US4922270A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inter pen offset determination and compensation in multi-pen thermal ink jet pen printing systems
Assignee: HP Inc
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Filing: 1989-01-31
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Granted: 1990-05-01
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Expires: 2009-01-31
Abstract
Abstract Apparatus for determining inter-pen offsets in a multiple pen ink jet printer including a drop detector for measuring flight time of ink drops, an aperture plate disposed in the print media plane, and a carriage position sensor for determining carriage position when ink drop flight time exceeds a predetermined value, which indicates that an ink jet is at the edge of the aperture plate. The sensed carriage positions for the respective pens provides information indicative of inter-pen offset in the scan axis direction. In a further embodiment of the invention, the aperture plate can have a stair-shaped boundary to facilitate the calibration of a plurality of nozzles in one scan. For determination of inter-pen offset in the media scan direction, the aperture includes a comb-like boundary that is utilized to produce the detect/no detect pattern for a nozzle array in each of the pens, whereby the pattern for each of the pens provides information indicative of the offset between pens.
Inventors
- 👤 Keith E. Cobbs
- 👤 Robert D. Haselby
- 👤 William S. Osborne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:18
CPC Classifications
G; G01; G01D; G01D15/00; G01D15/16; G01D15/18; B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/07; B41J2/125; B41J2/21; B41J2/2132; B41J2/2135; B41J25/00; B41J25/34
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
85 words
Apparatus for providing inter-pen offset determination and compensation in a multi-pen thermal ink jet printer, said apparatus comprising: (a) drop detector means for measuring the time of flight of ink drops between a selected pen and the detector means; (b) an aperture plate disposed at the print media plane; and (c) high resolution carriage position sensor means for determining carriage location when the time of flight exceeds a predetermined threshold value, whereby the sensed carriage positions for respective pens provides information indicative of inter-pen offset.
Claim 2
Dependent Claim
85 words
Apparatus for providing inter-pen offset determination and compensation in a multi-pen thermal ink jet printer, said apparatus comprising: (a) drop detector means for measuring the time of flight of ink drops between a selected pen and the detector means; (b) an aperture plate disposed at the print media plane; and (c) high resolution carriage position sensor means for determining carriage location when the time of flight exceeds a predetermined threshold value, whereby the sensed carriage positions for respective pens provides information indicative of inter-pen offset.
Claim 3
Dependent Claim
86 words
Apparatus for providing inter-pen offset determination and compensation in a multi-pen thermal ink jet printer, said apparatus comprising: (a) optical drop detector means for measuring the time of flight of ink drops between a selected pen and the detector means; (b) an aperature plate disposed at the print media plane; and (c) high resolution carriage position sensor means for determining carriage location when the time of flight exceeds a predetermined threshold value, whereby the sensed carriage positions for respective pens provides information indicative of inter-pen offset.
Claim 4
Dependent Claim
86 words
Apparatus for providing inter-pen offset determination and compensation in a multi-pen thermal ink jet printer, said apparatus comprising: (a) optical drop detector means for measuring the time of flight of ink drops between a selected pen and the detector means; (b) an aperature plate disposed at the print media plane; and (c) high resolution carriage position sensor means for determining carriage location when the time of flight exceeds a predetermined threshold value, whereby the sensed carriage positions for respective pens provides information indicative of inter-pen offset.
Claim 5
Dependent Claim
34 words
The apparatus of claim 2 which further comprises: interpolation means coupled to the carriage position sensor means and drop detector means for interpolating the position of the carriage at the time of drop detection.
Claim 6
Dependent Claim
107 words
In a multi-pen thermal ink jet printer having movable carriage containing a plurality of pens, a registration calibration system comprising: (a) an optical drop detector for measuring flight time of drops of ink; (b) an aperture plate interposed between the pens and the drop detector for providing a precision location reference, and (c) high resolution carriage position sensor means integral with the carriage for indicating the position of the carriage at the insant the flight time of a drop of ink exceeds a predetermined threshold value as measured by the optical drop detector, whereby the sensed carriage positions for respective pens provides information indicative of inter-pen offset.
Claim 7
Dependent Claim
107 words
In a multi-pen thermal ink jet printer having movable carriage containing a plurality of pens, a registration calibration system comprising: (a) an optical drop detector for measuring flight time of drops of ink; (b) an aperture plate interposed between the pens and the drop detector for providing a precision location reference, and (c) high resolution carriage position sensor means integral with the carriage for indicating the position of the carriage at the insant the flight time of a drop of ink exceeds a predetermined threshold value as measured by the optical drop detector, whereby the sensed carriage positions for respective pens provides information indicative of inter-pen offset.
Claim 8
Dependent Claim
29 words
The apparatus of claim 4 wherein the aperture plate further comprises a stair-shaped aperture pattern disposed in the aperture plate, whereby a plurality of nozzles can be calibrated simultaneously.
Claim 9
Dependent Claim
96 words
In a multi-pen thermal ink jet printer, a method for determining relative offset between pens, said method comprising the steps of: (a) positioning each pen over a vernier comb-like pattern in an aperture plate interposed between the pens and an optical drop detector; (b) firing each nozzle so that some of the drops impact the comb pattern and are not detected, while others pass through the comb pattern and are detected, creating a detect/no detect pattern for each pen; and (c) comparing the patterns from each pen to determine the relative offsets from pen to pen.
Claim 10
Dependent Claim
96 words
In a multi-pen thermal ink jet printer, a method for determining relative offset between pens, said method comprising the steps of: (a) positioning each pen over a vernier comb-like pattern in an aperture plate interposed between the pens and an optical drop detector; (b) firing each nozzle so that some of the drops impact the comb pattern and are not detected, while others pass through the comb pattern and are detected, creating a detect/no detect pattern for each pen; and (c) comparing the patterns from each pen to determine the relative offsets from pen to pen.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-30 | 1993-10-30 | 1994-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-30 | 1997-10-30 | 1998-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-30 | 2001-10-30 | 2002-05-01 | $7700.00 | Window Closed / Lapsed |