US3602138A - Hammer driver timing from a print buffer ring - Google Patents

Hammer driver timing from a print buffer ring Download PDF

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Publication number
US3602138A
US3602138A US889022A US3602138DA US3602138A US 3602138 A US3602138 A US 3602138A US 889022 A US889022 A US 889022A US 3602138D A US3602138D A US 3602138DA US 3602138 A US3602138 A US 3602138A
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United States
Prior art keywords
hammer
address
print
core
planes
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Expired - Lifetime
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US889022A
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English (en)
Inventor
James G Barcomb
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International Business Machines Corp
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International Business Machines Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J9/00—Hammer-impression mechanisms
    • B41J9/14—Means for selecting or suppressing individual hammers

Definitions

  • the present invention generally relates to high speed printer apparatus, and more particularly to hammer driver timing using the print line buffer address ring. While not necessarily limited thereto, the invention has particular utility in a chain printer apparatus of the type shown in U.S. Pat. No. 2,993,437 of F. M. Demer et al., issued July 25, I961; U.S. Pat. No. 3,066,601 of H. E. Eden, issued Dec. 4, 1962; and U.S. Pat. No. 3,289,576 of E. M. Bloom et al., issued Dec. 6, 1966.
  • the chain printer apparatus as described in the above patents comprises a print mechanism and controls designed to print data a line at a time on a record medium
  • the print mechanism comprises a constantly moving type chain, a plurality of hammers arranged in a row parallel to a straight portion of the path of travel of the type and means for guiding and feeding a record medium between the hammer array and type chain.
  • the type chain comprises plural type elements attached to a flexible belt or the like. Each type element bears one or more type characters, and the elements are arranged on the belt so that one or more character sequences in a continuous loop is formed.
  • the print hammers are arranged in a linear array so that one hammer is located at each print position in a line. Since the type chain is moving constantly, the characters coming into alignment with various hammers are constantly changing. The process whereby the characters move into alignment is referred to as scanning.
  • the printer control for accomplishing this preferably comprises a magnetic core storage device, means for identifying the characters in the sequence in which they appear on the type chain, means for selecting hammers as the characters register therewith, means for timing the various control and print functions, and means for initiating and terminating the printer operation, paper feeding and data storage transfers.
  • the core storage device which may be part of the data processing system or may be a separate buffer storage for receiving data from the central processor, stores one line of data at a time. Within the core storage device, an individual core storage position is provided for each hammer position, and there are as many storage positions as there are hammers.
  • the readout means scans the core storage positions in the same sequence in which the characters are alignable with the hammer positions. During the course of a print scan, every position of data storage is scanned once. The process is repeated as many times as there are different characters in the type set.
  • the type identifying means which is a character code generator such as binary counters or the like, is generating a sequence of signals which identify those characters which are registering with the print hammer during the print scan.
  • the data signals read out of the various storage positions are compared with the character signals generated by the character generator for the corresponding print positions.
  • an equal compare signal is produced and used for sending a hammer operate signal through the hammer selection means to the addressed hammer.
  • the timing for the scanning of storage and the stepping of the type identifying counters is provided by a pulse generator, driven in synchronism with the type chain, and a cyclically operable electronic clock.
  • the pulse generator is designed to generate a timing pulse at the beginning of each print scan.
  • the timing pulse initiates clock operation whereupon a series of pulses is generated by the clock each clock cycle to stop the type tracking counters, advance the storage readout and hammer selection means, and tire hammers in the event of an equal compare signal.
  • the clock is designed to repeatedly generate a sequence of pulses whereby address, compare, hammer firing functions occur in sequence along with various checking functions as described in the above Eden patent.
  • an object of this invention is to provide magnetic core storage devices for checking the operation of printing apparatus and timing the operation of the print harnmers.
