Automatic focusing system of photographic camera

Claim 2

An automatic focusing system of a photographic camera comprising: a distance measuring device to produce an analog signal representative of distance from a film plane to subjects, said distance measuring device including a light emitting means for throwing light toward the subjects, and a position detector receiving light reflected from the subjects for producing said distance signal, and in which the place on the position detector where the light falls varies according to the distance to the subject illuminated; means for driving said distance measuring device to scan a range to be photographed; an analog peak and hold memory for detecting and holding a value of said distance signal appearing during the scanning and corresponding to the nearest subject; and means responsive to said value of said distance signal held by said memory for moving a photographic lens of the camera to focus the image of the nearest subject on said film plane.

Claim 3

An automatic focusing system of a photographic camera comprising: a distance measuring device to produce continuously an analog signal representative of distance from a film plane to subjects, said distance measuring device includes a light emitting means for throwing light toward the subjects, and a position detector receiving light reflected from the subjects for producing said distance signal, and in which the place on the position detector where the light falls varies according to the distance to the subject illuminated; means for driving said distance measuring device to scan a certain predetermined zone within a range to be photographed, and to measure the distance between the film place and each of the scanned subjects; a memory for detecting and holding a value of said distance signal appearing during the scanning and corresponding to the nearest subject; and means responsive to said value of said distance signal held by said memory for moving a photographic lens of the camera to focus the image of the nearest subject on said film plane.

Claim 4

An automatic focusing system of a photographic camera comprising: a distance measuring device to produce continuously an analog signal representative of distance from a film plane to subjects, said distance measuring device includes a light emitting means for throwing light toward the subjects, and a position detector receiving light reflected from the subjects for producing said distance signal, and in which the place on the position detector where the light falls varies according to the distance to the subject illuminated; means for driving said distance measuring device to scan a certain predetermined zone within a range to be photographed, and to measure the distance between the film place and each of the scanned subjects; a memory for detecting and holding a value of said distance signal appearing during the scanning and corresponding to the nearest subject; and means responsive to said value of said distance signal held by said memory for moving a photographic lens of the camera to focus the image of the nearest subject on said film plane.

Claim 5

An automatic focusing system of a photographic camera as claimed in claim 2, in which said means for driving said distance measuring device is arranged to rotate said distance detector through an angle within a range which can be photographed, thereby to cause said distance measuring device to scan.

Claim 6

An automatic focusing system of a photographic camera as claimed in claim 2, in which said light emitting means comprises a light emitting diode, and a first optical system through which the light emitted from said light emitting diode is directed toward the subjects, and in which said position detector comprises a second optical system through which light reflected from the subjects is focused on a photoelectric converter having a definite length, the place on said photoelectric converter where the light falls varying according to the distance to the subjects.

Claim 7

An automatic focusing system of a photographic camera as claimed in claim 4, in which said light emitting diode and said photoelectric converter are fixed while said first and second optical systems are moved by a common drive mechanism in a direction parallel with a lengthwise direction of said photoelectric converter.

Claim 8

An automatic focusing system of a photographic camera as claimed in claim 4, in which said first and second optical systems are fixed while said light emitting diode and said photoelectric converter are moved by a common drive mechanism in a direction parallel with a lengthwise direction of said photoelectric converter.

Claim 9

An automatic focusing system of a photographic camera comprising: a distance measuring device to continuously produce an analog distance signal representative of distance from a film plane to subjects; means for driving said distance measuring device to scan a certain predetermined zone within a range to be Photographed, and to measure the distance between the film plane and each of the scanned subjects; an analog peak and hold memory for detecting and holding a value of said distance signal appearing during the scanning and corresponding to the nearest subject; and means responsive to said value of said distance signal held by said memory for moving a photographic lens of the camera to focus the image of the nearest subject on said film plane.

Claim 10

An automatic focusing system of a photographic camera comprising: a distance measuring device to continuously produce an analog distance signal representative of distance from a film plane to subjects; means for driving said distance measuring device to scan a certain predetermined zone within a range to be Photographed, and to measure the distance between the film plane and each of the scanned subjects; an analog peak and hold memory for detecting and holding a value of said distance signal appearing during the scanning and corresponding to the nearest subject; and means responsive to said value of said distance signal held by said memory for moving a photographic lens of the camera to focus the image of the nearest subject on said film plane.

Claim 11

An automatic focusing system of a photographic camera as claimed in claim 7 in which said means for driving said distance measuring device is arranged to rotate said distance detector through an angle within a range which can be photographed, thereby to cause said distance measuring device to scan.