Self-cleaning lens shield

• US 20020139394A1
• Filed: 04/03/2001
• Published: 10/03/2002
• Est. Priority Date: 04/03/2001
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Bronson, Barry
• Granted Patent: US 6,607,606 B2
• Time in Patent Office: Days
• US Class Current: 134/6
• CPC Class Codes: B08B 17/02 Preventing deposition of fouling or of dust
• CPC Class Codes: G02B 27/0006 with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation G02B1/18 takes precedence; cleaning in general B08B

Abstract

The present invention is a method and apparatus for shielding the lens and the field of view of an optical device, such as a camera or an image projector, from obstruction by unwanted contaminants such as dust, dirt, rain, and the like. The invention employs a transparent shield positioned to protect the lens from such contaminants. A wiper is positioned to be in contact with the shield but the wiper is also positioned to not obstruct the field of view. A rotation mechanism is used to cause rotation of the shield. Contaminants that may be deposited upon the shield may be wiped from the shield by the wiper yet the wiper does not obstruct the field of view. Rotation of the shield allows a portion of the shield that is obstructed by a contaminant to be rotated away from the field of view. Rotation of the shield allows a portion of the shield that has been wiped to be rotated into the field of view.

Claims

1. An apparatus for shielding the field of view of an optical device from obstruction by unwanted contaminants such as dust, dirt, rain, insects and insect excreta, and the like, the apparatus comprising:

a transparent shield positioned to protect the optical device from contaminants;

a wiper positioned to be in contact with said shield but said wiper positioned not to obstruct the field of view;

a rotation mechanism for causing rotation of said shield;

whereby contaminants that may be deposited upon said shield may be wiped from said shield by said wiper and whereby said wiper does not obstruct the field of view.

2. The apparatus of claim 1 further comprising a controller for activating and deactivating said rotation mechanism.

3. The apparatus of claim 2 further comprising:

a video screen for viewing through the field of view and

a screen based human interface for linked to said controller, the screen based human interface for operating said controller to thereby activate and deactivate said rotation mechanism.

4. The apparatus of claim 3 further comprising a network link between said video screen and said controller.

5. The apparatus of claim 1 wherein said rotation mechanism has an axle fixed to said shield and wherein rotation of said axle causes rotation of said shield.

6. The apparatus of claim 1 wherein said rotation mechanism has no axle fixed to said shield.

7. The apparatus of claim 6 wherein said mechanism imparts a torque along a periphery of said shield.

8. The apparatus of claim 1 further comprising a system for automatic detection of contaminants on said shield whereby the contaminants on said shield may be automatically detected.

9. The apparatus of claim 8 wherein said system for automatic detection of contaminants further comprises a library of reference images of said shield.

10. The apparatus of claim 9 further comprising a system automatic rotation of said shield whereby said shield may be automatically rotated upon said automatic detection of the contaminants.

11. The apparatus of claim 1 further comprising a cleaning fluid applicator for applying a cleaning fluid to said shield whereby cleaning fluid may be wiped from said shield by said wiper as a result of such rotation.

13. The method of claim 12 further comprising:

a step of positioning a cleaning fluid applicator such that it may apply cleaning fluid to said shield; and

a step of applying cleaning fluid to said shield whereby said cleaning fluid may be wiped from said shield by said wiper as a result of such rotation.

14. The method of claim 12 further comprising:

a step of providing an automatic monitoring system for automatically monitoring for the presence of the contaminant on said shield, and

a step of using said automatic monitoring system for automatically monitoring for the presence of the contaminant on said shield.

15. The method of claim 14 further comprising:

upon the detection of the contaminant, automatically activating said rotation.

16. The method of claim 14 wherein said step of automatically monitoring further comprises:

a step of obtaining at least one reference image of said shield, a reference image being one that is obtained when said shield is known to be free of contaminants;

a step of obtaining at least one test image of said shield, a test image being one that is obtained to determine if a contaminant is present on said shield;

a step of comparing said test image with at least one said reference image to determine if there is a significant difference between said test image and said reference image.

18. The method of claim 12 further comprising:

a step of making a video screen based human interface link between a video screen and said rotation mechanism;

a step of using said interface link to control said rotation mechanism.

19. The method of claim 18 wherein said interface link is made using the internet.

12. A method for shielding the field of view of an optical device from obstruction by unwanted contaminants such as dust, dirt, rain, insects and insect excreta, and the like, the comprising:

a step of positioning a transparent shield to protect the optical device from contaminants;

a step of positioning a wiper to be in contact with said shield but positioning said wiper to not obstruct the field of view;

a step of providing a rotation mechanism for causing rotation of said shield;

a step of using said rotation mechanism to cause rotation of said shield;

whereby contaminants that may be deposited upon said shield may be rotated away from the field of view, whereby contaminants that may be deposited upon said shield may be wiped from said shield by said wiper, and whereby said wiper does not obstruct the field of view.

17. The method of step 16 wherein:

said step of obtaining at least one reference image of said shield comprises a step of obtaining a plurality of reference images where ambient lighting conditions are associated with each reference image;

wherein

said step of obtaining at least one test image comprises a step of determining ambient lighting conditions associated with said test image; and

further comprising the step of;

selecting a reference image for comparison with said test image where such selection is performed by matching ambient lighting conditions associated with said test image with ambient lighting conditions associated with said reference image.