Line generator optical apparatus

• US 6,688,758 B2
• Filed: 06/28/2002
• Issued: 02/10/2004
• Est. Priority Date: 06/14/2002
• Status: Active Grant

• Current Assignee: Institut national d'optique
• Original Assignee: Institut national d'optique
• Inventors: Thibault, Simon
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Cranson, Jr., James W
• Application Number:
  US10/185,341
• Publication Number:
  US 20030231511A1
• Time in Patent Office: 592 Days
• Field of Search: 362/268, 362/551, 359/668, 359/641, 369/112.1, 369/44, 235/462.2, 235/462.21, 235/462.22, 235/454
• US Class Current: 362/368
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50
• CPC Class Codes: G02B 19/0014 at least one surface having optical power
• CPC Class Codes: G02B 19/0052 the light source comprising a laser diode coupling into light guides using intermediate optical elements G02B6/4204; semiconductor lasers having optical devices external to the laser cavity H01S5/005
• CPC Class Codes: G02B 27/0944 Diffractive optical elements, e.g. gratings, holograms gratings per se G02B5/18; holograms used as optical elements per se G02B5/32
• CPC Class Codes: G02B 27/0966 Cylindrical lenses cylindrical lenses per se G02B3/06

Abstract

An apparatus for generating linear patterns of light comprises a light source emitting a first light beam. An anamorphic system is positioned downstream of the light source and is adapted to receive the first light beam of the light source for concentrating the first light beam such that the first light beam would project a first linear pattern on a far field. A diffractive optical element is positioned downstream of the anamorphic system for receiving and diffusing the first light beam of the anamorphic system a plurality of second light beams. The plurality of second light beams overlap one another at least partially so as to project a second linear pattern on the far field of altered intensity with respect to the first linear pattern.

Claims

1. An apparatus for generating linear patterns of light, comprising at least one light source emitting a first light beam, an anamorphic system positioned downstream of the light source and adapted to receive the first light beam of the light source for concentrating the first light beam such that the first light beam would project a first linear pattern on a far field, and at least one diffractive optical element positioned downstream of the anamorphic system for receiving and diffusing the first light beam of the anamorphic system in at least two second light beams, the at least two second light beams overlapping one another at least partially so as to project a second linear pattern on the far field of altered intensity with respect to the first linear pattern.

2. The apparatus according to claim 1, wherein the second linear pattern has a non-Gaussian longitudinal light intensity profile.

3. The apparatus according to claim 1, wherein the anamorphic system includes at least one cylindrical lens to adjust a length dimension of the first light beam.

4. The apparatus according to claim 3, wherein the anamorphic system has at least one spherical lens to adjust a width dimension of the first light beam.

5. The apparatus according to claim 4, wherein there are provided two of the diffractive optical element and wherein the anamorphic system has a beam splitter and two cylindrical lenses, the beam splitter separating the first beam into two first light beams each adapted to pass through a respective one of the two cylindrical lenses, the cylindrical lenses being positioned generally at a 90°

offset with respect to one another, so as to each concentrate a respective one of the first light beams on a respective one of the two diffractive optical elements to project a cross-shaped second linear pattern on the far field.

6. The apparatus according to claim 1, wherein the light source is a multimode fiber.

7. The apparatus according to claim 1, comprising a plurality of light sources such that the first light beam is a summation of light beams produced by each one of the light sources and at least partly overlapping one another to project the second linear pattern with enhanced intensity on the far field.

8. The apparatus according to claim 7, wherein the light sources are laser diodes.

9. A system of apparatuses for generating linear patterns of light, comprising at least one light source emitting a light signal, at least two optical fibers each emitting a first light beam to one of the apparatuses, each apparatus comprising an anamorphic system positioned downstream of a respective one of the optical fibers and adapted to receive the first light beam of the respective one of the optical fibers for concentrating the first light beam such that the first light beam would project a first linear pattern on a far field, and at least one diffractive optical element positioned downstream of the anamorphic system for receiving and diffusing the first light beam of the anamorphic system in at least two second light beams, the two second light beams overlapping one another at least partially so as to project a second linear pattern on the far field of altered intensity with respect to the first linear pattern.

10. The system according to claim 9, wherein the optical fiber is a multimode optical fiber.

11. The system according to claim 9, wherein the second linear pattern has a non-Gaussian longitudinal light intensity profile.

12. The system according to claim 9, wherein the anamorphic system includes at least one cylindrical lens to collimate a length dimension of the first light beam.

13. The system according to claim 12, wherein the anamorphic system has at least one spherical lens to collimate a width dimension of the first light beam.

14. The system according to claim 13, wherein there are provided two of the diffractive optical element and wherein the anamorphic system has a beam splitter and two cylindrical lenses, the beam splitter separating the first beam into two first light beams each adapted to pass through a respective one of the two cylindrical lenses, the cylindrical lenses being positioned generally at a 90°

offset with respect to one another, so as to each concentrate a respective one of the first light beams on a respective one of the two diffractive optical elements to project a cross-shaped second linear pattern on the far field.