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US3629861A Expired / Lapsed US ⏱️ 0.0 years remaining

Control for chain printer

Assignee: DECISION DATA Inc A CORP OF
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Filing: 1969-11-17
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Granted: 1971-12-21
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Expires: 1989-11-17
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Abstract

Abstract A control system for a horizontal-type carrier, or ''''chain,'''' printer wherein a recirculating shift register memory is employed to store the code representations of characters to be printed on the printline. A tracking or address counter is advanced in synchronism with the movement of data through the shift register and serves to identify each character stored therein with the particular print position in which it is to be printed. Generation of print command signals is accomplished by comparing, in sequence, each character stored in the memory with the output of a character generation counter which is advanced in synchronism with the movement of the type carrier to identify the order in which the types on the carrier move past the print positions. Actuation of the comparator and advancement of the character generation counter are controlled directly by the output of the tracking counter. Beginning-of-font sync pulses are generated by gating a primary index signal derived directly from the type carrier with a secondary index signal derived from a rotating code disc. A plurality of index marks are provided on the code disc in a manner to enable generation of properly timed beginning-of-font signals for any of a variety of different font length type carriers interchangeably employable in the printer.

Inventors

  • 👤 Lynn W Marsh Jr
  • 👤 Edward M Schneiderhan

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 19:31
CPC Classifications
G; G06; G06K; G06K15/00; G06K15/02; G06K15/08

