Abstract: A portable label printing system for printing on a variety of materials is disclosed. A retractable platen roller cooperates with a self-aligning print head in three planes cooperates for proper label printing registration. A display screen allows the user to view precisely what the actual label and associated indicia will look like when printed on a selected label. In addition, the printing system includes an optical sensor positioned to sense data marks on the backside of a label, located on a label supply roll, allowing the printing system to identify the label specifications and make necessary adjustments to affect print quality. Reverse feed of the label supply roll is possible. The label printing system further comprises a communication port for cooperation with various devices, such as online databases and computers.

Abstract: A method of correcting a conveyance error of a continuous sheet having a train of segments each including a respective segment mark and being conveyed for printing in accordance with the number of steps is disclosed. The method counts steps between consecutive segment marks during conveyance of the sheet to thereby output an actual number of steps, compares the actual number of steps with a preselected number of steps determined by a distance between the consecutive segment marks, and corrects, based on the result of comparison, the start of a new line at even positions of a single segment during subsequent conveyance. An apparatus for practicing the method is also disclosed.

Abstract: An apparatus and method for controlling operation of a printer enables the transport rate of the print media to be coordinated with the print rate in order to precisely compensate for top-of-form and image stretch errors. The printer comprises a platen roller driven by a stepper motor to transport the print media in step increments. A print head is disposed in proximity to the platen roller so that the print media is transported therebetween by operation of the platen roller and step motor. A step rate control circuit for the printer comprises a clock adapted to provide a series of regular clock pulses at a fixed rate, and a first and a second counter respectively coupled to the clock for counting the clock pulses. The first counter provides a first interrupt signal with each of a first number of clock pulses which is provided to the stepper motor to cause the print media to be advanced by one step.

Abstract: A label printer having a stepping motor and the ability to dynamically accurately control longitudinal label registration as a function of steps of the stepping motor. The effective length of the steps moving the labels between a known point prior to the printhead and the printhead are monitored and the number of steps actually used to move the labels between the known point and the printhead are adjusted as a function of changes in the effective step length. In one embodiment, a sensor counts the steps between consecutive labels or averages a number of labels to determine the effective step length. In another embodiment, a sensor detects the start of label and start of printing on the label and the step distance between the two is used to determine the effective step length.

Abstract: An apparatus and method for control of a stepper motor drive for controlling movement of a receiver sheet into transfer relationship with an image-bearing member that supports an image to be transferred to the receiver sheet. Initially, the stepper motor is driven by drive pulses generated in response to clock pulses not synched with movement of the member. However, in order to ensure accurate registration, stepper motor drive pulses are subsequently generated that are in sync with encoder clock pulses that are generated in response to movement of the member. The transition of generation of the drive pulses is determined by establishing a condition of concurrence of a non-synched stepper motor drive pulses with an edge of an encoder pulse. The term condition of concurrence may be established by generating a timing control pulse of relatively short pulsewidth to define an allowed period for determining the condition of concurrence.

Abstract: In a sheet transport unit for recording systems which uses a pulse motor to feed a recording sheet quantitatively and intermittently, multiple different current apply intervals are specified within the stop period during intermittent sheet feed, so that a maximum amount of current will be applied to the first interval immediately after the drive stops. Thereby, the pulse motor is never be damaged due to its temperature rise despite a load variation and the load variation can be absorbed enough to ensure high positioning accuracy.

Abstract: Printers and copiers have paper handling mechanisms that incorporate form feeding tractors to move a continuous form or web having edge holes. It has been discovered that the web can be driven at a high acceleration yet uses a small number of pins by setting the pin pitch of the tractor greater than the pitch of the edge holes.

Abstract: There is described a printing apparatus in which line feed is achieved by rotating a platen with a paper advancing motor and the printing is conducted while the platen is stopped by the paper advancing motor. The printer is further provided with a detent mechanism for stopping the platen at the interval of a determined angle, and a solenoid for deactivating the function of the detent mechanism.

Abstract: An image recording apparatus for effecting image recording on a recording medium has drive transmitting members for imparting a drive force to a displaceable member, a motor for imparting a drive force to the drive transmitting members, COMMAND UNIT for designating the drive torque of the drive means, and control unit for controlling electric power applied to the drive means in conformity with the drive torque designated by the COMMAND UNIT.

