Optical apparatus with focus adjusting function and focus adjustment control circuit

• US 6,157,782 A
• Filed: 02/01/2000
• Issued: 12/05/2000
• Est. Priority Date: 12/24/1997
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Aoyama, Keisuke
• Primary Examiner(s): PERKEY, WILLIAM B
• Application Number:
  US09/494,922
• Time in Patent Office: 308 Days
• Field of Search: 396/121, 396/122, 396/123, 396/104
• US Class Current: 396/104
• CPC Class Codes: G02B 7/34 using different areas in a pupil plane
• CPC Class Codes: G02B 7/36 using image sharpness techniques , e.g. image processing techniques for generating autofocus signals image data processing per se G06T; in cameras having a solid state image sensor H04N23/67

Abstract

An optical apparatus having a focus adjusting function, including: a focus detection unit for executing a focus detection operation for each of a plurality of focus areas set in an image plane; a grouping unit for grouping the image plane in accordance with a distribution of defocus amounts or distances obtained from focus detection results of the plurality of focus areas; a focus area selecting unit for selecting at least one focus area from the plurality of focus areas in accordance with a grouping result; a defocus amount comparing unit for comparing a defocus amount of the selected focus area selected with a predetermined defocus amount; a lens driving unit for driving a lens until the selected focus area is made in-focus, if a comparison result by the defocus amount comparing unit shows that the defocus amount of the selected focus area is smaller than the predetermined defocus amount; and a focus area re-selecting unit for re-selecting a focus area by driving the lens in accordance with the defocus amount of the selected focus area and thereafter again operating the focus detecting unit, the grouping unit, and the focus area selecting unit, if a comparison result by the defocus amount comparing unit shows that the defocus amount of the selected focus area is larger than the predetermined defocus amount.

Claims

1. An optical apparatus having a focus adjusting function, comprising:

a) focus detecting means for executing a focus detection operation for each of a plurality of focus areas set in an image plane;

b) grouping means for grouping the image plane in accordance with a distribution of defocus amounts or distances obtained from focus detection results of the plurality of focus areas by said focus detecting means;

c) focus area selecting means for selecting at least one focus area from the plurality of focus areas in accordance with a grouping result by said grouping means;

d) defocus amount comparing means for comparing a defocus amount of the focus area selected by said focus area selecting means with a predetermined defocus amount;

e) lens driving means for driving a lens until the selected focus area is made in-focus, if a comparison result by said defocus amount comparing means shows that the defocus amount of the selected focus area is smaller than the predetermined defocus amount; and

f) focus area re-selecting means for re-selecting a focus area by driving the lens in accordance with the defocus amount of the selected focus area and thereafter again operating said focus detecting means, said grouping means, and said focus area selecting means, if a comparison result by said defocus amount comparing means shows that the defocus amount of the selected focus area is larger than the predetermined defocus amount.

2. An optical apparatus having a focus adjusting function, comprising:

a) focus detecting means for executing a focus detection operation for each of a plurality of focus areas set in an image plane;

b) grouping means for grouping the image plane in accordance with a distribution of defocus amounts or distances obtained from focus detection results of the plurality of focus areas by said focus detecting means;

c) focus area selecting means for selecting at least one focus area from the plurality of focus areas in accordance with a grouping result by said grouping means;

d) defocus amount comparing means for comparing a defocus amount of the focus area selected by said focus area selecting means with a predetermined defocus amount;

e) lens driving means for driving a lens until the selected focus area is made in-focus, if a comparison result by said defocus amount comparing means shows that the defocus amount of the selected focus area is smaller than the predetermined defocus amount; and

f) focus area re-selecting means for re-selecting at least one focus area from the plurality of focus areas by driving the lens in accordance with the defocus amount of the selected focus area and thereafter again referring to a grouping result by said grouping means, if a comparison result by said defocus amount comparing means shows that the defocus amount of the selected focus area is larger than the predetermined defocus amount.

