초록 ▼

A single lens reflex camera including an objective having an optical axis for focusing an image of an object and a device for determining when the objective has properly focused an image at an image plane which is located at a position which is optically equivalent to the location of the film plane,

A single lens reflex camera including an objective having an optical axis for focusing an image of an object and a device for determining when the objective has properly focused an image at an image plane which is located at a position which is optically equivalent to the location of the film plane, the latter including an image-forming device including a first refracting device for receiving an image from the objective and for providing at least a pair of identical images of the object to be photographed at the image plane, a detecting plane provided along the optical axis having a pair of identical photosensitive detectors, each of which provides an output which varies as the image is moved longitudinally therealong and an image-transmitting device situated at least in part at the image plane which includes a second refracting device for receiving the images from a first refracting device and for participating in the transmission thereof to the detecting plane in a manner according to which the identical images simultaneously move equally in opposite directions along the pair of detectors in response to adjustment of the objective.

대표청구항 ▼

In a single lens reflex camera, objective means having a first optical axis for focusing an image of an object which is to be photographed in a film plane which is normal to said first optical axis, view finder means, and semitransparent reflector means extending across said first optical axis betwe

In a single lens reflex camera, objective means having a first optical axis for focusing an image of an object which is to be photographed in a film plane which is normal to said first optical axis, view finder means, and semitransparent reflector means extending across said first optical axis between said objective means and film plane for reflecting an image of the object to said view finder means while permitting an image also to be focused by said objective means at said film plane, light-deflecting means situated behind said reflector means between the latter and said film plane for deflecting light traveling through said semitransparent reflector means from said first optical axis to a path extending along a second optical axis which branches from said first optical axis, and a device for determining when said objective means has properly focused an image at said film plane, said device comprising an optical system situated at least in part along said second optical axis and including along said second optical axis an image plane normal to said second optical axis and having at said second optical axis a location which is optically equivalent to the location of said film plane along said first optical axis, said optical system including in advance of said image plane at least at one of said optical axes an image-forming means including a first refracting means for receiving an image from said objective means and for providing therefrom at least a pair of identical images of the object to be photographed at said image plane, and said optical system having beyond said image plane along said second optical axis a detecting plane also normal to said second optical axis and at said detecting plane at least a pair of identical elongated photosensitive detecting means which have respectively optically equivalent positions with respect to said second optical axis, each of said detecting means providing an output which varies as an image is moved longitudinally along each detecting means, said optical system including an imagetransmitting means situated at least in part at said image plane including a second refracting means situated at said image plane for receiving each of said identical images of the object to be photographed from said first refracting means and for participating in the transmission thereof to said detecting plane in a manner according to which said identical images of the object to be photographed simultaneously move equally in opposite directions along said pair of detecting means in response to adjustment of said objective means to focus an image at said film plane, said pair of detecting means providing equal outputs when the images at said pair of detecting means are respectively situated at identical positions with respect thereto and different outputs when said images at said pair of detecting means are respectively situated at different positions with respect thereto, and the image transmitted by said objective means to said film plane being properly focused at said film plane when the pair of images at said pair of detecting means are respectively at the same positions with respect thereto, and indicating means operatively connected with said pair of elongated detecting means for indicating that when the identical transmitted to said pair of elongated detecting means are respectively situated at identical positions therealong, this indicating when said objective means has been set to focus an image properly at said film plane.