounting detection signal / ACC_DET. If the signal level (potential) of the accessory mounting detection signal / ACC_DET is at the Hi level (predetermined potential), it is detected that the accessory 200 is not mounted, and if it is at the Lo level (GND potential as described later), it is detected that the accessory 200 is in the mounted state.

[0027] When the power of the camera 100 is turned on, the change of the signal level (potential) of the accessory mounting detection signal / ACC_DET from the Hi level to the Lo level serves as a trigger, and various transmissions via contacts are performed between the camera 100 and the accessory 200.

[0028] In response to detecting that the accessory 200 is in the mounted state, the camera control unit A101 supplies power to the accessory 200 via the TC05 as the power supply contact.

[0029] SCLK (Serial Clock) is connected to contact point TC07. MOSI (Master Out Slave In) is connected to contact point TC08. MISO (Master In Slave Out) is connected to contact point TC09. SS (Slave Select) is connected to TC10. SCLK, MOSI, MISO, and CS are signals for the camera control unit B102 to perform SPI (Serial Peripheral Interface) (registered trademark) communication as a communication master. In this embodiment, it is assumed that the communication clock frequency of SPI communication is 1 MHz, the data length is 8 bits (1 byte), the bit order is MSB first, and it is a full-duplex communication method.

[0030] A communication request signal / WAKE for the camera control unit A101 to request communication from the accessory 200 is connected to contact point TC11. The communication request signal / WAKE is pulled up to the camera microcomputer power supply VMCU_C via a resistor. The camera control unit A101 can receive a communication request from the accessory 200 by detecting the falling edge of the communication request signal / WAKE.

[0031] The signals SDA connected to the contact TC12 and the signal SCL connected to the contact TC13 are signals for the camera control unit A101 to perform I2C (Inter-Integrated Circuit) (registered trademark) communication as a communication master. The signals SDA and SCL have an open-drain output specification pulled up to the camera microcontroller power supply VMCU_C. Assume that the communication frequency of this communication is 100 kbps. In I2C communication, data transmission from the camera 100 and data transmission from the accessory 200 are both performed via SDA. Comparing SPI communication and I2C communication, I2C communication has a lower communication speed than SPI communication. Also, since SPI communication has a higher communication speed than I2C communication, it is suitable for communicating information with a large amount of data. Therefore, in the communication between the camera 100 and the accessory 200 in this embodiment, information with a large amount of data is communicated using SPI communication, and information with a small amount of data is communicated using I2C communication. For example, first, data is communicated using I2C communication, and when SPI communication is executable or necessary based on this data, further control can be performed to execute SPI communication.

[0032] Figures 17(a) and (b) are diagrams showing an example of I2C communication waveforms. Figure 17(a) shows an example of a waveform when the camera transmits N bytes of data (DATA[1] to DATA[N]) to the accessory. Figure 17(b) shows an example of a waveform when the camera receives N bytes of data (DATA[1] to DATA[N]) from the accessory.

[0033] In both Figures 17(a) and (b), the upper waveform shows the waveform of the signal SCL, and the lower waveform shows the waveform of the signal SDA.

[0034] Below the waveform of the signal SDA, it shows the meaning indicated by the signal SDA at each timing and whether the control unit controlling the output level of the signal SDA is the camera control unit A101 or the accessory control unit 201.

[0035] In addition, since the communication data is composed of 1-byte data and 1-bit information indicating a response, for easier understanding, the byte number of the data starting from the communication start is shown at the top of each of FIGS. 17(a) and (b).

[0036] Since the details of the communication content will be described in the flowcharts of FIGS. 18 to 20, FIGS. 17(a) and (b) will explain the outline.

[0037] In FIG. 17(a), in the communication of the 1st byte and the 2nd byte, the camera control unit A101 notifies the accessory control unit 201 of the storage address information of the data to be transmitted. In the communication from the 3rd byte to the (N + 2)th byte, the camera control unit A101 transmits N bytes of data (DATA[ADDRESS] to DATA[ADDRESS + N]) to the accessory control unit 201.

[0038] In FIG. 17(b), in the communication of the 1st byte and the 2nd byte, the camera control unit A101 notifies the accessory control unit 201 of the storage address information of the data to be received. In the communication from the 3rd byte to the (N + 3)th byte, the camera control unit A101 receives N bytes of data (DATA[ADDRESS] to DATA[ADDRESS + N]) from the accessory control unit 201.

[0039] Next, the flowcharts of FIGS. 18 to 20 will be described.

[0040] FIG. 18 is a flowchart showing the processing performed by the camera control unit A101 when transmitting N bytes of data from the camera control unit A101 to the accessory control unit 201. This processing is realized by the CPU in the camera control unit A101 expanding and executing the program stored in the ROM in the camera control unit A101 in the RAM (both not shown) in the camera control unit A101.

[0041] In step S3001, the camera control unit A101 stores a numerical value indicating the number of bytes to be transmitted in the variable NC. For example, when transmitting 3 bytes, 3 is stored in the variable NC. In this embodiment, it is assumed that 3 is stored in the variable NC.

[0042] In step S3002, the camera control unit A101 changes SDA to the Lo level while SCL is at the Hi level (START condition). Thereby, the accessory control unit 201 is notified of the start of communication.

[0043] In step S3003, the camera control unit A101 sets the slave address information indicating the slave address of the accessory control unit 201 in the upper 7 bits of the transmission data. In this embodiment, it is assumed that the slave address of the accessory control unit 201 is 1010000 in binary.

[0044] In step S3004, the camera control unit A101 sets the information indicating that it is a WRITE communication in the lower 1 bit of the transmission data. Setting 0 in this bit means that it is a WRITE communication.

[0045] In step S3005, the camera control unit A101 transmits the data (10100000 in binary, 0xA0 in hexadecimal) set as the transmission data in steps S3003 and S3004 to the accessory control unit 201.

[0046] In step S3006, the camera control unit A101 outputs SCL for 1 clock after transmitting 1 byte of data and checks the signal level of SDA. When the signal level of SDA is Lo, the camera control unit A101 determines that it is a data reception notification (ACK) from the accessory control unit 201 and proceeds to step S3007. On the other hand, when the signal level of SDA is Hi, the camera control unit A101 determines that the accessory control unit 201 has not received the data normally and proceeds to step S3014.

[0047] In step S3007, the camera control unit A101 sets, as transmission data, information on the storage address (start address information) of the data to be transmitted to the accessory control unit 201. In the present embodiment, it is assumed that the size of the start address information is 1 byte and the value is 0x00.

[0048] In step S3008, the camera control unit A101 transmits the set 1-byte start address information (value 0x00) to the accessory control unit 201. In step S3009, after transmitting the 1-byte start address information data, the camera control unit A101 outputs SCL for one clock and checks the signal level of SDA. If the signal level of SDA is Lo, the camera control unit A101 determines that it is a data reception notification (ACK) from the accessory control unit 201 and proceeds to step S3010. On the other hand, if the signal level of SDA is Hi, the camera control unit A101 determines that the accessory control unit 201 has not received the data normally and proceeds to step S3014.

[0049] In step S3010, the camera control unit A101 stores 1 in the variable MC. The variable MC is a variable for counting the number of transmission data. In step S3011, the camera control unit A101 outputs SCL for one byte and changes SDA to a desired signal level while SCL is Lo, thereby transmitting 1 byte of data to the accessory control unit 201. Here, since the start address information is 0x00 and the variable MC is 1, the camera control unit A101 transmits 1 byte of data corresponding to the address 0x00.

[0050] In step S3012, after transmitting the 1-byte data, the camera control unit A101 outputs SCL for one clock and checks the signal level of SDA. If the signal level of SDA is Lo, the camera control unit A101 determines that it is a data reception notification (ACK) from the accessory control unit 201 and proceeds to step S3013. On the other hand, if the signal level of SDA is Hi, the camera control unit A101 determines that the accessory control unit 201 has not received the data normally and proceeds to step S3014.

[0051] In step S3013, the camera control unit A101 determines whether the variable MC has the same value as the variable NC. If the variable MC has the same value as the variable NC, the camera control unit A101 determines that the transmission of all data is completed and proceeds to step S3014. If the variable MC does not have the same value as the variable NC, the camera control unit A101 determines that there is still data to be transmitted and proceeds to step S3015.

[0052] In step S3015, the camera control unit A101 adds 1 to the variable MC and returns to step S3011. In this way, after returning to step S3011, the camera control unit A101 sequentially increments the address of the data to be transmitted and transmits 1-byte data corresponding to each address.

[0053] By repeatedly transmitting 1-byte data in the process of step S3013 until the variable MC and the variable NC have the same value, the camera control unit A101 transmits N bytes of data to the accessory control unit 201. When the variable NC is set to 3 as in this embodiment, 3-byte data transmission can be performed.

[0054] In step S3014, the camera control unit A101 changes SDA to the Hi level while SCL is at the Hi level (STOP condition). Thereby, the accessory control unit 201 is notified of the end of communication.

[0055] FIG. 19 is a flowchart showing the processing performed by the camera control unit A101 when the camera control unit A101 receives N bytes of data from the accessory control unit 201. This processing is realized by the CPU in the camera control unit A101 expanding and executing a program stored in the ROM in the camera control unit A101 in the RAM (both not shown) in the camera control unit A101.

[0056] In step S3101, the camera control unit A101 stores a numerical value indicating the number of received bytes in the variable ND. For example, when receiving 3 bytes, 3 is stored in the variable ND. In this embodiment, it is assumed that 3 is stored in the variable ND. In steps S3102 to S3106, the camera control unit A101 executes the same processes as steps S3002 to S3006 respectively.

[0057] In step S3107, the camera control unit A101 sets the information (start address information) of the storage address of the data received from the accessory control unit 201 as transmission data. In this embodiment, it is assumed that the size of the start address information is 1 byte and the value is 0x00. In step S3108, the camera control unit A101 transmits the set 1-byte start address information (value 0x00) to the accessory control unit 201.

[0058] In step S3109, after transmitting the 1-byte start address information data, the camera control unit A101 outputs SCL for one clock and checks the signal level of SDA. If the signal level of SDA is Lo, the camera control unit A101 determines that it is a data reception notification (ACK) from the accessory control unit 201 and proceeds to step S3110. On the other hand, if the signal level of SDA is Hi, the camera control unit A101 determines that the accessory control unit 201 has not received the data normally and proceeds to step S3122.

[0059] In step S3110, similar to step S3102, the camera control unit A101 changes SDA to the Lo level while SCL is at the Hi level to notify the accessory control unit 201 of the START condition. In step S3111, the camera control unit A101 sets the slave address information indicating the slave address of the accessory control unit 201 in the upper 7 bits of the transmission data. In this embodiment, it is assumed that the slave address of the accessory control unit 201 is 1010000 in binary.

[0060] In step S3112, the camera control unit A101 sets information indicating that it is a READ communication in the lower 1 bit of the transmission data. Setting 1 in this bit means it is a READ communication.

[0061] In step S3113, the camera control unit A101 transmits the data (binary 10100001, hexadecimal 0xA1) set as the transmission data in steps S3103 and S3104 to the accessory control unit 201.

[0062] In step S3114, after transmitting 1 byte of data, the camera control unit A101 outputs SCL for 1 clock and checks the signal level of SDA. If the signal level of SDA is Lo, the camera control unit A101 determines that it is a data reception notification (ACK) from the accessory control unit 201 and proceeds to step S3115. On the other hand, if the signal level of SDA is Hi, the camera control unit A101 determines that the accessory control unit 201 has not received the data normally and proceeds to step S3122.

[0063] In step S3115, the camera control unit A101 stores 1 in the variable MD. The variable MD is a variable for counting the number of received data. In step S3116, the camera control unit A101 outputs SCL for 1 byte and reads the signal level of SDA at the timing when SCL changes from Lo to Hi. As a result, it becomes possible to receive 1 byte of data from the accessory control unit 201. The received 1-byte data can be stored in the volatile memory 125 or used for a predetermined process as the data corresponding to the address 0x00.

