Control systems for adaptive lens

• US 20070080280A1
• Filed: 10/11/2006
• Published: 04/12/2007
• Est. Priority Date: 10/11/2005
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Havens, William
• Granted Patent: US 8,027,095 B2
• Time in Patent Office: Days
• US Class Current: 250/201.100
• CPC Class Codes: G02B 3/14 of variable focal length
• CPC Class Codes: G06K 7/10702 Particularities of propagating elements, e.g. lenses, mirrors G06K7/10831 takes precedence

Abstract

Systems and methods for controlling a fluid lens in a data collection device. One or more micropump control systems are used to control one or more fluid lenses. The micropump control systems are used to change volume and/or pressure within the fluid lens system, changing the radius of curvature of the lens.

Claims

1. An imager for use in a data collection device, said imager comprising a fluid lens system for focusing light received by said data collection device from a target image, said fluid lens system comprising:

a) an optical, clear front window,

b) a fluid lens having a front surface and a rear surface,

c) a first volume bounded by said front window and said front surface of said fluid lens;

d) an optical, clear rear window; and

,

e) a second volume bounded by the front surface of said fluid lens and said rear window,

wherein said first volume and said second volume are operably linked through a pump that, in combination with said first volume and said second volume, forms a sealed system.

2. The imager as defined by claim 1, wherein said optical, clear front window is composed of a material selected from the group consisting of optical clear glass and optical clear plastic.

3. The imager as defined by claim 1, wherein said first volume contains a fluid having a diffractive index N₂ and said second volume contains a fluid having a diffractive index N₁, further wherein N₂≠

N₁.

4. The imager as defined by claim 1, wherein said first volume and said second volume are operably linked by a first channel connecting said first volume to said pump and a second channel connecting said second volume to said pump, wherein said pump comprises a plunger, electrostatic electrodes, or piezoelectric material.

5. The imager of claim 4, said pump comprising a seal separating said first and said second fluids, further wherein operation of said pump to effect a first change in the quantity of fluid in either of said first volume or said second volume results in a corresponding second change in the quantity of fluid in the other of said first volume or said second volume.

6. The imager of claim 5, wherein said corresponding second change in the quantity of fluid in the other of said first volume or said second volume is equal but opposite to said first change in the quantity of fluid in either of said first volume or said second volume.

7. The imager as defined in claim 4, wherein said pump is an electrostatic pump, further wherein said electrostatic pump comprises an interface between said first and second fluids, said interface being located within a capillary channel and being selectively moveable in response to changes in electric potential.

8. The imager as defined by claim 7, wherein said changes in electric potential are created by electrodes positioned adjacent either end of said capillary channel.

9. The imager as defined by claim 7, wherein said capillary channel has one dimension that is less than 10 microns.

10. The imager as defined by claim 8, further comprising a plurality of said capillary channels, each of said capillary channels having electrodes positioned adjacent either end thereof.

11. The imager as defined by claim 10, wherein said plurality of said capillary channels are substantially parallel to each other.

12. The imager of claim 1, further comprising means to prevent a corresponding second change in the quantity of fluid in the other of said first volume or said second volume in response to a first change in the quantity of fluid in either of said first volume or said second volume when said first change is not in response to deliberate actuation of said pump.

13. The imager of claim 12, wherein said means comprises a safety valve.

14. The imager of claim 12, wherein said first change is the result of thermal expansion of at least one of said first volume or said second volume.

15. The imager of claim 12, wherein said first change is the result of thermal contraction of at least one of said first volume or said second volume.

16. The imager of claim 12, wherein said first change is the result of mechanical shock to at least one of said first volume or said second volume.

17. The imager of claim 12 wherein said imager further comprises a fluid lens control module and a temperature sensor for measuring a temperature in a vicinity of said fluid lens, said fluid lens control module being configured to apply to said fluid lens a fluid lens control signal based on information output by said temperature sensor.

18. A data reader for reading an indicium, said data reader comprising a case configured to be held in a hand of a user of the data reader, said case configured to house components of said data reader, said components comprising:

a) a lens system for focusing illumination representing an image of said indicum, said lens system comprising a fluid lens;

b) a fluid lens control module configured to apply a fluid lens control signal to said fluid lens to control an operational parameter thereof;

c) an image sensor configured to receive said focused illumination representing said image of said indicium;

d) an image sensor control module configured to operate said image sensor to capture data comprising at least a portion of a frame of image data from said focused illumination representing said image of said indicium; and

e) a processing module configured to process said at least a portion of said frame of image data to extract therefrom information by the indicium, said lens system further comprising;

f) an optical, transparent front window,

g) a fluid lens having a front surface and a rear surface,

h) a first volume bounded by said front window and said front surface of said fluid lens,

i) an optical, clear rear window, and

j) a second volume bounded by the front surface of said fluid lens and said rear window,

wherein said first volume and said second volume are operably linked through a pump that, in combination with said first volume and said second volume, forms a sealed system.