System for detecting a position of a movable object without contact

• US 5,698,861 A
• Filed: 07/31/1995
• Issued: 12/16/1997
• Est. Priority Date: 08/01/1994
• Status: Expired due to Term

• Current Assignee: Konami Digital Entertainment Company Limited (Konami Holdings Corp.)
• Original Assignee: Konami Co., Ltd.
• Inventors: Oh, Ketsu
• Primary Examiner(s): Westin, Edward P.
• Assistant Examiner(s): PYO, KEVIN K
• Application Number:
  US08/509,314
• Time in Patent Office: 869 Days
• Field of Search: 250/559.29, 250/559.31, 250/559.32, 250/221, 250/203.3, 250/206.1, 348/147, 348/208, 348/262
• US Class Current: 250/559.29
• CPC Class Codes: A63H 18/16 Control of vehicle drives by interaction between vehicle and track; Control of track elements by vehicles
• CPC Class Codes: G01P 3/68 using optical means, i.e. using infrared, visible, or ultraviolet light G01P3/80 takes precedence ; by reflection of waves G01S17/58

Abstract

A position detecting system for detecting a position of a movable object having a light emitter without contact, the system includes: a first light sensor which has a first view area and receives light from the light emitter of the movable object in the first view area to produce image data, and a second light sensor which has a second view area and receives light from the light emitter of the movable object in the second view area to produce image data, a combination of the first and second view areas covering a space in which the movable object moves, and the first and second view areas overlapping each other; and a processor which calculates a position of the movable object based on image data produced by the first and second light sensors.

Claims

1. A position detecting system for detecting without contact a position of a movable object moving on a plane and having a light emitter, the system comprising:

a first light image sensor which has a first view area and receives light from the light emitter of the movable object in the first view area to produce image data;

a second light image sensor which has a second view area and receives light from the light emitter of the movable object in the second view area to produce image data;

a combination of the first and second view areas covering said plane on which the movable object moves, and the first and second view areas overlapping each other in an overlap area wherein a borderline on said plane is defined; and

a processor means for calculating a position of the movable object based on image data produced by the first and second light sensors, said processor means including;

first and second memories respectively provided for storing said image data of the first and second light image sensors according to respective local address systems of said first and second light image sensor and representing said first and second view areas; and

a position calculator means for calculating a position of the movable object in the terms of a general address system unifying said local address systems of the first and second memories, the position calculator means including;

a border address calculating means for calculating border addresses of said borderline in the local address systems of the first and second memories, the border addresses corresponding to said border line defined in said overlap area of the first and second view areas; and

an address converting means for converting addresses in the respective local address systems to those in the general address system based on the border addresses.

2. A position detecting system as defined in claim 1, wherein the position calculator means further includes:

a block designator means for designating an address block in the local address system of either the first memory or the second memory, the designated address block covering addresses bearing image data of the emitter provided on the movable object;

a reader which reads image data within the designated address block; and

a object position calculating means for calculating a position of the movable object within said address block based on the read image data.

3. A position detecting system as defined in claim 2, wherein:

said block designator means designates said address block in the local address system of the first memory when a portion of an address block having been designated in the local address system of the second memory is beyond the border addresses of the second memory, and designates said address block in the local address system of the second memory when a portion of an address block having been designated in the local address system of the first memory, is beyond the border addresses of the first memory.

4. A position detecting system as defined in claim 2, wherein;

each of the first and second light sensors includes an area sensor provided with photoelectric conversion elements arranged in a matrix; and

the object position calculating means includes;

a counting portion which counts the number of photoelectric conversion elements which have received light from the light emitter of the movable object based on the image data read by the reader;

a coordinate value accumulating portion which accumulates coordinate values of the photoelectric conversion elements counted by the counting portion; and

a calculating portion which calculates a position of the movable object based on the counted number and the accumulated coordinate values.

5. A position detecting system as defined in claim 2, wherein the block designator means includes:

a moved amount calculating means for calculating a moved amount of the movable object based on the calculated position of the movable object; and

a designating means for designating an address block based on a previously calculated position of the movable object and the calculated moved amount.

6. A position detecting system as defined in claim 1, wherein each of the first and second light sensors is provided with a lens for focusing a light image on a surface of the light sensor.

7. A position detecting system as defined in claim 1, wherein the light emitter is operable to emit light lying outside a frequency band for visible radiations;

and each of the first and second light sensors is operable to receive only light lying in the same frequency band of light emitted by the light emitter.

8. A position detecting system for detecting without contact a position of a movable object moving on a plane and having a light emitter, the system comprising:

a first light image sensor which has a first view area and receives light from the light emitter of the movable object in the first view area to produce image data;

a second light image sensor which has a second view area and receives light from the light emitter of the movable object in the second view area to produce image data;

a combination of the first and second view areas covering said plane on which the movable object moves, and the first and second view areas overlapping each other in an overlap area wherein a substantially straight borderline on said plane between the first and second view areas is defined; and

a processor means for calculating a position of the movable object based on image data produced by the first and second light sensors, said processor means including;

first and second memories respectively provided for storing said image data of the first and second light image sensors according to respective local address systems of said first and second light image sensor and representing said first and second view areas;

a border address calculating means for calculating border addresses of said substantially straight borderline in the local address systems of the first and second memories, the border addresses corresponding to curved borderlines in said local address systems due to distortion by the first and second light image sensors;

a distortion compensation means for calculating address deviations due to said distortion; and

a position calculator means for calculating a position of the movable object in the terms of a general address system unifying said local address systems of the first and second memories, the position calculator means including an address converting means for converting addresses in the respective local address systems to those in the general address system based on the border addresses and for correcting for said distortion by removing said address deviations from the position of the movable object in the general address system.