[0064] In step S3117, the camera control unit A101 determines whether 1 byte of data has been received normally. If it has been received normally, the camera control unit A101 proceeds to step S3118; if not, it proceeds to step S3119.

[0065] In step S3118, the camera control unit A101 determines whether the variable MD has the same value as the variable ND. If the variable MD has the same value as the variable ND, the camera control unit A101 determines that the reception of all data is completed and proceeds to step S3119. If the variable MD does not have the same value as the variable ND, the camera control unit A101 determines that there is still received data remaining and proceeds to step S3120.

[0066] In step S3120, the camera control unit A101 outputs one byte of SCL and controls SDA to the Lo level to send a data reception notification (ACK) to the accessory control unit 201 and notify it to continue data communication. In step S3121, the camera control unit A101 adds 1 to the variable MD and returns to step S3116. In this way, after returning to step S3116, the camera control unit A101 sequentially increments the address of the data to be received and receives one-byte data corresponding to each address.

[0067] By repeating the reception of one-byte data in the process of step S3118 until the variable MD and the variable ND have the same value, the camera control unit A101 receives N bytes of data from the accessory control unit 201. When the variable ND is set to 3 as in this embodiment, it is possible to receive 3 bytes of data.

[0068] In step S3119, the camera control unit A101 outputs one byte of SCL and controls SDA to the Hi level to notify the accessory control unit 201 that the data communication is completed (NACK). In step S3122, the camera control unit A101 changes SDA to the Hi level while SCL is at the Hi level (STOP condition). Thereby, the accessory control unit 201 is notified of the end of the communication.

[0069] FIG. 20 is a flowchart showing the processing performed by the accessory control unit 201 when N-byte data is transmitted and received between the camera control unit A101 and the accessory control unit 201. This processing includes the processing in which the accessory control unit 201 receives N-byte data from the camera control unit A101, and the processing in which the accessory control unit 201 transmits N-byte data to the camera control unit A101.

[0070] This processing is realized by the CPU in the accessory control unit 201 expanding and executing the program stored in the ROM in the accessory control unit 201 in the RAM (not shown in either case) in the accessory control unit 201.

[0071] In step S3201, the accessory control unit 201 waits for SDA to change to the Lo level (becoming the START condition) while SCL is at the Hi level. When the accessory control unit 201 detects the START condition, it proceeds to step S3202.

[0072] In step S3202, the accessory control unit 201 stores 0 in the variable ME. The variable ME is a variable for counting the number of transmitted and received data. In step S3203, the accessory control unit 201 receives 1-byte data transmitted from the camera control unit A101.

[0073] In step S3204, the accessory control unit 201 determines whether the upper 7-bit data of the 1-byte data received in step S3203 matches the slave address (0x50 in this embodiment) of the accessory control unit 201. If the upper 7-bit data matches the slave address of the accessory control unit 201, the accessory control unit 201 proceeds to step S3205. If the upper 7-bit data does not match the slave address of the accessory control unit 201, the accessory control unit 201 proceeds to step S3221.

[0074] In step S3205, the accessory control unit 201 controls SDA to the Lo level for the next SCL clock output after receiving one byte, thereby performing a data reception notification (ACK) to the camera control unit A101. In step S3206, the accessory control unit 201 determines the type of data for the next one-byte communication based on the lower 1-bit data of the one-byte data received in step S3203. When the lower 1-bit data is 0 (WRITE), the accessory control unit 201 determines that the data for the next one-byte communication is the start address information from the camera control unit A101 to the accessory control unit 201, and proceeds to step S3207. When the lower 1-bit data is 1, the accessory control unit 201 determines that the data for the next one-byte communication is the transmission data from the accessory control unit 201 to the camera control unit A101, and proceeds to step S3209.

[0075] In step S3207, the accessory control unit 201 receives one byte of data transmitted from the camera control unit A101. The received one-byte data is information (start address information) indicating the address where the data to be transmitted and received in subsequent communications is stored. In the present embodiment, as described with reference to FIGS. 18 and 19, it is assumed that the start address information is 0x00.

[0076] In step S3209, the accessory control unit 201 sets, as the start address information, the address information previously stored in the accessory control unit 201 or the address information previously notified from the camera control unit A101.

[0077] In step S3208, if the accessory control unit 201 determines that one byte of data has been received normally, it proceeds to step S3210; if it determines that one byte of data has not been received normally, it proceeds to step S3221. In step S3210, the accessory control unit 201 controls SDA to the Lo level for the next SCL clock output after receiving one byte of data, thereby performing a data reception notification (ACK) to the camera control unit A101.

[0078] In step S3211, the accessory control unit 201 determines whether SDA has changed to the Lo level (resulting in a START condition) while SCL is at the Hi level. If a START condition is detected, the accessory control unit 201 can determine that the data for the next communication byte is data to be transmitted from the camera control unit A101 to the accessory control unit 201. That is, the accessory control unit 201 determines that the data for the next communication byte is data indicating the slave address and communication type, and proceeds to step S3212. If a START condition is not detected, the accessory control unit 201 determines that the data for the next communication byte is data to be received by the accessory control unit 201 from the camera control unit A101, and proceeds to step S3216.

[0079] In step S3212, the accessory control unit 201 receives one byte of data transmitted from the camera control unit A101. In step S3213, the accessory control unit 201 determines whether the upper 7-bit data of the one-byte data received in step S3212 matches the slave address of the accessory control unit 201 (0x50 in this embodiment). If the upper 7-bit data matches the slave address of the accessory control unit 201, the accessory control unit 201 proceeds to step S3214. If the upper 7-bit data does not match the slave address of the accessory control unit 201, the accessory control unit 201 proceeds to step S3221.

[0080] In step S3214, the accessory control unit 201 determines the type of data for the next one-byte communication based on the lower 1-bit data of the one-byte data received in step S3203. If the lower 1-bit data is 0, the accessory control unit 201 proceeds to step S3221. If the lower 1-bit data is 1 (READ), the accessory control unit 201 determines that the data for the next one-byte communication is data to be transmitted from the accessory control unit 201 to the camera control unit A101, and proceeds to step S3215.

[0081] In step S3215, the accessory control unit 201 controls SDA to the Lo level in response to the next SCL clock output after receiving 1 byte, thereby notifying the camera control unit A101 of data reception (ACK). In step S3222, the accessory control unit 201 transmits 1 byte of data corresponding to the start address information received from the camera control unit A101 in step S3207 or the start address information set in step S3209 to the camera control unit A101.

[0082] In step S3223, the accessory control unit 201 adds 1 to the variable ME and proceeds to step S3224. In step S3224, the accessory control unit 201 checks the signal level of SDA after transmitting 1 byte of data. If the signal level of SDA is Hi, the accessory control unit 201 determines that it is a notification (NACK) that the camera control unit A101 has completed receiving all the data and proceeds to step S3225. On the other hand, if the signal level of SDA is Hi, the accessory control unit 201 determines that the camera control unit A101 is still requesting data transmission from the accessory control unit 201 and returns to step S3222.

[0083] In this way, after returning to step S3222, the accessory control unit 201 sequentially increments the address of the data to be transmitted and transmits 1 byte of data corresponding to each address. By repeatedly transmitting 1 byte of data in this manner until a NACK is notified from the camera control unit A101 in the process of step S3224, the accessory control unit 201 transmits N bytes of data to the camera control unit A101.

[0084] In step S3225, the accessory control unit 201 waits for SDA to change to the Hi level (becoming a STOP condition) while SCL is at the Hi level. When the accessory control unit 201 detects a STOP condition, it terminates the communication.

[0085] In step S3216, the accessory control unit 201 receives one-byte data. This one-byte data is stored in a non-volatile memory (not shown) or used for a predetermined process as data corresponding to the start address information received from the camera control unit A101 in step S3207.

[0086] In step S3217, the accessory control unit 201 adds 1 to the variable ME and proceeds to step S3218. In step S3218, the accessory control unit 201 determines whether one-byte data has been received normally. If the accessory control unit 201 determines that one-byte data has been received normally, it proceeds to step S3219. If it determines that one-byte data has not been received normally, it proceeds to step S3221.

[0087] In step S3219, the accessory control unit 201 notifies the camera control unit A101 of data reception (ACK) by controlling SDA to the Lo level in response to the next SCL clock output after receiving one byte. In step S3220, the accessory control unit 201 determines whether SDA has changed to the Hi level (resulting in a STOP condition) while SCL is at the Hi level. If the accessory control unit 201 detects a STOP condition, it terminates the communication. On the other hand, if the accessory control unit 201 does not detect a STOP condition, it determines that data will continue to be transmitted from the camera control unit A101 to the accessory control unit 201 and returns to step S3216.

[0088] In this way, after returning to step S3216, the accessory control unit 201 sequentially increments the address of the data to be received and receives one-byte data corresponding to each address. By repeatedly receiving one-byte data until a STOP condition is notified in step S3220 in this manner, the accessory control unit 201 receives N bytes of data from the camera control unit A101.

[0089] The FNC1 signal connected to contact point TC14, the FNC2 signal connected to contact point TC15, the FNC3 signal connected to contact point TC16, and the FNC4 signal connected to contact point TC17 are functional signals whose functions can be variably changed according to the type of the attached accessory 200. For example, when the accessory 200 is a microphone device, the signal communicated via contact point TC15 becomes an audio data signal. Also, when the accessory 200 is a lighting device (strobe unit), the signal communicated via contact point TC14 becomes a signal for notifying the light emission timing (strobe light emission timing signal).

[0090] Note that signals realizing different functions may be communicated via the same contact point depending on the type of the attached accessory (accessory type). For example, when the accessory 200 is an accessory other than lighting, a synchronization signal for controlling a timing different from the light emission timing may be communicated via TC14. TC14 to TC17 correspond to functional signal contact points. Communication using at least any one of the functional signal contact points is also referred to as functional signal communication. Functional signal communication can execute communication at a timing independent of I2C communication and SPI communication in parallel with I2C communication and SPI communication.

[0091] The accessory type (type) mentioned here refers to the above-described microphone device, lighting device, etc. Accessories that realize the same-purpose functions, such as different lighting devices with different performances, are accessories of the same type. Accessories that realize functions with different purposes, such as a microphone device and a lighting device, are accessories of different types. Functional signal communication is executed based on information acquired by I2C communication or SPI communication.

[0092] The contact TC18 as the second ground contact is also connected to GND, and like the contact TC04, it is a contact that serves as the reference potential for the camera 100 and the accessory 200. The differential signal D2N connected to the contact TC19 and the differential signal D2P connected to the contact TC20 are data communication signals that pair with each other to perform data communication and are connected to the camera control unit B102. Through TC19 and TC20, for example, USB communication can be performed.

[0093] The contact TC21 is connected to GND and not only serves as a reference potential contact but also serves as a contact for controlling the wiring impedance of the differential signal D2N and the differential signal D2P. The contact TC21 corresponds to the fourth ground contact. The contacts TC01, TC04, TC06, TC18, and TC21 are connected to the GND portion of the flexible substrate, for example, and the GND portion of the flexible substrate is fixed to a metallic member having the GND level of the camera 100 with screws or the like. Examples of the metallic member having the GND level include an engagement member that engages with the accessory 200 in the accessory attachment portion and a base plate (not shown) inside the camera 100.

[0094] In the present embodiment, a mounting detection contact TC06 to which an accessory mounting detection signal / ACC_DET is connected is arranged adjacent to a contact (first clock contact) TC07 that transmits an SCLK (first clock signal) which is a clock signal. Generally, noise (clock noise) associated with the potential fluctuation of the clock signal is transmitted to a contact adjacent to the contact of the clock signal, which can be a cause of malfunction. In particular, in a configuration where the number of contacts is large and the distance between contacts is short as in the present embodiment, the influence becomes greater. Therefore, by arranging the mounting detection contact TC06 adjacent to the SCLK contact TC07, the influence of clock noise can be suppressed.

