Optical object locator

• US 4,105,925 A
• Filed: 03/14/1977
• Issued: 08/08/1978
• Est. Priority Date: 03/14/1977
• Status: Expired due to Term

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Holland, Steven W., Dewar, Robert, Rossol, Lothar, Olsztyn, Joseph T.
• Primary Examiner(s): Dahl, Lawrence J.
• Application Number:
  US05/777,011
• Time in Patent Office: 512 Days
• Field of Search: 250/560, 250/561, 356/156, 356/167
• US Class Current: 250/559.37
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G01B 11/0691 of objects while moving G01B11/0616 takes precedence
• CPC Class Codes: G01B 11/2522 the position of the object changing and being recorded
• CPC Class Codes: G01B 11/28 for measuring areas

Abstract

In order to determine the position and orientation of an object on a conveyor, two planes of light intersect at a single transverse line on the conveyor surface, the planes of light each being at an acute angle to the conveyor. A linear diode array aligned with the single line of light on the conveyor detects light from that line. An object on the conveyor moving through the line of light intercepts the light above the conveyor at positions spaced laterally from the line of light. The linear array senses only the line segments on the conveyor beyond the object boundaries. By electronic sampling of the illumination of the linear array, the object boundaries are determined and the object shape and orientation are thus detected.

Claims

1. An electro optical locator device for determining the position of an object on a conveyor comprising

first and second light sources fixed in space above the said conveyor and emitting light in sheet form in first and second planes defining a dihedral angle with its apex substantially on the conveyor transverse to the movement thereof and each plane being at an acute angle in relation to the conveyor for projecting onto the conveyor a single line of light transverse to the conveyor motion, wherein an object carried by the conveyor intercepts the light above the surface of the conveyor at positions laterally spaced from the apex of the dihedral angle so that the single line of light is projected onto the conveyor only outside the boundaries of the said object,

a linear photosensor array of photo elements responsive to light in a plane perpendicular to the conveyor aligned with the apex of the dihedral angle for viewing the single line of light projected onto the conveyor outside an object boundary, the illumination of individual photo elements being dependent on the position of the boundaries of the object with respect to the conveyor and

means responsive to the respective photosensor elements effective to determine the pattern of illumination of said photosensor array at a particular conveyor position to determine the position of the boundaries of the object relative to the conveyor.

2. An electro optical locator device for determining the position of an object on a conveyor comprising

first and second light sources fixed in space above the said conveyor and emitting light in sheet form in first and second planes defining a dihedral angle with its apex substantially on the conveyor transverse to the movement thereof and each plane being at an acute angle in relation to the conveyor for projecting onto the conveyor a single line of light transverse to the conveyor motion, wherein an object carried by the conveyor intercepts the light above the surface of the conveyor at positions laterally spaced from the apex of the dihedral angle so that the single line of light is projected onto the conveyor only outside the boundaries of the said object,

a linear photosensor array of photoelements responsive to light in a plane perpendicular to the conveyor aligned with the apex of the dihedral angle for viewing the single line of light projected onto the conveyor outside an object boundary, the illumination of individual photoelements being dependent on the position of the boundaries of the object with respect to the conveyor,

conveyor position encoder means responsive to conveyor travel for providing a conveyor position signal, and

electronic means responsive to the conveyor position signal and to the respective photosensor elements effective to determine the pattern of illumination of said photosensor array at a particular conveyor position to determine the position of the boundaries of the object relative to the conveyor.