Patent US4040094A successfully refreshed from Google Patents.
US4040094A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic screening
Assignee: PRINTING TECHNOLOGIES ASSOCIATES Inc
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Filing: 1975-08-13
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Granted: 1977-08-02
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Expires: 1995-08-13
Abstract
Abstract This invention relates to a method and apparatus for the electronic screening of a graphic image to be reproduced by printing. The density of the graphic image is determined repetitively during the digital generation of each dot which will form a part of the half-tone image when produced, and the dot is modified according to changes in the density. Thus the structure of any half-tone dot may be modified during its construction.
Inventors
- 👤 Robert Charles Everett
- 👤 Paul Anthony Beaufort Radcliffe
- 👤 Alfred Henry Robinson
- 👤 Janusz Andrew Veltze
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:21
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/405; H04N1/4055; H04N1/4058; H04N1/4056
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
68 words
Apparatus for electronic screening of a graphic image to be reproduced by printing wherein means are provided for determining the density of said graphic image repetitively by means of digital sampling of the density during the generation of each dot which will form a part of the half-tone image when reproduced, and means for modifying the dot according to changes in the density during generation of the dot.
Claim 2
Dependent Claim
68 words
Apparatus for electronic screening of a graphic image to be reproduced by printing wherein means are provided for determining the density of said graphic image repetitively by means of digital sampling of the density during the generation of each dot which will form a part of the half-tone image when reproduced, and means for modifying the dot according to changes in the density during generation of the dot.
Claim 3
Dependent Claim
50 words
Apparatus as claimed in claim 1, comprising means for producing each dot within a predetermined area composed of a number of sub-areas and the size of each dot depends upon the number of sub-areas which are of one density and the number of sub-areas which are of a second density.
Claim 4
Dependent Claim
66 words
Apparatus as claimed in claim 2, wherein each area within which a dot may be produced is divided into an array of sub-areas and means are provided for coding the incoming video signal representing the optical density of the image to be screened so as to cause an appropriate number of said sub-areas to be reproduced as opaque areas depending upon the density of said image.
Claim 5
Dependent Claim
62 words
Apparatus as claimed in claim 3, wherein the array of sub-areas is arranged in rows and columns and patterns of said sub-areas representing different opaque areas are stored in a coding device, which is actuated in response to said video signal to reproduce selected ones of said patterns which represent most closely the density of the portion of the image being reproduced.
Claim 6
Dependent Claim
121 words
Apparatus as claimed in claim 4 comprising an amplitude discriminator fed with said video signal and feeding said coding device, a plurality of line selectors equal in number to the number of rows in said array and which are each fed by a plurality of outputs from said coding device which is equal to the number of sub-areas in a row, a column counter device connected to each of said line selectors, a row counter device feeding a row selector which is fed with the outputs from the line selectors, a pattern controller device controlling said column counter and said row counter and means for deriving an output signal representing a screened version of said video signal from said row selector.
Claim 7
Independent Claim
64 words
A method of electronic screening of a graphic image to be reproduced by printing which comprises determining the density of said graphic image repetitively by means of digital sampling of the density during the generation of each dot which will form a part of the half-tone image when reproduced, and modifying the dot according to changes in the density during generation of the dot.
Claim 8
Independent Claim
64 words
A method of electronic screening of a graphic image to be reproduced by printing which comprises determining the density of said graphic image repetitively by means of digital sampling of the density during the generation of each dot which will form a part of the half-tone image when reproduced, and modifying the dot according to changes in the density during generation of the dot.
Claim 9
Dependent Claim
51 words
A method as claimed in claim 6 wherein each dot is produced within a predetermined area composed of a number of sub-areas and the size of each dot is determined by the number of sub-areas which are of one density and the number of sub-areas which are of a second density.
Claim 10
Dependent Claim
111 words
Apparatus for electronic screening of a graphic image to be reproduced by printing, comprising: means for accepting a video signal representing successive scans of said graphic image, means for digitally generating a screened video signal representing dots which will form part of the half-tone image reproduced such that each dot is formed from a plurality of said successive scans, means for repetitively determining the amplitude of the incoming video signal representative of the changes in density of said graphic image during the generation of each of said dots, and means for modifying each dot produced according to said changes in the density of the scanned image during generation of the dot.
Claim 11
Dependent Claim
111 words
Apparatus for electronic screening of a graphic image to be reproduced by printing, comprising: means for accepting a video signal representing successive scans of said graphic image, means for digitally generating a screened video signal representing dots which will form part of the half-tone image reproduced such that each dot is formed from a plurality of said successive scans, means for repetitively determining the amplitude of the incoming video signal representative of the changes in density of said graphic image during the generation of each of said dots, and means for modifying each dot produced according to said changes in the density of the scanned image during generation of the dot.
Claim 12
Independent Claim
109 words
A method of electronic screening of a graphic image to be reproduced by printing, said method comprising the steps of: accepting a video signal representing successive scans of said graphic image, digitally generating a screened video signal representing dots which will form part of the half-tone image reproduced such that each dot is formed from a plurality of said successive scans, determining repetitively the amplitude of the incoming video signal representative of the changes in density of said graphic image during the duration of each of said dots, and modifying each dot produced according to said changes in the density of the scanned surface during generation of the dot.
Claim 13
Independent Claim
109 words
A method of electronic screening of a graphic image to be reproduced by printing, said method comprising the steps of: accepting a video signal representing successive scans of said graphic image, digitally generating a screened video signal representing dots which will form part of the half-tone image reproduced such that each dot is formed from a plurality of said successive scans, determining repetitively the amplitude of the incoming video signal representative of the changes in density of said graphic image during the duration of each of said dots, and modifying each dot produced according to said changes in the density of the scanned surface during generation of the dot.
References Cited (Backward Citations)
US3197558A
Cited
US3742129A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-01 | 1981-01-31 | 1981-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-01 | 1985-01-31 | 1985-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-01 | 1989-01-31 | 1989-08-02 | $7700.00 | Window Closed / Lapsed |