Focus detecting system using light from an imaging optical system for focus detection

Claim 2

A focus detecting system comprising: an imaging optical system having an exit pupil; an auxiliary optical system disposed rearwardly of said imaging optical system, said auxiliary optical system forming a plurality of intensity distributions regarding an object by light beams passed through a plurality of different portions of the exit pupil of said imaging optical system; photoelectric conversion element arrays each comprising a plurality of elements and disposed at locations whereat said plurality of intensity distributions are formed, said photoelectric conversion element arrays putting out electrical signals corresponding to said intensity distributions, each of the elements of the first one of said photoelectric conversion element arrays having a first and a second correspondence relation with each of the elements of the second one of said photoelectric conversion element arrays; signal processing operation means comparing the output signals from an element of said first photoelectric conversion element array and from an element of said second photoelectric conversion element array which are in said first correspondence relation, extracting one of the minimum and maximum of said output signals, extracting the same with respect to all elements which are in said first correspondence relation and obtaining an integrated signal value A 1 , said signal processing operation means comparing the output signals from an element of said first photoelectric conversion element array and from an element of said second photoelectric conversion element array which are in said second correspondence relation, extracting one of the minimum and maximum of said output signals, extracting one of the minimum and maximum output signals with respect to all elements which are in said second correspondence relation and obtaining an integrated signal A 2 , said signal processing operation means calculating and finding a signal value A from said signal values A 1 and A 2 by an equation A=A 1 -A 2 ; and focusing state discriminating means for discriminating the state of focus of said imaging optical system by the use of said signal value A.

Claim 3

A focus detecting system according to claim 1, wherein the number of elements of said first photoelectric conversion element array is the same as the number of elements of said second photoelectric conversion element array.

Claim 4

A focus detecting system according to claim 2, wherein the first and second correspondence relations between each element of said first photoelectric conversion element array and each element of said second photoelectric conversion element array are such that the elements of said two photoelectric conversion element arrays are shifted by an amount corresponding to at least one element.

Claim 5

A focus detecting system according to claim 1, wherein said auxiliary optical system is disposed near the image plane of said imaging optical system and has a plurality of lenses, at least two photoelectric conversion elements are disposed rearwardly of said lenses, one of said at least two photoelectric conversion elements is a part of said first photoelectric conversion element array and the other of said at least two photoelectric conversion elements is a part of said second photoelectric conversion element array.

Claim 6

A focus detection method for system comprising: an imaging optical system having an exit pupil; an auxiliary optical system disposed rearwardly of said imaging optical system, said auxiliary optical system forming a plurality of intensity distribution regarding an object by light beams passed through a plurality of different portions of the exit pupil of said imaging optical system; and photoelectric conversion element arrays each comprising a plurality of elements and disposed at locations whereat said plurality of intensity distributions are formed, said photoelectric conversion element arrays putting out electrical signals corresponding to said intensity distributions, said method comprising the steps: causing each of the elements of the first one of said photoelectric conversion element arrays to have a first and a second correspondence relation with each of the elements of the second one of said photoelectric conversion element arrays; comparing the output signals from an element of said first photoelectric conversion element array and from an element of said second photoelectric conversion element array which are in said first correspondence relation; extracting one of the minimum and maximum of said output signals; extracting one of the minimum and maximum signal with respect to all elements which are in said first correspondence relation; obtaining an integrated signal value A 1 ; comparing the output signals from an element of said first photoelectric conversion element array and from an element of said second photoelectric conversion element array which are in said second correspondence relation; extracting one of the minimum and maximum of said output signals; extracting one of the minimum and maximum signals with respect to all elements which are in said second correspondence relation and obtaining an integrated signal value A 2 ; calculating and finding a signal value A from said signal values A 1 and A 2 by an equation A=A 1 -A 2 ; successively varying the first and second correspondence relations between said first and second photoelectric conversion element arrays and obtaining a signal value group B of the signal value A of a number corresponding to the number of variations; and calculating the amount of defocus of said imaging optical system by the use of said signal value group B.

