Three-dimensional image capturing device and its laser emitting device

• US 6,822,687 B1
• Filed: 07/07/2000
• Issued: 11/23/2004
• Est. Priority Date: 07/08/1999
• Status: Expired due to Fees

• Current Assignee: PENTAX RICOH IMAGING COMPANY, LTD.
• Original Assignee: Pentax Corporation (Hoya Corporation)
• Inventors: Tani, Nobuhiro, Kakiuchi, Shinichi, Seo, Shuzo
• Primary Examiner(s): Christensen, Andrew
• Assistant Examiner(s): Tran, Nhan
• Application Number:
  US09/612,499
• Time in Patent Office: 1,600 Days
• Field of Search: 348/207.99, 348/348, 348/345, 348/370, 396/109, 356/4-1-, 356/3.1
• US Class Current: 348/348
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/894 3D imaging with simultaneous measurement of time-of-flight at a 2D array of receiver pixels, e.g. time-of-flight cameras or flash lidar
• CPC Class Codes: G01S 7/4813 Housing arrangements
• CPC Class Codes: G01S 7/486 Receivers
• CPC Class Codes: G01S 7/4863 Detector arrays, e.g. charge-transfer gates
• CPC Class Codes: H04N 13/207 using a single 2D image sensor

Abstract

A three-dimensional image capturing device comprises a plurality of laser devices, and an imaging device, such as a CCD, having a plurality of photo-diodes. Each of the laser devices radiates a pulse modulated laser beam so as to detect distance information or data relating to a topography of a measurement subject. The laser beam is radiated onto the measurement subject and a reflected light beam is sensed by the CCD. Signal charge corresponding to a distance from the image capturing device to the measurement subject is accumulated in each of the photo-diodes, and thus the above distance information is sensed. Each laser beam, respectively radiated from each of the laser devices, shares illuminating area at the distance of the measurement subject, so that radiant energy of each laser beam can be reduced by sharing a single distance measurement operation among the plurality of laser devices.

Claims

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

a plurality of laser devices that radiate pulse modulated laser beams for a distance measurement in order to detect distance information related to a topography of a measurement subject;

an imaging device that accumulates a signal charge corresponding to a quantity of light received at said imaging device; and

a laser radiating control processor that controls said plurality of laser devices to radiate said pulse modulated laser beams in a predetermined order, each laser device of said plurality of laser devices being disposed at predetermined intervals, each illuminating area of said laser beam radiated from said each laser beam overlapping each other at the distance of said measurement subject, said laser radiating control processor controlling said plurality of laser devices to radiate said laser beams in a predetermined order consecutively, so that consecutive said laser beams compose a single pulse beam for said distance measurement.

2. The device of claim 1, wherein said single pulse beam comprises a rectangular pulse.

3. The device of claim 1, wherein said plurality of laser devices are disposed at regular intervals along a periphery of a photographing lens in a circular arrangement.

4. The device of claim 3, wherein said laser radiating control processor controls each of said laser devices, so that said laser beams are radiated from each of said laser devices successively around said circular arrangement.

5. The device of claim 1, wherein said plurality of laser devices are arranged at regular intervals along a line in a predetermined direction.

6. The device of claim 5, wherein each of said laser devices repeatedly radiates said laser beams successively along said line.

7. The device of claim 1, wherein said imaging device receives a reflected light beam of said single pulse beam, and detects said distance information, which relates to said measurement subject, from signal charge accumulated in said imaging device, due to said single pulse beam, during a predetermined period.

8. The device of claim 7, wherein said laser radiating control processor is driven repeatedly and said imaging device respectively accumulates said signal charge in each of said predetermined periods that corresponds to each of said single pulse beams.

9. The device of claim 8, wherein said imaging, device comprises:

a plurality of photoelectric conversion elements that accumulate said signal charge in each of said photoelectric conversion elements;

a signal charge holding unit disposed adjacent to each of said photoelectric conversion elements; and

wherein said signal charge accumulated in each of said photoelectric conversion elements is transferred to each of corresponding said signal charge holding units for each of said predetermined periods.