Abstract: A paper feed control apparatus for a dot printer is provided which supplies a step pulse to a stepping motor in a one-pitch feed mode at an interval of a reference time to intermittently rotate the stepping motor in increments of a step angle, and which also supplies a step pulse to the stepping motor in a multi-pitch feed mode at an interval of a time shorter than the reference time to continuously rotate the stepping motor over a plurality of step angles. A motor drive control circuit is adapted to supply a step pulse to the stepping motor in the multi-pitch feed mode at a gradually shorted time interval, and to supply a final step pulse to the stepping motor in a final portion of a driving cycle when the reference time passes after the generation of the step pulse.

Abstract: A carriage drive control device to enable printing on a printing sheet from the leading edge thereof. A carriage drive control device repositions a carriage supporting a print head and a paper guide member at the midpoint of a printing line prior to each advance of the printing sheet as long as the leading edge of the printing sheet has been advanced beyond the printing line by a distance less than a predetermined distance.

Abstract: A paper check device for a printer including paper feed means, a light emitter, a light receiver, reflectance determination means, and paper check means. The paper check means determines that a paper is not on the platen when the platen is detected to be moving and a determined reflectance is in a preset range for a time interval longer than another preset value. The paper check device correctly detects whether the paper is on the platen even if the paper with already printed patterns of low reflectance is employed.

Abstract: In a printer in which a printing medium is moved by a line-feed stepping motor during line-feed operation, and the line-feed stepping motor is stopped during printing operation and in a ready state, the line-feed stepping motor is caused to generate a first holding torque for preventing unwanted movement of the printing medium while permitting the operator to feed the printing medium manually, in the ready state of the printer, and the line-feed stepping motor is caused to generate a second holding torque which is greater than the first holding torque, during the printing operation.

Abstract: A method and apparatus for loading a web into a printer is disclosed. The apparatus has a normal mode for moving the web in normal operation and a load assist mode for operating at a slower than normal rate for loading the web into the printer. The printer comprises means for recording information on the web including a platen attached to the printer and a print head for generating characters. The print head is disposed in a predetermined spaced relationship from the platen to define a print station therebetween. A means for engaging and moving the web through the print station and signal means for generating normal and load assist mode signals are provided.

Abstract: A printer for performing recording successively while a recording head moves backwards and forwards in a predetermined direction with respect to a recording medium such as paper. A paper hold roller for pressing the recording medium against a platen in the vicinity of a recording area opposite to a print head is detachable from the platen in relation to the movement of a carriage for carrying the recording head. The presence and absence of paper is detected to control the paper feed. An ink ribbon is provided which has color zones and an ink absorption zone in the direction of the ribbon width for multi-color printing by shifting the ribbon in the width direction by means of the carriage movement so that a selected color zone faces the recording head. The printer further includes a ribbon cassette, means for controlling paper insertion and feeding and means for cleaning the recording head. Also included are a paper bail control, color zone selector and paper detector.

Abstract: For step motors positioned in response to an external reference location, correction for potential one step misalignment is provided. The method and the apparatus of the invention provide a read/write memory, for storing therein a phase state of the step motor at a particular location, e.g. a home position. The home position may coincide with the external reference location or may be offset therefrom by some predetermined move of the step motor. During cold starts, where memory is not retained, the step motor is moved to its home position and then the phase state of the machine is saved. On subsequent warm starts, after the step motor is moved to the assumed home position, the step motor is controlled to assume the phase state that has been previously stored.

Abstract: A paper feed control system in a printer allows two types of manual paper feed operation. In a first type of manual paper feed operation, a course manual paper feed is conducted while an electrical detent operation is conducted by a paper feed drive pulse motor. In a second type of manual paper feed operation, a fine adjustment of the paper position is carried out while the electrical detent operation is precluded. A counter system is associated with the rotation of the paper feed drive pulse motor so as to provide the electrical detent operation at preselected positions. When the second type of manual paper feed operation is completed, the counter system is reset so that the subsequent electrical detent operation is carried out with reference to the finely adjusted paper position.

Abstract: A positioning system for a line printer uses dc servomotors for driving a forms feed mechanism in increments of one or more line spaces at a time. The system includes a microprocessor and a position counter that counts either 1/4 or 1 degree displacement pulses generated by a motion indicating means including optical transducers and an emitter disk coupled to the motors. The motion indicating means includes an error hold and compensation counter that counts and stores 1/4 degree pulses generated during error movement of the motors relative to a stop position during the uncontrolled state and supplies a corrected 1 degree pulse to the position counter upon start up.

