Interchangeable camera lens assembly

Claim 1

An interchangeable lens assembly for a single lens reflex camera having complementary coupling means and complementary retainer means thereon comprising: a first lens assembly including first lens barrel means, first coupling means adapted to be engaged with said complementary coupling means on said camera by rotative operation of said first lens barrel means when said interchangeable lens assembly is mounted on said camera so as to couple said interchangeable lens assembly with said camera, adapter means mounted inside said first lens barrel means and arranged to be rotative relative to said first lens barrel means, retainer means operating in cooperation with said complementary retainer means on said camera so as to fix said adapter means on said camera, light control means for controlling the light entering said camera through said interchangeable lens assembly either by manual operation thereof or in response to exposure information from said camera, signal transmission means including a signal transmission member held by said adapter means for transmission of exposure control signals between said interchangeable lens assembly and said camera, and second coupling means arranged at one end of said first lens barrel means; a second lens assembly including second lens barrel means, and third coupling means for coupling said second lens barrel means with said first lens barrel means, said second lens barrel means having a focus adjustable phototaking lens.