Optical apparatus with focus adjusting function and focus adjustment control circuit

• US 6,088,539 A
• Filed: 12/21/1998
• Issued: 07/11/2000
• Est. Priority Date: 12/24/1997
• Status: Expired due to Term

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Aoyama, Keisuke
• Primary Examiner(s): Perkey, W. B.
• Application Number:
  US09/217,552
• Time in Patent Office: 568 Days
• Field of Search: 396/147, 396/121, 396/122, 396/123
• US Class Current: 396/123
• 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, includes: a focus detecting 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, grouping unit, and 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 plurality of focus areas set in an image plane, comprising:

a) focus area selecting means for selecting at least one focus area to be used for focus adjustment, from the plurality of focus areas;

b) lens driving means for driving a lens until the selected focus area is made in-focus; and

c) focus area displaying means for displaying focus areas which are in an in-focus state and are positioned in a predetermined range defined by using a position of the selected focus area as a reference, after said lens driving means drives the lens.

2. An optical apparatus according to claim 1, wherein said predetermined range is a range containing focus areas on one circumference area about the focus area selected by said focus area selecting means.

3. An optical apparatus according to claim 1, wherein said predetermined range is a range containing focus areas on two circumference areas about the focus area selected by said focus area selecting means.

4. An optical apparatus having a plurality of focus areas set in an image plane, comprising:

a) focus area selecting means for selecting at least one focus area to be used for focus adjustment, from the plurality of focus areas;

b) lens driving means for driving a lens until the selected focus area is made in-focus; and

c) focus area displaying means for displaying focus areas disposed in line over the selected focus area in an in-focus state, and focus areas disposed in line over the selected focus area in a range of a depth of field.