Abstract: A method of controlling noise in an impact printer that modulates the input pulse to the power amplifier of the printer. The resulting current waveform is then applied to the print wire solenoids. The final shape of the force input to the platen reduces or spreads the spectral envelope containing problem harmonics and acoustic output noise.

Abstract: A printer and control method for printing to various types of recording media store printing modes appropriate to those various types of recording media in a mode/media memory section. When a particular printing mode is selected while a particular type of recording media is selected, the correlation between that printing mode an recording media is stored. Whenever that type of recording media is subsequently selected for printing, the corresponding printing mode is automatically selected from memory to control the printing operation. It is therefore possible to select what printing mode is used with what recording media, and thereafter automatically select, by simply selecting the type of recording media, the printing mode that is most appropriate to the type of recording media, the thickness of the media, and other particular media specifications. Printing appropriate to the type of recording media is then possible by simply selecting the type of recording media used.

Abstract: Method and apparatus for altering the length of time a print head in a dot-matrix type of printer mechanism receives driving voltage in accordance with the type of recording media being used by the printer, and preselected print head driving modes selected as a result of control commands provided by a host computer. The print head driving voltage is also measured and digitized, and then used along with the paper type as a parameter for altering the print mode. Memory elements can be used to establish print mode, print media, and drive voltage relationships for automatically selecting an optimum driving time interval in response to one of the selected parameters.

Abstract: The wire motion detecting apparatus according to the present invention comprises a velocity detecting portion for detecting the velocity of a printing wire, a comparator output signal generating portion for generating a first comparator output signal CMP and a second comparator output signal CMPR corresponding to the detected velocity, a first counter 101 for measuring a motion time T.sub.S for the printing wire, a second counter 102 for measuring a print time T.sub.P for the printing wire, and a third counter 103 for measuring a return time T.sub.R for the printing wire. When the signal level of the first comparator output signal CMP is repeatedly changed between a high level and a low level, the first counter 101 stops counting. Even if an armature is rebounded, the first counter 101 does not resume counting.

Abstract: A low cost, integrated circuit compatible, circuit for constantly controlling the current in a print hammer coil is provided. The circuit is suitable for use with a hammer coil driven from the low voltage side (bottom drive) and in series with a sense resistor. A programmable reference that actively compensates the coil current for drift in the hammer coil bias power supply reference generating means is included to allow accurate detection of coil current levels. The control circuit reduces generated noise and has good noise immunity.

Abstract: The present invention provides a print head control device for a wire dot printer, capable of preventing the occurrence of ghost dots to enable the wire dot printer to print characters and the like with a high print quality. The print head control device comprises a print head driving circuit for charging and discharging piezoelectric elements to advance and retract a printing wire, and a print head control circuit for controlling the print head driving circuit.

Abstract: An apparatus for embossing sheet material by applying pressure to punch and die members positioned on both sides of the sheet material using force developed by one or more solenoids to force the punch and die members together to apply an imprinting force. In order to reduce the impact force, noise and wear on the mechanical parts, the solenoid may be energized in two separate steps, the first to move the punch and die members into contact with the surface of the card and the second to apply the embossing force to the punch and die members. Both rotary and linear solenoids may be used with differing coupling linkages in various embodiments of the embossing mechanism.

Abstract: In a wire-dot impact printer having a capacitance detector for detecting a displacement of each armature by a sensor electrode arranged opposite the armature, a space is formed between each sensor electrode and its associated armature, and a shield pattern is formed with a small space left around each sensor electrode. The shield pattern is fed with a potential at least equal to the potential of each sensor electrode. This makes it possible to reduce the influence of noise upon detection of a capacitance by the capacitance detector. A noise canceling electrode is also disposed around each sensor electrode and is connected to the sensor electrode, whereby a noise canceling circuit is further provided to eliminate noise voltage. The noise canceling circuit can eliminate a noise voltage picked up by the sensor electrode and the noise canceling electrode.

