US4498108A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screen for reproducing continuous-tone pictures
Assignee: Heidelberger Druckmaschinen AG
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Filing: 1983-02-14
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Granted: 1985-02-05
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Expires: 2003-02-14
Abstract
Abstract A screen for reproducing continuous-tone pictures of the kind which has an orthogonal, equally spaced screen structure and which is rotated through 45° from the direction of scanning. In this invention, the individual screen dots are split up into four parts by lines extending parallel and perpendicular to the direction of reproduction which pass through the centers of the screen dots, thus producing square part screen-configuration which, in two opposite corners, each contain covered segments which derive from two different screen dots. Prior to reproduction, one such screen-configuration is stored for each tonal value liable to occur and at the time of reproduction these are called up again for selected tonal values and reproduced under the control of the scanning process.
Inventors
- 👤 Eckhard Lindemann
- 👤 Wolfgang Neumann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:46
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/405; H04N1/4055; H04N1/4058
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
150 words
A 45° screening pattern half-tone reproduction comprised of a multiplicity of tonal screen dots extending in a pattern of diagonal equally spaced lines perpendicular to each other and at an angle of 45° to the direction of scan during reproduction, with dots at intersections of the lines, each tonal dot being divisible into four adjoining dot parts by lines parallel to and orthogonal to the direction of scan and passing through said intersections, diagonally adjacent tonal dots having substantially equal diagonally adjacent dot parts, and the center of area of each of said tonal dots being determined by the respective areas of the four adjoining dot parts forming a tonal dot, and wherein the four adjoining dot parts forming at least some of said tonal dots of the reproduction are of different size from each other so that the center of area of such dots is offset from said intersections.
Claim 2
Dependent Claim
150 words
A 45° screening pattern half-tone reproduction comprised of a multiplicity of tonal screen dots extending in a pattern of diagonal equally spaced lines perpendicular to each other and at an angle of 45° to the direction of scan during reproduction, with dots at intersections of the lines, each tonal dot being divisible into four adjoining dot parts by lines parallel to and orthogonal to the direction of scan and passing through said intersections, diagonally adjacent tonal dots having substantially equal diagonally adjacent dot parts, and the center of area of each of said tonal dots being determined by the respective areas of the four adjoining dot parts forming a tonal dot, and wherein the four adjoining dot parts forming at least some of said tonal dots of the reproduction are of different size from each other so that the center of area of such dots is offset from said intersections.
Claim 3
Dependent Claim
28 words
A half-tone reproduction according to claim 1 wherein the size of all four adjoining dot parts of a plurality of the tonal dots of said reproduction are different.
Claim 4
Independent Claim
89 words
A method of making a 45° screening pattern half-tone reproduction comprising, scanning an original in parallel lines to obtain data indicative of the tonal value at equally spaced regions of the original, forming in the 45° screening pattern in the reproduction a plurality of equally spaced dots of tonal values corresponding to the tonal values of the original by separately forming four adjoining quarter sections of each dot, and while forming each quarter section of a dot, substantially simultaneously forming a similar quarter section of a diagonally adjacent dot.
Claim 5
Independent Claim
89 words
A method of making a 45° screening pattern half-tone reproduction comprising, scanning an original in parallel lines to obtain data indicative of the tonal value at equally spaced regions of the original, forming in the 45° screening pattern in the reproduction a plurality of equally spaced dots of tonal values corresponding to the tonal values of the original by separately forming four adjoining quarter sections of each dot, and while forming each quarter section of a dot, substantially simultaneously forming a similar quarter section of a diagonally adjacent dot.
Claim 6
Dependent Claim
24 words
A method according to claim 3 wherein diagonally adjoining quarter sections of at least some of said tonal dots are different from each other.
Claim 7
Independent Claim
113 words
A method of forming a half-toner screen for reproducing an original as a half-tone comprised of a multiplicity of tonal screen dots extending in a pattern of diagonal equally spaced intersecting screen lines at the same acute angle to the direction of scan during reproduction, said method comprising, forming each tonal dot in four adjoining quarter sections, at one intersection of the screen lines, by separately forming a first quarter section and then a second quarter section, and subsequently separately forming a third quarter section and then a fourth quarter section, and while forming each quarter section of said tonal dots, substantially simultaneously forming a quarter section of a diagonally adjacent tonal dot.
Claim 8
Independent Claim
113 words
A method of forming a half-toner screen for reproducing an original as a half-tone comprised of a multiplicity of tonal screen dots extending in a pattern of diagonal equally spaced intersecting screen lines at the same acute angle to the direction of scan during reproduction, said method comprising, forming each tonal dot in four adjoining quarter sections, at one intersection of the screen lines, by separately forming a first quarter section and then a second quarter section, and subsequently separately forming a third quarter section and then a fourth quarter section, and while forming each quarter section of said tonal dots, substantially simultaneously forming a quarter section of a diagonally adjacent tonal dot.
Claim 9
Dependent Claim
55 words
A method according to claim 5 wherein said forming of the adjoining quarter sections of at least some of the tonal dots comprises forming adjoining quarter sections of areas of different size so that the center of area of at least some of the tonal dots is offset from the intersections of the screen lines.
Claim 10
Dependent Claim
36 words
A method according to claim 5 wherein said forming of a quarter section of a tonal dot and a quarter section of a diagonally adjacent tonal dot comprises forming quarter sections of substantially the same areas.
Claim 11
Dependent Claim
23 words
A method according to claim 5 wherein said dots of the screen extend along 45° screen lines which are perpendicular to each other.
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) | 1988-02-05 | 1988-08-06 | 1989-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-05 | 1992-08-06 | 1993-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-05 | 1996-08-06 | 1997-02-05 | $7700.00 | Window Closed / Lapsed |