Three-dimensional shape measuring apparatus

• US 6,674,893 B1
• Filed: 09/06/2000
• Issued: 01/06/2004
• Est. Priority Date: 10/19/1999
• Status: Expired due to Fees

• Current Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Inventors: Egawa, Yutaka, Abe, Tsutomu
• Primary Examiner(s): Au, Amelia M.
• Assistant Examiner(s): KIBLER, VIRGINIA M
• Application Number:
  US09/655,915
• Time in Patent Office: 1,217 Days
• Field of Search: 382/106, 382/108, 382/154, 348/136, 348/139, 348/143, 348/144, 356/603-610, 356/3, 356/3.01, 356/3.09, 356/3.1, 356/12
• US Class Current: 382/154
• CPC Class Codes: G01B 11/2527 with phase change by in-plane movement of the patern
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G06T 7/521 from laser ranging, e.g. using interferometry; from the projection of structured light
• CPC Class Codes: G06V 10/145 Illumination specially adapted for pattern recognition, e.g. using gratings

Abstract

A three-dimensional shape measuring apparatus capable of simultaneously obtaining range information and luminance information with high precision, independently of an object. A controller scans slit light, emitted from a laser beam source and shaped by a cylindrical lens, on an object plural times, by mirror surfaces of a polygon mirror, while causing the laser beam source to flash by using a laser beam source driver. The slit light is time-sequentially combined into projection pattern light having plural light stripes, respectively 3-level or more intensity-modulated, and the projection pattern light is projected onto the object. An image processor obtains the range information and the luminance information based on reflection light obtained by image pickup by first and second cameras.

Claims

1. A three-dimensional shape measuring apparatus comprising:

a light source that emits a laser beam;

a projection part that generates pattern light having plural areas, intensity-modulated to ternary or higher representation values based on a pattern code, using the laser beam, and projects the pattern light onto an object;

an image pickup part that performs image pickup on the light reflected from the object by projection of the pattern light to simultaneously obtain a pattern image and a luminance image; and

an arithmetic part that calculates range information about a distance to the object based on the pattern code and the pattern image.

2. The three-dimensional shape measuring apparatus according to claim 1, wherein the projection part comprises:

a shaping part that shapes the laser beam emitted from the light source into slit light;

a deflection part that deflects the slit light to scan the object; and

a control part that controls the light source and the deflection part based on the pattern code to generate the pattern light using the slit light.

3. The three-dimensional shape measuring apparatus according to claim 2, wherein the deflection part is a polygon mirror.

4. The three-dimensional shape measuring apparatus according to claim 2, wherein the control part controls the deflection part to scan the object with the slit light several times, and generates the pattern light by causing the laser beam to flash in accordance with the number of scans of the slit light and scan positions.

5. The three-dimensional shape measuring apparatus according to claim 1, wherein the image pickup part comprises:

a first image pickup part that performs image pickup on the light from the object in a projection direction of the projection part to obtain a first pattern image; and

a second image pickup part that performs image pickup on the light from the object in a projection direction different from that of the projection part to obtain a second pattern image,

wherein the arithmetic part modifies the pattern code based on the first pattern image, and calculates range information about a distance to the object based on the modified pattern code and the second pattern image.

6. A three-dimensional shape measuring apparatus comprising:

a light source that emits a laser beam;

a projection part that generates pattern light having plural areas, intensity-modulated to ternary or higher representation values based on a pattern code, using the laser beam, and projects the pattern light onto an object;

an image pickup part that performs image pickup on the light, reflected from the object by projection of the pattern light to simultaneously obtain a pattern image and a luminance image;

an arithmetic part that calculates range information about a distance to the object based on the pattern code and the pattern image; and

a three-dimensional image formation part that forms a three-dimensional image based on the range information obtained by calculation by the arithmetic part and luminance information obtained by the image pickup part.

7. A three-dimensional shape measuring apparatus comprising:

a light source that emits a laser beam;

a projection part that generates pattern light having plural areas, intensity-modulated to ternary or higher representation values based on a pattern code, using the laser beam, and projects the pattern light onto an object;

a camera having a first and second image pickup part, and the camera receiving reflected light from the object and dividing the reflected light to the first and second image pickup part so that the first and second image pickup part obtains respectively a first and second pattern image; and

an arithmetic part that modifies the pattern code based on the first pattern image, and calculates range information about a distance to the object based on the modified pattern code and the second pattern image.

8. The three-dimensional shape measuring apparatus according to claim 7, wherein the projection part comprises:

a shaping part that shapes the laser beam emitted from the light source into slit light;

a deflection part that deflects the slit light to scan the object; and

a control part that controls the light source and the deflection part based on the pattern code to generate the pattern light using the slit light.

9. The three-dimensional shape measuring apparatus according to claim 8, wherein the deflection part is a polygon mirror.

10. The three-dimensional shape measuring apparatus according to claim 8, wherein the control part controls the deflection part to scan the object with the slit light several times, and generates the pattern light by causing the laser beam to flash in accordance with the number of scans of the slit light and scan positions.