3. An optical apparatus having a focus adjusting function, comprising:

a) focus detecting means for executing a focus detection operation for each of a plurality of focus areas set in an image plane;

b) focus area selecting means for selecting at least one focus area from the plurality of focus areas;

c) defocus amount comparing means for comparing a defocus amount of the focus area selected by said focus area selecting means with a predetermined defocus amount;

d) lens driving means for driving a lens until the selected focus area is made in-focus, if a comparison result by said defocus amount comparing means shows that the defocus amount of the selected focus area is smaller than the predetermined defocus amount; and

e) focus area re-selecting means for re-selecting at least one focus area from the plurality of focus areas after driving the lens in accordance with the defocus amount of the selected focus area, if a comparison result by said defocus amount comparing means shows that the defocus amount of the selected focus area is larger than the predetermined defocus amount.

4. A focus adjustment control circuit comprising:

a) focus detecting means for executing a focus detection operation for each of a plurality of focus areas set in an image plane;

b) grouping means for grouping the image plane in accordance with a distribution of defocus amounts or distances obtained from focus detection results of the plurality of focus areas by said focus detecting means;

c) focus area selecting means for selecting at least one focus area from the plurality of focus areas in accordance with a grouping result by said grouping means;

d) defocus amount comparing means for comparing a defocus amount of the focus area selected by said focus area selecting means with a predetermined defocus amount;

e) lens driving signal outputting means for outputting a signal which drives a lens until the selected focus area is made in-focus, if a comparison result by said defocus amount comparing means shows that the defocus amount of the selected focus area is smaller than the predetermined defocus amount; and

f) focus area re-selecting means for re-selecting a focus area by outputting a signal which drives the lens in accordance with the defocus amount of the selected focus area and thereafter again operating said focus detecting means, said grouping means, and said focus area selecting means, if a comparison result by said defocus amount comparing means shows that the defocus amount of the selected focus area is larger than the predetermined defocus amount.

5. A focus adjustment control circuit comprising:

a) focus detecting means for executing a focus detection operation for each of a plurality of focus areas set in an image plane;

b) grouping means for grouping the image plane in accordance with a distribution of defocus amounts or distances obtained from focus detection results of the plurality of focus areas by said focus detecting means;

c) focus area selecting means for selecting at least one focus area from the plurality of focus areas in accordance with a grouping result by said grouping means;

d) defocus amount comparing means for comparing a defocus amount of the focus area selected by said focus area selecting means with a predetermined defocus amount;

e) lens driving signal outputting means for outputting a signal which drives a lens until the selected focus area is made in-focus, if a comparison result by said defocus amount comparing means shows that the defocus amount of the selected focus area is smaller than the predetermined defocus amount; and

f) focus area re-selecting means for re-selecting at least one focus area from the plurality of focus areas by outputting a signal which drives the lens in accordance with the defocus amount of the selected focus area and thereafter again referring to a grouping result by said grouping means, if a comparison result by said defocus amount comparing means shows that the defocus amount of the selected focus area is larger than the predetermined defocus amount.

6. A focus adjustment control circuit comprising:

a) focus detecting means for executing a focus detection operation for each of a plurality of focus areas set in an image plane;

b) focus area selecting means for selecting at least one focus area from the plurality of focus areas;

c) defocus amount comparing means for comparing a defocus amount of the focus area selected by said focus area selecting means with a predetermined defocus amount;

d) lens driving signal outputting means for outputting a signal which drives a lens until the selected focus area is made in-focus, if a comparison result by said defocus amount comparing means shows that the defocus amount of the selected focus area is smaller than the predetermined defocus amount; and

e) focus area re-selecting means for re-selecting at least one focus area from the plurality of focus areas after outputting a signal which drives the lens in accordance with the defocus amount of the selected focus area, if a comparison result by said defocus amount comparing means shows that the defocus amount of the selected focus area is larger than the predetermined defocus amount.