On-Axis And Diffuse Illumination For Inspection Systems

• US 20180100808A1
• Filed: 10/06/2017
• Published: 04/12/2018
• Est. Priority Date: 10/07/2016
• Status: Active Grant

• Current Assignee: Hutchinson Technology Incorporated (TDK Corporation)
• Original Assignee: Hutchinson Technology Incorporated (TDK Corporation)
• Inventors: Lang, Matthew S., Maday, Timothy J., Johnson, Dennis R.
• Granted Patent: US 11,442,020 B2
• Time in Patent Office: Days
• CPC Class Codes: G01N 2021/8816 by using multiple sources, e.g. LEDs
• CPC Class Codes: G01N 21/8806 Specially adapted optical and illumination features
• CPC Class Codes: G01N 2201/062 LED's
• CPC Class Codes: G01N 2201/065 Integrating spheres
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0066 in the form of an LED array
• CPC Class Codes: G02B 27/0994 Fibers, light pipes optical fibers per se G02B6/02
• CPC Class Codes: G02B 7/1815 with cooling or heating systems cooling arrangements for laser mirrors H01S3/0401
• CPC Class Codes: H04N 23/56 provided with illuminating means

Abstract

An inspection system is described. The inspection system includes a camera and a housing. The housing contains a reflective dome. The reflective dome includes an apex and a viewport. The viewport is offset from the apex. The camera is mounted to capture light exiting the reflective dome through the viewport. And, a plurality of light sources are arranged about the reflective dome such that light output from the plurality of light sources enters the dome.

Claims

1. An inspection system, comprising:

a camera; and

a housing, the housing having;

a reflective dome, the reflective dome including an apex and a viewport, the viewport offset from the apex, the camera mounted to capture light exiting the reflective dome through the viewport; and

a plurality of light sources, the plurality of light sources arranged about the reflective dome such that light output from the plurality of light sources enters the dome.

2. The system of claim 1, wherein the light exiting the reflective dome through the viewport and received by the camera contains light that is diffuse and replicates light that is on-axis and with respect to the orientation of the camera.

3. The system of claim 1, wherein the reflective dome includes a top side and a bottom side, the bottom side including a highly reflective concave surface.

4. The system of claim 3, wherein each light source of the plurality of light sources includes a back side and a face from which illumination generated by the light source is emitted, and wherein the highly reflective concave surface and the faces of the plurality of light sources are arranged in the housing to face a downward direction.

5. The system of claim 4, further comprising a reflector ring that overlaps the bottom side of the reflective dome, the reflector ring including a highly reflective surface that reflects a substantial amount of the light directly emitted in a downward direction from the plurality of light sources into the reflective dome, the reflector ring including a center void, wherein the light that is reflected by the reflector ring into the reflective dome reflects off of the highly reflective concave surface and through the center void to reflect off of a part being reflected and back through the center void into the reflective dome.

6. The system of claim 5, wherein the reflector ring includes a plurality of scallops arrayed around the reflector ring in a circle, the plurality of scallops including a plurality of highly reflective concave surfaces, respectively, the plurality of highly reflective concave surfaces facing an upward direction that is opposite the downward direction in which the highly reflective concave surface of the reflective dome faces.

7. The system of claim 6, wherein the plurality of scallops are located below the plurality of light sources, respectively, in a 1:

1 relationship.

8. The system of claim 4, further comprising a heat sink ring that surrounds the reflective dome, wherein the backs of the plurality of light sources abut the heat sink ring to transfer heat energy generated by the plurality of light sources to the heat sink ring.

9. The system of claim 8, wherein the camera is supported by a camera mounting structure, and wherein the housing is mechanically supported by only two metal tubes, the metal tubes connected to both of the camera mounting structure and the housing.

10. The system of claim 9, wherein a fluid circuit of coolant fluid runs through each of the two metal tubes and the housing.

11. The system of claim 1, wherein the plurality of light sources form a ring that is disposed around a circumference of the reflective dome.

12. The system of claim 1, wherein the apex of the reflective dome is formed from reflective metal and is not transparent.

13. The system of claim 1, wherein the view port includes a hole having a profile that is elongated along the highly reflective concave surface of the reflective dome.

14. The system of claim 1, wherein the housing further includes a coolant fluid circuit that extends around at least part of the reflective dome, the coolant fluid circuit configured to remove heat generated by the plurality of light sources.

15. The system of claim 1, wherein the plurality of light sources are light emitting diodes.

16. An illumination housing for an inspection system, the illumination housing comprising:

a reflective dome, the reflective dome including an apex and a viewport, the viewport offset from the apex; and

a plurality of light sources, the plurality of light sources arranged about the reflective dome such that light output from the plurality of light sources enters the dome.

17. The illumination housing of claim 16, wherein illumination housing is configured such that light from the plurality of light sources exits the reflective dome through the viewport and is diffuse and replicates light that is on-axis and with respect to an orientation of a camera.

18. The illumination housing of claim 16, wherein the reflective dome includes a top side and a bottom side, the bottom side including a highly reflective concave surface.

19. The illumination housing of claim 18, wherein each light source of the plurality of light sources includes a back side and a face from which illumination generated by the light source is emitted, and the highly reflective concave surface and the faces of the plurality of light sources are arranged in the housing to face a downward direction.

20. The illumination housing of claim 19, further comprising a reflector ring that overlaps the bottom side of the reflective dome, the reflector ring including a highly reflective surface that reflects a substantial amount of the light directly emitted in a downward direction from the plurality of light sources into the reflective dome, the reflector ring including a center void, wherein the light that is reflected by the reflector ring into the reflective dome reflects off of the highly reflective concave surface and through the center void to reflect off of a part being reflected and back through the center void into the reflective dome.