Three-dimensional range finder

• US 4,664,512 A
• Filed: 12/14/1984
• Issued: 05/12/1987
• Est. Priority Date: 04/16/1983
• Status: Expired due to Fees

• Current Assignee: Naoki Shimizu
• Original Assignee: Naoki Shimizu
• Inventors: Shimizu, Naoki
• Primary Examiner(s): Adams, Russell E.
• Application Number:
  US06/689,054
• Time in Patent Office: 879 Days
• Field of Search: 356/1, 354/408
• US Class Current: 356/3.16
• CPC Class Codes: G01C 3/085 with electronic parallax measurement

Abstract

A range finder which measures positions in three-dimensional space of object points within a field of view. Pixel data outputted from pixels in different depths of focus are detected, while said depth of focus is moved. Pairs of pixel data, one outputted from each of two cameras, and which have the same value and each of which is different from pixel data outputted from pixels adjacent the pairs of pixel data are detected. Since the same object point forms its image in pairs of pixels, outputting the pairs of pixel data, permits the object range to be calculated from three factors as the interval between the two cameras, angle of two axes, and the positions of pixels in the two cameras.

Claims

1. An apparatus for measuring ranges to points of an object comprising:

(A) a pair of cameras, each having;

a pair of lenses, each having an optical axis, and

a pair of image sensing devices each of which is disposed at positions on each optical axis of each lens and each image sensing device having a plurality of light receiving elements which are aligned perpendicular to said optical axes to produce element analog signals indicative of radiation received thereon from said object points;

(B) means for moving the position of the depth of focus of each camera;

(C) a pair of signal processing circuits which convert said element analog signals to digital data;

(D) a pair of focus extraction sections each of which includes a plurality of memories to store said digital data, a subtractor connected to each memory to provide contrasts between digital data which are fed from said light receiving elements aligned adjacent to each other, a plurality of comparators connected to receive a signal corresponding to an output of said subtractor to provide focus element data representing the contrasts of a peak value of said digital data and a plurality of coincidence circuits;

(E) each coincidence circuit including

one of said comparators to detect coincidence between one digital datum from one light receiving element in one image sensing device and other digital datum from another light receiving element in the other image sensing device, said two light receiving elements being displaced by a displacement distance, said displacement distance being variable,

and an AND circuit to provide coincidence data to represent coincidence when said two focus element data are provided;

(F) a range calculator responsive to said displacement distance for calculating range when said coincidence datum is provided;

(G) a range memory for storing said ranges; and

(H) a central processing unit for generating signals corresponding to said position of the depth of focus for providing same to said cameras, and said displacement distance for providing same to said cameras and said range calculator.

2. An apparatus according to claim 1, further comprising:

(A) a pair of signal processing sections which convert said element analog signals to digital data and which measure high-frequency parts contained in said element analog signals; and

(B) said pair of focus extraction sections including said plurality of memories to store said digital data and said high-frequency parts, and said plurality of comparators in each focus extraction section to provide focus element data to represent the high-frequency parts showing each peak value of said digital data, each of which provides digital data corresponding to said focus element data to said coincidence circuit.

3. An apparatus according to claim 1, wherein said pair of image sensing devices includes a pair of TCL sensors each of which has a plurality of pairs of photoelectric elements, which are disposed at corresponding positions to light receiving elements respectively, to produce pairs of element analog signals.

4. An apparatus for measuring ranges to points of object comprising:

(A) a pair of cameras each having

a pair of lenses, each having an optical axis, and

a pair of image sensing devices each of which is disposed at positions on each optical axis of each lens and each image sensing device having a plurality of light receiving elements which are aligned perpendicular to said optical axes to produce element signals indicative of radiation received thereon from said object points;

(B) means for moving the position of the depth of focus of each camera;

(C) a pair of signal processing circuits which convert said element signals to digital data;

(D) means for varying the interval distance between said pair of cameras;

(E) a pair of focus extraction sections each of which includes a plurality of memories to store said digital data, a subtractor connected to each memory to provide contrasts between digital data whlich are fed from said light receiving elements aligned adjacent to each other, and a plurality of comparators to provide focus element data representing the contrasts of a peak value of said digital data, i.e., to represent the light receiving elements being in depth of focus;

(F) each coincidence circuit including;

one of said comparators to detect coincidence between one digital datum from one light receiving element in one image sensing device and other digital datum from another light receiving element in the other image sensing device, said elements displaced by a variable interval distance,

and an AND circuit to provide coincidence data to represent coincidence when said two focus element data are provided;

(G) a range calculator responsive to said interval distance for calculating range when said coincidence datum is provided;

(H) a range memory for storing said ranges; and

(I) a central processing unit which provides the position of the depth of focus to said cameras, and said interval distance to said cameras and said range calculator.

