Apparatus for and method of measuring distances to objects present in a plurality of directions with plural two-dimensional detectors

• US 4,749,848 A
• Filed: 02/07/1986
• Issued: 06/07/1988
• 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:
  US06/827,016
• Time in Patent Office: 851 Days
• Field of Search: 250/201, 250/204, 250/578, 250/558, 356/1, 356/4, 354/402, 354/408, 382/1, 358/88, 358/107
• US Class Current: 250/208.1
• 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. An apparatus for measuring the distances to objects present in a plurality of directions, comprising:

a pair of optical systems, said pair of optical systems being disposed so that the optic axes thereof are parallel to each other at a predetermined distance;

a pair of illumination distribution measuring means respectively disposed behind said pair of optical systems, said pair of measuring means being disposed perpendicularly to the optic axes, respectively, of said pair of optical systems, each of said pair of measuring means including a plurality of two-dimensionally arranged light-receiving elements, said plurality of light-receiving elements of said pair of measuring means being separable into a plurality of sets of portions each comprising a plurality of light-receiving elements of each said measuring means, correspondingly to a direction relative to the position in an object space at which the object to be measured lies; and

means for calculating the distances to the objects to be measured present in a plurality of directions corresponding to said plurality of sets of portions by taking the correlation between the illumination distributions of the images of each object to be measured in at least parts of each said set of portions.

2. An apparatus according to claim 1, wherein said calculating means finds the difference between the amounts of deviation of two images from said optic axes of taking said correlation and calculates the distance to the object to be measured on the basis thereof.

3. An apparatus according to claim 1, wherein said correlation is taken with respect to the illumination distributions of the images on the parts of said set of portions.

4. An apparatus according to claim 1, wherein said calculating means has a plurality of parallel-disposed signal processing means, the output signals of said set of portions are input as a set to each of said signal processing means and the distances to be measured present in the plurality of directions are calculated in parallel.

5. An apparatus according to claim 1, wherein said pair of optical systems have the same focal length.

6. An apparatus according to claim 5, wherein said pair of illumination distribution measuring means are disposed at the same distance of said focal length behind said pair of optical systems.

7. An apparatus according to claim 1, wherein one of the two directions of arrangement of said light-receiving elements are parallel to a plane containing the optic axes of said pair of optical systems.

8. An apparatus according to claim 1, wherein said pair of illumination distribution measuring means have substantially identical light-receiving element arrangements.

9. An apparatus according to claim 8, wherein the dispositions of said pair of illumination distribution measuring means relative to the optic axes of said optical systems deviate from each other in a direction parallel to a plane containing said pair of optic axes.

10. An apparatus according to claim 7, wherein said set of portions each comprise a light-receiving element row extending in said one direction of arrangement.

11. An apparatus according to claim 8, wherein said set of portions each comprise the same part of the light-receiving element arrangement, and said correlation is taken with respect to the illumination distributions of the images on the mutually complementary parts of said set of portions.

12. An apparatus according to claim 8, wherein said set of portions each comprise the same part of the light-receiving element arrangement, and said correlation is taken with respect to the illumination distributions of the images on the non-complementary parts of said set of portions.

13. An distance measuring method comprising disposing two optical systems at a predetermined distance from each other so that the optic axes thereof are parallel to each other, disposing a pair of illumination distribution measuring means behind said optical systems perpendicularly to said optic axes, using two-dimensionally arranged light-receiving elements as the measuring means, taking the correlation between the illumination distributions of the images of an object to be measured, formed by said optical systems, on at least parts of a set of portions in the pair of said measuring means, thereby calculating the distance to the object to be measured present in a direction corresponding to said set of portions, and effecting said calculation with respect to the plural sets of portions of said measuring means, thereby calculating the distances to objects present in a plurality of directions corresponding to said plural sets of portions.

14. A method according to claim 13, wherein said two optical systems have the same focal length.

15. A method according to claim 14, wherein said pair of illumination distribution measuring means are disposed at the same distance of said focal length behind said pair of optical systems.

16. A method according to claim 13, wherein one of the two directions of arrangement of said light-receiving elements are parallel to a plane containing the optic axes of said pair of optical systems.