[0095] The accessory attachment detection signal / ACC_DET is pulled up before the accessory is attached, but is set to the GND potential after the accessory is attached. On the other hand, the SCLK contact TC07 that transmits the clock signal does not transmit the clock signal before the accessory is attached, so there is no potential fluctuation, and the potential fluctuates only after the accessory is attached in order to transmit the clock signal.

[0096] When the SCLK contact TC07 transmits the clock signal, the attachment detection contact TC06 is at the GND potential. Therefore, even if the attachment detection contact TC06 receives clock noise, the potential of the control units of the camera 100 and the accessory 200 is less likely to fluctuate, so malfunction can be prevented. Also, it is possible to suppress the transmission of clock noise to a position farther away from the attachment detection contact TC06. As a result, it is not necessary to arrange the GND terminal, so the influence of clock noise can be suppressed without increasing the number of contacts.

[0097] Also, an SCL (second clock signal) as a clock signal is transmitted to the contact (second clock contact) TC13. However, the SCLK transmitted to the SCLK contact TC07 has a higher frequency than the SCL, and more clock noise is generated from the SCLK contact TC07 than from the SCL contact TC13. For this reason, it is more effective to prevent malfunction due to clock noise by arranging the attachment detection contact TC06 next to the SCLK contact TC07 rather than next to the SCL contact TC13.

[0098] Furthermore, not only is there a difference in frequency, but the SCL transmitted at the SCL contact TC13 is a clock signal of the I2C communication standard, and the voltage fluctuation of the signal line is driven by an open drain connection. On the other hand, the SCLK transmitted at the SCLK contact TC07 is a clock signal of the SPI communication standard, and the voltage fluctuation of the signal line is driven by a CMOS output. For this reason, the edge of the voltage fluctuation of the SCL contact TC13 is more likely to be gentle compared to the SCLK contact TC07, and clock noise is less likely to occur. Therefore, it is more effective to prevent malfunction due to clock noise by arranging the attachment detection contact TC06 next to the SCLK contact TC07 rather than next to the SCL contact TC13.

[0099] Also, differential signals D1N and D1P may be transmitted in pairs to the first and second differential signal contacts TC19 and TC20, and a clock signal may be transmitted. At this time, a clock signal (third clock signal) having a higher frequency than the SCLK contact TC07 or the SCL contact TC13 may be transmitted. However, since the differential signals D1N and D1P are paired signals, the radiation of clock noise is less than that of the SCLK contact TC07 or the SCL contact TC13 that transmits single-ended signals. Therefore, arranging the mounting detection contact TC06 next to the SCLK contact TC07 rather than next to the first and second differential signal contacts TC19 and TC20 has a greater effect of preventing malfunction due to clock noise.

[0100] Note that a contact (first data contact) TC08 arranged next to the mounting detection contact TC06 on the opposite side of the SCLK contact TC07 transmits MOSI (first data signal). Since MOSI is a data signal, it seems to be easily affected by clock noise. However, since MOSI is a data signal of the same SPI communication standard as the clock signal transmitted at the SCLK contact TC07, the potential fluctuation timing is synchronized with the clock signal, and it is not easily affected by clock noise. Therefore, the contact TC08 does not have to be fixed to the GND potential and can be used as a MOSI contact.

[0101] The accessory 200 has a battery 205, receives power supply from the battery 205, and also receives power supply from the camera 100 via the camera-side connection portion 141 and the accessory-side connection portion 211. The accessory control unit 201 is composed of a microcomputer incorporating a CPU or the like and controls the entire accessory 200.

[0102] The accessory power supply unit 202 is composed of a DC-DC converter, an LDO, a charge pump, etc., and generates electric power for supplying each part of the accessory 200. A voltage of 1.8V generated by the accessory power supply unit 202 is constantly supplied to the accessory microcomputer power supply VM CU_A to the accessory control unit 201. Note that the configuration may be such that the voltage generated by the accessory power supply circuit 202 is a value different from 1.8V. The accessory control unit 201 controls the on / off of the power supply to each part of the accessory 200 by controlling the accessory power supply unit 202.

[0103] The charging unit 204 is a circuit unit for charging the battery 205 using the electric power supplied from the camera 100. The accessory control unit 201 controls the charging unit 204 to charge the battery 205 when it can be determined that sufficient electric power is supplied from the camera 100 to perform the charging operation. Note that in the present embodiment, the case where the battery 205 is mounted on the accessory 200 will be described, but the accessory 200 may operate only with power supplied from the camera 100 without the battery 205 being mounted. In this case, the charging unit 204 becomes unnecessary.

[0104] The differential communication unit 207 is a circuit for performing differential communication with the camera 100 and can transmit and receive data to and from the camera 100. The external communication IF unit 208 is an IF (interface) for performing data communication with an external device (not shown), such as an Ethernet communication IF, a wireless LAN communication IF, and a public network communication IF.

[0105] The accessory control unit 201 can transmit the data received from the camera 100 to an external device or transmit the data received from the external device to the camera 100 by controlling the differential communication unit 207 and the external communication IF unit 208. The functional unit 206 is a circuit unit that exhibits different functions according to the type of the accessory 200. For example, when the accessory 200 is a strobe device, a light emitting unit and its charging unit, etc. exist inside the functional unit 206. Also, when the accessory 200 is a microphone device, an audio codec unit, a microphone unit, etc. exist inside the functional unit 206.

[0106] The external connection terminal 209 is a connector terminal for connecting to an external device. As an example, it is a USB TYPE-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 control unit 201 can detect the connection of an external device to the external connection terminal 209 by receiving the output signal of the connection detection unit 210. The power switch 203 is a switch for turning on and off the operation of the accessory 200. The accessory control unit 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.

[0107] The operation switch 212 is an operator 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. When the accessory control unit 201 detects that the operation switch 212 is operated, it executes a predetermined process according to the operation.

[0108] The accessory side connection part 211 is a connector for making an electrical connection with the camera 100 via 21 contacts TA01 to TA21 arranged in a row. The contacts TA01 to TA21 are arranged in this order from one end to the other end in the arrangement direction thereof.

[0109] The contact TA01 is connected to GND, and serves not only as a reference potential contact but also as a contact for controlling the wiring impedance of the differential signal D1N and the differential signal D1P. The contact TA01 corresponds to the third ground contact.

[0110] The differential signal D1N connected to the contact TA02 and the differential signal D1P connected to the contact TA03 are data communication signals that perform data communication in pairs with each other. The contacts TA02 and TA03 are connected to the differential communication unit 207. The contacts TA02, TA03, TA07 to TA17, TA19, and TA20 are all communication contacts.

[0111] The contact TA04 as the first ground contact is connected to GND and serves as the reference potential contact for the camera 100 and the accessory 200. The contact TA04 is arranged outside in the contact arrangement direction compared to the contact TA05. The accessory power supply unit 202 and the charging unit 204 are connected to the contact TA05 as the power supply contact, and the accessory power supply VACC supplied from the camera 100 is connected thereto.

[0112] The contact TA06 as the attachment detection contact is directly connected to GND. When the accessory 200 is attached to the camera 100, the contact TA06 makes the accessory attachment detection signal / ACC_DET the GND level (ground potential) at the Lo level, serving as the contact for detecting the attachment of the accessory 200 to the camera 100.

[0113] The SCLK connected to the contact TA07, the MOSI connected to the contact TA08, the MISO connected to the contact TA09, and the CS connected to TA10 are signals for the accessory control unit 201 to perform SPI communication as a communication slave.

[0114] The communication request signal / WAKE for the accessory control unit 201 to request communication with the camera 100 is connected to the contact TA11. When the accessory control unit 201 determines that communication with the camera 100 is necessary, it requests communication with the camera 100 by outputting the communication request signal / WAKE at the Lo level.

[0115] In response to detecting that the accessory 200 is in the attached state, power is supplied from the camera control unit A101 to the accessory 200 via TC5. Then, the accessory control unit 201 notifies the camera control unit A101 that it has received the power supply by changing the signal level (potential) of the communication request signal / WAKE from the Hi level to the Lo level.

[0116] Even when there is no request from the camera 100, the accessory control unit 201 can notify that a factor for the accessory 200 to communicate with the camera 100 has occurred by changing the signal level (potential) of the communication request signal / WAKE from the Hi level to the Lo level. With this configuration, the camera control unit A101 can omit the operation of periodically checking whether a factor for communicating with the accessory 200 has occurred by polling. Also, when a factor for communication occurs, the accessory 200 can communicate that fact to the camera 100 in real time.

[0117] SDA connected to the contact TA12 and SCL connected to the TA13 are signals for the accessory control unit 201 to function as a communication slave and perform I2C communication.

[0118] The FNC1 signal connected to the contact TA14, the FNC2 signal connected to the TA15, the FNC3 signal connected to the TA16, and the FNC4 signal connected to the TA17 are function signals whose functions can be made variable according to the type of the accessory 200. For example, when the accessory 200 is a microphone device, these function signals become voice data signals, and when the accessory 200 is a strobe unit, they become strobe emission timing signals for notifying the emission timing.

[0119] The contact TA18 as the second ground contact is also connected to GND, and like the contact TA04, it becomes a contact for the reference potential between the camera 100 and the accessory 200. The differential signal D2N connected to the contact TA19 and the differential signal D2P connected to the TA20 are data communication signals that pair with each other to perform data communication and are connected to the external connection terminal 209.

[0120] The contact TA21 is connected to GND and serves not only as a contact for the reference potential but also as a terminal for controlling the wiring impedance of the differential signal D2N and the differential signal D2P. The contact TA21 corresponds to the fourth ground contact.

[0121] The contacts TA01, TA04, TA06, TA18, and TA21 are connected to the GND part of the flexible substrate, for example, and the GND part of the flexible substrate is fixed to a metallic member that becomes the GND level of the accessory 200 with a screw or the like (not shown). The metallic member that becomes the GND level is, for example, a screw mounting leg that engages with the accessory attachment part of the camera 100 or a base plate (not shown) inside the accessory 200.

[0122] In the present embodiment, the camera 100 and the accessory 200 can support two types of communication protocols as the SPI communication method. Among these, the first communication protocol is a method in which the camera 100 does not check whether the accessory 200 is in a communicable state before outputting the SCLK signal, and in the present embodiment, this is referred to as SPI protocol A. The second communication protocol is a method in which the camera 100 checks whether the accessory 200 is in a communicable state before outputting the SCLK signal, and in the present embodiment, this is referred to as SPI protocol B.

[0123] The camera 100 may incorporate built-in accessories 151 and 152. For example, the built-in accessories 151 and 152 are a built-in microphone and a built-in flash, respectively. The number of built-in accessories provided is not limited.

[0124] Figure 2(a) is a diagram showing an outline of the communication waveform of SPI protocol A. Figure 2(b) is a diagram showing an outline of the communication waveform of SPI protocol B. In Figures 2(a) and (b), the CS signal is active low.

[0125] First, as shown in Figure 2(a), in SPI protocol A, the camera control unit B102 changes the CS signal to the Lo level at timing A1 and requests SPI communication from the accessory control unit 201.

[0126] At timing A2 after a predetermined time T_CS has elapsed since timing A1, camera control unit B102 starts outputting the SCLK signal and the MOSI signal. Similarly, when accessory control unit 201 detects a falling edge of the SCLK signal, it starts outputting the MISO signal.

[0127] Camera control unit B102 stops SCLK output at timing A3 when the SCLK output for one byte is completed. Camera control unit B102 stops SCLK output until a predetermined time T_INTERVAL has elapsed since timing A3, resumes SCLK output at timing A4 when the predetermined time T_INTERVAL has elapsed, and performs the next one-byte communication.

