Large area, high quality print scanner apparatus

• US 20050099619A1
• Filed: 08/14/2003
• Published: 05/12/2005
• Est. Priority Date: 08/14/2002
• Status: Abandoned Application

• Current Assignee: Cross Match Technologies Incorporated (Assa Abloy AB)
• Original Assignee: Cross Match Technologies Incorporated (Assa Abloy AB)
• Inventors: McClurg, George W., Carver, John F.
• Application Number:
  US10/640,688
• Publication Number:
  US 20050099619A1
• Time in Patent Office: Days
• US Class Current: 356/71
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence

Abstract

The present invention relates to systems and methods for biometric object image capturing. More specifically, the present invention relates to systems and methods for generating large area, high-quality images. An embodiment of the present invention comprises a sliding mechanical stage and a plurality of sensors mounted on the sliding mechanical stage. At least one sensor generates a large area a preview image. Another sensor generates a large area high quality image.

Claims

1. A large area, high-quality scanning apparatus for scanning a biometric object, said apparatus comprising:

a stage assembly;

a first sensor, mounted on said stage assembly, wherein said first sensor is used to capture a preview image of the biometric object; and

a second sensor, mounted on said stage assembly, wherein said second sensor is used to capture a second image of the biometric object,

wherein said second image is of high quality relative to said preview image.

2. The apparatus of claim 1, wherein a proper alignment condition of the biometric object with respect to a platen area is determined by the preview image prior to capture of the high resolution image.

3. The apparatus of claim 1, wherein said second sensor is a high-resolution sensor.

4. The apparatus of claim 1, wherein said second sensor is a low-distortion sensor.

5. The apparatus of claim 1, further comprising:

an illumination source configured to illuminate at least a portion of the platen area.

6. The apparatus of claim 5, wherein said illumination source is a single source of illumination.

7. The apparatus of claim 6, wherein said illumination source illuminates the entire platen area.

8. The apparatus of claim 5, wherein said illumination source is an array of light emitting diodes.

9. The apparatus of claim 8, wherein said array illuminates a strip of the platen area.

10. The apparatus of claim 1, wherein said stage assembly is a sliding stage assembly.

11. The apparatus of claim 10, further comprising:

an optical assembly,

wherein said optical assembly is tuned for both the first sensor and the second sensor.

12. The apparatus of claim 11, said optical assembly comprising along an optical path:

an illumination source to produce light;

a prism that receives the biometric object and light from said illumination source;

an objective lens that receives reflected light from the prism; and

a lens group that processes the reflected light from the prism,

wherein a surface of said prism forms the platen area.

13. The apparatus of claim 10, further comprising:

at least one lens attached to one of said first and second sensors, whereby the at least one lens moves with the one of said first and second sensors.

14. A method of high-resolution scanning of a biometric object over a large platen area, said method comprising:

imaging the platen area in its entirety at low-resolution; and

scanning the area line-by-line at high resolution.

15. The method of claim 14, further comprising after said imaging step but before said scanning step:

determining a proper alignment condition of the biometric object with respect to a platen area.

16. The method of claim 14, further comprising before said imaging step:

illuminating the platen area in its entirety.

17. The method of claim 14, further comprising before said scanning step:

illuminating a strip of the platen area.