Patent US4897736A successfully refreshed from Google Patents.
US4897736A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color image processing apparatus using a deformed dot matrix
Assignee: Canon Inc
•
Filing: 1989-05-22
•
Granted: 1990-01-30
•
Expires: 2009-05-22
Abstract
Abstract A color image processing apparatus avoids uneven recording of date used to form the reproduced color image, which using a reduced memory capacity, by suitable deformation of square dot submatrices within a square dot matrix used in halftone dot reproduction, to provide desired screen angles, and by reproducing different density levels with different arrangements of dots within the same dot pattern.
Inventors
- 👤 Takashi Sugino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:21
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/405; H04N1/4055; H04N1/4058; H04N1/46; H04N1/52
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
189 words
Image reproducing apparatus comprising: image forming means for printing an image by scanning in main and sub-scanning directions; image data generating means for generating digital density data for an image frame to be printed by said image forming means responsive to first and second pulse signals representing an image forming position of said image forming means in the main and sub-scanning directions; position data generating means for generating position data, the position data being obtained in response to the first and second pulse signals; and a table memory, accessed in accordance with an address specified by the digital density data and the position data obtained in response to the first and second pulse signals for providing recording density data to be recorded by said image forming means at main and sub-scanning positions thereof corresponding to the position data, wherein the table memory includes a first table memory which is addressed in response to said first and second pulse signals for providing the position data and a second table memory which is addressed in response to the position data and the digital density data and provides the recording density data.
Claim 2
Dependent Claim
189 words
Image reproducing apparatus comprising: image forming means for printing an image by scanning in main and sub-scanning directions; image data generating means for generating digital density data for an image frame to be printed by said image forming means responsive to first and second pulse signals representing an image forming position of said image forming means in the main and sub-scanning directions; position data generating means for generating position data, the position data being obtained in response to the first and second pulse signals; and a table memory, accessed in accordance with an address specified by the digital density data and the position data obtained in response to the first and second pulse signals for providing recording density data to be recorded by said image forming means at main and sub-scanning positions thereof corresponding to the position data, wherein the table memory includes a first table memory which is addressed in response to said first and second pulse signals for providing the position data and a second table memory which is addressed in response to the position data and the digital density data and provides the recording density data.
Claim 3
Dependent Claim
54 words
Image reproducing apparatus according to claim 1, wherein said position data generating means includes a first counter for counting pulses of the first pulse signal and a second counter for counting pulses of the second pulse signal, and wherein the position data is obtained in response to outputs of the first and second counters.
Claim 4
Dependent Claim
94 words
An apparatus according to claim 1, wherein the position data represents a position in a deformed matrix, a plurality of the deformed matrices being at least partially included in a rectangular matrix of n×m matrix elements, and wherein a plurality of the deformed matrices are arranged abutting each other at a predetermined angle by arranging a plurality of the n×m rectangular matrices in the main and sub-scanning directions in such a manner that none of said rectangular matrices is spaced apart from adjoining ones of the rectangular matrices or overlaps said adjoining rectangular matrices.
Claim 5
Dependent Claim
180 words
Image reproducing apparatus comprising: image forming means for forming an image by scanning in main and sub-scanning directions; a modulo-n first counter for counting a first pulse signal corresponding to the position of said image forming means in the main scanning direction; a modulo-m second counter for counting a second pulse signal corresponding to the position of said image forming means in the sub-scanning direction; density data output means for providing digital image density data corresponding to image pixels in the main and sub-scanning directions; and a table memory, accessed in accordance with an address specified by the digital image density data and position data determined by the counts of said first and second counters, for providing recording density data to be recorded by said image forming means at main and sub-scanning positions thereof corresponding to the position data, wherein the table memory includes a first table memory which is addressed by said first and second counters for providing the position data and a second table memory which is addressed by the position data and provides the recording density data.
Claim 6
Dependent Claim
180 words
Image reproducing apparatus comprising: image forming means for forming an image by scanning in main and sub-scanning directions; a modulo-n first counter for counting a first pulse signal corresponding to the position of said image forming means in the main scanning direction; a modulo-m second counter for counting a second pulse signal corresponding to the position of said image forming means in the sub-scanning direction; density data output means for providing digital image density data corresponding to image pixels in the main and sub-scanning directions; and a table memory, accessed in accordance with an address specified by the digital image density data and position data determined by the counts of said first and second counters, for providing recording density data to be recorded by said image forming means at main and sub-scanning positions thereof corresponding to the position data, wherein the table memory includes a first table memory which is addressed by said first and second counters for providing the position data and a second table memory which is addressed by the position data and provides the recording density data.
Claim 7
Dependent Claim
11 words
Apparatus according to claim 4, wherein n is equal to m,
Claim 8
Dependent Claim
15 words
Apparatus according to claim 4, wherein said first and second table memories are read-only memories.
Claim 9
Dependent Claim
180 words
Image reproducing apparatus comprising: image forming means for forming an image by scanning in main and sub-scanning directions; a modulo-n first counter for counting a first pulse signal corresponding to the position of said image forming means in the main scanning direction; a modulo-n second counter for counting a second pulse signal corresponding to the position of said image forming means in the sub-scanning direction; density data output mean for providing digital image density data corresponding to image pixels in the main and sub-scanning directions; and a table memory, accessed in accordance with an address specified by the digital image density data and position data determined by the counts of said first and second counters, for providing recording density data to be recorded by said image forming means at main and sub-scanning positions thereof corresponding to the position data, wherein the table memory includes a first table memory which is addressed by said first and second counters for providing the position data and a second table memory which is addressed by the position data and provides the recording density data.
Claim 10
Dependent Claim
180 words
Image reproducing apparatus comprising: image forming means for forming an image by scanning in main and sub-scanning directions; a modulo-n first counter for counting a first pulse signal corresponding to the position of said image forming means in the main scanning direction; a modulo-n second counter for counting a second pulse signal corresponding to the position of said image forming means in the sub-scanning direction; density data output mean for providing digital image density data corresponding to image pixels in the main and sub-scanning directions; and a table memory, accessed in accordance with an address specified by the digital image density data and position data determined by the counts of said first and second counters, for providing recording density data to be recorded by said image forming means at main and sub-scanning positions thereof corresponding to the position data, wherein the table memory includes a first table memory which is addressed by said first and second counters for providing the position data and a second table memory which is addressed by the position data and provides the recording density data.
References Cited (Backward Citations)
US3742129A
Cited
DE2262824A1
Cited
US3922484A
Cited
US4052715A
Cited
US4149194A
Cited
US4185304A
Cited
US4412225A
Cited
US4486788A
Cited
US4783837A
Cited
US4752822A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-29 | 1993-07-31 | 1994-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-29 | 1997-07-31 | 1998-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-29 | 2001-07-31 | 2002-01-30 | $7700.00 | Window Closed / Lapsed |