[0128] Figure 3(a) is a flowchart showing the processing of camera control unit B102 in SPI protocol A. This processing is realized by the CPU in camera control unit B102 expanding and executing a program stored in the ROM in camera control unit B102 in the RAM (both not shown) in camera control unit B102.

[0129] In step S101, camera control unit B102 stores a numerical value indicating the number of bytes to be communicated in variable NA. For example, when communicating 3 bytes, 3 is stored in variable NA. In step S102, camera control unit B102 changes the CS signal to the Lo level to request SPI communication.

[0130] In step S103, camera control unit B102 waits until a predetermined time T_CS has elapsed since the CS signal changed to the Lo level, and proceeds to step S104 after the predetermined time T_CS has elapsed. In step S104, for communicating one-byte data, camera control unit B102 controls the output of the SCLK, and also controls the output of the MOSI data and the input of the MISO data.

[0131] In step S105, the camera control unit B102 stores, as a new variable NA, a value obtained by subtracting 1 from the numerical value of the variable NA. In step S106, the camera control unit B102 determines whether the variable NA has become 0. Then, if the variable NA has become 0, the camera control unit B102 proceeds to step S107, and if the variable NA is other than 0, the camera control unit B102 proceeds to step S108.

[0132] In step S108, the camera control unit B102 waits until a predetermined time T_INTERVAL has elapsed since the communication of 1-byte data was completed in step S104, and then returns to step S104 after the predetermined time T_INTERVAL has elapsed. In step S107, the camera control unit B102 changes the CS signal to the Hi level and ends the series of SPI communications shown in Fig. 3(a).

[0133] Fig. 3(b) is a flowchart showing the processing of the accessory control unit 201 in the SPI protocol A. This processing is executed in parallel with the processing shown in Fig. 3(a). This processing is realized by the CPU in the accessory control unit 201 expanding and executing a program stored in the ROM in the accessory control unit 201 in the RAM (both not shown) in the accessory control unit 201.

[0134] In step S201, the accessory control unit 201 waits until the CS signal changes to Lo, and if the CS signal changes to Lo, it proceeds to step S202. In step S202, the accessory control unit 201 controls the input of MOSI data and the output of MISO data in response to the input of the SCLK signal, and performs the communication of 1-byte data.

[0135] In step S203, the accessory control unit 201 determines whether the CS signal has changed to Hi. Then, if the CS signal has not changed to Hi, the accessory control unit 201 returns to step S202 to perform the next 1-byte communication, and if the CS signal has changed to Hi, it ends the series of SPI communications shown in Fig. 3(b).

[0136] Next, the SPI protocol B will be described. As shown in FIG. 2(b), in the SPI protocol B, the camera control unit B102 changes the CS signal to the Lo level at timing B1 and requests SPI communication from the accessory control unit 201. Along with the communication request, the camera control unit B102 checks the potential of the MISO signal. If the MISO signal is at the Hi level, the camera control unit B102 determines that the accessory control unit 201 is in a communicable state; if the MISO signal is at the Lo level, the camera control unit B102 determines that the accessory control unit 201 is in a non - communicable state.

[0137] On the other hand, when the accessory control unit 201 detects the falling edge of the CS signal, if it is in a state where SPI communication is possible, it controls MISO to the Hi level, and if it is in a state where SPI communication is impossible, it controls MISO to the Lo level (timing B2).

[0138] At timing B3, when the camera control unit B102 confirms that the MISO signal is at the Hi level, it starts outputting the SCLK signal and the MOSI signal. Similarly, when the accessory control unit 201 detects the falling - edge change of the SCLK signal, it starts outputting the MISO signal.

[0139] At timing B4, when the camera control unit B102 completes the SCLK output for one byte, it stops the SCLK output. After the accessory control unit 201 has performed data transmission and reception for one byte, if it is in a state where SPI communication is possible, it controls the MISO signal to the Hi level, and if it is in a state where SPI communication is impossible, it controls the MISO signal to the Lo level (timings B5, B6).

[0140] At timing B7, the camera control unit B102 checks the potential of the MISO signal. Then, if the MISO signal is at the Hi level, the camera control unit B102 determines that the accessory control unit 201 is in a communicable state; if the MISO signal is at the Lo level, the camera control unit B102 determines that the accessory control unit 201 is in a non - communicable state.

[0141] Figure 4(a) is a flowchart showing the processing of the camera control unit B102 in the SPI protocol B. This processing is realized by the CPU in the camera control unit B102 expanding and executing the program stored in the ROM in the camera control unit B102 in the RAM (both not shown) in the camera control unit B102.

[0142] In step S111, the camera control unit B102 stores a numerical value indicating the number of bytes to be communicated in the variable NB. For example, when communicating 3 bytes, 3 is stored in the variable NB. In step S112, the camera control unit B102 changes the CS signal to the Lo level to request SPI communication. In step S113, the camera control unit B102 waits until the MISO signal changes to the Hi level, and if the MISO signal changes to the Hi level, it proceeds to step S114.

[0143] In step S114, for communicating 1-byte data, the camera control unit B102 controls the output of SCLK, and also controls the output of MOSI data and the input of MISO data. In step S115, the camera control unit B102 stores the value obtained by subtracting 1 from the numerical value of the variable NB as a new variable NB. In step S116, the camera control unit B102 determines whether all data communication has been completed (whether the variable NB has become 0). Here, when the variable NB becomes 0, it is determined that all data communication has been completed.

[0144] If all data communication has been completed, the camera control unit B102 proceeds to step S117; if not, it proceeds to step S118. In step S118, the camera control unit B102 waits until the MISO signal changes to the Hi level, and when the MISO signal changes to the Hi level, it returns to step S114. In step S117, the camera control unit B102 changes the CS signal to the Hi level to end the series of SPI communications shown in Figure 4(a).

[0145] Figure 4(b) is a flowchart showing the processing of the accessory control unit 201 in the SPI protocol B. This processing is executed in parallel with the processing shown in Figure 4(a). This processing is realized by the CPU in the accessory control unit 201 expanding and executing the program stored in the ROM in the accessory control unit 201 in the RAM (both not shown) in the accessory control unit 201.

[0146] In step S211, the accessory control unit 201 waits until the CS signal changes to Lo, and if the CS signal changes to Lo, it proceeds to step S212. In step S212, the accessory control unit 201 determines whether it is in a state where SPI communication is possible. If SPI communication is possible, it proceeds to step S213, and if SPI communication is not possible, it proceeds to step S214.

[0147] In step S213, the accessory control unit 201 controls the MISO signal to the Hi level and proceeds to step S215. In step S214, the accessory control unit 201 controls the MISO signal to the Lo level and returns to step S212. In step S215, the accessory control unit 201 performs input control of MOSI data and output control of MISO data in response to the SCLK signal input, and performs 1-byte data communication.

[0148] In step S216, the accessory control unit 201 determines whether the CS signal has changed to Hi. If the CS signal has not changed to Hi, the accessory control unit 201 returns to step S212 to perform the next 1-byte communication. If the CS signal has changed to Hi, the SPI communication shown in Figure 4(b) is terminated.

[0149] Figure 5 is a diagram showing the communication content when notifying the accessory 200 of an operation execution command (command) from the camera 100 by SPI communication.

[0150] In the first byte of communication, the camera control unit B102 transmits information CMD indicating the command number as MOSI data. On the other hand, the accessory control unit 201 transmits a value of 0xA5 as MISO data as information indicating a communicable state. If the accessory control unit 201 cannot execute the communication process of the first byte, it transmits a value other than 0xA5 as MISO data.

[0151] In the second byte of communication, the camera control unit B102 transmits the argument MOSI_DATA1 corresponding to the command number CMD. Similarly, from the third byte to the (N - 2)th byte and later, the camera control unit B102 transmits the arguments MOSI_DATA2 to MOSI_DATA[N - 3] corresponding to the command number CMD.

[0152] On the other hand, in the second byte of communication, the accessory control unit 201 transmits the command number CMD received in the first byte as MISO data. Thereby, the camera control unit B102 can determine that the accessory control unit 201 has received the MOSI data correctly.

[0153] In the third byte of communication, the accessory control unit 201 transmits the return value MISO_DATA1 corresponding to the command number CMD as MISO data. Similarly, from the fourth byte to the (N - 2)th byte and later, the accessory control unit 201 transmits the arguments MISO_DATA2 to MISO_DATA[N - 4] corresponding to the command number CMD. Note that the number of arguments and return values is determined in advance for each command number. Also, either the argument or the return value may be absent.

[0154] In the (N - 1)th byte of communication, the camera control unit B102 transmits 'CheckSum_C' as checksum data as MOSI data. This CheckSum_C is calculated by the camera control unit B102 from the data transmitted by the camera control unit B102 to the accessory control unit 201 using the following formula 1. On the other hand, the accessory control unit 201 transmits a value of '0x00' as MISO data.

[0155] In the N - th byte communication, the camera control unit B102 transmits '0x00' as MOSI data. On the other hand, the accessory control unit 201 transmits 'CheckSum_A' as MISO data as checksum data.

[0156] CheckSum_A is either the first CheckSum_A calculated by the following formula 2 or the second CheckSum_A calculated by the following formula 3. That is, the accessory control unit 201 calculates CheckSum_C_A from the actually received data. Then, the accessory control unit 201 determines whether the received CheckSum_C and the CheckSum_C_A calculated from the received data match. When CheckSum_C and CheckSum_C_A match, the accessory control unit 201 calculates the first CheckSum_A by the following formula 2 and transmits it to the camera control unit B102.

[0157] On the other hand, when the accessory control unit 201 determines that CheckSum_C and CheckSum_C_A do not match, it calculates the second CheckSum_A by the following formula 3 and transmits it to the camera control unit B102. CheckSum_C = EXOR(AND(SUM(CMD, MOSI_DATA1, …, MOSI_DATA[N - 3]), 0xFF), 0xFF)…(1) CheckSum_A = EXOR(AND(SUM(0xA5, CMD, MIS0_DATA1, …, MOSI_DATA[N - 4]), 0xFF), 0xFF)…(2) CheckSum_A = AND(SUM(0xA5, CMD, MIS0_DATA1, …, MOSI_DATA[N - 4]), 0xFF)…(3)

[0158] FIG. 6 is a diagram showing an example of accessory information. This accessory information is stored in a non-volatile memory (not shown) in the accessory 200. The accessory information is information for allowing the camera 100 to identify the type of the accessory 200 and the specifications regarding communication and operations (functions). The accessory information is mapped to the memory space of addresses 0x00 to 0x0F. It is possible to read the accessory information from the accessory 200 by I2C communication. In the I2C communication in the present embodiment, a checksum value for the read data is added as the final data of the communication. Details of the accessory information will be described later.

[0159] FIG. 7 is a diagram showing a sequence when the accessory 200 is attached to the camera 100. Here, an outline at the time of attaching the accessory will be described, but details of the processing by each of the camera 100 and the accessory 200 will be described later.

[0160] When the accessory 200 is attached to the camera 100, the accessory attachment detection signal / ACC_DET becomes the GND level, and the camera control unit A101 determines that the accessory 200 has been attached. When it is determined that the accessory 200 has been attached, the camera control unit A101 sets the power control signal CNT_VACC1 to the Hi level in order to turn on the output of the accessory power supply unit A131. The accessory power supply unit A131 outputs the accessory power VACC in response to the power control signal CNT_VACC1 becoming Hi.

[0161] In the accessory 200, when the accessory power supply unit 202 receives the accessory power VACC, it generates the power VMCU_A for the accessory control unit 201. Thereby, the accessory control unit 201 starts up. After starting up, the accessory control unit 201 initializes each block in the accessory 200. Thereafter, when it becomes in a state where communication with the camera 100 is possible, the accessory control unit 201 sets the / WAKE terminal to the Lo level. In the camera 100, when the camera control unit A101 detects that the / WAKE terminal has become the Lo level, it detects that the accessory 200 has become in a communicable state.

