EP0183095A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Print hammer flight time control system
Assignee: International Business Machines Corp
•
Filing: 1985-11-05
•
Granted: —
•
Expires: 2005-11-05
Abstract
Abstract @ A hammer timing control system for the print hammers of a line printer uses a plurality of read/write RAMs (24-30) in place of individual ,fire control circuits for controlling the firing periods of the hammers. A delay value RAM (90) stores individual delay values to be interposed before each hammer is fired, and a terminate fire RAM or register (84) stores a delay to be interposed before the firing of a hammer is terminated. The hammers are turned on and turned off by signals incrementally clocked out from two pairs of RAMs which store each hammer address at memory locations corresponding to the hammer's assigned delay values.
Inventors
- 👤 James E. Carrington
- 👤 Gerald R. Westcott
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 19:47
CPC Classifications
B; B41; B41J; B41J9/00; B41J9/44; B41J9/46
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
241 words
A system for timing the impact of a set of hammers in an on-the-fly high speed line printer with the alignment of type of a moving type carrier with said hammers, said hammers each having inherent flight times which may differ relative to a predetermined flight time, comprising: a plurality of hammer driver circuits (14) for driving said hammers (17) against said type carrier in response to a hammer fire signal; hammer select means (24, 28, 104), coupled in common to all of said hammer driver circuits, for supplying, in response to control signals, a hammer address signal (52) representing a particular hammer to be fired; circuit means (20, 21), responsive to said hammer address signal, for supplying a hammer fire signal to the driver circuit (14) of said particular hammer; and signal generating means (88, 92, 94, 96) for generating an initiate fire signal when said type carrier is properly aligned with said particular hammer; characterized by: variable flight time control means (90, 76, 80, 68, 72, 86, 98), coupled to said hammer select means (24, 28, 104) and to said signal generating means (88, 96), for generating said control signals in response to said initiate fire signal (96 output), said control signals being designated as a first control signal (98 output) representing the address of said particular hammer and a second control signal (90 output) representing an individual delay period of the hammer fire signal for said particular hammer.
Claim 2
Independent Claim
241 words
A system for timing the impact of a set of hammers in an on-the-fly high speed line printer with the alignment of type of a moving type carrier with said hammers, said hammers each having inherent flight times which may differ relative to a predetermined flight time, comprising: a plurality of hammer driver circuits (14) for driving said hammers (17) against said type carrier in response to a hammer fire signal; hammer select means (24, 28, 104), coupled in common to all of said hammer driver circuits, for supplying, in response to control signals, a hammer address signal (52) representing a particular hammer to be fired; circuit means (20, 21), responsive to said hammer address signal, for supplying a hammer fire signal to the driver circuit (14) of said particular hammer; and signal generating means (88, 92, 94, 96) for generating an initiate fire signal when said type carrier is properly aligned with said particular hammer; characterized by: variable flight time control means (90, 76, 80, 68, 72, 86, 98), coupled to said hammer select means (24, 28, 104) and to said signal generating means (88, 96), for generating said control signals in response to said initiate fire signal (96 output), said control signals being designated as a first control signal (98 output) representing the address of said particular hammer and a second control signal (90 output) representing an individual delay period of the hammer fire signal for said particular hammer.
Claim 3
Dependent Claim
315 words
A system for timing the impact of a set of hammers in accordance with claim 1, wherein said circuit means comprises a plurality of latch means (21) respectively coupled to said hammer driver circuits (14), and hammer address signal decoder means (20, 22) coupled in common to all of said latch means; and wherein said hammer select means comprises a plurality of set and reset read/write random access memories (24, 26, 28, 30, 104, 106) each having an output port coupled to said decoder means (20, 22) and an input port coupled to said variable flight time control means (98), and having an address port coupled to other of said variable flight time control means (68, 70, 72, 74) for selecting the memory locations in which said first control signal (98 output) is stored and from which said hammer address signal (52, 54) is read, said memory locations representing the timing of the hammer fire signal; so that said first control signal (98 output) is stored in a set memory (24, 28, 104) location representing a first delay period (90 output) and in a reset memory (26, 30, 106) location representing a second delay period (84 output) and said hammer address signal (52) is subsequently read from said set memory location after said first delay period and inputted to said decoder means (20) which decodes said hammer address signal and provides a set pulse to a corresponding one of said latch means (21) to supply a hammer fire signal to the hammer driver circuit (14) corresponding to said particular hammer, and said same hammer address signal (54) is subsequently read from said reset memory location after said second delay period and inputted to said decoder means (22) which decodes said hammer address signal and provides a reset pulse to the same corresponding one of said latch means (21) to terminate the said hammer fire signal.