Abstract: An impact-type printing device includes a printer for printing characters with a plurality of impression pressures including a high impression pressure sufficient for printing on all of the sheets of a set of copy sheets. The device also include a keyboard having a key for selecting one of the plurality of impression pressures when the device operates in a normal operation mode. The device further includes a switch for switching the device between the normal operation mode and a copy mode of operation. In the normal mode the printer is capable of printing in any of the plurality of impression pressures selected by the operator at the keyboard. In the copy mode the printer prints only with a high pressure, sufficient for printing on all of the sheets of the set of copy sheets. The device also erases a previously printed character when in the normal mode and overstrikes the previously printed character in the copy mode.

Abstract: The method for determining impact energy of a type element of the printing machine includes providing at least two different-length flight paths for the type elements by changing a distance between a resting position of the hammer and a place of impact of the type elements by at least one known amount; measuring at least two different hammer flight times corresponding to the at least two different-length flight paths of the type elements differing by the at least one known amount, each of the different hammer flight times being equal to a difference between a time of impact of one of the type elements and a time of onset of current flow in the hammer electromagnet; forming a difference between two different hammer flight times; dividing the known amount by which the two flight paths associated with the two different hammer flight times differ by the difference determined for the two hammer flight times to obtain a speed of the type element at impact and thus the impact energy of the type element.

Abstract: In a driving apparatus for a wire-dot print head having electromagnets for driving print wires, each electromagnet comprising a core and a coil, sensing coils are provided in association with the respective electromagnets and provided to interlink the magnetic flux passing through the core of the associated electromagnet, a magnetic flux detecting circuit is connected to the sensing coils for detecting the magnetic flux passing through the core, and a control and drive circuit is responsive to the detected magnetic flux for deciding the termination of the energization of the drive coil.

Abstract: A serial impact printer including a platen mounted for rotation upon a support frame, a print element having character imprinting portions disposed thereon and a print element selector for moving the print element to position a selected character imprinting portion at a printing position. A high effective mass hammer, driven toward and away from the platen in a timed manner, drives each selected character imprinting portion for deforming the platen with a printing force. A carriage mounted for reciprocating movement generally parallel to the platen, supports thereon the print element, the print element selector, the hammer and the hammer driver, and a stationary reaction bar secured to the support frame is spaced from and extends parallel to the platen. The reaction bar incudes a reaction surface against which the carriage is urged for developing the printing force as the hammer deforms the platen.

Abstract: A system and method for automatically compensating for inaccuracies in the positioning of the timing mark sensor of a band line printer. A selected hammer is operated to impact a test character and an adjacent space between characters or a space provided by a blank character on the type band. The flight times of the hammer for the character and space impacts are measured under control of a microprocessor programmed to locate the edge of the test character and to compute a timing adjustment value for use by the printer control to obtain centered impacts of characters during printing.

Abstract: The invention relates to a method in printheads (1) with a plurality of print elements (4) arranged movable in relation to each other and a moving mechanism (7, 9, 11, 12, 14) with magnetic field-responsive forces for moving selectable print elements to print or inactive positions. With utilization of the method the forces with which selected print elements are moved in appropriate cases to their print positions can be changed in coordination for a plurality of print elements. In accordance with the invention this is achieved by a magnetic field change coordinated for several print elements. The invention also relates to a printhead (1) with a plurality of first electromagnet means (9, L1 L24) for moving selectable print elements (4) and also a second electromagnet means (LB) common to a plurality of print elements, for coordinated change of the forces for a plurality of print elements with which the print elements can be moved to their print positions.

Abstract: An impact mechanism for use in an impact printer, to deliver a printing force to drive a character element against a platen by means of a print tip movable toward and away from the platen. A rockable bail bar having an axis of rotation substantially parallel to the axis of the platen is constrained to limited angular movement toward and away from the platen by a prime mover connected to the bail bar. A push rod interconnects the print tip and the bail bar for delivering impact forces to the platen as the bail bar is moved toward the platen. The push rod is normally coupled to the bail bar for delivering impact forces to the platen and may be decoupled from the bail bar for drawing the pring tip away from the platen so as to allow the character element to be removed. A decoupling mechanism is provided to lift the push rod off of the bail bar and to recouple it to the bail bar as required.

