MODULAR ILLUMINATOR FOR EXTREMELY WIDE FIELD OF VIEW

• US 20170059838A1
• Filed: 01/12/2016
• Published: 03/02/2017
• Est. Priority Date: 08/25/2015
• Status: Active Grant

• Current Assignee: Rockwell Automation Technologies Incorporated (Rockwell Automation, Inc.)
• Original Assignee: Rockwell Automation Technologies Incorporated (Rockwell Automation, Inc.)
• Inventors: Tilleman, Michael M.
• Granted Patent: US 9,798,126 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F21V 5/007 Array of lenses or refractors for a cluster of light sources, e.g. for arrangement of multiple light sources in one plane combination of two or more refractors F21V5/008
• CPC Class Codes: F21V 5/008 Combination of two or more successive refractors along an optical axis
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 Semiconductor lasers
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• 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 7/4815 using multiple transmitters
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G02B 19/0014 at least one surface having optical power
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0047 for use with a light source G02B19/009, G02B19/0095 take precedence; details of lighting devices in general F21V; non-semiconductor lasers having optical devices external to the laser cavity H01S3/005
• CPC Class Codes: G02B 19/0057 in the form of a laser diode array, e.g. laser diode bar semiconductor laser arrays with beam combining arrangement H01S5/4012
• CPC Class Codes: G02B 19/0066 in the form of an LED array
• CPC Class Codes: G02B 19/0071 adapted to illuminate a complete hemisphere or a plane extending 360 degrees around the source
• CPC Class Codes: G02B 27/0905 Dividing and/or superposing multiple light beams
• CPC Class Codes: G02B 27/0961 Lens arrays lens arrays per se G02B3/0006
• CPC Class Codes: G02B 27/0966 Cylindrical lenses cylindrical lenses per se G02B3/06
• CPC Class Codes: G02B 27/30 Collimators
• CPC Class Codes: G02B 3/04 with continuous faces that are rotationally symmetrical but deviate from a true sphere , e.g. so called "aspheric" lenses
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A modular illumination system is capable of producing a light beam having a wide field of view—e.g., in excess of ninety degrees—while maintaining a high collection efficiency as well as a high degree of beam homogeneity. The illumination system comprises an elementary unit having a linear array of light sources. Light from the light sources is collimated using a corresponding array of catadioptric lenses, and the collimated light is homogenized in the tangential plane using two cylindrical lens arrays set in tandem to one another. The homogenized light is then collimated in the sagittal plane using a cylindrical lens that is set perpendicular to the lenses of the two cylindrical lens arrays to yield a wide linear beam. To produce an area beam, the linear array of light sources can be replaced with a two-dimensional array, and the cylindrical lenses can be replaced with spherical lenses.

Claims

1. An illumination system, comprising:

an array of light sources;

one or more catadioptric lenses arranged to collect light from the array of light sources;

a first array of lenses arranged in a first row that is substantially perpendicular to an optical path of light from the one or more catadioptric lenses;

a second array of lenses arranged in a second row that is substantially parallel to the first row and substantially perpendicular to the optical path; and

an output lens arranged to collect and project light from the second array of lenses to yield and output beam.

2. The illumination system of claim 1, wherein the array of light sources comprises at least one of a linear array of light emitting diodes, a laser array, or a vertical-cavity surface-emitting laser (VCSEL) array.

3. The illumination system of claim 2, wherein the first array and the second array comprise cylindrical lenses oriented substantially parallel with one another.

4. The illumination system of claim 3, wherein the output lens comprises a cylindrical output lens.

5. The illumination system of claim 4, wherein an axis of the cylindrical output lens is substantially perpendicular to axes of the cylindrical lenses of the first and second arrays.

6. The illumination system of claim 5, wherein the cylindrical output lens is configured to collimate the light from the second array of lenses in a sagittal plane to yield a collimated light beam.

7. The illumination system of claim 1, wherein the first array and the second array comprise spherical lenses, and the output lens comprises a spherical lens.

8. The illumination system of claim 1, further comprising a modulation component configured to modulate the light from the array of light sources.

9. The illumination system of claim 1, wherein the array of light sources comprises a first array of light sources, the one or more catadioptric lenses comprise one or more first catadioptric lenses, the output lens comprises a first output lens, and the optical path comprises a first optical path, and

the illumination system further comprises:

a second array of light sources oriented substantially ninety degrees relative to the first array of light sources;

one or more second catadioptric lenses arranged to collect light from the second array of light sources;

a third array of lenses arranged in a third row that is substantially perpendicular to a second optical path of light from the one or more second catadioptric lenses;

a fourth array of lenses arranged in a fourth row that is substantially parallel to the third row and substantially perpendicular to the second optical path; and

a second output lens arranged to collect light from the fourth array of lenses.

10. The illumination system of claim 9, wherein the first array of light sources and the second array of light sources are configured to emit light of respective different wavelengths or to emit light of a same wavelength.

11. The illumination system of claim 9, wherein the first array of light sources is configured to emit S-polarized light and the second array of light sources is configured to emit P-polarized light.

12. The illumination system of claim 9, further comprising:

a third array of light sources oriented substantially ninety degrees relative to the second array of light sources;

one or more third catadioptric lenses arranged to collect light from the third array of light sources;

a fifth array of lenses arranged in a fifth row that is substantially perpendicular to a third optical path of light form the one or more third catadioptric lenses;

a sixth array of lenses arranged in a sixth row that is substantially parallel to the fifth row and substantially perpendicular to the third optical path; and

a third output lens arranged to collect light from the sixth array of lenses.

13. The illumination system of claim 12, further comprising:

a fourth array of light sources oriented substantially ninety degrees relative to the third array of light sources;

one or more fourth catadioptric lenses arranged to collect light from the fourth array of light sources;

a seventh array of lenses arranged in a seventh row that is substantially perpendicular to a fourth optical path of light form the one or more fourth catadioptric lenses;

an eighth array of lenses arranged in an eight row that is substantially parallel to the seventh row and substantially perpendicular to the fourth optical path; and

a fourth output lens arranged to collect light from the eighth array of lenses.

14. The illumination system of claim 1, wherein the illumination system is an integrated component of a time-of-flight camera.

15. A method for producing a beam of light, comprising:

generating light by a linear array of light sources;

collimating the light by one or more catadioptric lenses to yield first collimated light;

homogenizing the first collimated light in a tangential plane by two cylindrical lens arrays set in tandem to one another to yield homogenized light; and

collimating the homogenized light in a sagittal plane by a cylindrical lens set perpendicular to the two cylindrical lens arrays to yield second collimated light.

16. The method of claim 15, wherein the generating comprises generating the light by at least one of an array of light emitting diode dies, a laser array, or a vertical-cavity surface-emitting laser (VCSEL) array.

17. The method of claim 15, wherein the generating comprises at least one of modulating the light or generating a pulsed light beam.

18. A method for producing a beam of light, comprising,

generating light by an array of light sources;

collimating the light in a tangential plane and expanding the light in a sagittal plane by one or more lenses to yield first collimated light;

diffusing and homogenizing the first collimated light to yield homogenized light; and

collimating the homogenized light in the tangential plane and a sagittal plane by a cylindrical lens.

19. The method of claim 18, wherein the generating comprises generating the light by a vertical-cavity surface-emitting laser (VCSEL) array.

20. The method of claim 19, wherein

the collimating comprises collimating the light using three biconic lenses,

the diffusing and homogenizing comprises diffusing and homogenizing the first collimated light using a diffuser, and

the collimating the homogenized light comprises collimating the homogenized light using a Fresnel lens.