Light scanner with cylindrical lenses

• US 6,624,919 B2
• Filed: 02/22/2001
• Issued: 09/23/2003
• Est. Priority Date: 03/31/1999
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Lambert, Nicolaas
• Primary Examiner(s): Phan, James
• Application Number:
  US09/790,189
• Publication Number:
  US 20010038483A1
• Time in Patent Office: 943 Days
• Field of Search: 359/204-207, 359/209-211, 359/216-219
• US Class Current: 359/205.1
• CPC Class Codes: G02B 26/0875 by means of one or more refracting elements
• CPC Class Codes: G02B 26/108 having one or more prisms as scanning elements
• CPC Class Codes: H04N 9/3117 by using a sequential colour filter producing two or more colours simultaneously, e.g. by creating scrolling colour bands

Abstract

A scrolling scan optical band scanner is provided having a scrolling scan optic with a scan function that inherently deviates from an ideal imaging function over wide apertures. Compensation optics are provided to correct the scrolling scan optic performance to provide accurate imaging over a wide aperture. The compensation optics and the scrolling scan optic together accurately scroll the input pattern to an output pattern according to the formula:

x_o(t)/X=(t/T+x_i/X) modulo 1,

with X being the total height of input and output beam, x_i being the ray height in the input beam, x_o being the corresponding ray height in the output beam as a function of time, T being the frame period, and t being the time, and said scroll patterns remains telecentric even where X is large with respect to a physical size of the scanning optic system.

Claims

1. An optical scanner having a scan optic subsystem with a scan function subject to substantial nonlinear aberrations in image transfer over wide apertures, wherein compensation optics are provided to correct said aberrations in image transfer in said scan optic subsystem, said compensation optics having a prefocus optic of lens with a line focus for transmitting a light pattern to be scanned by said scan optic subsystem, and a postfocus optic of lens with a line focus for receiving a scanned light pattern from said optic subsystem and wherein said prefocus and postfocus optics are symmetric.

2. The optical scanner according to claim 1, wherein said compensation optics are stationary.

3. The optical scanner according to claim 1, wherein said optical scanner has an input aperture angle corresponding to about 1/f=1.

4. The optical scanner according to claim 1, wherein said scan optic subsystem comprises an input optical element having at least two discontinuities separated by a continuous optical function, wherein said optical scanner has an imaging input aperture of about a separation distance of said at least two discontinuities.

5. The optical scanner according to claim 1, wherein said scan function is a scrolling scan function.

6. The optical scanner according to claim 1, wherein said optical scanner receives a plurality of stationary light bands over a wide aperture and produces an image of said plurality of light bands in a scrolling movement pattern.

7. The optical scanner according to claim 1, wherein said compensation optics correct said image aberrations to provide a sharp scanned image over a full input aperture range.

8. The optical scanner according to claim 1, wherein said image aberrations are, corrected to provide an accurate scanned two-dimensional image.

9. The optical scanner according to claim 1, wherein the compensation optics and the scan optic subsystem together accurately scroll the input pattern to an output pattern according to the formula:

10. The optical scanner according to claim 1, wherein said compensation optics are arranged to prefocus an input pattern on, and postfocus an output optical pattern from, the scan optic subsystem, to achieve transfer of a scanned image.

11. The optical scanner according to claim 1, wherein said compensation optics comprise:

(a) an input compensation optic, arranged to prefocus an input pattern comprising a set of parallel light rays as a set of converging rays; and

(b) an output compensation optic, arranged to postfocus a set diverging rays as a set of parallel rays,

and said scan optic subsystem is disposed in an optical path between said input compensation optic and said output compensation optic, said scan optic subsystem having an axis of movement and being for converting said set of converging rays into a set of scrolling diverging rays,

wherein said optical scanner images said input pattern as said set of scrolling parallel rays.

12. The optical scanner according to claim 1, wherein said scan optic subsystem comprises a linearly displaceable array of cylindrical lenses.

13. The optical scanner according to claim 1, wherein said scan optic subsystem comprises a rotatable array of quasi-cylindrical lenses.

14. The optical scanner according to claim 1, wherein said scan optic subsystem comprises a lens structure disposed on a rotatable disk to provide a time-variable optical function with respective rotation of said disk.

15. The optical scanner according to claim 1, wherein said scan optic subsystem comprises an array of lens structures disposed concentrically on a rotatable drum.

16. The optical scanner according to claim 1, wherein said scan optic subsystem comprises a pair of arrays of lens structures having a virtual focus and moving antiparallel with respect to each other.

17. The optical scanner according to claim 1, wherein said scan optic subsystem comprises a pair of arrays of lens structures having a real focus and moving parallel with respect to each other.

18. The optical scanner according to claim 1, wherein said scan optic subsystem comprises a pair of arrays of lens structures and a centrally located relay lens structure.

19. The optical scanner according to claim 1, wherein said compensation optics are approximately cylindrical.

20. The optical scanner according to claim 1, wherein said compensation optics comprise static pre- and post-focus lenses, and said scan optic subsystem comprises displaceable lens portions, wherein each of said pre and post focus lenses and said displaceable lens portions have a focal length approximating a distance between input and output image planes.