Abstract: A method and apparatus for energizing a printhead by maintaining substantially constant peak current in the actuator means of the printhead regardless of the duty cycle of the actuator means. The method and apparatus establishes a minimum time period for energizing the actuator means and a supplemental time period for energizing the actuator means in response to the determined duty cycle. The actuator means are then energized for an extended time period in dependence upon the minimum time period and the established supplemental time period to thereby maintain substantially constant peak current in the actuator means regardless of the duty cycle thereof.

Abstract: A digital printhead energy control system includes a first storage device for receiving hammer pulse duration data, a second storage device for receiving hammer pulse energization data and for producing a trigger signal and hammer pulse energization signals, a counter for counting to a value equal to the value stored in the first storage device, a comparator for comparing the value stored in the first storage device with the incrementing counter value, latch means for latching the output of the comparator to produce an end pulse signal, first gating means for combining the end pulse signal and a reset signal for controlling the clearing of the second storage device and terminating the hammer pulse energization signals, and second gating means for combining the trigger signal and a reset signal for controlling the clearing of the counter.

Abstract: An impact printer which can be equipped with an auto sheet feeder comprises printing means, driving means for driving the printing means and controlling means for controlling the driving means so as to reduce the printing strength of the printing means when equipped with the auto sheet feeder. The impact printer makes it possible to reduce impact noises even when equipped with the auto sheet feeder, without lowering the quality of the characters, etc. printed.

Abstract: A print head driving system for driving a print head having a plurality of print wire controlling magnetic circuits and a plurality of print wires respectively operatively associated with the print wire controlling magnetic circuits regulates the flight starting timing of the print wires through the regulation of respective timings for supplying driving currents to the print wire controlling magnetic circuits to be used for a preceding printing cycle and the print wire controlling magnetic circuits to be used for a succeeding printing cycle, according to control data calculated on the basis of the number of the print wires which were used for the preceding printing cycle and the number of the print wires to be used for the succeeding printing cycle so that dots are printed at expected positions to thereby provide a clear print.

Abstract: Commencing with the first print hammer(s) "out", or actuated, on each print line the hammer drive current is boosted 10% for a period, ranging from 25%=650 microseconds for single part forms to 50% for multi-part forms, of the total print hammer flight time. Earlier striking hammers on each print line strike harder, alleviating displaced first-printed characters on single part forms and light characters on multipart forms due to hammer energy loss in forms compression.

Abstract: Disclosed is a wire dot matrix printer capable of printing letters on a plurality of superposed sheets of paper, in which there is provided a drive current adjuster for continuously increasing and decreasing the drive current of solenoids which move printing wires, in association with a distance adjuster for adjusting the relative distance between the front end of the printing wires and a platen roller, thereby the impact force of the printing wires can be continuously changed in accordance with the number of superposed sheets of paper.

Abstract: A method for controlling printing impact in an impact type dot printer which controls printing impact energy to be increase in case of normal density imprint function and to be decreased in case of high density imprint function in the controlling means of the impact type dot printer in which the printing stylus strikes the printing paper so that the printing paper can be prevented from being damaged during the high density imprint function.

Abstract: A dot drive circuit for a wire dot type printer including dot pins of a print head different in gaps with respect to a platen sets dot drive time intervals for each dot pin or for each dot pin group in accordance with the size of the gap.

Abstract: There is disclosed a print pressure control device for a printer having at least two types of type wheels for printing characters, which gives different limits to a print pressure regulation switch depending on the type of the type wheel.

Abstract: An impact printer has a flux regulator for each of the coils in its printhead. Each regulator provides a reference voltage indicative of the desired flux in the associated coil. A circuit is provided for measuring the flux in the coil and for providing a voltage representative thereof. The measured flux representation is compared with the reference flux representation and any difference is applied to a power circuit which then provides more or less power to the associated coil.

