COUPLED MULTI-WAVELENGTH CONFOCAL SYSTEMS FOR DISTANCE MEASUREMENTS

• US 20120316830A1
• Filed: 06/09/2011
• Published: 12/13/2012
• Est. Priority Date: 06/09/2011
• Status: Abandoned Application

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Eyal, Ophir
• Application Number:
  US13/156,572
• Publication Number:
  US 20120316830A1
• Time in Patent Office: Days
• US Class Current: 702/159
• CPC Class Codes: G01B 11/026 by measuring distance between sensor and object G01B11/0608 takes precedence
• CPC Class Codes: G01B 11/14 for measuring distance or clearance between spaced objects or spaced apertures G01B11/26 takes precedence; rangefinders G01C3/00
• CPC Class Codes: G01B 2210/50 Using chromatic effects to achieve wavelength-dependent depth resolution

Abstract

A system for measuring a distance to a substrate includes a first light source, emitting a first wavelength on a region of the substrate though a lens. A second light source emits a second wavelength region of the substrate through the lens. A first and second detector are configured to detect the first and second wavelength light reflected from the substrate. A processor is configured to compute a first response function wherein the first response function represents reflected light intensity emitted from the first light source as a function of the distance between the imaging device and substrate. A second response function represents reflected light intensity emitted from the second light source as a function of the distance between the imaging device and substrate. A ratio response function represents the ratio of the first and second response function as a function of distance between the imaging device and substrate.

Claims

1. A system for measuring a distance to a substrate comprising:

a first light source, emitting a first wavelength on a region of the substrate through a lens;

a second light source emitting a second wavelength on the region of the substrate through the lens;

wherein the lens is confocal and dispersive;

a first detector configured to detect first wavelength light reflected from the substrate;

a second detector configured to detect second wavelength light reflected from the substrate; and

a processor configured to compute;

a) a first response function wherein the first response function represents reflected light intensity emitted from the first light source as a function of the distance between the imaging device and substrate;

b) a second response function wherein the second response function represents reflected light intensity emitted from the second light source as a function of the distance between the imaging device and substrate; and

c) a ratio response function wherein the ratio response function represents the ratio of the first response function and the second response function as a function of distance between the imaging device and substrate.

2. The system in claim 1 wherein more than two light sources and detectors are used and wherein each of the light sources emits light of a different wavelength.

3. The system of claim 1 wherein the laser sources and the detectors are coupled by fiber optic couplers.

4. The system of claim 1 wherein the optical port is the distal tip of a fiber.

5. The system of claim 1 wherein the laser source and detectors are coupled utilizing mirrors, reflectors, optical fibers, and fiber optic elements.

6. The system of claim 1 wherein the optical port is a pin hole.

7. The system of claim 1 wherein the optical element is composed of mirrors and lenses.

8. The system of claim 1 wherein the optical element is a telemetric lens.

9. The system of claim 1 wherein the detector is a photonic or bolometric detector.