  • timing logic operable with the magnetic core storage of a high speed chain printer apparatus for accurately timing the print hammers to any duration that is needed regardless of the print scan timing.
  • the on duration of the print hammers is timed for 2.5 print scans during the regular cycle by modifying the hammer address by one-half of a print scan. Assuming a total of print positions, this is accomplished by modifying the address when a compare is obtained for print position 1 to address l+75 and by changing the condition of the 75 trigger and writing a bitinto position 76 of hammer number 1 core plane.
  • HMR plane I and HMR plane 2 are checked for a RESET condition (I, l) which does not yet exist.
  • the scan continues, and at this address 76 the contents of the HMR planes are modified again to read out the l in HMR 1 plane and write a 1 into HMR 2 plane at buffer address 76.
  • a check is made for a RESET condition, which does not yet exist.
  • the contents of the HMR planes are again modified by reading out the number 2 plane and writing a l in both the number 1 and number 2 planes.
  • a 1 exists in both number 1 and number 2 planes, and a RESET condition signal exists, permitting the firing of a reset for hammer number 1 on minor cycle (hammer address 1 This is 2.5 scans from the time hammer l was fired.
  • the two core planes are used as a binary counter to count the desired number of print scans.
  • FIG. I is a logic block diagram of the printer control which incorporates the hammer driver timing logic according to the invention.
  • FIG. 2 is a timing diagram showing the sequence of clock pulses and cycles employed by the logic of FIG. 1;
  • FIG. 3 is an exemplary pulse timing diagram illustrating the sequence for hammer driver timing for a pulse duration of 2.5 print scans.
  • the printer control system for selectively operating the print hammers comprises a multiposition data storage device such as a multiplane magnetic core storage matrix 10 having as many positions of storage as there are print hammers.
  • matrix 10 would have seven core planes for each bit of a 7-bit binary code, and each plane comprises plural cores arranged in a row and column configuration.
  • a specific core plane arrangement might comprise 150 cores arranged in 15 rows of 10 cores each to accommodate a corresponding number of hammers.
  • the information to be printed is written into different positions of matrix 10 from a data input channel.
  • the writing of information in the various storage locations of matrix 10 is performed in a well-known manner by the read/write drive control 11 which selectively energizes write windings of different cores in matrix 10 that are addressed by the buffer address ring counter 12.
  • the stepping of the address ring 12 is under control of the RO timing pulse (see FIG. 2) of an electronic clock and oscillator, details of which may be had by referring to the above-mentioned patents.
  • the writing operation is completed when the write drivers are operated in response to a Wl clock signal in combination with a readin signal.
  • Inhibit latches 13 which are energized or set on readin by clock pulse R and selectively reset in response to data input, have output lines connected to selectively controlledinhibit windings of the cores in the multiple planes of matrix in opposition to the write lines. As is well known in the art, these inhibit lines which are energized will oppose switching of write windings energized by control 11. Addressed cores having nonenergized inhibit lines are switched from a 0 tea 1 state by the energizing of write windings through control 11.
  • Readout of information from the various storage positions of matrix 10 for printing is also effected in a manner well known in the art.
  • the different core positions that are addressed by control 11 under the control of address ring 12 are energized by read drivers in response to an R1 clock signal and a Print Scan signal.
  • Outputs upon readout from the sense windings of the cores are fed through sense amplifiers 14 via a feedback connection (not shown) to inhibit latches 13.
  • the readout is also fed to a compare circuit (also not shown).
  • the information in latches 13 is rewritten into the same position of storage by read/write drive control 11.
  • the print hammers are addressed in the same manner and sequence as matrix 10 is scanned.
  • the additional core planes comprise print line complete (PLC) plane 15, print error check (PEC) plane 16, hammer number 1 check plane 17, and hammer number 2 check plane 18.
  • PLC print line complete
  • PEC print error check
  • hammer number 1 check plane 17 hammer number 1 check plane 17
  • the cores of planes 15-18 are addressed simultaneously with the corresponding positions of storage matrix 10.
  • the cores of planes 15-18 are wound in a manner known in the art so that core addressing of matrix 10 produces concurrent addressing of corresponding cores in planes 15-18.
  • the function of the core planes 15-18 is to record various functions occurring in the control system and printer apparatus for checking purposes and for determining when print operation is to be terminated. A detailed description of these basic functions may be had by reference to the Eden and Bloom et al. patents.
