Method for high resolution printing

• US 5,614,937 A
• Filed: 06/07/1995
• Issued: 03/25/1997
• Est. Priority Date: 07/26/1993
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Nelson, William E.
• Primary Examiner(s): Reinhart, Mark J.
• Application Number:
  US08/484,463
• Time in Patent Office: 657 Days
• Field of Search: 358/296, 358/298, 358/300, 358/500, 358/451, 358/454, 347/240, 347/239, 347/251, 347/131
• US Class Current: 347/240
• CPC Class Codes: B41J 2/465 using masks, e.g. light-switching masks
• CPC Class Codes: B41J 2/52 Arrangement for printing a discrete number of tones, not covered by group B41J2/205, e.g. applicable to two or more kinds of printing or marking process B41J2/525 takes precedence
• CPC Class Codes: G06K 15/1257 on more than one main scanning line
• CPC Class Codes: H04N 1/00015 Reproducing apparatus
• CPC Class Codes: H04N 1/00031 Testing, i.e. determining the result of a trial H04N1/00029 takes precedence; using test signals for transmission mode changing H04N2201/33371
• CPC Class Codes: H04N 1/00047 using an image not specifically designed for the purpose
• CPC Class Codes: H04N 1/0005 in service, i.e. during normal operation
• CPC Class Codes: H04N 1/00063 using at least a part of the apparatus itself, e.g. self-testing
• CPC Class Codes: H04N 1/00082 Adjusting or controlling interrupting an operation H04N1/00915; inhibiting an operation H04N1/00925
• CPC Class Codes: H04N 1/04 Scanning arrangements , i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versaH04N1/387 takes precedence
• CPC Class Codes: H04N 1/19 using multi-element arrays
• CPC Class Codes: H04N 1/40025 Circuits exciting or modulating particular heads for reproducing continuous tone value scales H04N1/401, H04N1/407 take precedence
• CPC Class Codes: H04N 1/40031 for a plurality of reproducing elements simultaneously
• CPC Class Codes: H04N 2201/0458 Additional arrangements for improving or optimising scanning resolution or quality

Abstract

Higher quality printing is difficult in implementation in spatial light modulator printers. The two major problems are accomplishing gray scale within the line time constraints, and eliminating staircasing artifacts within the images printed (81). It can be improved by using an alternate way of resetting cells on the spatial light modulator when data is being loaded onto the cells, timing delay (86), horizontal offset (84), and differently sized pixels (80, 82).

Claims

1. A method of high resolution printing, comprising:

a. receiving image data at a processor;

b. using said processor to analyze said image data such that said processor determines operation of a spatial light modulator comprised of an array of elements having a standard size arranged generally in rows and columns to print a resulting image most accurately representing said image data; and

c. selectively operating said elements of said spatial light modulator wherein said operating further comprises;

i. delaying activation of certain ones of said elements with the image data thereby controlling vertical placement of an image of said element on said resulting image to achieve finer vertical control over print images;

ii. activating a predetermined area of said array, wherein said predetermined area has rows horizontally offset from other of said rows thereby horizontally offsetting pixel images in said resulting image allowing pixel images to shift horizontally to achieve finer horizontal control over said resulting image; and

iii. using elements with sizes corresponding to fractions of said standard size allowing smaller pixel images to achieve finer control over filling in print image.

2. The method of claim 1 wherein said operating step also includes operating said spatial light modulator to achieve gray scale.