Apparatus and methods for capturing defect data

• US 6,437,358 B1
• Filed: 02/04/1999
• Issued: 08/20/2002
• Est. Priority Date: 02/04/1999
• Status: Expired due to Fees

• Current Assignee: Eastman Kodak Company
• Original Assignee: Applied Science Fiction, Inc.
• Inventors: Polk, Darryl R., Edgar, Albert D., Potucek, Martin
• Primary Examiner(s): Le, Que T.
• Assistant Examiner(s): PYO, KEVIN K
• Application Number:
  US09/244,196
• Time in Patent Office: 1,293 Days
• Field of Search: 250/559.01, 250/559.02, 250/559.05, 250/559.07, 250/559.11, 250/559.4, 250/559.41, 250/559.44, 250/559.45, 250/559.48, 250/548, 250/216, 250/284, 250/208.1, 355/53, 355/67, 355/71, 356/237.1, 356/237.2, 356/239.1, 356/239.7, 356/239.8, 382/108, 382/112, 382/149, 382/254, 382/275
• US Class Current: 250/559.45
• CPC Class Codes: G01N 21/94 Investigating contamination, e.g. dust G01N21/85 takes precedence
• CPC Class Codes: H04N 1/00002 Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for error detection, error correction or monitoring in digital computers or digital computer components G06F11/00
• CPC Class Codes: H04N 1/00013 Reading apparatus
• CPC Class Codes: H04N 1/00037 Detecting, i.e. determining the occurrence of a predetermined state H04N1/00031 takes precedence
• CPC Class Codes: H04N 1/00053 out of service, i.e. outside of normal operation
• CPC Class Codes: H04N 1/00063 using at least a part of the apparatus itself, e.g. self-testing
• CPC Class Codes: H04N 1/00082 Adjusting or controlling interrupting an operation H04N1/00915; inhibiting an operation H04N1/00925
• CPC Class Codes: H04N 1/00092 relating to the original or to the reproducing medium, e.g. imperfections or dirt detecting properties of a sheet H04N1/00681
• CPC Class Codes: H04N 1/00795 Reading arrangements details of scanning heads H04N1/024; scanning arrangements therefor H04N1/04

Abstract

The present invention provides a system for image-capturing devices, such as scanners, to accurately identify defects in objects. The objects can be the physical images to be captured or elements of the image-capturing devices such as the platen and mirrors. The image-capturing devices can then use this defect information to remove defects from captured images. The invention teaches an advantageous arrangement of illumination and sensor elements to record defect data at an angle roughly equal to the angle at which light is directed to an object, i.e. where the angle of reflection roughly equals the angle of incidence. Light reflected from surface defects has a wider diffusion and thus a lower amplitude than light reflected from the surface of the object itself. Accordingly, this characteristic can be utilized to identify defect information. Image-capturing devices can use this defect information in software applications with mathematical algorithms to enhance captured images by removing the information that corresponds to defects.

Claims

1. A method of reproducing a portion of an image disposed on a media surface including the steps of:

illuminating a portion of image with a first light beam transmitted at a first predetermined angle with respect to the media surface;

detecting the first light beam to obtain image media data;

illuminating the portion of the image a second light beam transmitted at a second predetermined angle with respect to the media surface;

detecting the second light beam after the second light beam reflects off of the portion of the image to obtain defect data, wherein the reflected second light that is reflected at a third predetermined angle with respect to the media surface is detected, the difference between the second predetermined angle and the third predetermined angle being about 20 degrees or less; and

using the image media data and the defect data to reproduce the portion of the image.

2. A method according to claim 1 wherein the difference between the first predetermined angle and the third predetermined angle is about 10 degrees or less.

3. A method according to claim 1 wherein the first light beam is reflected off of the media surface and the step of detecting the first light beam detects the reflected first light beam.

4. A method according to claim 1 wherein the first light beam is transmitted through the media surface and the step of detecting the first light beam that has been transmitted through the media surface.

5. A method according to claim 1 wherein the step of detecting the second light beam includes the steps of:

focussing the reflected second light beam using an optical assembly to obtain a focussed reflected second light beam; and

detecting the focussed reflected second light beam.

6. A method according to claim 1 further comprising the step of steering the second light beam reflected off of the media surface using a mirror prior to the step of detecting the second light beam.

7. A method according to claim 1 wherein the step of detecting the second light beam detects a portion of the reflected second light beam that corresponds to an area of the portion of the image containing the defect as having a lesser intensity than another portion of the detected second light beam that is reflected on another area of the portion of the image that does not contain any defect.

8. A method according to claim 1 wherein the second predetermined angle is within the range of 35°

-145°

.

9. A method according to claim 8 wherein the second predetermined angle is within the range of 45°

-80° and

100°

-135°

.

10. An apparatus for producing a defect data stream that replicates a defect that exists on a portion of an image disposed on a media surface comprising:

a second light source for illuminating the portion of the image with a second light beam, the second light beam striking the portion of the image at a time that is different than when the first light source illuminates the portion of the image, and wherein the second light beam is detected in order to obtain image data;

a first light source for illuminating a portion of image with a light beam, the light beam striking the portion of the image at a first predetermined angle with respect to the media surface; and

a detector for detecting the light beam after the light beam reflects off of the portion of the image to obtain defect data, wherein the detector detects reflected light that is reflected off of the portion of the image at a second predetermined angle with respect to the media surface is detected, the difference between the first predetermined angle and the second predetermined angle being about 20 degrees or less.

11. An apparatus according to claim 10 further including at least one optical device for allowing the detector to detect both the first light beam and the second light beam, wherein the second light beam is transmitted through the media surface.

12. An apparatus according to claim 11 wherein the optical device is a mirror.

13. An apparatus according to claim 10 wherein the detector includes an optical assembly and a charge coupled device array.

14. An apparatus according to claim 10, wherein the first light beam illuminates the image at a time that is different than when the second light beam illuminates the image.

15. An apparatus according to claim 10, wherein at least one light source comprises a mirror.