Apparatus for and method of measuring distances to objects present in a plurality of directions

• US 4,916,302 A
• Filed: 03/28/1988
• Issued: 04/10/1990
• Est. Priority Date: 02/09/1985
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sorimachi, Kanehiro
• Primary Examiner(s): Nelms, David C.
• Application Number:
  US07/174,441
• Time in Patent Office: 743 Days
• Field of Search: 250/560, 250/561, 250/201, 250/558, 356/1, 356/4, 356/5, 356/12, 358/88
• US Class Current: 356/3.14
• CPC Class Codes: G01C 3/085 with electronic parallax measurement
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves

Abstract

This specification discloses a distance measuring apparatus and method in which two-dimensionally arranged light-receiving elements are used as illumination distribution measuring means, the correlation between the illumination distributions of the images of an object on the set of certain portions of the respective measuring means is taken to thereby calculate the distance to the object present in a certain direction corresponding to the set, and the calculations are effected with respect to a plurality of sets portions of the respective measuring means to thereby calculate the distances to objects present in a plurality of directions.

Claims

1. A method for measuring the distances to objects present in a plurality of directions, comprising the steps of:

setting a plurality of measuring regions for each of first and second photodetectors and predetermining a plurality of pairs of regions, each pair having a measuring region from said first photodetector and a measuring region from said second photodetector, each pair being associated with a different direction from one another;

receiving light from the objects by means of said first photodetector through a first optical system;

receiving light from the objects by means of said second light receiving surface through a second optical system, said first and second optical systems being disposed in a predetermined relationship to each other;

taking a correlation between the illumination distributions in said paired regions of said first and second photodetectors; and

calculating each of the distances to the objects present in different directions corresponding to said plurality of pairs of regions, on the basis of the result of said correlation-taking step for each said pair of regions to measure the distances to the objects.

2. A method according to claim 1, wherein said regions each comprises of an array of light-receiving elements arranged in a predetermined direction.

3. A method according to claim 2, wherein said correlation-taking step includes a step of taking out signals from said first and second photodetectors as a time-serial signal, serially, for each pair of regions.

4. A method according to claim 1, further comprising a step of storing in a memory information corresponding to distances to the objects obtained in said calculating step.

5. A method according to claim 3, wherein said signals from said first and second photodetectors are alternately taken out from said first and second photodetectors with every measuring region of said first and second photodetectors.

6. A method according to claim 2, wherein a number of light-receiving elements for each of said measuring regions of said second photodetector is set to be greater than that for said first photodetector.

7. A method according to claim 1, wherein the optical axes of said first and second optical systems are parallel and said first and second optical systems are arranged so as to have a same focal length.

8. A method of measuring the distances to objects present in different directions, comprising the steps of:

setting a plurality of measuring regions for each of first and second photodetectors and predetermining a plurality of pairs of regions, each pair having a measuring region from said first photodetector and a measuring region from said second photodetector, each pair being associated with a different direction from one another;

receiving light from the objects by means of said first photodetector through a first optical system;

receiving light from the objects by means of said second photodetector through a second optical system, said first and second optical systems being disposed in a predetermined relationship to each other; and

comparing output signals from each said pair of regions to measure the distance to the object present in the direction associated with each said pair of regions.

9. A method according to claim 8, further comprising a step of storing in a memory information corresponding to distances to the objects obtained in said comparing step.

10. A method according to claim 8, wherein said comparing step is conducted in region processing circuits prepared for each said pair of regions.

11. A method according to claim 10, wherein each said region processing circuit is supplied with direction information obtained by the corresponding pair of regions.

12. A method according to claim 8, wherein the optical axes of said first and second optical systems are parallel and said first and second optical systems are arranged so as to have a same focal length.