EP0030372A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Electrophotographic copier
Assignee: International Business Machines Corp
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Filing: 1980-12-04
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Granted: —
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Expires: 2000-12-04
Abstract
Abstract An alternating power supply for a copier fuser is sensed for zero crossings by detector (40), which steps counter (39). At the end of an apparatus cycle, the count in counter (39) gates latch (31) to store a new temperature reading from the fuser, according to a digital code (D). Stepping of the counter causes a stored predetermined sequence of numbers (B) to be fed, one at a time, from store (35 or 36) to comparator (32). If the comparator determines B > D, it causes a triac in the fuser circuit to pass the current half-cycle pulse from the power supply. The stored predetermined sequence of numbers is chosen so that the number of pulses generated per cycle varies inversely with the magnitude of the fuser temperature (D), for maintaining the fuser temperature constant.
Inventors
- 👤 Joseph Edwin Cunningham, Jr.
- 👤 Philip Theodore Gianos
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 21:44
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G05; G05D; G05D23/00; G05D23/19; G05D23/1917; G05D23/20
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
96 words
Apparatus for generating a variable number of pulses per cycle according to a respective input value (D) for that cycle, comprising means (34 to 40) for providing during each cycle a predetermined sequence of numbers (B numbers), one number following the preceding number through the cycle, determining means (32) for determining whether a predetermined mathematical relationship (B≥D) is satisfied between the input value relevant for that cycle and each succeeding number of the sequence, and means (7) for generating a pulse 6r not, for each said succeeding number, according to the determination by the determining means.
Claim 2
Dependent Claim
96 words
Apparatus for generating a variable number of pulses per cycle according to a respective input value (D) for that cycle, comprising means (34 to 40) for providing during each cycle a predetermined sequence of numbers (B numbers), one number following the preceding number through the cycle, determining means (32) for determining whether a predetermined mathematical relationship (B≥D) is satisfied between the input value relevant for that cycle and each succeeding number of the sequence, and means (7) for generating a pulse 6r not, for each said succeeding number, according to the determination by the determining means.
Claim 3
Dependent Claim
36 words
Apparatus as claimed in claim 1 in which said predetermined sequence of numbers is chosen so that the number of pulses generated per cycle varies in a given manner with the magnitude of the input value.
Claim 4
Dependent Claim
26 words
Apparatus as claimed in claim 1 or 2 in which, where there are a plurality of pulses generated per cycle, they are spread throughout the cycle.
Claim 5
Dependent Claim
33 words
Apparatus as claimed in any preceding claim in which each pulse can be a positive or negative half-cycle pulse, the numbers of positive and negative half-cycles being the same, or differing by one.
Claim 6
Dependent Claim
27 words
Apparatus as claimed in claim 4 in which said means for generating a pulse comprises a switch circuit (7) connected in an alternating current supply circuit (3).
Claim 7
Dependent Claim
45 words
Apparatus as claimed in claim 5 including a zero crossing detector circuit (40) for detecting zero crossings of the alternating current supply, said means for providing a predetermined sequence of numbers being controlled to provide successive numbers in timed relationship with successive detected zero crossings.
Claim 8
Dependent Claim
50 words
Apparatus as claimed in claim 6 including a counter (39) operable to issue a gate signal each time it counts the number of successive detected zero crossings in a cycle, and a latch (31) responsive to said gate signal for temporarily recording said input value (D) for the next cycle.
Claim 9
Dependent Claim
25 words
Apparatus as claimed in claim 7 in which said counter controls the addressing of a store (35 or 36) containing said predetermined sequence of numbers.
Claim 10
Dependent Claim
34 words
Apparatus as claimed in any preceding claim in which the input value is a sensed temperature of a copier fuser taken prior to each cycle, and said pulses are pulses for heating said fuser.
Claim 11
Dependent Claim
33 words
Apparatus as claimed in any preceding claim in which said means for providing a predetermined sequence of numbers can provide a selectable one of two different predetermined sequences (from 35 or 36) .
References Cited (Backward Citations)
No citation records indexed.
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