US4783667A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Printing of angled and curved lines using thermal dot matrix printer
Assignee: NCR Canada Ltd
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Filing: 1987-07-17
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Granted: 1988-11-08
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Expires: 2007-07-17
Abstract
Abstract A method and apparatus are described for enhancing the visual quality of dot matrix characters printed by means of thermal printing technologies, particularly in enhancing diagonal lines and blended radii of curvature. Two independent techniques can be combined or used in isolation to effect this print enhancement. The first, quarter dot step resolution, enables printed dots to be positioned at one quarter their previous step displacement distance. Memory must be expanded to handle increased dot position resolution. The second technique is element energy control, which enables each element in the printhead to emit different energy levels. The individual dot energy control translates into control of the printed dot shape and size, which when properly controlled, allows printing of diagonal lines and blended radii of curvature. This second technique further increases the required memory space by an additional factor.
Inventors
- 👤 Ralf M. Brooks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:03
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/315; B41J2/32; B41J2/35; B41J2/355; G; G06; G06K; G06K15/00; G06K15/02; G06K15/028
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
127 words
A method for thermal printing of characters having diagonal or curved portions, comprising the following steps: stepping a thermal printhead having a plurality of individual printhead elements with respect to a record member to be printed upon, taking incremental overlapping steps which are in length a fraction of the length of the printhead elements to minimize voids and staircase corners which would otherwise occur when a diagonal or curved line is printed with said print elements; and applying varying amounts of energy to each print element as appropriate during each incremental overlapping step to enlarge or reduce the area of the element impression on the record member to further aid in minimizing the occurrence of voids and staircase corners during printing of a diagonal or curved line.
Claim 2
Independent Claim
127 words
A method for thermal printing of characters having diagonal or curved portions, comprising the following steps: stepping a thermal printhead having a plurality of individual printhead elements with respect to a record member to be printed upon, taking incremental overlapping steps which are in length a fraction of the length of the printhead elements to minimize voids and staircase corners which would otherwise occur when a diagonal or curved line is printed with said print elements; and applying varying amounts of energy to each print element as appropriate during each incremental overlapping step to enlarge or reduce the area of the element impression on the record member to further aid in minimizing the occurrence of voids and staircase corners during printing of a diagonal or curved line.
Claim 3
Dependent Claim
22 words
The method of claim 1 in which each incremental step is approximately one-fourth of the length of a individual thermal print element.
Claim 4
Dependent Claim
28 words
The method of claim 1 in which the amount of energy applied to a thermal printhead element may vary from 80% to 120% of a nominal energy value.
Claim 5
Dependent Claim
15 words
The method of claim 1 in which said characters are printed in a parallel mode.
Claim 6
Dependent Claim
15 words
The method of claim 1 in which said characters are printed in a serial mode.
Claim 7
Dependent Claim
27 words
The method of claim 1 in which some elements of the thermal printhead are dedicated to a character font and other elements are utilized for other printing.
Claim 8
Dependent Claim
15 words
The method of claim 6 in which the method is used to print a check.
Claim 9
Independent Claim
202 words
A method for controlling a thermal printing operation employing a thermal printer having a plurality of print elements for printing characters having diagonal or curved portions, comprising the following steps: selecting print elements for printing portions of a character on a step-by-step basis with each step being a fraction less than one of the length of a print element, each selected print element being selected for repeated printing with a minimum overlap to form horizontal and vertical character lines, and being selected to minimize the printing of voids and corners when printing a diagonal or curved line; selecting a energy level for each energization of a print element, to selectively enlarge or reduce the area of the element impression, so as to further minimize the printing of voids and corners when printing a diagonal or curved line; providing a digital value for each print element during each step, representing whether or not said element is to be energized, and if so, the amount of such energization, based upon the print selection and energy levels selection steps; and storing said digital values in a memory from which they may be retrieved during a printing operation to control the energization of said print elements.
