Dual reflector system for linear lamp illuminators
View Patent ↗The present invention provides an illuminator system comprising a dual reflector system and a linear light source. The dual reflector system comprises a primary and secondary generally cylindrical reflector, which collimate light from a linear light source in two planes. The linear light source may comprise many light emitting devices, and may emit light in a strobe or continuous fashion. The reflectors may be of many cylindrical shapes, and may include additional mirror segments to capture light otherwise not collimated. Further, the reflectors may be in various configurations of position and orientation with respect to one another, and may be adjustable in this respect. The system is more efficient than existing illuminators, is compact, all reflective (no color), lightweight, simple and inexpensive to manufacture. The system has applications to many fields including machine vision, surveillance, spectroscopic inspection of materials, and converting linear light sources into rectangular beam spot lights.
1. An illuminator system, comprising:
a dual reflector system comprising
a primary generally cylindrical reflector having a primary focal axis and oriented to collimate light in a first plane, and
a secondary generally cylindrical reflector having a secondary focal axis and oriented to collimate light in a second plane, said primary generally cylindrical reflector and said secondary generally cylindrical reflector being mounted on a support structure such that said primary generally cylindrical reflector and said secondary generally cylindrical reflector are generally orthogonal to each other; and
a linear light source having an emission length disposed on the primary focal axis; wherein
said primary generally cylindrical reflector and the secondary generally cylindrical reflector are oriented relative to each other on said support structure so that light emitted by the linear light source is reflected and becomes collimated in both said first plane and said second plane.
2. The illuminator system according to claim 1 wherein
said primary generally cylindrical reflector is a primary generally cylindrical parabolic reflector having a primary vertex and a primary focal length between the primary vertex and said primary focal axis; and
said secondary generally cylindrical reflector is a secondary generally cylindrical parabolic reflector having a secondary vertex and a secondary focal length between the secondary vertex and said secondary focal axis.
3. The illuminator system according to claim 2 wherein the secondary focal axis is located on or behind the primary vertex.
4. The illuminator system according to claim 3 wherein said secondary focal axis is behind said primary vertex at a distance equal to said primary focal length from said primary vertex.
5. The illuminator system according to claim 2 wherein said secondary focal length is greater than or equal to half of the emission length of said linear light source.
6. The illuminator system according to claim 2 wherein one of said primary vertex, said secondary vertex, and said primary and secondary vertices are curved.
7. The illuminator system according to claim 2 wherein one of said primary vertex, said secondary vertex, and said primary and secondary vertices are linear.
8. The illuminator system according to claim 1 wherein said linear light source is one of a flash lamp, a continuous wave cylindrical linear light source, a tungsten halogen lamp, a sodium lamp, a metal halide lamp, and a fluorescent lamp.
9. The illuminator system according to claim 8 wherein said linear light source is a strobe light.
10. The illuminator system according to claim 1 wherein said dual reflector system further includes at least one mirror segment located parallel to said primary generally cylindrical reflector and oriented with respect to said primary generally cylindrical reflector to reflect stray light back through said primary focal axis.
11. The illuminator system according to claim 10 wherein said at least one mirror segment is positioned such that light passing through said primary focal axis and reflecting from said primary generally cylindrical reflector does not reflect from said at least one mirror segment.
12. The illuminator system according to claim 1 wherein one or both of said primary generally cylindrical reflector and said secondary generally cylindrical reflector comprise at least one flexible reflective sheet mounted to inserts.
13. The illuminator system according to claim 12 wherein said inserts are mounted to a single base.
14. The illuminator system according to claim 12 wherein said inserts form the flexible reflective sheet into the shape of a parabola.
15. The illuminator system according to claim 1 wherein one or both of said primary generally cylindrical reflector and said secondary generally cylindrical reflector are milled from reflective material.
16. The illuminator system according to claim 15 wherein said milled reflective material is mounted to a single base.
17. The illuminator system according to claim 15 wherein a surface of said milled reflective material is in the shape of a parabola.
18. The illuminator system according to claim 1 wherein said first and second planes are mutually orthogonal.
19. The illuminator system according to claim 1 wherein said primary generally cylindrical reflector and said secondary generally cylindrical reflector are positioned and oriented relative to each other on said support structure in an adjustable manner.
20. The illuminator system according to claim 19 wherein said linear light source has a longitudinal axis along said emission length, and wherein said linear light source is fixed with respect to the primary generally cylindrical reflector with its longitudinal axis aligned along the focal axis of the primary generally cylindrical reflector.
21. The illuminator system according to claim 19 wherein said primary generally cylindrical reflector is able to translate and rotate relative to said secondary generally cylindrical reflector in a plane perpendicular to said secondary focal axis.
22. The illuminator system according to claim 1 wherein said primary generally cylindrical reflector has two straight edges, and said primary focal axis lies between said primary generally cylindrical reflector and a plane defined by the two straight edges.
23. The illuminator system according to claim 1 wherein a portion of said primary generally cylindrical reflector is parabolic and a remaining portion of said primary generally cylindrical reflector wraps around the linear light source.
24. The illuminator system according to claim 23 wherein said portion of said primary generally cylindrical reflector that wraps around the linear light source is in the shape of a circle, and wherein said linear light source is disposed at a center of said circle.