Abstract: A printing device comprises a carriage having a printing wheel, a printing ribbon driver and printing hammer fixed thereto, carriage driver for driving the carriage along a platen, wheel driver for setting the printing wheel to a position corresponding to an input character code, and hammer for driving the printing hammer.

Abstract: A printer which operates to use selectively at least two different types of ink ribbons. The printer is characterized in that the printing pressure is varied in response to the selection of the type of ink ribbon.

Abstract: An impact-type, printing apparatus which is readily adjusted to enable the impact face of the associated print hammer to be precisely located with reference to the plane of a character (or a typewheel) to be printed to enable printing in special fonts like E13-B. First and second eccentric members and a separate moveable member are used to provide the adjustments necessary for the precise location of the impact face.

Abstract: A dot matrix print head energy control circuit (commonly known as voltage source compensation) utilizes two pulse width modulator circuits (one for receipt printing and one for forms printing). The control circuit also comprises control circuitry and a data latch, the circuitry including RC networks and comparators responsive to outputs of the data latch. A FORMS signal, when inactive and utilizing a source or applied voltage of 24 volts, sets or selects the RC network for receipt printing having an energizing pulse duration of approximately 340 microseconds, and the FORMS signal when active sets or selects the RC network for forms printing having an energizing pulse duration of approximately 380 microseconds. A source or applied voltage of 28 volts sets pulse durations of approximately 300 and 340 microseconds for receipt and forms printing, respectively.

Abstract: An improved serial impact printer designed to substantially reduce impact noise generation during the printing operation. The printer includes a print tip exhibiting high effective mass relatively movable with respect to a deformable platen, with a print element, a marking ribbon and an image receptor sheet interposed between the print tip and the platen which are urged together during a controlled contact period of extended length.

Abstract: An impacting element for an impact printer having a platen, selectable character elements and means for driving the impacting element to impart a printing force to a selected character element, to drive it against said platen for a contact period, the impacting element including a sensor thereon for generating a signal indicative of the initiation of the contact period.

Abstract: An improved serial impact printer designed to substantially reduce impact noise generation during the printing operation. The printer includes a print tip relatively movable with respect to a deformable platen, with a print element, a marking ribbon and an image receptor sheet interposed between the print tip and the platen which are urged together during a controlled contact period. Movement is subject to control by a kinetic drive mechanism which applies a first force for moving the print tip relative to the platen, prior to the initiation of the contact period, for closing the gap therebetween and then applies a second force for accelerating the print tip relative to the platen, subsequent to the initiation of the contact period, for causing the print tip to deform the platen.

Abstract: A device for monitoring and compensating for changes in the flight time of the print hammers of impact printers is disclosed. The flight time of the respectively monitored hammer is calculated from the elapsed time between the moment of firing of a hammer and the moment of impact of the print type carrier against the impact platen. In order to ensure automatic self-adjustment of all print hammers in predetermined test cycles, without the actual printing process itself being affected, and without there being any test imprints on the record carrier, the print type carrier includes, in addition to the standard print types, an additional test type. The impact surface area of the test type is large enough such that no visible imprint is made upon its impact on the record carrier because of the low impact pressure.

Abstract: There is provided a printing apparatus which drives a printing wheel in response to a rotation angle data corresponding to an input character code and drives a printing hammer with an impact force corresponding to this input character code. A data processing circuit reads out the rotation angle data from a first memory, supplies a drive data corresponding to this rotation angle data to wheel driving circuit through a first data bus, and reads out the impact force data from a second memory and supplies it to a hammer driving circuit through a second data bus. The information relating to a character is accessed from the first and second memories via the same address.

Abstract: A hammer timing control system for the print hammers of a line printer uses a plurality of read/write RAMs in place of individual fire control circuits for controlling the firing periods of the hammers. A delay value RAM stores individual delay values to be interposed before each hammer is fired, and a terminate fire RAM stores a delay value 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.