Claim 7

A focus detection method for system comprising: an imaging optical system having an exit pupil; an auxiliary optical system disposed rearwardly of said imaging optical system, said auxiliary optical system forming a plurality of intensity distribution regarding an object by light beams passed through a plurality of different portions of the exit pupil of said imaging optical system; and photoelectric conversion element arrays each comprising a plurality of elements and disposed at locations whereat said plurality of intensity distributions are formed, said photoelectric conversion element arrays putting out electrical signals corresponding to said intensity distributions, said method comprising the steps: causing each of the elements of the first one of said photoelectric conversion element arrays to have a first and a second correspondence relation with each of the elements of the second one of said photoelectric conversion element arrays; comparing the output signals from an element of said first photoelectric conversion element array and from an element of said second photoelectric conversion element array which are in said first correspondence relation; extracting one of the minimum and maximum of said output signals; extracting one of the minimum and maximum signal with respect to all elements which are in said first correspondence relation; obtaining an integrated signal value A 1 ; comparing the output signals from an element of said first photoelectric conversion element array and from an element of said second photoelectric conversion element array which are in said second correspondence relation; extracting one of the minimum and maximum of said output signals; extracting one of the minimum and maximum signals with respect to all elements which are in said second correspondence relation and obtaining an integrated signal value A 2 ; calculating and finding a signal value A from said signal values A 1 and A 2 by an equation A=A 1 -A 2 ; successively varying the first and second correspondence relations between said first and second photoelectric conversion element arrays and obtaining a signal value group B of the signal value A of a number corresponding to the number of variations; and calculating the amount of defocus of said imaging optical system by the use of said signal value group B.

Claim 8

A focus detecting system comprising: an imaging optical system having an exit pupil; an auxiliary optical system disposed rearwardly of said imaging optical system and having an entrance pupil, said auxiliary optical system forming a plurality of intensity distribution regarding an object by light beams passed through a plurality of different portions of the exit pupil of said imaging optical system; photoelectric conversion element arrays each comprising a plurality of elements and disposed at locations whereat said plurality of intensity distributions are formed, said photoelectric conversion element arrays putting out electrical signals corresponding to said intensity distributions, each of the elements of the first one of said photoelectric conversion element arrays having a first and a second correspondence relation with each of the elements of the second one of said photoelectric conversion element arrays; signal processing operation means comparing the output signals from an element of said first photoelectric conversion element array and from an element of said second photoelectric conversion element array which are in said first correspondence relation, extracting one of the minimum and maximum of said output signals, extracting the same with respect to all elements which are in said first correspondence relation and obtaining an integrated signal value A 1 , said signal processing operation means comparing the output signals from an element of said first photoelectric conversion element array and from an element of said second photoelectric conversion element array which are in said second correspondence relation, extracting one of the minimum and maximum of said output signals, extracting the same with respect to all elements which are in said second correspondence relation and obtaining an integrated signal value A 2 , said signal processing operation means calculating and finding a signal value A from said signal values A 1 and A 2 by an equation A=A 1 -A 2 , said signal processing operation means successively varying the first and second correspondence relations between said first and second photoelectric conversion element arrays and obtaining a signal value group B of the signal value A of a number corresponding to the number of variations; and focusing state discriminating means for calculating the amount of defocus of said imaging optical system by the use of said signal value group B.