[0162] The camera control unit A101 requests accessory information from the accessory 200 via I2C communication. In the accessory 200, the accessory control unit 201 transmits the accessory information in response to the accessory information request from the camera 100. When the accessory control unit 201 transmits the accessory information, it sets the communication request signal / WAKE to the Hi level.

[0163] In the camera 100, the camera control unit A101 analyzes the received accessory information and determines whether it can control the attached accessory 200, etc. Also, the camera control unit A101 turns on the accessory power supply unit B132. When the camera control unit A101 completes various settings of the camera 100, it notifies the accessory information to the camera control unit B102.

[0164] Based on the accessory type information (ACC type information), which is information indicating the type (category) of the accessory, the camera control unit B102 notifies the control command to the accessory 200 via SPI communication and controls the function signal in response to the received event. The accessory control unit 201 performs responses (events) to the control commands from the camera 100 via SPI communication and controls according to the function signals.

[0165] FIG. 8 is a diagram showing an example of accessory type information. In the accessory information shown in FIG. 6, the D7-D0 data at address 0x00 is the accessory type information (ACC type information). In FIG. 8, each number corresponds to the type of accessory. For example, the numbers 0x81, 0x82, and 0x83 indicate that the accessory is a strobe device, an interface conversion adapter device, and a microphone device, respectively. The number 0x84 indicates that the accessory is a multi-accessory connection adapter device for attaching a plurality of accessory devices to the camera 100. Here, the adapter device is an intermediate accessory mounted between the camera 100 and accessories such as a strobe device or a microphone device. The interface conversion adapter device is an adapter device that converts the interface to provide compatibility between the camera 100 and the accessory when the interfaces of the camera 100 and the accessory are different. The multi-accessory connection adapter device is an adapter device that can attach a plurality of accessories.

[0166] In FIG. 6, the D7-D0 data at address 0x01 is information indicating the accessory identification number (ACC identification number). The accessory model can be uniquely indicated by the accessory type information and the identification number. The D7-D0 data at address 0x02 is information indicating the version of the firmware of the accessory 200.

[0167] The D7-D6 data at address 0x03 is information indicating whether or not to request the supply of the accessory power VACC to the accessory 200 when the camera 100 turns off a power switch (not shown). When this information is "0", it indicates that power supply is not required. When this information is "1", it indicates a power supply request by the accessory power supply unit A131. When this information is "2", it indicates a power supply request by the accessory power supply unit B132.

[0168] The D5-D4 data at address 0x03 is information indicating whether to request the accessory power supply VACC to the accessory 200 when the camera 100 is in the power saving mode (auto-off mode). When this information is "0", it indicates that power supply is not required. When this information is "1", it indicates a power supply request by the accessory power supply unit A131. When this information is "2", it indicates a power supply request by the accessory power supply unit B132.

[0169] The D3-D2 data at address 0x03 is information indicating whether the accessory 200 is equipped with the battery 205. When this information is "0", it indicates that the battery 205 is not equipped. When this information is "1", it indicates that the battery 205 is equipped. The D1-D0 data at address 0x03 is information indicating whether the accessory 200 is equipped with a charging function for the battery 205. When this information is "0", it indicates that the charging function is not equipped. When this information is "1", it indicates that the charging function is equipped.

[0170] The D7-D0 data at 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 multiplying this information by 10 indicates the current value. When this information is 10, it indicates 100 mA. When this information is 100, it indicates 1 A. As a method for reducing the data amount of this information, this information may be associated with an arbitrary current value. For example, when this information is "0", "1", "3", "4", it may be assumed that they indicate requests for 100 mA, 300 mA, 450 mA, and 600 mA, respectively.

[0171] The D7 data at address 0x05 is information indicating whether the accessory 200 is in the firmware update mode state. When this information is "0", it indicates that it is not in the firmware update mode state, and when this information is "1", it indicates that it is in the firmware update mode state. The D6 data at address 0x05 is information indicating whether the accessory 200 has the firmware update function. When this information is "0" or "1", it indicates that the firmware update function is not equipped or equipped, respectively.

[0172] The D5-D4 data at address 0x05 is information indicating whether to permit the operation when the intermediate connection accessory is attached to the accessory 200. When this information is "0" or "1", it indicates that the operation is not permitted or permitted, respectively. The D3-D2 data at 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. When this information is "0" or "1", it indicates that confirmation is not required or confirmation is required, respectively.

[0173] The D1-D0 data at address 0x05 is information indicating whether the accessory 200 supports command notification by I2C communication. When this information is "0" or "1", it indicates that it does not support command notification or supports command notification, respectively.

[0174] The D5-D4 data at address 0x06 is information indicating the communication method that can notify the camera 100 of the reason for the communication request after the accessory 200 notifies the camera 100 of the communication request signal / WAKE. When this information is "0", "1", or "2", it indicates that I2C communication is supported, SPI communication is supported, or both I2C communication and SPI communication are supported, respectively.

[0175] The D0, D1, D2, and D3 data at address 0x06 are information indicating whether accessory 200 has the functions according to the FNC1 signal, FNC2 signal, FNC3 signal, and FNC4 signal, respectively. The D0 data corresponds to the FNC1 signal, the D1 data corresponds to the FNC2 signal, the D2 data corresponds to the FNC3 signal, and the D3 data corresponds to the FNC4 signal. When each data value is "0", it indicates that the corresponding function is not available, and when each data value is "1", it indicates that the corresponding function is available.

[0176] The D7 data at address 0x0A is information indicating whether to request activation of camera 100 when accessory 200 notifies the communication request signal / WAKE to camera 100. When this information is "0" and "1", it indicates requesting activation and not requesting activation, respectively.

[0177] The D6 - D0 data at address 0x0A is information indicating the cause of the communication request signal / WAKE notified by accessory 200 to camera 100.

[0178] Figure 9 is a diagram showing an example of the cause of the communication request signal / WAKE. In this example, an example where accessory 200 is a microphone device is shown. For example, the cause number 0x00 is a number indicating that the menu call switch (SW) among the operation switches 212 has been pressed. Also, the cause number 0x01 is a number indicating that accessory 200 has completed the output control of the audio signal. Also, the cause number 0x02 is a number indicating that accessory 200 has completed the mute process of the audio signal. In this way, information regarding the cause of the generation of the communication request signal / WAKE can be notified to camera 100.

[0179] The D1 data at address 0x0C shown in Figure 6 is information indicating the SPI communication protocol that accessory 200 supports. When this information is "0" and "1", it indicates corresponding to SPI protocol A and corresponding to SPI protocol B, respectively.

[0180] The D0 data at address 0x0C is information indicating the control logic of the CS signal for the SPI communication supported by the accessory 200. When this information is "0" and "1", it indicates that the CS signal is Lo - active logic and the CS signal is Hi - active logic, respectively.

[0181] The D7 - D0 data at address 0x0D is information indicating the time required as the communication byte interval when the accessory 200 communicates according to the SPI protocol A and the D7 data at address 0x05 is "0". When the D7 data at address 0x05 is "0", as described above, it is the case when the accessory 200 is not in the firmware update mode.

[0182] The D7 - D0 data at address 0x0E is information indicating the time required as the communication byte interval when the accessory 200 communicates according to the SPI protocol A and the D7 data at address 0x05 is "1". When the D7 data at address 0x05 is "1", as described above, it is the case when the accessory 200 is in the firmware update mode.

[0183] Figure 10(a) is a diagram showing the relationship between the communication byte and the communication interval for the data at address 0x0D. Figure 10(b) is a diagram showing the relationship between the communication byte and the communication interval for the data at address 0x0E.

[0184] The D7 - D0 data at address 0x0F shown in Figure 6 is information indicating the checksum.

[0185] FIG. 11 is a flowchart showing the first process when an accessory is attached. This flowchart shows the processing by the camera control unit A101 until the accessory 200 is attached to the camera 100 and the functions of the accessory 200 are enabled. This first process when the accessory is attached is realized by the CPU in the camera control unit A101 expanding and executing the program stored in the ROM in the camera control unit A101 in the RAM (both not shown) in the camera control unit A101. This process starts when the main power of the camera 100 is turned on or when returning from the auto-off mode (power saving mode). Note that this process is substantially executed in steps S2001 and S2005 of FIG. 15 described later.

[0186] In step S401, the camera control unit A101 monitors the signal level of the accessory attachment detection signal / ACC_DET and waits until this signal level becomes Lo. That is, the camera control unit A101 waits until the accessory 200 is attached. If the signal level of the accessory attachment detection signal / ACC_DET is Hi, it is determined that the accessory 200 is not attached. If the signal level is Lo, since it is determined that the accessory 200 is attached, the camera control unit A101 proceeds to step S402.

[0187] In step S402, the camera control unit A101 controls the power control signal CNT_VACC1 to the Hi level in order to turn on the output of the accessory power supply unit A131, and proceeds to step S403. When the power control signal CNT_VACC1 becomes Hi, the accessory power supply unit A131 outputs the accessory power VACC.

[0188] In step S403, the camera control unit A101 monitors the signal level of the overcurrent detection signal DET_OVC and determines whether this signal level is Lo. If the signal level is Lo, the camera control unit A101 can determine that no overcurrent is flowing, and thus proceeds to step S404. However, if the signal level is Hi, it can be determined that an overcurrent has flowed. Therefore, the camera control unit A101 ends the process shown in FIG. 11 and shifts to an error process (not shown).

[0189] In step S404, the camera control unit A101 monitors the signal level of the communication request signal / WAKE, which is a notification signal from the accessory 200, and waits until the signal level becomes Lo, that is, until the initialization of the accessory 200 is completed. When the signal level becomes Lo, the camera control unit A101 can determine that the initialization of the accessory 200 is completed, and thus proceeds to step S405.

[0190] Note that in step S404, if the signal level of the communication request signal / WAKE does not become Lo even after a predetermined time has elapsed, the process may shift to an error process (not shown). In each error process, the camera control unit A101 notifies the user by display or sound that the attached accessory 200 cannot be used effectively.

[0191] In step S405, the camera control unit A101 performs I2C communication with the accessory 200 as initial communication, and thereby reads 15 - byte accessory information. That is, the camera control unit A101 requests the accessory 200 for accessory information. In the accessory 200, the accessory control unit 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.

[0192] In step S406, based on the accessory information acquired in step S405, the camera control unit A101 determines whether the attached accessory 200 is a device corresponding to the camera 100. If the camera control unit A101 determines that the attached accessory 200 is a corresponding accessory, it proceeds to step S407. However, if the camera control unit A101 determines that the attached accessory 200 is a non - corresponding accessory, it ends the process shown in FIG. 11 and shifts to an error process (not shown). In this error process, the camera control unit A101 notifies the user by display or voice that the attached accessory 200 cannot be used effectively.

[0193] In step S407, in order to turn on the output of the accessory power supply unit B132, the camera control unit A101 controls the power control signal CNT_VACC2 to the Hi level and proceeds to step S408. When the power control signal CNT_VACC2 becomes Hi, the accessory power supply unit B132 outputs the accessory power VACC. In the present embodiment, when both the power control signal CNT_VACC1 and the power control signal CNT_VACC2 are controlled to the Hi level, it is assumed that the accessory power supply unit B132 outputs the accessory power VACC.

[0194] In step S408, the camera control unit A101 notifies the camera control unit B102 of the accessory information read in step S405 and ends the process shown in FIG. 11.

[0195] FIG. 12 is a flowchart showing the second process when an accessory is attached. This flowchart shows the process by the camera control unit B102 until the accessory 200 is attached to the camera 100 and the function of the accessory 200 is enabled. This second process when an accessory is attached is realized by the CPU in the camera control unit B102 expanding and executing the program stored in the ROM in the camera control unit B102 in the RAM (both not shown) in the camera control unit B102. This process starts when the first process when an accessory is attached (FIG. 11) starts.