Abstract: In a marking system for stamping materials such as aluminum strip, a pulse of determined energy is supplied to a solenoid, to impart a determined kinetic energy to a die. The die is guided to dissipate substantially all of this kinetic energy in the deformation of the material being stamped. The pulse of energy applied to the solenoid may be controlled by a programmable computer, programmed to control the duration of time that a current is applied to the solenoid. The computer may control a plurality of such solenoids, controlling the times and relative numbers of operation of each of the solenoids.

Abstract: A printing hammer rebound control system for use in impact-type printing machines is provided. The present system includes separate memory devices for storing the information of primary and its associated secondary energization. The primary energization is to move the printing hammer in the printing direction and the secondary energization is to slow down the hammer when it is in the returning motion. The present system applies an appropriate secondary energization in accordance with the intensity of the primary energization applied, thereby allowing to maintain the level of hammer rebound and production of noise at a minimum.

Abstract: In a printer, a printing clutch and a hammer impact changeover mechanism are controlled through a control member by one electromagnet, in such a manner that in response to a printing signal the clutch is engaged through the control member by the electromagnet to start one printing cycle and, in the second half of the printing cycle, the electromagnet is operated to enable a hammer impact change-over mechanism with the aid of the control member. The energizing forces of two weak spring members are applied to a cam follower member operatively coupled to the printing hammer so that when a printing type element having a large printing surface is selected, the energizing forces of the two spring members are utilized to allow the printing hammer to strike the type element strongly, and when a type element having a small printing surface is selected, the energizing force of only one of the two spring member is utilized to allow the printing hammer to strike the type element less strongly.

Abstract: A printing apparatus comprises a type wheel carrying a plurality of type elements and a platen for mounting and advancing a printing paper. A hammer can strike any one of the type elements against the printing paper and an ink ribbon is positionable between the type elements and the paper to imprint a character on the paper when any one of the type elements is struck. The ink ribbon is advanced by a driving mechanism. First, second, and third selecting systems respectively select one of a plurality of degrees of advancement of the printing paper, one of a plurality of time intervals of actuation of the hammer, and one of a plurality of amounts of advancement of the ink ribbon. First, second, and third counters each count pulses from respectively associated first, second, and third pulse generators to, respectively, first, second, and third set values determined by the selected degree of paper advancement, time interval of hammer actuation, and amount of ribbon advancement.

Abstract: A plunger armature printing system incorporates an opto-electronic sensor for sensing the movement of a vane fixed to the armature of the print mechanism. The output signal generated by the sensor is employed to define periods for measurement of the speed of movement of the armature. A microprocessor is employed for supplying accelerating and decelerating pulses to the armature magnet for causing the armature to achieve a preselected printing force, in response to the time intervals between similar signals produced by said sensor, and to return said armature to its rest position rapidly without rebound.

Abstract: An energizing circuit for printer hammer drive coils is provided in which a single MOSFET transistor and a single diode is employed for each drive coil. Two voltage source means, one of which may be a capacitor, are connected in series. The drive coil is connected in series with the single MOSFET transistor and one of the voltage sources and is energized when the transistor is on. The drive coil discharges in a series circuit including the diode and the other of the voltage sources and charges the later voltage source when the transistor is off. An energy recuperation circuit is disclosed for receiving energy from the later voltage source and returning it to the first voltage source.

Abstract: A print mechanism is described which has a constant current driven solenoid acting against an arch-shaped hammer to power the hammer through an arc of powered flight followed by an arc of free flight. The solenoid/hammer engagement point removes the solenoid to a position which does not obstruct print line visibility and the hammer rest position is withdrawn to improve print line visibility.

Abstract: A multicopy impact printer has a wire matrix stored energy printhead having circuitry for reducing the power requirement of the printhead. A permanent magnet is incorporated in the printhead to flex leaf springs each of which is attached to the corresponding activation end of a respective one of a plurality of print members. A coil is provided for each print member, being activated when selected, to provide a magnetic field in opposition to the magnetic field of the permanent magnet and of an amplitude sufficient to release the flexed leaf spring. The opposing field diverts the field of the magnetic coil into paths away from the activated coil, thereby increasing its intensity and requiring more current in other selected coils to release the corresponding flexed leaf springs. A common coil is connected at one end to one end of each of the printer element coils and wound and positioned to provide a field in opposition to that of the permanent magnet.

