Patent US6437877B1 successfully refreshed from Google Patents.
US6437877B1
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Print data processing method and apparatus
Assignee: NEC Corp
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Filing: 1999-01-19
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Granted: 2002-08-20
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Expires: 2019-01-19
Abstract
Abstract A print data processing technique for a printer device is disclosed. There has been stored error data in halftone level between an actual halftone characteristic of the printing device and a target halftone characteristic. After dividing input print data into halftone cells of a predetermined pattern to produce halftone-cell data for each of the halftone cells, the error data of a halftone cell is sequentially diffused over halftone-cell data of another halftone cell using a predetermined distribution ratio from the halftone cell to the other halftone cell to correct halftone-cell data of each of the halftone cells. Dither data of each of the halftone cells is produced from corrected halftone-cell data thereof.
Inventors
- 👤 Kenichi Takei
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:36
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/407; G; G06; G06K; G06K15/00; G06K15/02; G06K15/10; G06K15/102; G06K15/105; G06K15/107; H04N1/405; H04N1/4055
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
113 words
A print data processing method for a printing device, comprising the steps of: a) storing error data in halftone level between an actual halftone characteristic of the printing device and a target halftone characteristic; b) dividing input print data into halftone cells of a predetermined pattern to produce halftone-cell data for each of the halftone cells; c) sequentially diffusing the error data of a halftone cell over halftone-cell data of another halftone cell using a predetermined distribution ratio from the halftone cell to the other halftone cell to correct halftone-cell data of each of the halftone cells; and d) producing dither data of each of the halftone cells from corrected halftone-cell data thereof.
Claim 2
Dependent Claim
113 words
A print data processing method for a printing device, comprising the steps of: a) storing error data in halftone level between an actual halftone characteristic of the printing device and a target halftone characteristic; b) dividing input print data into halftone cells of a predetermined pattern to produce halftone-cell data for each of the halftone cells; c) sequentially diffusing the error data of a halftone cell over halftone-cell data of another halftone cell using a predetermined distribution ratio from the halftone cell to the other halftone cell to correct halftone-cell data of each of the halftone cells; and d) producing dither data of each of the halftone cells from corrected halftone-cell data thereof.
Claim 3
Dependent Claim
37 words
The print data processing method according to claim 1 , wherein the target halftone characteristic is set to an ideal gamma characteristic which makes an input halftone level and an output halftone level equal to each other.
Claim 4
Dependent Claim
37 words
The print data processing method according to claim 1 , wherein the target halftone characteristic is set to a predetermined gamma characteristic which makes an input halftone level and an output halftone level different from each other.
Claim 5
Dependent Claim
24 words
The print data processing method according to claim 1 , wherein the target halftone characteristic is selected from a plurality of predetermined gamma characteristics.
Claim 6
Dependent Claim
124 words
The print data processing method according to claim 1 , wherein the step c) comprises the steps of: c-1) determining first error data of a first halftone cell from first halftone-cell data thereof; c-2) correcting second halftone-cell data of a second halftone cell by subtracting a first corrective value from the second halftone-cell data to produce corrected second halftone-cell data, wherein the first corrective value is obtained based on the first error data and a first predetermined distribution ratio from the first halftone cell to the second halftone cell; and c-3) sequentially repeating the steps c-1) and c-2) to diffuse the error data of a halftone cell over halftone-cell data of another halftone cell to correct halftone-cell data of each of the halftone cells.
Claim 7
Dependent Claim
95 words
The print data processing method according to claim 1 , wherein the step c) comprises the step of calculating corrected halftone-cell data x(i) of a halftone cell using the following equation: x ( i ) = xo ( i ) - ∑ j ( x ( j ) - a ( j ) ) / k ( i , j ) wherein xo(i) is halftone-cell data of the i-th halftone cell before correction and k(i,j) is a distribution ratio from the j-th halftone cell to the i-th halftone cell.
Claim 8
Dependent Claim
128 words
A print data processing apparatus for a printing device, comprising: a memory for storing a data correction table containing error data in halftone level between an actual halftone characteristic of the printing device and a target halftone characteristic; an image divider for dividing input print data into halftone cells of a predetermined pattern to produce halftone-cell data for each of the halftone cells; an image correction processor for sequentially diffusing the error data of a halftone cell over halftone-cell data of another halftone cell using a predetermined distribution ratio from the halftone cell to the other halftone cell to correct halftone-cell data of each of the halftone cells; and a pattern dithering processor for producing dither data of each of the halftone cells from corrected halftone-cell data thereof.
Claim 9
Dependent Claim
128 words
A print data processing apparatus for a printing device, comprising: a memory for storing a data correction table containing error data in halftone level between an actual halftone characteristic of the printing device and a target halftone characteristic; an image divider for dividing input print data into halftone cells of a predetermined pattern to produce halftone-cell data for each of the halftone cells; an image correction processor for sequentially diffusing the error data of a halftone cell over halftone-cell data of another halftone cell using a predetermined distribution ratio from the halftone cell to the other halftone cell to correct halftone-cell data of each of the halftone cells; and a pattern dithering processor for producing dither data of each of the halftone cells from corrected halftone-cell data thereof.
Claim 10
Dependent Claim
37 words
The print data processing apparatus according to claim 7 , wherein the target halftone characteristic is set to an ideal gamma characteristic which makes an input halftone level and an output halftone level equal to each other.
Claim 11
Dependent Claim
37 words
The print data processing apparatus according to claim 7 , wherein the target halftone characteristic is set to a predetermined gamma characteristic which makes an input halftone level and an output halftone level different from each other.
Claim 12
Dependent Claim
24 words
The print data processing apparatus according to claim 7 , wherein the target halftone characteristic is selected from a plurality of predetermined gamma characteristics.
Claim 13
Dependent Claim
111 words
The print data processing apparatus according to claim 7 , wherein the image correction processor determines first error data of a first halftone cell from first halftone-cell data thereof and corrects second halftone-cell data of a second halftone cell by subtracting a first corrective value from the second halftone-cell data to produce corrected second halftone-cell data, wherein the first corrective value is obtained based on the first error data and a first predetermined distribution ratio from the first halftone cell to the second halftone cell to diffuse the error data of a halftone cell over halftone-cell data of another halftone cell to correct halftone-cell data of each of the halftone cells.
Claim 14
Dependent Claim
92 words
The print data processing apparatus according to claim 7 , wherein the image correction processor calculates corrected halftone-cell data x(i) of a halftone cell using the following equation: x ( i ) = xo ( i ) - ∑ j ( x ( j ) - a ( j ) ) / k ( i , j ) wherein xo(i) is halftone-cell data of the i-th halftone cell before correction and k(i,j) is a distribution ratio from the j-th halftone cell to the i-th halftone cell.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-08-19 | 2006-02-18 | 2006-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-08-19 | 2010-02-18 | 2010-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-08-19 | 2014-02-18 | 2014-08-20 | $7700.00 | Window Closed / Lapsed |