  • the present invention uses core planes 17 and 18 as a binary counter to accurately time the print hammers to any pulse duration. This is accomplished with address modification logic which, in one embodiment of the invention, provides a hammer timing pulse duration of 2.5 print scans.
  • the clock cycle is shown in FIG. 2 of the drawings, and in the specific embodiment to be described, comprises 10 sections. These include five read R0 to R4 and five write WO to W4 sections.
  • the clock can be arbitrarily divided into major and minor cycles. in the present embodiment, the first seven sections of the clock cycle comprise the major cycle, and the last three comprise the minor cycle.
  • the buffer and hammer addresses are the same as that of the address ring, while during the minor cycle, the buffer and hammer addresses are different from the address counter by a factor of 75.
  • a write operation write time minor
  • This modification of the buffer and hammer addresses on the minor cycle is the principal feature of the present invention. It is this feature which allows the timing to be changes to fit any requirement.
  • the output of sense amplifier 19 is connected to latch 20. Since a O was read out, latch 20 remains in its reset condition and latch 31 which is in reset state supplies a l to one input of AND gate 21 by way of OR gate 22. Normally during the write time of the clock cycle, AND gate 21 provides a1 output to inhibit driver latch (lNl-l DR) 23 by way of OR gate 24. However, AND gates 25 and 21 supply a 0 to inhibit driver 23 since a print compare has been generated at write time minor when the buffer address has been modified to 76. As a result, latch 23 remains off thereby permitting a l to be written in the core of plane 17 which would ordinarily correspond to address 76. in this manner, plane 17 records a bit each time a memory compare equal signal occurs.
  • latch 31 remains in its reset condition.
  • a l is gated by AND gate 21 to inhibit driver 23 resulting in a 0 being written at address 76 of core plane 17.
  • AND gates 32 and 33 and OR gate 34 which form a compare circuit for latches 20 and 31, provide a 0 output to AND gate 35.
  • the output of AND gate 35 is connected by way of OR gate 36 to inhibit driver 37 which remains turned off. This permits a l to be written at address position 76 in core plane 18. At this point, one-half of a print scan has taken pace.
  • the scan continues to address counter position and then stops and waits for another scan timing pulse to come from the printer. When this pulse occurs, another scan is started.
  • address counter 12 again reaches position 76 for the second time, the sense amplifiers 19 and 30 read out a 0 and 1, respectively. Latch 20, therefore, remains reset, and latch 31 is set. As a result, inhibit drivers 23 and 37 are both turned off, and 1 s are written into position 76 of both core planes l7 and 18. At this point in time, 1.5 print scans have taken place since the firing of hammer number 1.
  • any other hammer is essentially the same as that described above.
  • the two core planes 17 and 18 thus serve the dual purposes of timing the hammers and checking the hammers.
  • the number of hammer planes can be increased or decreased accordingly i.e., to tie from four to seven print scans, three hammer planes would be needed.
  • the circuit described in this application is for 2% scans.
  • the address ring is tailored for the one-half scan count of 75. This produces complement addresses, i.e.
  • hammer number 1 is timed in position 76 of the hammer check planes, and hammer 76 is times in position 1.
  • hammer number 2 is timed in position 77 and hammer number 77 in position 2.
  • 0 (150 is timed in position 75 and 75 is timed in position 0(150).
  • hammer timing logic comprising:
  • address modification means responsive to said print compare signal for changing the address of the currently ad dressed hammer and recording an indication of said print compare signal in the first of said plurality of additional core planes
  • c. means responsive to the readout from said plurality of ad ditional core planes for advancing the data stored therein in a binary progression during each print scan
  • d. means responsive to a predetermined count read out from said plurality of additional core planes for generating a reset pulse to the print hammer.
  • each print scan consists of a plurality of clock cycles, each clock cycle consisting of a sequence of pulses defining a plurality of read and write subcycles, a first group of said subcycles being termed a MAJOR cycle and a second group of said subcycles being termed a MINOR cycle, said MINOR cycle occurring at the latter portion of each of said clock cycles and comprising a plurality of write subcycles, said address modification means including:
  • a. address counter means for selectively designating an address corresponding to a location in said core planes
  • read/write control means responsive to said clock subcycles for addressing a location in said core planes designated by said counter means during a MAJOR cycle

