Camera with autofocusing device
AssigneeCanon Kabushiki Kaisha
InventorIchiro Shimizu
Life of this patent
Estimating the term…
Abstract
In a camera having a photo-taking lens adapted to be preceded by an attachment lens to effect a change in focal length, an autofocusing device whose distance measuring portion operates with an optical system outside the photo-taking lens. The autofocusing device is provided with a sensing device responsive to the detection of the attachment lens for excluding the operation of the automatic focus adjustment from the focusing mechanism for the photo-taking lens.
Claims13
A camera having a photo-taking lens mounting mechanism which is receptive of an optical accessory for effecting a change in focal length at the front end thereof, comprising:
- (a) a photo-taking lens mounting mechanism having:
- a photo-taking lens optical system;
- focusing adjusting means for performing focus adjustment of said photo-taking lens optical system, said focus adjusting means being manually operable;
- and
- coupling means for selectively mounting and de-mounting said optical accessory;
- (b) a view finder;
- (c) automatic focus adjustment means for automatically detecting a distance from the camera to an object to be photographed and for automatically controlling the operation of said focus adjusting means, said automatic focus adjustment means having:
- a distance measuring optical system arranged on an optical axis different from the optical axis of said photo-taking lens optical system;
- control circuit means responsive to a signal representative of the distance from said distance measuring optical system for producing a control signal;
- and
- drive means responsive to the control signal from said control circuit means for driving, said drive means being operatively connected to said focus adjusting means;
- and
- (d) detecting and changeover means responsive to the detection of the presence of said optical accessory at said coupling means for operatively excluding the operation of said automatic focus adjustment means, said detecting and changeover means including display means cooperative with the exclusion of the operation of said automatic focus adjustment means for indicating such exclusion in the field of view of said view finder.
A camera having a photo-taking lens mounting mechanism receptive of an optical accessory for effecting a change in focal length at the front end thereof, comprising:
- (a) a camera body for holding a photo-taking lens mounting mechanism;
- (b) a photo-taking lens mounting mechanism having:
- a photo-taking lens optical system;
- focus adjusting means for performing focus adjustment of said photo-taking lens optical system, said focus adjusting means being manually operable;
- and
- coupling means for selectively mounting and de-mounting said optical accessory;
- (c) a view finder;
- (d) automatic focus adjustment means for automatically detecting a distance from the camera to an object to be photographed and for automatically controlling the operation of said focus adjusting means, said means being arranged in said body and having;
- a distance measuring optical system arranged on an optical axis entirely independent of the optical axis of said photo-taking lens;
- control circuit means responsive to a signal representative of the distance from said distance measuring optical system for producing a control signal;
- and
- drive means responsive to the control signal from said control circuit means for driving, said drive means being operatively connected to said focus adjusting means;
- and
- (e) detecting and changeover means having a detecting portion for detecting the presence of said optical accessory at said coupling means and being arranged upon movement by the coupling of said optical accessory to operatively exclude the operation of said automatic focus adjustment means, said detecting and changeover means having display means cooperative with the exclusion of the operation of the automatic focus adjustment means to indicate such exclusion in the field of view of the view finder.
Dependencies are inferred from the claim text.