Exposure scheme for minimizing microbanding inslm-based printers

• US 5,615,016 A
• Filed: 11/04/1994
• Issued: 03/25/1997
• Est. Priority Date: 11/04/1994
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Thakur, Vivek K., Venkateswar, Vadlamannati
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US08/334,650
• Time in Patent Office: 872 Days
• Field of Search: 308/298, 308/503, 347/240, 347/251, 347/131, 347/239, 346/108, 346/106, 346/107 R
• US Class Current: 358/3.26
• CPC Class Codes: H04N 1/40031 for a plurality of reproducing elements simultaneously

Abstract

An improved method for time delay and integration printing for gray scale. A gray scale represented by a bit pattern is provided for time delay and integration printing onto a photosensitive substrate. The pattern (12) is rotated about the light intensity cycle of the light source such that microbands in the final image are minimized or eliminated and sent to a spatial light modulator (10) for transfer to a printing substrate.

Claims

1. An improved method of printing comprising:

a. determining a gray scale to be transferred to a photosensitive surface;

b. illuminating a spatial light modulator with a light source, wherein said light source has a predetermined light intensity cycle;

c. time delaying and integrating said pattern onto said photosensitive surface with a predetermined number of exposures; and

d. rotating the bits of a given line number around said light intensity cycle such that the number of bits rotated depends upon said line number and said predetermined number of exposures.

3. The method of claim 1 wherein said time delay and integration onto said photosensitive surface includes exposing said photosentive medium in phases.

2. An improved method of time delay and integration printing with light source modulation, where a gray scale is converted by a look up table to a bit pattern for illumination on a spatial light modulator, wherein said improvement comprises;

rotating said bit pattern about said light source'"'"'s light intensity cycle.