Device for searching objects within wide visual field

• US 4,660,969 A
• Filed: 08/05/1985
• Issued: 04/28/1987
• Est. Priority Date: 08/08/1984
• Status: Expired due to Term

• Current Assignee: CAON Kabushiki Kaisha
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sorimachi, Kanehiro, Kawabata, Takashi
• Primary Examiner(s): Hix, L. T.
• Assistant Examiner(s): Rutledge, D.
• Application Number:
  US06/762,557
• Time in Patent Office: 631 Days
• Field of Search: 356/1, 356/4, 356/375, 356/376, 364/460, 364/561, 901/47, 354/403
• US Class Current: 356/3.01
• CPC Class Codes: G01C 3/10 using a parallactic triangle with variable angles and a base of fixed length in the observation station, e.g. in the instrument
• CPC Class Codes: G01S 17/06 Systems determining position data of a target
• CPC Class Codes: G01S 3/784 using a mosaic of detectors

Abstract

A visual field searching device is arranged to divide the visual field to be searched into a plurality of intermediate fields each of which is larger than a constituent unit field; to select, for each of the intermediate fields, a typical or representative object distance data from among object distance data obtained for individual constituent unit fields included in each intermediate field; further, for each intermediate field, to discriminate whether the representative distance data thus selected is in a predetermined relation to other object distance data; and after that, to perform a signal processing operation to obtain necessary information by processing only the number of data representing the intermediate fields instead of processing all the data for all the constituent unit fields.

Claims

1. A visual field searching device comprising:

detecting means for detecting distance data indicative of distances to objects located within each of constituent unit domains of a visual field;

dividing means for dividing the visual field into intermediate domains each of which is larger than each of said constituent unit domains;

selecting means for selecting representative distance data from said distance data included in each of said divided intermediate domains;

discriminating means for discriminating whether other distance data within each of said intermediate domains are in a predetermined relation to said representative distance data of the same domain; and

storing means for storing said representative distance data and the result of said discrimination for each of said intermediate domains.

2. A device according to claim 1, wherein said detecting means includes a light projecting system and a light receiving system which are spaced a base length away from each other, said light receiving system including an image detector.

3. A device according to claim 2, wherein said image detector is a two-dimensional array of photo-sensors.

4. A device according to claim 2, wherein said light projecting system is arranged to scan a visual field with a beam or light.

5. A device according to claim 4, wherein said beam is a sheet-like beam.

6. A device according to claim 1, wherein said selecting means is arranged to select, as said representative distance data, distance data relative to the nearest object distance within each of said intermediate domains.

7. A device according to claim 1, wherein said discriminating means is arranged to detect the continuity among said distance data.

8. A signal processing method comprising:

a step of detecting distance data relative to a distance to an object for every picture element of an image detector;

a step of grouping and consolidating a plurality of picture elements into a plurality of grouped sections;

a step of selecting representative distance data from among distance data included in each of grouped section;

a step of detecting the continuity or discontinuity of said distance data relative to each other within each of said grouped sections; and

a step of having said representative distance data and the result of said discontinuity detection produced in a pair for each of said grouped sections.

9. A method according to claim 8 wherein said distance data are obtained in accordance with the method of triangulation.

10. A method according to claim 8, wherein said representative distance data is distance data indicative of the nearest object distance among distance data within each of said grouped sections.