5. An apparatus according to claim 4, further comprising:

(A) a pair of signal processing sections which convert said element signals to digital data and which measure high-frequency parts contained in element signals; and

(B) said pair of focus extraction sections including said plurality of memories to store said digital data and said high-frequency parts, and said plurality of comparators in each focus extraction section to provide focus element data to represent the high-frequency parts showing each peak value of said digital data, each of which provides digital data corresponding to said focus element data to said coincidence circuit.

6. An apparatus according to claim 4, wherein said pair of image sensing devices includes a pair of TCL sensors each of which has a plurality of pairs of photoelectric elements, which are disposed at corresponding positions to light receiving elements respectively, to produce pairs of element signals.

7. An apparatus for measuring ranges to points of an object comprising:

(A) a pair of cameras each having;

a pair of lenses, each having an optical axis, and

a pair of image sensing devices each of which is disposed at positions on each optical axis of each lens and each image sensing device having a plurality of light receiving elements which are aligned perpendicular to said optical axes to produce element signals indicative of radiation received thereon from said object points;

(B) means for moving the position of the depth of focus of each camera;

(C) a pair of signal processing circuits which convert said element signals to digital data;

(D) means for varying the angle between said optical axes;

(E) a pair of focus extraction sections each of which includes a plurality of memories to store said digital data, a subtractor connected to each memory to provide contrasts between digital data which are fed from said light receiving elements aligned adjacent to each other, and a plurality of comparators to provide focus element data representing the contrasts of a peak value of said digital data;

(F) each coincidence circuit including;

one of said comparators to detect coincidence between one digital datum from one light receiving element in one image sensing device and other digital datum from another light receiving element in the other image sensing device,

and an AND circuit to provide coincidence data to represent coincidence when said two focus element data are provided;

(G) a range calculator responsive to said angle for calculating said range when salid coincidence datum is provided;

(H) a range memory for storing said ranges; and

(I) a central processing unit which provides said position of depth of focus to said cameras, and said angle to said cameras and said range calculator.

8. An apparatus according to claim 7, further comprising:

(A) a pair of signal processing sections which convert said element signals to digital data and which measure high-frequency parts contained in said element signals; and

(B) said pair of focus extraction sections including said plurality of memories to store said digital data and said high-frequency parts, and said plurality of comparators in each focus extraction section to provide focus element data to represent the high-frequency parts showing each peak value of said digital data,

each of which provides digital data corresponding to said focus element data to said coincidence section.

9. An apparatus according to claim 7, wherein said pair of image sensing devices includes a pair of TCL sensors each of which has a plurality of pairs of photoelectric elements, which are disposed at corresponding positions to light receiving elements respectively, to produce pairs of element signals.

10. An apparatus for measuring ranges to points of object comprising:

(A) a camera having

a lens having an optical axis, and

an image sensing device which has a plurality of light receiving elements which are aligned perpendicular to the optical axis of said lens to produce element signals indicative of radiation received on said light receiving elements from said object points;

(B) means for moving the position of the depth of focus of said camera;

(C) a signal processing circuit which converts said element signals to digital data;

(D) a focus extraction section which has a plurality of memories to store said digital data, a subtractor connected to each memory to provide contrasts between digital data which are fed from said light receiving elements aligned adjacent to each other, and a plurality of comparators to provide focus element data representing the contrasts of a peak value, i.e., to represent the light receiving elements being in depth of focus;

(E) a range calculator responsive to said position of depth of focus for calculating said range when said focus element datum is provided;

(F) a range memory for storing said ranges; and

(G) a central processing unit which provides the position of depth of focus to said camera and said range calculator.

11. An apparatus for measuring ranges to points of object comprising:

(A) a camera having

a lens having an optical axis, and

an image sensing device which has a plurality of light receiving elements which are aligned perpendicular to the optical axis of said lens to produce element signals indicative of radiation received on said light receiving elements from said object points;

(B) means for moving the position of the depth of focus of said camera;

(C) a signal processing section which measures high-frequency parts contained in said element signals;

(D) a focus extraction section which has a plurality of memories to store said high-frequency parts and a plurality of comparators to provide focus element data representing the high-frequency parts of a peak value, i.e., to represent the light receiving elements being in depth of focus;

(E) a range calculator responsive to said position of depth of focus for calculating said range when said focus element datum is provided;

(F) a range memory for storing said ranges; and

(G) a central processing unit which provides said depth of focus to said camera and said range calculator.

12. An apparatus for measuring ranges to points of object comprising:

(A) a camera having

a lens

and a TCL sensor which has a plurality of pairs of photoelectric elements to produce pairs of photoelectric data;

(B) means for moving the position of the depth of focus of said camera;

(C) a focus extraction section which has one comparator to provide focus element data to represent the pairs of photoelectric data of each same value, i.e., to represent the light receiving elements being in depth of focus;

(D) a range calculator to be fed with said depth of focus for calculating said range when said focus element datum is provided;

(E) a range memory for storing said ranges; and

(F) a central processing unit which provides said position of depth of focus to said camera and said range calculator.