[0196] In step S501, the camera control unit B102 waits until accessory information is notified from the camera control unit A101. This accessory information is notified in step S408 of FIG. 11. When the accessory information is received, in step S502, the camera control unit B102 sets function signals (FNC1 to FNC4) based on the notified accessory information.

[0197] For example, if based on the accessory information, the accessory 200 is a microphone device, the camera control unit B102 sets the FNC1 signal to function as a clock signal for audio data. Similarly, the camera control unit B102 sets the FNC2 signal to function as a channel signal for audio data and the FNC3 signal to function as an audio data signal, respectively.

[0198] As another example, when the accessory 200 is a strobe device, the camera control unit B102 may set the FNC4 signal to function as a strobe emission synchronization signal (strobe emission timing signal). Note that for function signals that do not require control for the accessory 200, they may also be set so as not to interfere with the operations of the camera 100 and the accessory 200.

[0199] In step S503, the camera control unit B102 sets the control logic of the SPI communication CS signal based on the accessory information notified from the camera control unit A101. In step S504, the camera control unit B102 waits until an event for the accessory 200 occurs (is detected), and when an event occurs, it proceeds to step S505.

[0200] In step S505, the camera control unit B102 determines whether the event detected in step S504 is an event that requires SPI communication with the accessory 200. If the detected event is an event that requires SPI communication, the camera control unit B102 proceeds to step S506, and if the detected event is not an event that requires SPI communication, it proceeds to step S507.

[0201] In step S506, the camera control unit B102 performs SPI communication control on the accessory 200. Examples of the SPI communication control executed here include, for example, when 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. Also, when the accessory 200 is a strobe device, examples of the above SPI communication include communication for reading the setting information of the strobe, communication for notifying the setting information to the strobe, etc. After step S506, the camera control unit B102 returns to step S504.

[0202] In step S507, the camera control unit B102 determines whether the detected event is an event that requires control using a function signal with the accessory 200. Then, when the detected event is an event that requires control using a function signal, the camera control unit B102 proceeds to step S508, and when the detected event is not an event that requires control using a function signal, the camera control unit B102 proceeds to step S509.

[0203] In step S508, the camera control unit B102 performs control using a function signal on the accessory 200. Examples of the control using a function signal executed here include, for example, when the accessory 200 is a microphone device, starting the output of the clock signal for audio data of FNC1 and the channel signal for audio data of FNC2, and capturing the audio data signal of FNC3. Thereby, the camera 100 can acquire audio data from the accessory 200. Also, when the accessory 200 is a strobe device, controlling the strobe emission synchronization signal of FNC4 at a predetermined timing can be mentioned. Thereby, a light emission instruction can be notified to the strobe. After step S508, the camera control unit B102 returns to step S504.

[0204] In step S509, the camera control unit B102 executes "other control" according to the event detected in step S504. In the other control, if the detected event is an event that requires I2C communication, the camera control unit B102 performs I2C communication control on the accessory 200. In addition, in the other control, the camera control unit B102 performs in-camera control according to the detected event. Examples of the in-camera control executed here include, when the accessory 200 is a microphone device, in addition to the start and end control of recording audio data to the recording memory 126, the equalizer processing control for the audio data, etc. Also, when the accessory 200 is a strobe device, examples include photometry control for accumulating and acquiring the light emitted by the strobe with the imaging sensor 122, and arithmetic control of the emission amount instruction value of the strobe. After step S509, the camera control unit B102 returns to step S504.

[0205] FIG. 13 is a flowchart showing the processing when an accessory is attached. This flowchart shows the processing by the accessory control unit 201 until the accessory 200 is attached to the camera 100 and the functions of the accessory 200 are enabled. This processing is realized by the CPU in the accessory control unit 201 expanding and executing the program stored in the ROM in the accessory control unit 201 in the RAM (both not shown) in the accessory control unit 201. This processing starts when the accessory 200 is attached to the camera 100.

[0206] Note that in the processing shown in FIGS. 11 and 12, the camera-side connection unit 141, the camera control unit A101, and the camera control unit B102 cooperate to function as the communication means in the present invention. Also, the camera control unit A101 functions as the acquisition means, determination means, and control means in the present invention.

[0207] In step S601, the accessory control unit 201 waits until the accessory power supply VACC from the camera 100 is turned on. When the accessory power supply VACC is turned on, it proceeds to step S602. Separately from this method, in a configuration where the accessory 200 has a battery 205, and further the accessory control unit 201 has a configuration for monitoring the voltage value of the accessory power supply VACC, it may be possible to detect that the accessory power supply VACC has been turned on. In the case of a configuration where the accessory 200 does not have a battery 205, it may be determined that the accessory power supply VACC has been turned on when power is supplied to the accessory control unit 201 and the accessory control unit 201 itself starts operating.

[0208] In step S602, the accessory control unit 201 performs initial settings. These initial settings include, for example, setting the operating frequency of the microcontroller, setting the input / output control ports of the microcontroller, initializing the timer function of the microcontroller, initializing the interrupt function of the microcontroller, and the like. In step S603, the accessory control unit 201 notifies the camera 100 that the initial settings have been completed (the communication-enabled state) by controlling the communication request signal / WAKE to Lo.

[0209] In step S604, the accessory control unit 201 responds to the I2C communication as the initial communication from the camera 100 and transmits 15-byte accessory information (Figure 6). In step S605, the accessory control unit 201 controls the communication request signal / WAKE to Hi. In step S606, the accessory control unit 201 waits until an event occurs (is detected). When an event occurs, it proceeds to step S607. Therefore, the accessory information is transmitted in the first communication after notifying the information indicating communication availability and before starting the operation based on the event.

[0210] In step S607, the accessory control unit 201 determines whether the event detected in step S606 is an event that requires SPI communication with the camera 100. Then, if the detected event is an event that requires SPI communication, the accessory control unit 201 proceeds to step S608; if the detected event is not an event that requires SPI communication, the accessory control unit 201 proceeds to step S609.

[0211] In step S608, the accessory control unit 201 performs SPI communication control with the camera 100. When the communication request signal / WAKE is in the Lo output state during the execution of this SPI communication control, the accessory control unit 201 controls the communication request signal / WAKE to be in the Hi output state after the SPI communication.

[0212] As the SPI communication control executed in step S608, for example, when the accessory 200 is a microphone device, there is instruction communication for turning on / off the microphone operation from the camera 100. Also, as SPI communication, there is instruction communication for switching the sound collection directivity of the microphone, instruction communication for switching the equalizer function of the microphone, etc. Also, when the accessory 200 is a strobe device, as SPI communication control, there is communication for reading the strobe setting information, communication for notifying the strobe of the setting information, etc. After step S608, the accessory control unit 201 returns to step S606.

[0213] In step S609, the accessory control unit 201 determines whether the detected event is an event that requires I2C communication with the camera 100. Then, if the detected event is an event that requires I2C communication, the accessory control unit 201 proceeds to step S610; if the detected event is not an event that requires I2C communication, the accessory control unit 201 proceeds to step S611.

[0214] In step S610, the accessory control unit 201 performs I2C communication control with the camera 100. When the communication request signal / WAKE is in the Lo output state during the execution of the SPI communication control, the accessory control unit 201 controls the communication request signal / WAKE to be in the Hi output after the SPI communication. Examples of the I2C communication control executed in step S610 include readout communication of the communication request factor for the communication request signal / WAKE notified from the accessory control unit 201 to the camera 100. After step S610, the accessory control unit 201 returns to step S606.

[0215] In step S611, the accessory control unit 201 determines whether the event detected in step S606 is an event that performs control using a function signal. Then, when the detected event is an event that requires control using a function signal, the accessory control unit 201 proceeds to step S612, and when the detected event is not an event that requires control using a function signal, the accessory control unit 201 proceeds to step S613.

[0216] In step S612, the accessory control unit 201 performs control using a function signal on the camera 100. When the accessory 200 is a microphone device, examples of the control using a function signal executed in step S612 include the following control.

[0217] For example, receiving and controlling the clock signal for the audio data of FNC1 and the channel signal for the audio data of FNC2 output from the camera 100, and outputting and controlling the audio data signal of FNC3 in synchronization with these signals. On the other hand, when the accessory 200 is a strobe device, an example of the control using a function signal executed in step S612 is performing strobe emission control by receiving and controlling the strobe emission synchronization signal of FNC4. After step S612, the accessory control unit 201 returns to step S606.

[0218] In step S613, the accessory control unit 201 determines whether the event detected in step S606 is an event that notifies the camera by the communication request signal / WAKE. Then, if the detected event is an event that requires notification to the camera by the communication request signal / WAKE, the accessory control unit 201 proceeds to step S614. On the other hand, if the detected event is not an event that requires notification to the camera by the communication request signal / WAKE, the accessory control unit 201 proceeds to step S615.

[0219] In step S614, the accessory control unit 201 stores the communication request factor number for the camera 100 corresponding to the event detected in step S606 in a volatile memory (not shown) of the accessory 200, and controls the communication request signal / WAKE to Lo. As this communication request factor number, as described in FIG. 9, a unique number assigned for each factor content corresponds. After step S614, the accessory control unit 201 returns to step S606.

[0220] In step S615, the accessory control unit 201 performs in-accessory control corresponding to the event detected in step S606. Examples of the in-accessory control executed in step S615 include battery remaining amount detection control when the accessory 200 has a battery 205, and detection control of the operation switch 212, among others. After step S615, the accessory control unit 201 returns to step S606.

[0221] Note that the process shown in FIG. 13 ends when the main power supply of the camera 100 is turned off, when shifting to the auto-off mode, when the accessory 200 is removed from the camera 100, and the like.

[0222] As described above, by going through the processes shown in FIGS. 11, 12, and 13, the camera 100 can control the attached accessory 200, and the accessory 200 can perform functional operations.

[0223] (Example 1) Hereinafter, the operation of the camera 100 as an imaging device in Embodiment 1 of the present invention will be described.

[0224] FIG. 14 is a diagram showing the state of the camera 100 recognized by the accessory control unit 201 (state recognition means).

[0225] When the accessory control unit 201 detects that the accessory 200 is attached to the camera 100, it proceeds to step S141 and recognizes that the camera 100 has transitioned from the initial state to the camera connection state. In this embodiment, when the accessory control unit 201 receives a predetermined signal from the accessory power supply unit 202, it detects that the accessory 200 is attached to the camera 100. Specifically, when the accessory 200 is attached to the camera 100, the camera 100 outputs the accessory power supply VACC to the TC05 terminal of the camera-side connection portion 141. In the accessory 200, the accessory power supply VACC is input to the accessory power supply unit 202 via the TA05 terminal of the accessory-side connection portion 211. When the accessory power supply unit 202 receives the accessory power supply VACC, it starts outputting a predetermined signal to the accessory control unit 201. When the accessory control unit 201 receives a predetermined signal from the accessory power supply unit 202, it detects that the accessory 200 is attached to the camera 100. On the other hand, when the accessory 200 is removed from the camera 100 and the input of the accessory power supply VACC to the accessory power supply unit 202 is interrupted, the accessory power supply unit 202 stops outputting a predetermined signal to the accessory control unit 201. When the transmission of the predetermined signal from the accessory power supply unit 202 is interrupted, the accessory control unit 201 detects that the accessory 200 has been removed from the camera 100.

[0226] The detection of the attachment of the accessory 200 to the camera 100 and the detection of the removal of the accessory 200 from the camera 100 may be determined by a method other than the output of a predetermined signal from the accessory power supply unit 202. For example, these detections may be determined by the FNC1 to FNC4 signals received via the functional unit 206.