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  • Impact Printers (AREA)
  • Record Information Processing For Printing (AREA)
US889022A 1969-12-30 1969-12-30 Hammer driver timing from a print buffer ring Expired - Lifetime US3602138A (en)

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US88902269A 1969-12-30 1969-12-30

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US (1) US3602138A (enrdf_load_stackoverflow)
JP (1) JPS514817B1 (enrdf_load_stackoverflow)
DE (1) DE2057675A1 (enrdf_load_stackoverflow)
FR (1) FR2072119B1 (enrdf_load_stackoverflow)
GB (1) GB1322964A (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3680480A (en) * 1971-04-26 1972-08-01 Ibm Chain printer hammer control
US3691947A (en) * 1971-05-13 1972-09-19 Ibm Hammer control for chain printer
US3742845A (en) * 1970-11-11 1973-07-03 Honeywell Inf Systems Italia Control system for high-speed printing machines
US3872788A (en) * 1972-10-26 1975-03-25 Honeywell Bull Sa Hammer flight time aligning system for impact printers
US3921517A (en) * 1974-06-21 1975-11-25 Ibm Random firing of multiple width print hammers
US3952648A (en) * 1973-01-19 1976-04-27 Compagnie Honeywell Bull (Societe Anonyme) Character printing device
US3998152A (en) * 1975-03-26 1976-12-21 General Electric Company Protection system for hammer drive circuits in impact printers

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2993437A (en) * 1959-10-05 1961-07-25 Ibm High speed printer apparatus
US3066601A (en) * 1959-12-29 1962-12-04 Ibm Error checking devices
US3289576A (en) * 1964-12-02 1966-12-06 Ibm High speed printer with variable cycle control
US3303776A (en) * 1963-09-30 1967-02-14 Ibm Selective character arrangement of the print member in printing devices
US3303775A (en) * 1963-09-20 1967-02-14 Ibm Variable speed printer apparatus and type carrier device therefor
US3312174A (en) * 1965-12-23 1967-04-04 Ibm Variable cycle control system for a high speed printer
US3343131A (en) * 1964-12-31 1967-09-19 Ibm Printer control apparatus including code modification means

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2993437A (en) * 1959-10-05 1961-07-25 Ibm High speed printer apparatus
US3066601A (en) * 1959-12-29 1962-12-04 Ibm Error checking devices
US3303775A (en) * 1963-09-20 1967-02-14 Ibm Variable speed printer apparatus and type carrier device therefor
US3303776A (en) * 1963-09-30 1967-02-14 Ibm Selective character arrangement of the print member in printing devices
US3289576A (en) * 1964-12-02 1966-12-06 Ibm High speed printer with variable cycle control
US3343131A (en) * 1964-12-31 1967-09-19 Ibm Printer control apparatus including code modification means
US3312174A (en) * 1965-12-23 1967-04-04 Ibm Variable cycle control system for a high speed printer

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3742845A (en) * 1970-11-11 1973-07-03 Honeywell Inf Systems Italia Control system for high-speed printing machines
US3680480A (en) * 1971-04-26 1972-08-01 Ibm Chain printer hammer control
US3691947A (en) * 1971-05-13 1972-09-19 Ibm Hammer control for chain printer
US3872788A (en) * 1972-10-26 1975-03-25 Honeywell Bull Sa Hammer flight time aligning system for impact printers
US3952648A (en) * 1973-01-19 1976-04-27 Compagnie Honeywell Bull (Societe Anonyme) Character printing device
US3921517A (en) * 1974-06-21 1975-11-25 Ibm Random firing of multiple width print hammers
US3998152A (en) * 1975-03-26 1976-12-21 General Electric Company Protection system for hammer drive circuits in impact printers

Also Published As

Publication number Publication date
DE2057675A1 (de) 1971-07-01
JPS514817B1 (enrdf_load_stackoverflow) 1976-02-14
GB1322964A (en) 1973-07-11
FR2072119A1 (enrdf_load_stackoverflow) 1971-09-24
FR2072119B1 (enrdf_load_stackoverflow) 1973-02-02

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