PURPOSE: To transfer open-aperture value information and automatic-manual exposure switching information through one common couple of contacts by providing a switch for inputting the open-aperture value of a lens effectively to a body-side circuit by operating electric resistance having the value corresponding to the open-aperture value at an automatic exposure position.
CONSTITUTION: An electric contact 5 is provided to the front surface of a body- side mount 2 and an electric contact 11 is provided to a lens-side mount 7. The electric resistance r1 having the value corresponding to the open-aperture value of the lens is connected between conductive members 17 and 18 in the lens, and the free end part of a switch contact piece 19 contacts or leaves the conductive member 18 according to the turning of an aperture ring 8 to constitute the switch SW. The lens is mounted on the body 1 and when the aperture ring 8 of the lens is set in automatic exposure mode, the switch SW turns on to input open-aperture value information on the lens to the automatic exposure control circuit of the body 1 effectively through the contacts 11 and 5. When the aperture ring 8 is switched to manual exposure mode, the switch SW turns off.
| JPS5640816 | INTERCHANGEABLE LENS |
ARAKI KUNIHIKO
HOKARI SABUROU
| JPS52152220A | 1977-12-17 | |||
| JPS5677824A | 1981-06-26 |