Claim 9

A focus detecting system comprising: an imaging optical system having an exit pupil; an auxiliary optical system disposed rearwardly of said imaging optical system and having an entrance pupil, said auxiliary optical system forming a plurality of intensity distribution regarding an object by light beams passed through a plurality of different portions of the exit pupil of said imaging optical system; photoelectric conversion element arrays each comprising a plurality of elements and disposed at locations whereat said plurality of intensity distributions are formed, said photoelectric conversion element arrays putting out electrical signals corresponding to said intensity distributions, each of the elements of the first one of said photoelectric conversion element arrays having a first and a second correspondence relation with each of the elements of the second one of said photoelectric conversion element arrays; signal processing operation means comparing the output signals from an element of said first photoelectric conversion element array and from an element of said second photoelectric conversion element array which are in said first correspondence relation, extracting one of the minimum and maximum of said output signals, extracting the same with respect to all elements which are in said first correspondence relation and obtaining an integrated signal value A 1 , said signal processing operation means comparing the output signals from an element of said first photoelectric conversion element array and from an element of said second photoelectric conversion element array which are in said second correspondence relation, extracting one of the minimum and maximum of said output signals, extracting the same with respect to all elements which are in said second correspondence relation and obtaining an integrated signal value A 2 , said signal processing operation means calculating and finding a signal value A from said signal values A 1 and A 2 by an equation A=A 1 -A 2 , said signal processing operation means successively varying the first and second correspondence relations between said first and second photoelectric conversion element arrays and obtaining a signal value group B of the signal value A of a number corresponding to the number of variations; and focusing state discriminating means for calculating the amount of defocus of said imaging optical system by the use of said signal value group B.

Claim 10

A focus detecting system according to claim 6, wherein the number of elements of said first photoelectric conversion element array is the same as the number of elements of said second photoelectric conversion element array.

Claim 11

A focus detecting system according to claim 6, further comprising a field lens disposed near the imaging plane of said imaging optical system, said field lens imaging the entrance pupil of said auxiliary optical system near the exit pupil of said imaging optical system.

Claim 12

A focus detecting system according to claim 6, wherein said auxiliary optical system is disposed near the image plane of said imaging optical system and has a plurality of lenses, at least two photoelectric conversion elements are disposed rearwardly of said lenses, one of said at least two photoelectric conversion elements is a part of said first photoelectric conversion element array and the other of said at least two photoelectric conversion elements is a part of said second photoelectric conversion element array.

Claim 13

A focus detecting system according to claim 6, wherein when electrical signals put out from the respective elements of said first and second photoelectric conversion element arrays are a 1 , a 2 , a 3 , . . . a i . . . , a N and b 1 , b 2 , b 3 , . . . b i . . . , b N , said first correspondence relation is a i and b i+k-m and said second correspondence relation is a i+k and b i-m , where i is a suffix indicative of the number of each element of said photoelectric conversion element arrays, m is an amount of relation displacement, and k is a parameter corresponding to the variation in the correspondence relation.

Claim 14

A focus detecting system comprising: an imaging optical system having an exit pupil; an auxiliary optical system disposed rearwardly of said imaging optical system, said auxiliary optical system forming a plurality of intensity distributions regarding an object by light beams passed through a plurality of different portions of the exit pupil of said imaging optical system; photoelectric conversion element arrays each comprising a plurality of elements and disposed at locations whereat said plurality of intensity distributions are formed, said photoelectric conversion element arrays putting out electrical signals corresponding to the distribution states of said intensity distributions, each of the elements of the first one of said photoelectric conversion element arrays having a predetermined correspondence relation with each of the elements of the second one of said photoelectric conversion element arrays; signal processing operation means comparing the output signals from an element of said first photoelectric conversion element array and from an element of said second photoelectric conversion element array which are in said predetermined correspondence relation, extracting one of the minimum and maximum of said output signals, extracting the same with respect to all elements which are in said predetermined correspondence relation and obtaining an integrated signal value A, said signal processing operation means successively varying the predetermined correspondence relation between said first and second photoelectric conversion element arrays and obtaining a signal value group B of the signal value A of a number corresponding to the number of variations; and focusing state discriminating means for calculating the amount of defocus of said imaging optical system by the use of said signal value group B.

