Patent ID: 8213787

Claim:
A camera system comprising a replaceable lens and a body unit in which the replaceable lens is installed, wherein the replaceable lens comprises: a focus lens for changing a focal point location; a driver for driving the focus lens; a detector for detecting a location of the focus lens; and a lens controller comprising a timer for measuring a point of time, wherein the lens controller transmits information corresponding to the detected location of the focus lens to the body unit, the body unit comprises: an imaging device for capturing light transmitted through the replaceable lens and for generating an image signal; an imaging-device controller for generating a timing signal and for controlling the imaging device to capture the light in synchronization with the timing signal; and a camera controller for: performing auto focusing (AF) detection on the image signal to calculate an AF estimation value, storing the AF estimation value for each of respective AF detection time according to the timing signal, calculating the focal point location by using location information transmitted from the replaceable lens and the stored AF estimation value, and transmitting the result of the calculation to the replaceable lens, and wherein the lens controller transmits the information corresponding to the location of the focus lens to the body unit asynchronously with the timing signal.