[0227] When the current recognized state of the camera 100 by the accessory control unit 201 is the camera connection state, upon receiving the initial communication from the camera 100, it proceeds to step S142 and recognizes that the camera 100 has transitioned to the camera photometry stop state. The initial communication from the camera 100 is performed using SPI communication (the first communication) or I2C communication (the second communication) with different granularities of information to be transmitted. As described above, SPI communication is a communication using the SCLK, MOSI, and MISO signals output from the TC07 - TC09 terminals of the camera-side connection unit 141. Also, I2C communication is a communication using the SDA and SCL signals output from the TC12 and TC13 terminals of the camera-side connection unit 141.

[0228] When the current recognized state of the camera 100 by the accessory control unit 201 is the camera photometry stop state, upon receiving the in-photometry notification from the camera 100, it proceeds to step S143 and recognizes that the camera 100 has transitioned to the camera in-photometry state.

[0229] When the current recognized state of the camera 100 by the accessory control unit 201 is the camera photometry stop state, upon receiving the auto power-off notification from the camera 100, it proceeds to step S144 and recognizes that the camera 100 has transitioned to the camera auto power-off state.

[0230] Also, when the current recognized state of the camera 100 by the accessory control unit 201 is the camera photometry stop state, upon receiving the power-off notification from the camera 100, it proceeds to step S145 and recognizes that the camera 100 has transitioned to the camera power-off state. Similarly, when the current recognized state of the camera 100 by the accessory control unit 201 is the camera auto power-off state, upon receiving the power-off notification from the camera 100, it proceeds to step S145 and recognizes that the camera 100 has transitioned to the camera power-off state.

[0231] When the accessory control unit 201 receives a metering-off notification from the camera 100 when the currently recognized state of the camera 100 is the camera metering state, it proceeds to step S142 and recognizes that the camera 100 has transitioned to the camera metering stop state.

[0232] When the accessory control unit 201 receives an activation notification from the camera 100 when the currently recognized state of the camera 100 is the camera auto power-off state, it proceeds to step S142 and recognizes that the camera 100 has transitioned to the camera metering stop state.

[0233] When the accessory control unit 201 receives an activation notification from the camera 100 when the currently recognized state of the camera 100 is the camera power-off state, it proceeds to step S142 and recognizes that the camera 100 has transitioned to the camera metering stop state.

[0234] When the accessory control unit 201 (removal detection means) detects that the accessory 200 has been removed from the camera 100 when the currently recognized state of the camera 100 is each of the states shown in FIG. 14, it recognizes that the state of the camera 100 has returned to the initial state. As described above, in this embodiment, when the transmission of a predetermined signal from the accessory power supply unit 202 stops, the accessory control unit 201 detects that the accessory 200 has been removed from the camera 100.

[0235] When the camera 100 is in the photometry state, the camera control unit B102 (the first communication means) periodically performs SPI communication with the accessory 200 to obtain the information held by the accessory 200, and displays the obtained information on the display unit 127 as accessory-related information. Also, on the display unit 127, together with the accessory-related information, the subject image formed on the imaging sensor 122 is displayed in a through manner, and the shooting parameters such as the shutter speed, aperture, and ISO used at the time of shooting are displayed. Specifically, when the accessory 200 is a strobe device, the following shooting parameters are displayed on the display unit 127. For example, when information indicating that the accessory 200 is in a state where it can emit light is obtained by SPI communication, the shooting parameters for strobe emission are displayed on the display unit 127. On the other hand, when information indicating that the accessory 200 is in a state where it cannot emit light is obtained by SPI communication, the shooting parameters for non-strobe emission are displayed on the display unit 127. In this embodiment, the state where light emission is possible refers to a state where the charging of the light emitting unit by the charging unit is completed inside the functional unit 206 and the light emitting unit can emit light. Also, the state where light emission is impossible includes a state where the charging of the light emitting unit by the charging unit inside the functional unit 206 has not reached a predetermined charge level and the light emitting unit cannot emit light.

[0236] When the camera 100 is in the photometry stop state (the first state), the camera control unit B102 stops the SPI communication with the accessory 200, but continues to display the through image and the shooting parameters on the display unit 127.

[0237] When the camera 100 is in the auto power-off state (the second state), the power supply from the system power supply unit 112 to the camera control unit B102 is stopped. Therefore, the camera control unit B102 not only stops the SPI communication with the accessory 200, but also stops the display of the through image and the shooting parameters on the display unit 127.

[0238] When the camera 100 is in the photometric stop state or the auto power-off state, power is supplied to the camera control unit A101, and the camera control unit A101 is in the standby mode. This standby mode is released when a switch (not shown) connected to the camera control unit A101 is operated and the camera 100 is activated, or when there is a change in the signal state of the communication request signal / WAKE at the TC11 terminal of the camera-side connection unit 141.

[0239] When the camera 100 is in the camera power-off state, the power supply from the system power unit 112 to the camera control unit B102 is stopped. On the other hand, power is supplied to the camera control unit A101, and although the communication with the accessory 200 is stopped, the camera control unit A101 is in the standby mode. Therefore, the standby mode of the camera control unit A101 is released only when the power switch among the switches (not shown) for camera operations connected to the camera control unit A101 is operated.

[0240] FIG. 15 is a flowchart showing the notification process to the camera 100 when the accessory 200 is a strobe device and the light control correction value in its automatic light control mode is changed.

[0241] First, in step S1501, the accessory control unit 201 checks whether the light control correction value of the accessory 200 has been changed. If the light control correction value has been changed (YES in step S1501), the process proceeds to step S1502; otherwise, it returns to step S1501 to check the change in the light control correction value again. The light control correction value of the accessory 200 can be changed, for example, when the user operates the operation switch 212.

[0242] In step S1502, the accessory control unit 201 checks whether the currently recognized state of the camera 100 is the camera photometry state (the third state) shown in step S143. If it is not in the camera photometry state (NO in step S1502), the process proceeds to step S1503; otherwise, it returns to step S1501 to confirm the change of the light adjustment correction value again. As described above, when the camera 100 is in the photometry state, the camera control unit B102 periodically acquires information such as the light adjustment correction value that the accessory 200 has through SPI communication with the accessory 200. Also, the light adjustment correction value of the accessory 200 acquired periodically is displayed as accessory-related information on the display unit 127 of the camera 100.

[0243] In step S1503, the accessory control unit 201 checks whether the currently recognized state of the camera 100 is the camera photometry stop state shown in step S142. If it is in the camera photometry stop state (YES in step S1503), the process proceeds to step S1510; otherwise, it proceeds to step S1504.

[0244] In step S1504, the accessory control unit 201 checks whether the currently recognized state of the camera 100 is the camera auto power-off state shown in step S144. If it is in the camera auto power-off state (YES in step S1504), the process proceeds to step S1505; otherwise, it returns to step S1501 to confirm the change of the light adjustment correction value again.

[0245] In step S1505, the accessory control unit 201 checks whether the light adjustment correction value has been changed from a value other than 0 (another value) to 0 (the first value). If the light adjustment correction value has been changed from a value other than 0 to 0, the process proceeds to step S1511; otherwise, it proceeds to step S1506.

[0246] In step S1506, the accessory control unit 201 checks whether the dimming correction value has changed from 0 to a non-zero value. If the dimming correction value has changed from 0 to a non-zero value, the process proceeds to step S1511; otherwise, it returns to step S1501 to check for changes in the dimming correction value again.

[0247] In step S1510, the accessory control unit 201 (notification means) notifies the camera 100 that the accessory state has changed and ends this process. Here, the accessory control unit 201 operates the TA11 terminal of the accessory side connection unit 211 to change the signal state of the communication request signal / WAKE of the TC11 terminal of the camera side connection unit 141, thereby notifying the camera 100 that the accessory state has changed. When the camera control unit A101 is notified that the accessory state has changed from the accessory control unit 201, it releases the standby mode. Then, the camera control unit A101 accesses the address 0x0A of the non-volatile memory of the accessory 200 via I2C communication and inquires about the communication request signal / WAKE cause. In response to this inquiry, the accessory control unit 201 sets 0, which is information requesting the activation of the camera 100, in the D7 data, and sets response data indicating that the dimming correction value has changed in the D6 - D0 data, and transmits the response data to the camera 100. The camera control unit B102 resumes the SPI communication with the stopped accessory 200 upon receiving the activation request for the camera 100 in this response data. The accessory control unit 201 (first transmission means) transmits information (detailed information) such as the dimming correction value, which the accessory 200 has, to the camera 100 as a response to the SPI communication resumed by the camera control unit B102. When the camera control unit B102 receives the above detailed information from the accessory control unit 201, it displays this information on the display unit 127.

[0248] In step S1511, the accessory control unit 201 (notification means) notifies the camera 100 that the accessory state has changed, and ends this process. When the camera control unit A101 (second communication means) is notified that the accessory state has changed from the accessory control unit 201, it releases the standby mode. After that, the camera control unit A101 accesses the address 0x0A of the non-volatile memory included in the accessory 200 by I2C communication, and makes an inquiry about the communication request signal / WAKE factor. In response to this inquiry, the accessory control unit 201 transmits response data to the camera 100 in which 1, which is information not requesting the activation of the camera 100, is set in the D7 data, and a value indicating that the dimming correction value has changed is set in the D6-D0 data. That is, as a result of the above notification from the accessory control unit 201 to the camera 100 in step S1511, simple information indicating that the dimming correction value has changed is transmitted from the accessory control unit 201 (second transmission means) to the camera 100.

[0249] According to this process, even when the camera 100 is in the photometry stop state, the user can know the dimming correction value (detailed information) of the accessory 200 from the display on the display unit 127 (display means). In this embodiment, the first information indicating the value of the control parameter regarding the accessory 200 is defined as detailed information, and the second information indicating whether or not the accessory 200 satisfies a predetermined condition is defined as simple information. For example, the value of the control parameter is a dimming correction value, a manual light emission amount, a bounce angle, a zoom position of the optical system, or the like. For example, the predetermined condition is that the dimming correction value is set, the set dimming correction value has changed, the set manual light emission amount has changed, the bounce angle has changed, it is in a light-emitting enabled state, a change has occurred between the light-emitting enabled state and the non-light-emitting state, or the like.

[0250] Even when the camera 100 is in the auto power-off state, the camera control unit A101 can determine whether a light adjustment correction value is set in the accessory 200 (simple information). Therefore, for example, when the light adjustment correction value of the camera 100 can be set exclusively from that of the accessory 200, the camera control unit A101 can instantaneously determine whether the light adjustment correction value can be set in the camera 100. For example, when acquiring information that the light adjustment correction value is set in the accessory 200 as simple information, the camera control unit A101 determines that the light adjustment correction value cannot be set from the camera 100 side.

[0251] Furthermore, when the camera is in the auto power-off state, the accessory control unit 201 notifies the camera 100 that the accessory state has changed only when the light adjustment correction value of the accessory 200 changes to 0 or changes to a non-zero value. Thereby, the communication frequency between the camera 100 and the accessory 200 can be suppressed.

[0252] In addition, after confirming that the currently recognized state of the camera 100 is the camera photometry stop state (YES in step S1503), when the accessory control unit 201 detects that the accessory 200 has been removed from the camera 100, this process ends at that point. Similarly, after confirming that the currently recognized state of the camera 100 is the camera auto power-off state (YES in step S1504), when such detection is made, this process ends at that point.

[0253] (Embodiment 2) Hereinafter, the operation of the camera 100 as an imaging device in Embodiment 2 of the present invention will be described. Among the configurations of this embodiment, the same configurations as those in Embodiment 1 are denoted by the same reference numerals, and duplicate explanations are omitted.

[0254] FIG. 16 is a flowchart showing a notification process to the camera 100 when the accessory 200 is a sender strobe in a fill-in strobe system and the light emission control state of the fill-in strobe system changes.