Claim 15

A focus detecting system comprising: an imaging optical system having an exit pupil; an auxiliary optical system disposed rearwardly of said imaging optical system, said auxiliary optical system forming a plurality of intensity distributions regarding an object by light beams passed through a plurality of different portions of the exit pupil of said imaging optical system; photoelectric conversion element arrays each comprising a plurality of elements and disposed at locations whereat said plurality of intensity distributions are formed, said photoelectric conversion element arrays putting out electrical signals corresponding to the distribution states of said intensity distributions, each of the elements of the first one of said photoelectric conversion element arrays having a predetermined correspondence relation with each of the elements of the second one of said photoelectric conversion element arrays; signal processing operation means comparing the output signals from an element of said first photoelectric conversion element array and from an element of said second photoelectric conversion element array which are in said predetermined correspondence relation, extracting one of the minimum and maximum of said output signals, extracting the same with respect to all elements which are in said predetermined correspondence relation and obtaining an integrated signal value A, said signal processing operation means successively varying the predetermined correspondence relation between said first and second photoelectric conversion element arrays and obtaining a signal value group B of the signal value A of a number corresponding to the number of variations; and focusing state discriminating means for calculating the amount of defocus of said imaging optical system by the use of said signal value group B.

Claim 16

A focus detecting system according to claim 11, wherein when electrical signals put out from the respective elements of said first and second photoelectric conversion element arrays are a 1 , a 2 , a 3 , . . . a i . . . , a N and b 1 , b 2 , b 3 , . . . b i . . . , b N , said correspondence relation is a i and b i-m , where i is a suffix indicative of the number of each element of said photoelectric conversion element arrays, and k is a parameter corresponding to the variation in the correspondence relation.

Claim 17

A focus detection method for system comprising: an imaging optical system having an exit pupil; an auxiliary optical system disposed rearwardly of said imaging optical system, said auxiliary optical system forming a plurality of intensity distributions regarding an object by light beams passed through a plurality of different portions of the exit pupil of said imaging optical system; and photoelectric conversion element arrays each comprising a plurality of elements and disposed at locations whereat said plurality of intensity distributions are formed, said photoelectric conversion element arrays putting out electrical signals corresponding to said intensity distributions, said method comprising the steps: causing each of the elements of the first one of said photoelectric conversion element arrays to have predetermined correspondence relation with each of the elements of the second one of said photoelectric conversion element arrays; comparing the output signals from an element of said first photoelectric conversion element array and from an element of said second photoelectric conversion element array which are in said predetermined correspondence relation; extracting one of the minimum and maximum of said output signals; extracting one of the minimum and maximum signals with respect to all elements which are in said predetermined correspondence relation; obtaining an integrated signal value A; successively varying the predetermined correspondence relation between said first and second photoelectric conversion element arrays and obtaining a signal value group B of the signal value A of a number corresponding to the number of variations; and calculating the amount of defocus of said imaging optical system by the use of said signal value group B.

Claim 18

A focus detection method for system comprising: an imaging optical system having an exit pupil; an auxiliary optical system disposed rearwardly of said imaging optical system, said auxiliary optical system forming a plurality of intensity distributions regarding an object by light beams passed through a plurality of different portions of the exit pupil of said imaging optical system; and photoelectric conversion element arrays each comprising a plurality of elements and disposed at locations whereat said plurality of intensity distributions are formed, said photoelectric conversion element arrays putting out electrical signals corresponding to said intensity distributions, said method comprising the steps: causing each of the elements of the first one of said photoelectric conversion element arrays to have predetermined correspondence relation with each of the elements of the second one of said photoelectric conversion element arrays; comparing the output signals from an element of said first photoelectric conversion element array and from an element of said second photoelectric conversion element array which are in said predetermined correspondence relation; extracting one of the minimum and maximum of said output signals; extracting one of the minimum and maximum signals with respect to all elements which are in said predetermined correspondence relation; obtaining an integrated signal value A; successively varying the predetermined correspondence relation between said first and second photoelectric conversion element arrays and obtaining a signal value group B of the signal value A of a number corresponding to the number of variations; and calculating the amount of defocus of said imaging optical system by the use of said signal value group B.