Claim 4
Dependent Claim
72 words
A system for timing the impact of a set of hammers in accordance with claim 2, wherein said hammer address signal decoder means further comprises: a first decoder (20), having a plurality of output terminals coupled to respective ones of said latch means (21), for providing set pulses; and a second decoder (22), having a plurality of output terminals coupled to respective ones of said latch means (21) for providing reset pulses.
Claim 5
Dependent Claim
181 words
A system for timing the impact of a set of hammers in accordance with claim 2 or 3, wherein an option cycle is defined as the time period in which a hammer may be fired, wherein said plurality of random access memories are divided into an even pair of set and reset memories (28, 30) and an odd pair of set and reset memories (24, 26), said pairs being alternately addressed for reading or, respectively, for writing during successive option cycles designated as an even cycle and an odd cycle, and wherein during each cycle said hammer address signal is read out of a memory location previously designated by said second control signal and said first control signal is stored in a. memory location presently designated by said second control signal, said even pair of memories outputting said hammer address signal during said even cycle and storing said first control signal during said odd cycle, and said odd pair of memories reading out said hammer address signal during said odd cycle and storing said first control signal during said even cycle.
Claim 6
Dependent Claim
116 words
A system for timing the impact of a set of hammers in accordance with claim 2 or 3, wherein an option cycle is defined as the time period in which a hammer may be fired, and wherein said plurality of random access memories comprise a set memory (104) and a reset memory (106), said memories being simultaneously addressed twice during each option cycle, said option cycle being divided into a read cycle and a write cycle, wherein said hammer address signal is first read out of said set and reset memories during said read cycle, and wherein said first control signal (98 output) is subsequently stored in said set and reset memories during said write cycle.
Claim 7
Independent Claim
298 words
A system for timing the impact of a set of hammers in accordance with a previous claim, said variable flight time control means further comprising: a hammer address table (86) for providing said first control signal representing the position of each particular printing hammer which is ready to be fired, a delay value random access memory (90) for providing a first delay value representing said first delay period between the generation of said initiate fire signal and the firing of each hammer, a clock (23) for providing periodic increment address register pulses, address register means (32, 34, 108) for counting said increment address register pulses and having output ports for constantly outputting the incremented value, said output ports being coupled to said even memory address ports (64, 66) during said even cycle and coupled to said odd memory address ports (60, 62) during said odd cycle, said address register means being reset at the beginning of each line print cycle, a terminate fire register (84) for providing a second delay value representing said second delay period between the generation of said initiate fire signal (96 output) and the termination of hammer firing, and adder means (76, 78, 80, 82) having adder input ports coupled to said address register means, to said delay value random access memory and to said terminate fire register, and adder output ports coupled to said address ports; wherein said adder means adds the current value of said address registers to said first and second dalay values, wherein said adder output ports are coupled to said even memory address ports (64, 66) during said odd cycle and are coupled to said odd memory address ports (60, 62) during said even cycle, and wherein the outputs of said adders represent said first and second delay periods.
Claim 8
Independent Claim
208 words
A method of timing the impact of a set of hammers (17) in an on-the-fly high speed line printer with the alignment of type of a moving type carrier with said hammers, said hammers each having inherent flight times which may differ relative to a predetermined nominal flight time, the method characterized by the steps of: assigning (86) a different hammer address to each of said hammers; providing (90) stored predetermined time delay values for the respective hammers, each value being related to the actual flight time of a corresponding hammer such that, when the delay value modifies the time at which the hammer is fired, the impact of the hammer is timed to occur when the hammer and a type on said type carrier are aligned; selecting (88, 96) a hammer to be fired; storing (68, 72, 98) the address of the selected hammer in a random access memory means (24, 28), common to all the hammers, and at a memory location corresponding to the selected hammer's predetermined delay value; and reading out (52) the stored hammer address from said memory locations to produce (20, 21) a firing pulse for the selected hammer such that the impact thereof occurs when the hammer and the type are aligned.
Claim 9
Independent Claim
208 words
A method of timing the impact of a set of hammers (17) in an on-the-fly high speed line printer with the alignment of type of a moving type carrier with said hammers, said hammers each having inherent flight times which may differ relative to a predetermined nominal flight time, the method characterized by the steps of: assigning (86) a different hammer address to each of said hammers; providing (90) stored predetermined time delay values for the respective hammers, each value being related to the actual flight time of a corresponding hammer such that, when the delay value modifies the time at which the hammer is fired, the impact of the hammer is timed to occur when the hammer and a type on said type carrier are aligned; selecting (88, 96) a hammer to be fired; storing (68, 72, 98) the address of the selected hammer in a random access memory means (24, 28), common to all the hammers, and at a memory location corresponding to the selected hammer's predetermined delay value; and reading out (52) the stored hammer address from said memory locations to produce (20, 21) a firing pulse for the selected hammer such that the impact thereof occurs when the hammer and the type are aligned.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.