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 326 words
In a control system for a line printer having a type carrier moving parallel to the printline and having individual types thereon spaced apart from one another by a distance Y which is greater than the space W between print positions on said line, the combination comprising: a memory for storing code representations of all characters to be printed on said line; a memory address counter for controlling access to said memory so as to present all said stored code representations at the output of said memory during a single uninterrupted count sequence; pulse-generating means for driving said counter through X uninterrupted count sequences during the time said type carrier moves the distance Y, where X equals Y/Y-W; a character generation counter operable at the beginning of each said count sequence to generate a code representation of the type character on said carrier next coming into alignment with a stationary reference position; a phase counter for counting 1 through X; means for advancing said phase counter once for each said memory address count sequence; means for advancing said character generation counter upon each advance of said memory address counter; first means for comparing the count of said phase counter with the count of the lowest order positions of said memory address counter and for generating a signal in response to each equal comparison detected; means for inhibiting said character generation counter advancing means during the occurrence of said signal from said first comparing means; print hammer means associated with said print positions for printing characters therein; selectively actuatable second comparing means for receiving and comparing the code representations at said memory output and the code representations of said character generation counter and for generating a print hammer actuation signal in response to each equal comparison condition detected; and means for actuating said second comparing means each time the count of said lowest order positions of said memory address counter equals the count of said phase counter.
Claim 2
Dependent Claim 326 words
In a control system for a line printer having a type carrier moving parallel to the printline and having individual types thereon spaced apart from one another by a distance Y which is greater than the space W between print positions on said line, the combination comprising: a memory for storing code representations of all characters to be printed on said line; a memory address counter for controlling access to said memory so as to present all said stored code representations at the output of said memory during a single uninterrupted count sequence; pulse-generating means for driving said counter through X uninterrupted count sequences during the time said type carrier moves the distance Y, where X equals Y/Y-W; a character generation counter operable at the beginning of each said count sequence to generate a code representation of the type character on said carrier next coming into alignment with a stationary reference position; a phase counter for counting 1 through X; means for advancing said phase counter once for each said memory address count sequence; means for advancing said character generation counter upon each advance of said memory address counter; first means for comparing the count of said phase counter with the count of the lowest order positions of said memory address counter and for generating a signal in response to each equal comparison detected; means for inhibiting said character generation counter advancing means during the occurrence of said signal from said first comparing means; print hammer means associated with said print positions for printing characters therein; selectively actuatable second comparing means for receiving and comparing the code representations at said memory output and the code representations of said character generation counter and for generating a print hammer actuation signal in response to each equal comparison condition detected; and means for actuating said second comparing means each time the count of said lowest order positions of said memory address counter equals the count of said phase counter.
Claim 3
Dependent Claim 51 words
The control system set forth in claim 1 wherein said memory comprises: a shift register having capacity for storing all characters to be printed on said line; and wherein said memory address counter drives said register so that it shifts one character position for each advance of said memory address counter.
Claim 4
Dependent Claim 81 words
The control system set forth in claim 2 further comprising: a master counter operable to set a count into said character generation counter prior to each count sequence of said memory address counter, means for advancing said master counter one count each time said carrier moves the distance Y, and means for resetting said master counter to a predetermined reference count each time said carrier moves the distance ZY, where Z represents the number of types in the full type font.
Claim 5
Dependent Claim 290 words
In a system for generating print hammer actuation control signals in a line printer having a type carrier moving parallel to a print line having N possible print positions, said carrier having individual types thereon spaced apart from one another by a distance Y which is greater than the space W between said print positions, the combination comprising: a first counter; means for driving said first counter through X count sequences each time said carrier moves the distance Y, X equalIng Y/Y-W, each said count sequence comprising at least N steps; a second counter operable at the beginning of each said count sequence to generate a code representation of the type character on said carrier coming into alignment with a stationary reference position; a third counter for counting 1 through X; first means for advancing said third counter once for each said count sequence of said first counter; second means for advancing said second counter upon each advance of said first counter; first means for comparing the count of said third counter with the count of the lowest order positions of such first counter and for generating a signal in response to each equal comparison detected; means for inhibiting said second advancing means during the occurrence of said signal from said first comparing means; selectively actuatable second means for comparing the code representation of the character to be printed in the print position identified by the count of said first counter with the count of said second counter and for generating a hammer actuation control signal in response to a match condition and; means for actuating said second comparing means each time the count of the lowest order positions of said first counter equals the count of said third counter.
Claim 6
Dependent Claim 290 words
In a system for generating print hammer actuation control signals in a line printer having a type carrier moving parallel to a print line having N possible print positions, said carrier having individual types thereon spaced apart from one another by a distance Y which is greater than the space W between said print positions, the combination comprising: a first counter; means for driving said first counter through X count sequences each time said carrier moves the distance Y, X equalIng Y/Y-W, each said count sequence comprising at least N steps; a second counter operable at the beginning of each said count sequence to generate a code representation of the type character on said carrier coming into alignment with a stationary reference position; a third counter for counting 1 through X; first means for advancing said third counter once for each said count sequence of said first counter; second means for advancing said second counter upon each advance of said first counter; first means for comparing the count of said third counter with the count of the lowest order positions of such first counter and for generating a signal in response to each equal comparison detected; means for inhibiting said second advancing means during the occurrence of said signal from said first comparing means; selectively actuatable second means for comparing the code representation of the character to be printed in the print position identified by the count of said first counter with the count of said second counter and for generating a hammer actuation control signal in response to a match condition and; means for actuating said second comparing means each time the count of the lowest order positions of said first counter equals the count of said third counter.
Claim 7
Dependent Claim 217 words
In a system for generating print command signals in a line printer wherein a type carrier moves parallel to an N-position print line and carries individual types spaced apart from one another by a distance Y which is greater than the space between print positions on said line, the combinations comprising: a recirculating memory storing code representations of all characters to be printed on said line; timing means for driving said memory to circulate all said stored code representations past the output of said memory a plurality of times during the time said type carrier moves the distance Y; memory address counting means driven by said timing means to advance one count each time a code representation is presented at said memory output, each output count from said counting means identifying a different one of said N print positions; character generation means operating in sync with the movement of said carrier to generate code representations identifying the order in which the types on said carrier move past said print positions; and comparing means operable in response to the presentation of predetermined output counts from said counting means for comparing the code representation appearing at said memory output with that generated by said character generation means and for generating a print command signal upon detection of a match.
Claim 8
Dependent Claim 217 words
In a system for generating print command signals in a line printer wherein a type carrier moves parallel to an N-position print line and carries individual types spaced apart from one another by a distance Y which is greater than the space between print positions on said line, the combinations comprising: a recirculating memory storing code representations of all characters to be printed on said line; timing means for driving said memory to circulate all said stored code representations past the output of said memory a plurality of times during the time said type carrier moves the distance Y; memory address counting means driven by said timing means to advance one count each time a code representation is presented at said memory output, each output count from said counting means identifying a different one of said N print positions; character generation means operating in sync with the movement of said carrier to generate code representations identifying the order in which the types on said carrier move past said print positions; and comparing means operable in response to the presentation of predetermined output counts from said counting means for comparing the code representation appearing at said memory output with that generated by said character generation means and for generating a print command signal upon detection of a match.
Claim 9
Dependent Claim 43 words
The system set forth in claim 5 wherein said timing means drives said memory to circulate said stored code representations Y/Y-W times during the time said carrier moves the distance Y, where W represents the spacing between adjacent print positions on said line.
Claim 10
Dependent Claim 26 words
The system set forth in claim 6 wherein said comparing means is operable every Xth advance of said memory address counting means, where X equals Y/Y-W.
Claim 11
Dependent Claim 72 words
The system set forth in claim 7 wherein said character generation means comprises: a character counter operable at the beginning of each circulation cycle of said memory to generate a code representation of the type character on said carrier next coming into alignment with a stationary reference position; and means for advancing said character counter in response to each advance of said memory address counting means occurring intermediate each said Xth advance.

References Cited (Backward Citations)

US2831424A Cited
US2918865A Cited
US3216348A Cited
US3303775A Cited
US3314360A Cited
US3463081A Cited
US3430201A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1974-12-20 1975-06-21 1975-12-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1978-12-20 1979-06-21 1979-12-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1982-12-20 1983-06-21 1983-12-21 $7700.00 Window Closed / Lapsed

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