Method and apparatus for measuring a distance

• US 4,746,790 A
• Filed: 09/16/1987
• Issued: 05/24/1988
• Est. Priority Date: 11/12/1984
• 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): LaRoche, Eugene R.
• Assistant Examiner(s): Mis, David
• Application Number:
  US07/097,426
• Time in Patent Office: 251 Days
• Field of Search: 250/201 PF, 250/204, 354/406, 354/407, 354/408, 356/1, 356/4
• US Class Current: 250/201.2
• CPC Class Codes: G02B 7/30 using parallactic triangle with a base line

Abstract

There is disclosed a method for measuring the distance to an object, using an apparatus having two optical systems which have optical axes parallel with each other, and detecting means on which images are respectively formed by the two optical systems, comprising the steps of:

(a) obtaining correlation between illumination distributions of object images formed on the two detecting means;

(b) changing the positional relationships between the respective optical systems and detecting means on the basis of the correlation obtained in the step (a);

(c) obtaining positional relationship between the two optical systems and the two detecting means when a desired correlation is obtained in steps (a) and (b); and

(d) obtaining the distance between an object and said apparatus on the basis of the desired positional relationship obtained in the step (c).

Claims

1. A method for measuring the distance from a detecting apparatus to each of a plurality of objects, the apparatus having two optical systems which have optical axes parallel with each other, and two corresponding detecting means on which images of each object are respectively formed by said two optical systems, the optical systems and the corresponding detecting means being arranged with predetermined positional relationships therebetween, the method comprising the steps of;

(a) obtaining correlation between illumination distributions of object images respectively formed on said two detecting means;

(b) changing at least one of said positional relationships on the basis of the correlation obtained in step (a);

(c) determining the change in at least one of the positional relationships between said two optical systems and said two detecting means when a desired correlation is obtained in steps (a) and (b);

(d) determining the distance between each object and said apparatus on the basis of the change in at least one of the positional relationships determined in step (c);

(e) performing steps (a) through (d) for each of the objects; and

(f) storing information corresponding to the distance and direction of each object from the apparatus in a memory.

2. A method according to claim 1, wherein, in step (b), the positional relationship between said first optical system and the corresponding detecting means is fixed, and the positional relationship between said second optical system and the corresponding detecting means is changed.

3. A method according to claim 2, wherein, in step (b), the detecting means corresponding to said second optical system is moved in a direction perpendicular to an optical axis of said second optical system.

4. A method according to claim 2, wherein, in step (b), the detecting means corresponding to said second optical system is moved in a direction parallel with an optical axis of said second optical system.

5. A method according to claim 2, wherein, in step (b), the positional relationships between one of the optical systems and the two detecting means are fixed, and the other optical system is moved.

6. A method according to claim 2, wherein, in step (b), the detecting means corresponding to said second optical system is linearly moved.

7. An apparatus for measuring the distance between the apparatus and each of a plurality of objects, comprising:

a first optical system having a first optical axis;

a second optical system having a second optical axis parallel with the first optical axis of said first optical system;

first detecting means on which an object image is formed by said first optical system, said first optical system and said first detecting means being arranged in a predetermined positional relationship;

second detecting means on which an object image is formed by said second optical system, said second optical system and said second detecting means being arranged in a predetermined positional relationship;

first means for changing at least one of the respective positional relationships between said first and second optical systems and said first and second detecting means to obtain correlation between illumination distributions of said object images respectively formed on said first and second detecting means, and for obtaining the respective positional relationships between said first and second optical systems and said first and second detecting means when a desired correlation is obtained;

second means for determining the distance between each said object and said apparatus on the basis of the positional relationships obtained by said first means; and

means for storing information corresponding to the distance and direction of each said object from said apparatus.