Abstract: A variable impact printing mechanism includes a supporting magnetic structure having a plurality of circumferential coils mounted thereon and having a central bore in which a magnetic hammer element is positioned for linear movement to cooperate with a type member positioned adjacent to one end of the bore in order to effect printing on a record member positioned between the hammer and the type member. A controller is provided to energize drivers for the various coils in predetermined sequences to vary the velocity achieved by the hammer element at the end of its printing movement in accordance with varying printing requirements.

Abstract: A printing device in a typewriter including a rocker bracket turned in a direction of printing by a cam rotated when a key is pressed, a type head vertically movable and rotatably supported by the rocker bracket, a vertically movable pulley and rotatable pulley which are mounted on the bracket which are connected to a letter selecting mechanism and rotated by a predetermined value in accordance with a letter selected by the key, a printing arm for pivotally supporting a trigger detachably engageable with the rocker bracket and abutting against and being rotated by the cam to turn the rocker bracket, vertical direction selecting means for moving to a predetermined position in accordance with a value of rotation of the vertically movable pulley, rotational direction selecting means provided on the rotatable pulley and a printing pressure control member for being movable in accordance with the movements of the vertical directional selecting means and the rotational direction selecting means and having at least t

Abstract: In an impact printer including a print wheel having a plurality of selectable character type bearing elements for respectively printing a plurality of characters, said print wheel being rotatable for selectively positioning selected type elements in successive print positions, impact means impellable against the selected elements to drive said elements against the printing medium and means for impelling the impact means against said selected type element, the present invention provides the improvement comprising the combination of means for sensing the flight time of the impelled impact means until impact by sensing variations in the velocity of said impact means, means for comparing the sensed flight time to a predetermined ideal flight time, and means for selectively varying the amplitude of the current to the impelling means to adjust the sensed flight time to equal the ideal flight time.

Abstract: A method and apparatus for controlling a printer of the type having plural print heads, each being selectively energizable to print an indicium whose relative intensity is determined by the duration of energization of that printer. Data representing the intensity of the indicia to be printed by each of the print heads is received and stored. Respective ones of the print heads are selectively energized over time durations determined by the data. The number of print heads which are energized is detected, and the duration that the respective print heads are energized is varied as a function of the number of print heads which are concurrently energized.

Abstract: Print impression control mechanism for regulating the impact velocity of a single element printing head against a platen. The printing head is normally retained to a rest position which is in a fixedly spaced relationship to the platen independent of manual adjustment of an impression control lever so as to provide best visibility of printed characters on the record medium. In a first part of each print cycle, the head is brought to an intermediate position from which it is accelerated to get sufficient velocity for printing in a subsequent second part of the print cycle. Such an intermediate position is determined depending upon manual adjustment of the control lever whereby the impression of the printed characters can be determined accordingly.

Abstract: For use in an electronic printing system having a serial impact printer, apparatus is provided to accurately control the velocity of the print hammer during printing and provide accurately controlled impact energy, which is proportional to the character face area. The apparatus includes a servo feedback system where the primary driver for the print hammer is a moving coil in a magnetic field, and the velocity sensing required for the servo feedback loop is the back emf in the moving coil with the back emf being proportional to the hammer velocity.

Abstract: The impact velocity with which a single element printer prints is determined by the velocity with which the printing element is propelled toward the record sheet. The mechanism disclosed herein is capable of adjusting the velocity with which a print element is projected toward the page such that the impact velocity and, thus the impact forces which are related to the velocity, are controlled and varied to provide a minimum of compromise with respect to printing forces and, thus, print quality. The control of the velocity with which the print element is propelled against the record sheet is accomplished by a cam which rotates with the print element during character selection and has thereon a plurality of rises corresponding to a displacement of a cam follower engaged with a print cam. The print cam is formed to present, in a plurality of different planes perpendicular to its axis, a like plurality of cam profiles and rises.