Focus detecting device for use with cameras

• US 4,952,966 A
• Filed: 04/11/1988
• Issued: 08/28/1990
• Est. Priority Date: 01/10/1983
• Status: Expired due to Term

• Current Assignee: Minolta Camera Kabushiki Kaisha
• Original Assignee: Minolta Camera Kabushiki Kaisha
• Inventors: Hamada, Masataka, Ishida, Tokuji
• Primary Examiner(s): Perkey, W. B.
• Application Number:
  US07/180,290
• Time in Patent Office: 869 Days
• Field of Search: 354/402-409, 250/201 PF, 250/204, 250/211 R, 250/211 J, 250/578, 358/213.19
• US Class Current: 396/96
• CPC Class Codes: G02B 7/34 using different areas in a pupil plane

Abstract

An image sensing device capable of being utilized in an automatic focus detecting system includes a pair of sets of light sensing elements that are spaced from each other. These light sensing elements can have a variable accumulation time of storing electric charges depending upon the intensity of the light level incident thereon. Since the automatic focus detection system must be managed within the parameters of photography, a first and second light measuring element is uniquely positioned adjacent each of the sets of light sensing elements. The outputs of these light measuring elements can control the charge accumulation period.

Claims

1. An image sensing device comprising:

first light sensing means capable of accumulating electric charges in response to light incident thereon, said first light sensing means having a first group of a plurality of light sensing elements extending along a line;

second light sensing means capable of accumulating electric charges in response to light incident thereon, said second light sensing means having a second group of a plurality of light sensing elements extending along a line;

a first light measuring element exclusively located in the vicinity of said first group of light sensing elements on one side of the line;

a second light measuring element exclusively located in the vicinity of said second group of light sensing elements on the other side of the line;

means for transferring the charges accumulated by said first and second light sensing means to obtain a signal indicative of the sensed image; and

means responsive to said first and second light measuring elements for controlling the charge accumulation period in which said first and second light sensing means carry out the accumulation of electric charges.

2. An image sensing device comprising:

means for forming an image of an object field;

light sensing means capable of accumulating electric charges in response to light incident thereon, said light sensing means having a plurality of light sensing elements extending along a line, said light sensing elements being located to receive light coming from a sensed area in the object field through said image forming means;

means for measuring through said image forming means light coming from a pair of areas on both sides of sensed area in the object field;

means for transferring the charges accumulated by said light sensing means to obtain a signal indicative of the sensed image; and

means responsive to said light measuring means for controlling the charge accumulation period in which said light sensing means carry out the accumulation of electric charges.

3. The invention according to claim 2, wherein said measuring means includes first and second light measuring elements both located in the vicinity of said light sensing elements for receiving light coming from the pair of areas, respectively.

4. The invention according to claim 3, wherein said first light measuring element is located on one side of the line, while said second light measuring element is located on the other side thereof.

5. An image sensing device comprising:

light sensing means capable of accumulating electric charges in response to light incident thereon, said light sensing means having a plurality of light sensing elements arranged in a row;

means for measuring light during a time period that said light sensing elements are sensing light, said measuring means including portions located between an adjacent two of said light sensing elements at a plurality of positions along said row;

means for transferring the charges accumulated by said light sensing means to obtain a signal indicative of the sensed image; and

means responsive to said light measuring means for controlling the charge accumulation period in which said light sensing means carry out the accumulation of electric charges.

6. The invention according to claim 5, wherein said controlling means includes means for monitoring said measuring means during the charge accumulation period to terminate the current charge accumulation period in response to the monitored measuring means.

7. An image sensing device in combination with an automatic focus control of a camera comprising:

an objective lens;

first light sensing means capable of accumulating electric charges in response to light incident thereon, said first light sensing means having a first group of a plurality of light sensing elements extending along a line;

second light sensing means capable of accumulating electric charges in response to light incident thereon, said second light sensing means having a second group of a plurality of light sensing elements extending along a line;

a first light measuring element exclusively located in the vicinity of said first group of light sensing elements on one side of the line;

a second light measuring element exclusively located in the vicinity of said second group of light sensing elements on the other side of the line;

means for transferring the charges accumulated by said first and second light sensing means to obtain a signal indicative of the sensed image;

means responsive to said first and second light measuring elements for controlling the charge accumulation period in which said first and second light sensing means carry out the accumulation of electric charges; and

means for controlling the focus of said objective lens in accordance with the signal obtained through said transmitting means.

8. An image sensing device in combination with an automatic focus control of a camera comprising:

an objective lens;

means for forming an image of an object field;

light sensing means capable of accumulating electric charges in response to light incident thereon, said light sensing means having a plurality of light sensing elements extending along a line, said light sensing elements being located to receive light coming from a sensed area in the object field through said image forming means;

means for measuring through said image forming means a light coming from a pair of areas on both sides of the sensed area in the object field;

means for transferring the charges accumulated by said light sensing means to obtain a signal indicative of the sensed image;

means responsive to said light measuring means for controlling the charge accumulation period in which said light sensing means carry out the accumulation of electric charges; and

means for controlling the focus of said objective lens in accordance with the signal obtained through said transmitting means.

9. The invention according to claim 8, wherein said image forming means includes means for forming the image through said objective lens.

10. An image sensing device in combination with an automatic focus control of a camera comprising:

an objective lens;

light sensing means capable of accumulating electric charges in response to light incident thereon, said light sensing means having a plurality of light sensing elements, greater than two in, number, and arranged in a row;

means for measuring light during as time period in which said light sensing elements are sensing light, said measuring means including portions each located between an adjacent two of said light sensing elements in the row;

means for transferring the charges accumulated by said light sensing means to obtain a signal indicative of the sensed image;

means responsive to said light measuring means for controlling the charge accumulation period in which said light sensing means carry out the accumulation of electric charges; and

means for controlling the focus of said objective lens in accordance with a signal obtained through said transmitting means.