Patent ID: 6183145
Filing Date: 2001-02-06
Classification: G03B

Abstract:
An accessory device constituting at least part of a photographic optical system and adapted to be mounted on a camera, said camera including a power source therein, a mount, a first electric circuit for producing control signals, first terminal means for outputting said control signal, second terminal means for supplying power from said power source, and first and second ground terminals for said power source, said first and second ground terminals being connected to said power source through separate electrical conductors, said accessory device comprising:(a) means for attaching the accessory device onto said mount of the camera;(b) third terminal means to be connected with said second terminal means when said accessory device is mounted on the camera and third and fourth ground terminals to be independently connected with said first and second ground terminals, respectively, said third terminal means and said third ground terminal being arranged so as to supply power to a motor circuit, said third terminal means and said fourth ground terminal being arranged so as to supply power to a second electric circuit; and(c) fourth terminal means to be connected with said first terminal means when said accessory device is mounted on the camera, said fourth terminal means being arranged to transmit said control signals to an input terminal means of said second electric circuit for operating said second electric circuit in accordance with said control signals.