Pair of binary diffraction optics for use in overfilled raster output scanning systems

• US 5,315,427 A
• Filed: 12/14/1992
• Issued: 05/24/1994
• Est. Priority Date: 12/14/1992
• Status: Expired due to Fees

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Harris, Ellis D., Rauch, Russell B.
• Primary Examiner(s): Ben, Loha
• Assistant Examiner(s): Phan, James
• Application Number:
  US07/990,491
• Time in Patent Office: 526 Days
• Field of Search: 359/196-197, 359/212, 359/223, 359/226, 359/558, 359/563, 359/566, 359/569, 359/216-219, 359/17, 359/18
• US Class Current: 359/216.1
• CPC Class Codes: G02B 27/0037 with diffracting elements G02B27/0056 takes precedence; holographic optical elements G02B5/32; zone systems G02B5/1876
• CPC Class Codes: G02B 27/0944 Diffractive optical elements, e.g. gratings, holograms gratings per se G02B5/18; holograms used as optical elements per se G02B5/32
• CPC Class Codes: G02B 27/4227 in image scanning systems
• CPC Class Codes: G02B 27/4244 in wavelength selecting devices spectrometry G01J
• CPC Class Codes: G02B 27/425 in illumination systems mask illumination systems in photolithographic systems G03F7/70158
• CPC Class Codes: G02B 27/4277 being separated by an air space

Abstract

An optical system is disclosed which utilizes a pair of binary diffraction optic lenses to reprofile the intensity of a light beam. Both binary diffraction optic lenses have a plurality of segments. Depending on the shape of a desired intensity profile, each segment of the first binary diffraction optic lens either diverges or converges a portion of a light beam and as needed deflects the same portion of the beam. The second binary diffraction optic lens, which is located down stream of the first binary diffraction optic lens, has an equal number of segments as the first binary diffraction optic lens. Each segment of the second binary diffraction optic lens receives the light beam from a respective segment of the first binary diffraction optic lens and collimates the light beam.

Claims

1. An overfilled raster scanning system comprising:

a light source emitting a light beam;

a binary diffraction optic lens system comprising a first binary diffraction optic lens element and a second binary diffraction optic lens element spaced along said light beam path from said first binary diffraction optic lens element;

said binary diffraction optic lens system being arranged to receive said light beam from said light source and reprofile the intensity of said light beam;

a photo sensitive medium; and

a rotating scanning means arranged to receive said reprofiled light beam from said binary diffraction optic lens system and scan said reprofiled light beam across said photo sensitive medium.

2. The structure recited in claim 1, wherein said first binary diffraction optic lens element converges and diverges portions of said light beam and said second binary diffraction optic lens element collimates said light beam.

3. The structure recited in claim 1, wherein said first binary diffraction optic lens element converges portions of said light beam to compress said portions of said light beam and diverges portions of said light beam to expand said portions of said light beam to change the intensity of said portions of said light beam.