Binary diffractive optical element scanner

• US 5,448,403 A
• Filed: 04/08/1994
• Issued: 09/05/1995
• Est. Priority Date: 12/11/1992
• Status: Expired due to Fees

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Harris, Ellis D.
• Primary Examiner(s): Lerner, Martin
• Application Number:
  US08/225,415
• Time in Patent Office: 515 Days
• Field of Search: 359/17, 359/18, 359/19, 359/565, 359/566, 359/569, 359/562, 359/209
• US Class Current: 359/562
• CPC Class Codes: G02B 26/106 having diffraction gratings as scanning elements, e.g. holographic scanners holographic optical elements G02B5/32, holography G03H
• CPC Class Codes: G02B 5/1876 Diffractive Fresnel lenses; Zone plates; Kinoforms G02B5/1842, G02B5/1847 take precedence; optical systems having diffractive correction means G02B27/0037; Fresnel lenses operating by refraction G02B3/08
• CPC Class Codes: G02B 5/188 Plurality of such optical elements formed in or on a supporting substrate

Abstract

An optical scanning system uses a stationary binary diffractive optical element and a rotating binary diffractive element to focus and scan a beam along the scan line.

Claims

1. An optical scanner for scanning a light beam along a scan line comprising:

a light source for emitting a coherent light beam,

means to collimate said coherent light beam,

a first stationary binary diffractive optical element to condition said collimated light beam,

a rotating disc with a plurality of second binary diffractive optical elements to diffract said light beam from said first stationary binary diffractive optical element to focus and scan along said scan line, wherein said diffracted beam to scan along said scan line is the first order diffracted beam, and

means to block light from said plurality of second binary diffractive optical elements which is not diffracted into said first diffraction order to scan along said scan line.

2. The optical scanner for scanning a light beam along a scan line of claim 1 wherein plurality of second binary diffractive optical elements separates said first order diffracted beam from a zero order, nondiffracted beam and other diffraction order beams.

3. The optical scanner for scanning a light beam along a scan line of claim 1 wherein said plurality of second binary diffractive optical elements are negative elements.

4. The optical scanner for scanning a light beam along a scan line of claim 1 wherein said plurality of second binary diffractive optical elements are positive elements.

5. The optical scanner for scanning a light beam along a scan line of claim 1 wherein the multilevel phase relief structure of said plurality of second binary diffractive optical elements are along a radius of said rotating disc to diffract said light beam along said scan line.

6. An optical scanner for scanning a light beam along a scan line comprising:

a light source for emitting a coherent light beam,

means to collimate said coherent light beam,

a first stationary binary diffractive optical element to condition and focus said collimated light beam along said scan line,

a rotating disc with a plurality of second binary diffractive optical elements to diffract said light beam from said first stationary binary diffractive optical element to scan along said scan line, wherein said diffracted beam to scan along said scan line is the first order diffracted beam, and

means to block light from said plurality of second binary diffractive optical elements which is not diffracted into said first diffraction order to scan along said scan line.

7. The optical scanner for scanning a light beam along a scan line of claim 6 wherein plurality of second binary diffractive optical elements separates said first order diffracted beam from a zero order, nondiffracted beam and other diffraction order beams.

8. The optical scanner for scanning a light beam along a scan line of claim 6 wherein said plurality of second binary diffractive optical elements are negative elements.

9. The optical scanner for scanning a light beam along a scan line of claim 6 wherein said plurality of second binary diffractive optical elements are positive elements.

10. The optical scanner for scanning a light beam along a scan line of claim 6 wherein the multilevel phase relief structure of said plurality of second binary diffractive optical elements are along a radius of said rotating disc to diffract said light beam along said scan line.