Three-dimensional image capturing device

• US 6,456,368 B2
• Filed: 04/30/2001
• Issued: 09/24/2002
• Est. Priority Date: 05/02/2000
• Status: Expired due to Fees

• Current Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
• Original Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
• Inventors: Seo, Shuzo
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): ANDREA, BRIAN K
• Application Number:
  US09/843,839
• Publication Number:
  US 20020015144A1
• Time in Patent Office: 512 Days
• Field of Search: 356/5.09, 356/5.01, 356/5.15
• US Class Current: 356/5.01
• CPC Class Codes: G01C 11/00 Photogrammetry or videogrammetry, e.g. stereogrammetry; Photographic surveying
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01S 17/10 using transmission of interrupted, pulse-modulated waves determination of distance by phase measurements G01S17/32
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/483 Details of pulse systems

Abstract

A three-dimensional image capturing device performs sensing operations of a first reflected light beam component and a second reflected light beam component. In the sensing operation of the first reflected light beam component, the pulse shape of a distance measuring light beam is triangular. The electric charge accumulating period starts at the same time as the disappearance of a pulse of the distance measuring light beam, and ends after the disappearance of a pulse of the reflected light beam. In the sensing operation of the second reflected light beam component, the pulse shape of a correction light beam is rectangular. The electric charge accumulating period starts at the same time as the disappearance of a pulse of the correction light beam, and ends after the disappearance of a pulse of the reflected light beam. A signal charge obtained by the first reflected light beam component sensing operation is divided by a signal charge obtained by the second reflected light beam component sensing operation.

Claims

1. A three-dimensional image capturing device, comprising:

a distance measuring light beam irradiating processor that irradiates a distance measuring light beam to a measurement subject, said distance measuring light beam being a pulsed beam, the height of the pulse of said distance measuring light beam changing linearly with time, the measurement subject reflecting said distance measuring light beam to generate a first reflected light beam pulse;

a first reflected light beam component sensing processor that receives said first reflected light beam pulse for a first sensing period to sense a first reflected light beam component, the first sensing period starting at the extinction of the pulse of said distance measuring light beam;

a correction light beam irradiating processor that irradiates a correction light beam to the measurement subject, said correction light beam being a pulsed beam, the height of the pulse being constant, said measurement subject reflecting said correction light beam to generate a second reflected light beam pulse;

a second reflected light beam component sensing processor that receives said second reflected light beam pulse for a second sensing period to sense a second reflected light beam component, the second sensing period starting at the extinction of the pulse of said correction light beam; and

a distance information calculating processor that divides said first reflected light beam component by said second reflected light beam component to obtain the distance from said device to each point of a surface of the measurement subject.

2. A device according to claim 1, wherein the height of the pulse of said distance measuring light beam linearly decreases.

3. A device according to claim 1, wherein the pulse of said distance measuring light beam is saw-toothed.

4. A three-dimensional image capturing device, comprising:

means for irradiating a distance measuring light beam to a measurement subject, said distance measuring light beam being a pulsed beam, the height of the pulse changing linearly with time, the measurement subject reflecting said distance measuring light beam to generate a first reflected light beam pulse;

means for receiving said first reflected light beam pulse for a first sensing period to sense a first reflected light beam component, the first sensing period starting at the extinction of the pulse of said distance measuring light beam;

means for irradiating a correction light beam to the measurement subject, said correction light beam being a pulsed beam, the height of the pulse being constant, the measurement subject reflecting said correction light beam to generate a second reflected light beam pulse;

means for receiving said second reflected light beam pulse for a second sensing period to sense a second reflected light beam component, the second sensing period starting at the extinction of the pulse of said correction light beam; and

means for dividing said first reflected light beam component by said second reflected light beam component to obtain the distance from said device to each point of a surface of the measurement subject.