Claim 10
Independent Claim
202 words
A method for controlling a thermal printing operation employing a thermal printer having a plurality of print elements for printing characters having diagonal or curved portions, comprising the following steps: selecting print elements for printing portions of a character on a step-by-step basis with each step being a fraction less than one of the length of a print element, each selected print element being selected for repeated printing with a minimum overlap to form horizontal and vertical character lines, and being selected to minimize the printing of voids and corners when printing a diagonal or curved line; selecting a energy level for each energization of a print element, to selectively enlarge or reduce the area of the element impression, so as to further minimize the printing of voids and corners when printing a diagonal or curved line; providing a digital value for each print element during each step, representing whether or not said element is to be energized, and if so, the amount of such energization, based upon the print selection and energy levels selection steps; and storing said digital values in a memory from which they may be retrieved during a printing operation to control the energization of said print elements.
Claim 11
Dependent Claim
18 words
The method of claim 8 in which each step is approximately one-fourth the length of a print element.
Claim 12
Dependent Claim
27 words
The method of claim 8 in which the amount of energy applied to a print element may vary from 80% to 120% of a nominal energy value.
Claim 13
Dependent Claim
15 words
The method of claim 8 in which said characters are printed in a parallel mode.
Claim 14
Dependent Claim
15 words
The method of claim 8 in which said characters are printed in a serial mode.
Claim 15
Dependent Claim
27 words
The method of claim 8 in which some elements of the thermal printhead are dedicated to a character font and other elements are utilized for other printing.
Claim 16
Dependent Claim
15 words
The method of claim 13 in which the method is used to print a check.
Claim 17
Dependent Claim
204 words
Apparatus for printing characters having diagonal or curved portions on a record medium comprising: a thermal printhead having a plurality of thermal printing character elements; means for selecting print elements for printing portions of a character on a step-by-step basis, each selected print element being selected for repeated printing with a minimum overlap to form horizontal and vertical character lines, and being selected to minimize the printing of voids and corners when printing a diagonal or curved line; means for providing relative incremental step movements between the printhead and the record medium; means for selecting an energy level for each energization of a print element, to selectively enlarge or reduce the area of the element impression, so as to further minimize the printing of voids and corners when printing a diagonal or curved line; means for storing a digital value for each print element during each step, representing whether or not said element is to be energized, and if so, the amount of such energization, based upon the print selection and energy level selection; and means for retrieving said digital values during a printing operation and controlling said selecting means in accordance with said digital values to control the energization of said print elements.
Claim 18
Dependent Claim
204 words
Apparatus for printing characters having diagonal or curved portions on a record medium comprising: a thermal printhead having a plurality of thermal printing character elements; means for selecting print elements for printing portions of a character on a step-by-step basis, each selected print element being selected for repeated printing with a minimum overlap to form horizontal and vertical character lines, and being selected to minimize the printing of voids and corners when printing a diagonal or curved line; means for providing relative incremental step movements between the printhead and the record medium; means for selecting an energy level for each energization of a print element, to selectively enlarge or reduce the area of the element impression, so as to further minimize the printing of voids and corners when printing a diagonal or curved line; means for storing a digital value for each print element during each step, representing whether or not said element is to be energized, and if so, the amount of such energization, based upon the print selection and energy level selection; and means for retrieving said digital values during a printing operation and controlling said selecting means in accordance with said digital values to control the energization of said print elements.
Claim 19
Dependent Claim
23 words
The apparatus of claim 15 in which each incremental step is approximately one-fourth of the length of an individual thermal printing character element.
Claim 20
Dependent Claim
32 words
The apparatus of claim 15 in which the amount of energy which may be applied to a thermal printing character element may vary from 80% to 120% of a nominal energy value.
Claim 21
Dependent Claim
15 words
The apparatus of claim 15 in which said characters are printed in a parallel mode.
Claim 22
Dependent Claim
15 words
The apparatus of claim 15 in which said characters are printed in a serial mode.
Claim 23
Dependent Claim
26 words
The apparatus of claim 15 in which the means for providing relative incremental step movements moves the thermal printhead incrementally with respect to the record medium.
Claim 24
Dependent Claim
27 words
The apparatus of claim 15 in which some elements of the thermal printhead are dedicated to a character font and other elements are utilized for other printing.
Claim 25
Dependent Claim
15 words
The apparatus of claim 21 in which said apparatus is used to print a check.
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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) | 1991-11-08 | 1992-05-09 | 1992-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-08 | 1996-05-09 | 1996-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-08 | 2000-05-09 | 2000-11-08 | $7700.00 | Window Closed / Lapsed |