[0255] In this embodiment, the accessory 200 controls a plurality of receiver strobes wirelessly as a sender strobe, thereby forming a multi-flash strobe system. Each receiver strobe also includes a functional unit having a light emitting unit and a charging unit for the light emitting unit inside, similar to the accessory 200.

[0256] The light emission control state of the accessory 200 is such that when the charging of the light emitting unit is completed by the charging unit inside the functional unit 206, it becomes a light emission possible state, and when the charging is not completed, it becomes a light emission impossible state. Similarly, the light emission control state of each receiver strobe is such that when the charging of the light emitting unit is completed by the charging unit inside the functional unit, it becomes a light emission possible state, and when the charging is not completed, it becomes a light emission impossible state. The accessory control unit 201 acquires the light emission control state of each receiver strobe by wireless communication.

[0257] Also, when the sender strobe and all the receiver strobes are in a light emission possible state, the accessory control unit 201 determines that the multi-flash strobe system is in a light emission possible state (first value). On the other hand, when any one of the sender strobe and the receiver strobes is in a light emission impossible state, the accessory control unit 201 determines that the multi-flash strobe system is in a light emission impossible state (other value).

[0258] First, in step S1601, the accessory control unit 201 checks whether the light emission control state of each strobe of the sender strobe (accessory 200) and each receiver strobe has changed. If the light emission control state of any strobe has changed (YES in step S1601), the process proceeds to step S1602; otherwise, the process returns to step S1601 to check again for changes in the light emission control state of each strobe.

[0259] In step S1602, the accessory control unit 201 checks whether the state of the currently recognized camera 100 is the camera photometry state shown in step S143. If it is not in the camera photometry state (NO in step S1602), it proceeds to step S1603. If so, it returns to step S1601 to check again for changes in the light emission control state of each strobe. As described above, when the camera 100 is in the photometry state, the camera control unit B102 periodically acquires the light emission control state of the accessory 200, which is the sender strobe, and the light emission control states of each receiver strobe through SPI communication with the accessory 200. Also, the camera 100 displays the periodically acquired light emission control states of the sender strobe and each receiver strobe on the display unit 127.

[0260] In step S1603, the accessory control unit 201 checks whether the state of the currently recognized camera 100 is the camera photometry stop state shown in step S142. If it is in the camera photometry stop state (YES in step S1603), it proceeds to step S1610. If not, it proceeds to step S1604.

[0261] In step S1604, the accessory control unit 201 checks whether the state of the currently recognized camera 100 is the camera auto power-off state in step S144. If it is in the camera auto power-off state (YES in step S1604), it proceeds to step S1605. If not, it returns to step S1601 to check again for changes in the light emission control state of each strobe.

[0262] In step S1605, the accessory control unit 201 checks whether the light emission control state of the lamp-up strobe system has changed. If it has changed (YES in step S1605), it proceeds to step S1611. If not, it returns to step S1601 to check again for changes in the light emission control state of each strobe.

[0263] In step S1610, the accessory control unit 201 notifies the camera 100 that the accessory state has changed and ends this process. Here, the accessory control unit 201 operates the TA11 terminal of the accessory side connection unit 211 to change the signal state of the communication request signal / WAKE of the TC11 terminal of the camera side connection unit 141, and notifies the camera 100 that the accessory state has changed. When the camera control unit A101 is notified that the accessory state has changed from the accessory control unit 201, it releases the standby mode. Then, the camera control unit A101 accesses the address 0x0A of the non-volatile memory of the accessory 200 by I2C communication and inquires about the communication request signal / WAKE cause. In response to this inquiry, the accessory control unit 201 sets 0, which is information for requesting the activation of the camera 100, in the D7 data, and transmits response data in which a value indicating that the light emission enable state of the auxiliary strobe system has changed is set in the D6-D0 data to the camera 100. The camera control unit B102 resumes the SPI communication with the stopped accessory 200 upon receiving the camera 100 activation request in this response data. As a response to the SPI communication resumed by the camera control unit B102, the accessory control unit 201 transmits to the camera 100 the light emission control states of the sender strobe and each receiver strobe as information (detailed information) held by the accessory 200. When the camera control unit B102 receives the above detailed information from the accessory control unit 201, it displays this information on the display unit 127.

[0264] In step S1611, the accessory control unit 201 notifies the camera 100 that the accessory state has changed, and ends this process. When the camera control unit A101 is notified by the accessory control unit 201 that the accessory state has changed, it releases the standby mode. Thereafter, the camera control unit A101 accesses the address 0x0A of the non-volatile memory of the accessory 200 by I2C communication, and makes an inquiry about the communication request signal / WAKE factor. In response to this inquiry, the accessory control unit 201 sets 1, which is information not requesting the activation of the camera 100, in the D7 data, and sets response data indicating that the light-emitting enabled state of the fill-in flash system has changed in the D6-D0 data, and transmits the response data to the camera 100. That is, as a result of the above notification from the accessory control unit 201 to the camera 100 in step S1611, simple information indicating that the light-emitting enabled state of the fill-in flash system has changed is transmitted from the accessory control unit 201 (second transmission means) to the camera 100.

[0265] According to this process, even when the camera 100 is in the photometric stop state, the user can know the light emission control states (detailed information) of the sender flash and each receiver flash from the display on the display unit 127.

[0266] Also, even when the camera is in the auto power-off state, the user can know the light emission control state (simple information) of the fill-in flash system from the display on the display unit 127. Therefore, for example, when the camera 100 performs shooting immediately after the auto power-off state, the user can instantly determine whether flash shooting using the fill-in flash system is possible, and can shorten the time until the shooting operation.

[0267] Furthermore, the accessory control unit 201 notifies the camera 100 that the accessory state has changed only when the light-emitting enabled state of the fill-in flash system changes in the camera auto power-off state. Thereby, the communication frequency between the camera 100 and the accessory 200 can be suppressed.

[0268] After the accessory control unit 201 confirms that the currently recognized state of the camera 100 is the camera photometric measurement stop state (YES in step S1603), if it detects that the accessory 200 has been removed from the camera 100, it ends this process at that point. Similarly, after the accessory control unit 201 confirms that the currently recognized state of the camera 100 is the camera auto power-off state (YES in step S1604), if it detects such a situation, it ends this process at that point.

[0269] In addition, in the above embodiment, the form in which the accessory 200 is directly attached to the camera 100 has been mainly described, but other forms may also be possible. For example, a form in which the camera 100 and the main accessory communicate via an intermediate accessory such as a main accessory corresponding to the accessory 200 and an adapter device to which the camera 100 is attached may be used. In such a form, at least a part of the communication control executed by the accessory 200 and the communication control executed by the camera 100 described in the above embodiment may be executed by the intermediate accessory. Alternatively, the intermediate accessory may function as an information transmission path for outputting information corresponding to the information input from the camera 100 to the main accessory and outputting information corresponding to the information input from the main accessory to the camera 100. As described above, the accessory referred to in the present invention includes various accessories such as a microphone device, a lighting device, and an adapter device. In addition, the adapter device may also be included in an electronic device.

[0270] As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist thereof.

[0271] (Other Embodiments) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium and having one or more processors in the computer of the system or device read and execute the program. It can also be executed by a circuit (for example, ASIC) that realizes one or more functions.

Description of Symbols

[0272] 100 Camera 101 Camera Control Unit A 102 Camera Control Unit B 112 System Power Supply Unit 131 Accessory Power Supply Unit A 132 Accessory Power Supply Unit B 133 Protection Unit 134 Resistance Element 141 Camera Side Connection Port 200 Accessory 201 Accessory Control Unit 202 Accessory Power Supply 203 Power Switch 204 Charging Unit 205 Battery 206 Function Unit 211 Accessory Side Connection Port 212 Operation Switch

Claims

1. An accessory that can be detachably connected to an electronic device, a first transmitting means for transmitting first information included in information held by the accessory to the electronic device in response to a first communication from a first communication means of the electronic device at regular intervals; a second transmission means for responding to an inquiry by a second communication from a second communication means of the electronic device; A state recognition means for recognizing a state of the electronic device; and a notification means for, when a state of the electronic device recognized by the state recognition means is either a first state in which the first communication is stopped and the second communication means is in standby mode, or a second state in which power supply to the first communication means is stopped and the second communication means is in standby mode, and when information held by the accessory changes, notifying the electronic device of information based on the change in information held by the accessory.

2. The accessory described in Claim 1, characterized in that when the state of the electronic device is the second state, the second transmitting means transmits second information different from the first information of the information held by the accessory in response to an inquiry regarding the notification from the second communication means that has released the standby mode by the notification.

3. The accessory described in claim 1, characterized in that when the state of the electronic device is the first state, the second transmitting means transmits a startup request for the electronic device in response to an inquiry about the notification from the second communication means that has released the standby mode in response to the notification, and resumes the first communication.

4. The electronic device further includes a removal detection unit for detecting removal of the accessory from the electronic device, The accessory described in any one of claims 1 to 3, characterized in that after the state recognition means recognizes that the state of the electronic device is either the first or second state, when the removal detection means detects the removal, processing by the notification means is terminated at that point.

5. when the state of the electronic device recognized by the state recognition means is a third state in which the information held by the accessory is periodically transmitted to the electronic device by the first transmission means, if the information held by the accessory changes, the notification is not performed using the notification means; 5. The accessory according to claim 1, wherein the information held by the accessory is transmitted to the electronic device by the first transmission means.

6. 6. The accessory according to claim 1, wherein the granularity of the information transmitted by the second transmitting means is different from the granularity of the information transmitted by the first transmitting means.

7. An accessory as described in any one of claims 1 to 6, characterized in that when the state of the electronic device recognized by the state recognition means is the second state, even if the information held by the accessory changes, if at least information held by the accessory that can take a first value has not changed from the first value to another value and has not changed from another value to the first value, the notification is not performed using the notification means.

8. the first information is information indicating a value of a control parameter related to the accessory, 3. The accessory according to claim 2, wherein the second information is information indicating that a state of the accessory has changed.

9. An electronic device to which an accessory is detachably connected, a first communication means for periodically acquiring first information of the information included in the accessory from the accessory through a first communication; a second communication means for making an inquiry to the accessory through a second communication and obtaining a response thereto; When the state of the electronic device is either a first state in which the first communication is stopped and the second communication means is in standby mode, or a second state in which power supply to the first communication means is stopped and the second communication means is in standby mode, when the accessory notifies the electronic device of information based on a change in information held by the accessory, the second communication means cancels the standby mode.

10. The electronic device described in claim 9, characterized in that when the state of the electronic device is the second state, the second communication means, which has released the standby mode in response to the notification, sends an inquiry to the accessory in response to the notification via the second communication, and obtains second information from the accessory in response, the second information being different from the first information held by the accessory.

11. When the state of the electronic device is the first state, the second communication means, which has been released from the standby mode, transmits an inquiry to the accessory in response to the notification through the second communication, and receives a startup request for the electronic device from the accessory in response to the inquiry.

10. The electronic device according to claim 9, wherein the first communication means, upon receiving the start-up request and restarting the first communication, acquires the first information from the accessory.

12. 12. The electronic device according to claim 11, further comprising a display unit that displays the first information acquired after the first communication is resumed.

13. 13. The accessory according to claim 9, wherein the first information is information indicating a value of a control parameter related to the accessory.

14. An imaging system including an imaging device and an accessory detachably connected to the imaging device, The imaging device includes: a first communication means for periodically acquiring first information of the information included in the accessory from the accessory through a first communication; a second communication means for making an inquiry to the accessory through a second communication and obtaining a response thereto; The accessory includes: a state recognition means for recognizing a state of the imaging device; an imaging system comprising: a notification means for, when a state of the imaging device recognized by the state recognition means is either a first state in which the first communication is stopped and the second communication means is in standby mode, or a second state in which power supply to the first communication means is stopped and the second communication means is in standby mode, and when information held by the accessory changes, notifying the imaging device of information based on the change in information held by the accessory.

Images