Image capturing apparatus, accessory apparatus, and control method therefor

An accessory apparatus to which an image capturing apparatus is attachable, the accessory apparatus comprising:

• a communication control section implemented by at least one processor and configured to control reception of a signal from the image capturing apparatus through a first communication channel, reception of data from the image capturing apparatus through a third communication channel, and transmission of data from the accessory apparatus through a second communication channel, and to control transmission of accessory attribute information of the accessory apparatus through the second communication channel,
• wherein the communication control section is configured to control communication to transmit first accessory attribute information of the accessory attribute information through the second communication channel by using a first communication method, then to switch from the first communication method to a second communication method different from the first communication method, and to control communications to transmit second accessory attribute information of the accessory attribute information including information indicating function that can be performed by the accessory apparatus through the second communication channel by using the second communication method,
• wherein the first communication method is a communication method in which, at a timing corresponding to reception, through the first communication channel, of a clock signal of which a signal level switches alternately between a first signal level and a second signal level different from the first signal level, reception of data through the third communication channel and transmission of data through the second communication channel are performed,
• wherein the second communication method is a communication method in which, in response to transmission of data through the second communication channel in response to switching of the signal level of the first communication channel from the first signal level to the second signal level, data is received through the third communication channel, and
• wherein the second accessory attribute information contains information indicating function that can be performed by the second communication method which is not included in the first accessory attribute information.

A control method for an image capturing apparatus to which an accessory apparatus is attachable, wherein the image capturing apparatus includes a communication control section implemented by at least one processor and configured to control transmission of a signal to the accessory apparatus through a first communication channel, transmission of data to the accessory apparatus through a third communication channel, and reception of data from the accessory apparatus through a second communication channel, and to control reception of accessory attribute information including information indicating function that can be performed by the accessory apparatus through the second communication channel, the control method comprising:

• controlling to receive, by the communication control section, first accessory attribute information of the accessory attribute information through the second communication channel by using a first communication method, then switching from the first communication method to a second communication method different from the first communication method, and controlling communication to receive second accessory attribute information of the accessory attribute information through the second communication channel by using the second communication method,
• wherein the first communication method is a communication method in which, at a timing corresponding to transmission, through the first communication channel, of a clock signal of which a signal level switches alternately between a first signal level and a second signal level different from the first signal level, transmission of data through the third communication channel and reception of data through the second communication channel are performed,
• wherein the second communication method is a communication method in which, in response to reception of data through the second communication channel transmitted in response to switching of the signal level of the first communication channel from the first signal level to the second signal level, data is transmitted through the third communication channel, and
• wherein the second accessory attribute information contains information indicating function that can be performed by the second communication method which is not included in the first accessory attribute information.

A control method for an accessory apparatus to which an image capturing apparatus is attachable, wherein the accessory apparatus includes a communication control section implemented by at least one processor and configured to control reception of a signal from the image capturing apparatus through a first communication channel, reception of data from the image capturing apparatus through a third communication channel, and transmission of data from the accessory apparatus through a second communication channel, and to control transmission of accessory attribute information of the accessory apparatus through the second communication channel, the control method comprising:

• controlling communications to transmit, by the communication control section, first accessory attribute information of the accessory attribute information through the second communication channel by using a first communication method, then switching from the first communication method to a second communication method different from the first communication method, and controlling communications to transmit second accessory attribute information of the accessory attribute information including information indicating function that can be performed by the accessory apparatus through the second communication channel by using the second communication method,
• wherein the first communication method is a communication method in which, at a timing corresponding to reception, through the first communication channel, of a clock signal of which a signal level switches alternately between a first signal level and a second signal level different from the first signal level, reception of data through the third communication channel and transmission of data through the second communication channel are performed,
• wherein the second communication method is a communication method in which, in response to transmission of data through the second communication channel in response to switching of the signal level of the first communication channel from the first signal level to the second signal level, data is received through the third communication channel, and
• wherein the second accessory attribute information contains information indicating function that can be performed by the second communication method which is not included in the first accessory attribute information.