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US5152619A
Expired / Lapsed
US
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Dot-matrix printer with dot counter and temperature sensor for efficient high-quality printing
Assignee: Brother Industries Ltd
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Filing: 1991-01-24
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Granted: 1992-10-06
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Expires: 2011-01-24
Abstract
Abstract A dot-matrix printer with a print head having plural print elements which are disposed in a row and selectively activated to form a dot or dots in a vertical row of a dot matrix pattern representing a character, having a device for adding to a content of a memory the numbers of dots which are formed by the elements; a device for measuring a time lapse; a temperature sensor for sensing a temperature of the print head; a device for substracting a predetermined value based upon the temperature sensed by the temperature sensor at predetermined time intervals; a device for checking whether the content of the memory has exceeded a reference value; and a control device for controlling the print head so as to cool the print head if the content of the memory has exceeded the predetermined value.
Inventors
- 👤 Takeshi Niikawa
- 👤 Masashi Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:20
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/22; B41J2/23; B41J2/30
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
202 words
A dot-matrix printer including a print head having plural print elements which are selectively activated, during a movement of the print head, to form a dot or dots in a vertical row of a dot matrix pattern representing a character, comprising: a dot-number memory; adding means for adding to a current content of the dot-number memory, numbers of dots which are formed by the print elements during movements of the print head; time-measuring means for measuring a time lapse; subtracting means for subtracting a predetermined subtraction value from the current content of the dot-number memory each time the time-measuring means has measured a predetermined time interval; a temperature detecting means for detecting a temperature of the print head; a subtraction value changing means for changing said subtraction-value to be subtracted from the current content of the dot-number memory according to the temperature detected by the temperature detecting means; judging means for checking whether the current content of the dot-number memory has exceeded a predetermined reference value; and printing control means for controlling the print head so as to cool the print head if the judging means has judged that the current content of the dot-number memory has exceeded the predetermined reference value.
Claim 2
Dependent Claim
202 words
A dot-matrix printer including a print head having plural print elements which are selectively activated, during a movement of the print head, to form a dot or dots in a vertical row of a dot matrix pattern representing a character, comprising: a dot-number memory; adding means for adding to a current content of the dot-number memory, numbers of dots which are formed by the print elements during movements of the print head; time-measuring means for measuring a time lapse; subtracting means for subtracting a predetermined subtraction value from the current content of the dot-number memory each time the time-measuring means has measured a predetermined time interval; a temperature detecting means for detecting a temperature of the print head; a subtraction value changing means for changing said subtraction-value to be subtracted from the current content of the dot-number memory according to the temperature detected by the temperature detecting means; judging means for checking whether the current content of the dot-number memory has exceeded a predetermined reference value; and printing control means for controlling the print head so as to cool the print head if the judging means has judged that the current content of the dot-number memory has exceeded the predetermined reference value.
Claim 3
Dependent Claim
17 words
A dot-matrix printer as claimed in claim 1 wherein said temperature detecting means comprises a temperature sensor.
Claim 4
Dependent Claim
15 words
A dot-matrix printer as claimed in claim 1 wherein said time lapse is 9 msec.
Claim 5
Dependent Claim
65 words
A dot-matrix printer as claimed in claim 1 wherein said printing control means further comprises means for activating specific groups of print wires during each movement of the print head along a print line such that each time the print head moves along the print line a different group of print wires is activated until a complete line is printed according to appropriate character data.
Claim 6
Dependent Claim
38 words
A dot-matrix printer as claimed in claim 1 wherein said printing control means controls the print head to cease printing until said subtracting means has reduced the current content of the dot-number memory below the predetermined reference value.
Claim 7
Dependent Claim
71 words
A dot matrix printed as claimed in claim 1, wherein said subtraction value changing means has a comparing means for comparing the temperature from the temperature detecting means to a predetermined temperature and when the temperature is greater than the predetermined temperature selects a first subtraction value and when the temperature is not greater than the predetermined temperature selects a second subtraction value that is larger than the first subtraction value.
Claim 8
Dependent Claim
22 words
A dot matrix printer as claimed in claim 6, wherein in the second subtraction value is two times the first subtraction value.
Claim 9
Dependent Claim
29 words
A dot matrix printer as claimed in claim 6, wherein the second subtraction value is greater than said first subtraction value and further is a function of the temperature.
Claim 10
Dependent Claim
136 words
A process for preventing overheating of the print head of a dot-matrix printer, comprising the steps of: initializing a dot-number count in a printer memory, adding to a current dot-number count a count of dots which are formed by print elements of the print head during movements of the print head; measuring a time lapse; subtracting a predetermined subtraction value from the current dot-number count each time the time-measuring means measures a predetermined time interval; detecting a temperature of the print head; changing said subtraction-value to be subtracted from the current dot-number count according to the detected temperature; judging whether the current dot-number count has exceeded a predetermined reference value; and modifying print operations so as to cool the print head when it is judged that the current dot-number count has exceeded the predetermined reference value.
Claim 11
Dependent Claim
136 words
A process for preventing overheating of the print head of a dot-matrix printer, comprising the steps of: initializing a dot-number count in a printer memory, adding to a current dot-number count a count of dots which are formed by print elements of the print head during movements of the print head; measuring a time lapse; subtracting a predetermined subtraction value from the current dot-number count each time the time-measuring means measures a predetermined time interval; detecting a temperature of the print head; changing said subtraction-value to be subtracted from the current dot-number count according to the detected temperature; judging whether the current dot-number count has exceeded a predetermined reference value; and modifying print operations so as to cool the print head when it is judged that the current dot-number count has exceeded the predetermined reference value.
Claim 12
Dependent Claim
14 words
A process as claimed in claim 9 wherein said time lapse is 9 msec.
Claim 13
Dependent Claim
67 words
A process as claimed in claim 9 wherein said step of modifying print operations further comprises the steps of activating specific groups of point wires during each movement of the print head along a print line such that each time the print head moves along the print line a different group of print wires is activated until a complete line is printed according to appropriate character data.
Claim 14
Dependent Claim
31 words
A process as claimed in claim 9, wherein said step of modifying print operation comprises stopping print operations until the current dot-number count has been reduced below said predetermined reference value.
Claim 15
Dependent Claim
53 words
A process as claimed in claim 9, further comprising the steps of: comparing the detected temperature to a predetermined temperature; and selecting a first subtraction value when the detected temperature is greater than the predetermined temperature and selecting a second subtraction value when the detected temperature is not greater than the predetermined temperature.
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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) | 1995-10-06 | 1996-04-06 | 1996-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-06 | 2000-04-06 | 2000-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-06 | 2004-04-06 | 2004-10-06 | $7700.00 | Window Closed / Lapsed |