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US4426651A Expired / Lapsed US ⏱️ 0.0 years remaining

Strip chart recorder

Assignee: Applied Biosystems Inc
•
Filing: 1982-03-03
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Granted: 1984-01-17
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Expires: 2002-03-03
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Abstract

Abstract An improvement to a chart recorder where the chart paper is driven by a motor responsive to pulses counted by a microprocessor makes it possible for the operator to return the pen at any time to the starting point of the last chart scan by merely pressing a key. Using a programmed counter the microprocessor keeps track constantly of the number of counts since the start of the scan. On key command the microprocessor directs the motor to return through this number of counts plus 50; then to go forward 50 counts thus taking up any backlash in the chart drive so as to return exactly to the initial point of the scan. The subroutine also raises the pen during return and lowers it at the starting point.

Inventors

  • 👤 William C. Muellner
  • 👤 Walter Hvostik

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 13:34
CPC Classifications
G; G01; G01D; G01D15/00; G01D15/24; G01D15/26

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 134 words
A strip-chart recorder having means initiated by operator command for returning the strip-chart to the initial starting point of a scan without residual backlash comprising, in combination: a pulse drive for driving said strip-chart; means for supplying drive pulses to said motor, said means including a microprocessor controlled pulse drive circuit, means for counting the number of said drive pulses, said means starting to count from zero when the pen contacting the chart driven by said motor is at an initial starting position; and said drive pulse supplying means and said counter means being operative to effect a routine upon operator command, to drive said motor thereby to return said counter to zero count, the final part of said return being driven in the same direction as that of the initial approach to zero.
Claim 2
Dependent Claim 134 words
A strip-chart recorder having means initiated by operator command for returning the strip-chart to the initial starting point of a scan without residual backlash comprising, in combination: a pulse drive for driving said strip-chart; means for supplying drive pulses to said motor, said means including a microprocessor controlled pulse drive circuit, means for counting the number of said drive pulses, said means starting to count from zero when the pen contacting the chart driven by said motor is at an initial starting position; and said drive pulse supplying means and said counter means being operative to effect a routine upon operator command, to drive said motor thereby to return said counter to zero count, the final part of said return being driven in the same direction as that of the initial approach to zero.
Claim 3
Dependent Claim 19 words
A strip-chart recorder according to claim 1, wherein said operator command is effected by the operator pressing a key.
Claim 4
Dependent Claim 51 words
Strip-chart recorder as claimed in claim 1, wherein said routine is programmed to drive said motor until said counter counts a predetermined count past zero before reversing said motor until said count returns to zero whereby backlash is eliminated in the reset of the strip-chart to the initial starting position thereof.

References Cited (Backward Citations)

US3360799A Cited
US3806948A Cited
US4038664A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-01-16 1987-07-18 1988-01-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-01-16 1991-07-18 1992-01-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-01-16 1995-07-18 1996-01-17 $7700.00 Window Closed / Lapsed

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