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US 5,393,969 AGranted
Device for detecting focus at different areas of an image field
AssigneeNikon Corporation
InventorKeiji Ohsawa
Life of this patent
Estimating the term…
Abstract
A focus state detecting device of divided-pupil phase difference system, having plural distance measuring areas, in which photosensors are provided respectively corresponding to the distance measuring areas in the image field in order to effect focus state detection in the plural distance measuring areas, and at least a part of the photosensors are constructed as an independent unit separate from others, whereby optical adjustment is rendered possible independently in each distance measuring area.
Claims33
A focus state detecting device provided with:
- plural re-imaging means positioned at the image plane side of an objective lens and adapted to form different images of an object, respectively utilizing lights reaching different areas in the image field;
- and
- plural photosensor means for respectively receiving plural lights coming from the object and transmitted by said plural re-imaging means;
- and
- adapted to detect the focus state of said objective lens based on signals from said photosensor means, comprising:
- plural condenser lens means positioned respectively corresponding to said different areas in the image field;
- wherein said plural condenser lens means are integrally constructed as a single unit;
- said plural re-imaging means are integrally constructed as a single unit;
- and
- among said plural photosensor means, at least one is constructed as an independent unit separate from other photosensor means.
7 more elements
A focus state detecting device provided with:
- plural re-imaging means positioned at the image plane side of an objective lens and adapted to form different images of an object, respectively utilizing lights reaching different areas in the image field;
- and
- plural photosensor means for respectively receiving plural lights coming from the object and transmitted by said plural re-imaging means;
- and adapted to detect the focus state of said objective lens based on signals from said photosensor means, comprising:
- plural condenser lens means positioned respectively corresponding to said different areas in the image field;
- wherein said plural condenser lens means are integrally constructed as a single unit;
- among said plural re-imaging means, at least one is constructed independently from other re-imaging means;
- and
- among said plural photosensor means, at least one is constructed as an independent unit separate from other photosensor means.
6 more elements
A focus state detecting device provided with:
- plural re-imaging means positioned at the image plane side of an objective lens and adapted to form different images of an object, respectively utilizing lights reaching different areas in the image field;
- and
- plural photosensor means for respectively receiving plural lights coming from the object and transmitted by said plural re-imaging means;
- and adapted to detect the focus state of said objective lens based on signals from said photosensor means, comprising:
- plural condenser lens means positioned respectively corresponding to said different areas in the image field;
- wherein, among said plural photosensor means, at least one is constructed as an independent unit separate from other photosensor means;
- the photosensor means constructed as said independent unit includes two pairs of photosensor units;
- and
- said re-imaging means corresponding to said photosensor means constructed as said independent unit includes two pairs of re-imaging lenses.
6 more elements
A focus state detecting device provided with:
- plural re-imaging means positioned at the image plane side of an objective lens for forming images of different areas, respectively, of an image field of the objective lens, respectively utilizing lights reaching said different areas of the image field;
- and
- plural photosensor means respectively receiving plural lights coming from an object and transmitted by said plural re-imaging means for performing focus detection at said different areas of the image field and detecting the focus state of said objective lens based on signals from said photosensor means, comprising:
- plural condenser lens means positioned respectively corresponding to said different areas of the image field;
- wherein, among said plural photosensor means, at least one is constructed as an independent unit separate from other photosensor means, and at least one of photosensor means in said independent unit is so supported as not to be parallel to other photosensor means.
2 more elements
A focus state detecting device provided with:
- plural re-imaging means positioned at the image plane side of an objective lens for forming images of different areas, respectively, of an image field of the objective lens, respectively utilizing lights reaching said different areas of the image field;
- and
- plural photosensor means respectively receiving plural lights coming from an object and transmitted by said plural re-imaging means for performing focus detection at said different areas of the image field and detecting the focus state of said objective lens based on signals from said photosensor means, comprising:
- condenser lens means positioned between said objective lens and said re-imaging means including plural condenser lenses corresponding to said different areas in the same optical path;
- wherein at least one of said plural photosensor means is constructed as an independent unit separate from other photosensor means.
2 more elements
A focus state detecting device provided with:
- plural re-imaging lenses adapted to form images of different areas of an image field, respectively utilizing lights reaching said different areas of the image field;
- and
- plural light-receiving parts respectively receiving plural lights coming from an object and transmitted by said plural re-imaging lenses to detect the focus state of an objective lens based on signals from said light-receiving parts, comprising:
- plural condenser lenses positioned respectively corresponding to said different areas of the image field;
- wherein said plural condenser lenses are integrally constructed as a single unit;
- said plural re-imaging lenses are integrally constructed as a single unit;
- and
- at least one of said plural light-receiving parts is constructed as an independent unit separate from other light-receiving parts.
5 more elements
A focus state detecting device provided with:
- plural re-imaging lenses adapted to form images of different areas of an image field, respectively utilizing lights reaching said different areas of the image field;
- and
- plural light-receiving parts respectively receiving plural lights coming from an object and transmitted by said plural re-imaging lenses to detect the focus state of an objective lens based on signals from said light-receiving parts, comprising:
- plural condenser lenses positioned respectively corresponding to said different areas of the image field;
- wherein said plural condenser lenses are integrally constructed as a single unit;
- at least one of said plural re-imaging lenses is constructed independently from other re-imaging lenses;
- and
- at least one of said plural light-receiving parts is constructed as an independent unit separate from other light-receiving parts.
5 more elements
A focus state detecting device provided with:
- plural re-imaging lenses adapted to form images of different areas of an image field, respectively utilizing lights reaching said different areas of the image field;
- and
- plural light-receiving parts respectively receiving plural lights coming from an object and transmitted by said plural re-imaging lenses to detect the focus state of an objective lens based on signals from said light-receiving parts, comprising:
- plural condenser lenses positioned respectively corresponding to said different areas of the image field;
- wherein, at least one of said plural light-receiving parts is constructed as an independent unit separate from other light-receiving parts;
- said at least one light-receiving part constructed as said independent unit includes two pairs of light-receiving elements;
- and
- said re-imaging lenses transmitting lights coming from one condenser lens of said plural condenser lenses to said at least one light-receiving part constructed as said independent unit include two pairs of re-imaging lenses.
5 more elements
A focus state detecting device provided with:
- plural re-imaging lenses adapted to form images of different areas of an image field, respectively utilizing lights reaching said different areas of the image field;
- and
- plural light-receiving parts respectively receiving plural lights coming from an object and transmitted by said plural re-imaging lenses and performing focus detection at said different areas of the image field to detect the focus state of an objective lens based on signals of said light-receiving parts, comprising:
- plural condenser lenses positioned respectively corresponding to said different areas of the image field;
- wherein at least one of said plurality of light-receiving parts is constructed as an independent unit separate from other light-receiving parts, and at least one of said light-receiving parts in said independent unit is so supported as not to be parallel to other light-receiving parts.
2 more elements
A focus state detecting device provided with:
- plural re-imaging lenses adapted to form images of different areas of an image field, respectively utilizing lights reaching said different areas of the image field;
- and
- plural light-receiving parts respectively receiving plural lights coming from an object and transmitted by said plural re-imaging lenses and determining the focus state of said images to detect the focus state of an objective lens based on signals of said light-receiving parts, comprising:
- plural condenser lenses positioned respectively corresponding to said different areas of the image field in the same optical path;
- wherein at least one of said plural light-receiving parts is constructed as an independent unit separate from other light-receiving parts.
2 more elements
Dependencies are inferred from the claim text.