Abstract: A recorder comprises first drive means for feeding a record paper to a stand-by position, second drive means for feeding the record paper from the stand-by position to a record position, and transport means for retracting a retainer which retains the record paper at the record position, during the operation of the first drive means and returning the retainer to the record position in response to the feed of the record paper during the operation of the second drive means.

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 dot matrix line printer incorporates plural print element driver assemblies each including N electromagnets driving N print rods, with each electromagnet having a local magnetic circuit that includes a working air gap and a passive air gap; a permanent magnet is connected to all of the local magnetic circuits. A magnetic circuit connects all of the local passive air gaps in parallel to afford a passive air gap common to all local circuits, the reluctance of the common passive air gap being of the order of 1/N times the maximum effective reluctance of the working air gap of each electromagnet. Each armature is supported by a cantilever bias spring, biasing the armature and associated print rod away from the electromagnet poles toward a print position; a stop member progressively reduces the effective length of the cantilever spring as the armature moves toward the electromagnet poles.

Abstract: A serial impact printer 11 includes a frame 15 mounted drive motor 47 coupled to a print wheel 31 to effect rotation thereof. The print wheel 31 is mounted on a movable print carrier 29 which serially moves from print position to print position along the print line. The motor 47 is coupled to the wheel pulley 51 of the print wheel 31 through a belt 49 which is wrapped about two idler pulleys 57 and 59 located on a sub-carrier 61. The sub-carrier 61 moves one half the distance of the print carrier 29 so that during escapement motion of the print carrier 29, the belt 49 imparts no rotary motion to the wheel pulley 51 and hence to the print wheel 31. The print carrier 29 may be clamped by clamp 77 to the belt 49 to effect the return motion thereof. The motor 47 is also coupled through a clutch 127 to the line feed apparatus of the platen 23.

Abstract: A single stepper motor is utilized in a printing device to lift a print head from the surface of recording material upon the initial angular rotation of the stepper motor output drive shaft and to move the recording material within the printing device upon further rotation of said drive shaft. The print head is returned to the surface of the recording material by operating the stepper motor in the reverse direction until the output drive shaft of the stepper motor traverses an angular displacement equal but opposite to the initial angular displacement. A cam surface couples the output drive shaft of the stepper motor to a drive gear and transforms the initial angular displacement of the output drive shaft into linear motion to lift the print head from the surface of the recording material. Further rotation of the stepper motor drive shaft rotates the drive gear to move material within the printing device.

Abstract: A microcomputer controls a ribbon drive assembly in a high speed wire matrix printer to eliminte ribbon slack, to insure proper ribbon positioning and to conduct diagnostics in conjunction with turning on the printer such as start-up time each day and after replacement of the ribbon with a new ribbon, the diagnostics checking to be sure that a ribbon is actually in the proper position, that it is threaded across the print line and also checking for proper operation of the ribbon drive, logic, and electronics. Tests are also made for proper ribbon drive during normal ribbon feeding operations.

Abstract: The specification discloses a method and apparatus for setting and varying margins, line spacing and printing direction of a data printing machine by a machine user before and during printing by use of a keyboard with push-button control which is coupled to a digital controller to input information about the actual and the desired location of a print head relative to a printing surface, in response to which the controller outputs signals which control relative motion of the print head and indexes its relative position, from the actual to the desired direction and location.

Abstract: A teleprinter includes a carriage for conveying a dot matrix-type print head along an operating path parallel to a print-receiving surface. The carriage is mounted on parallel-spaced support rods by means of spaced bearings slidably engaged to one of the support rods, and a pair of perpendicularly-aligned guide rollers which engage the other guide rod. The carriage is advanced by a drive belt which extends along the carriage operating path and is attached to the carriage at either end. A stepper motor coupled to one of the pulleys drives the belt to position the carriage. A removable cartridge on the carriage contains an inked ribbon which is advanced with movement of the carriage by a drive gear engaged to the drive belt. A unidirectional clutch prevents the inked ribbon from moving in a reverse direction during carriage return.

Abstract: A printer having an ink ribbon with a bidirectional ribbon drive in which a pair of stepper motors have their windings cross-coupled so that a drag current flows through one stepper motor to apply drag torque to the ribbon when the other stepper motor is operated for driving.

Abstract: A control for platen rotation in printers, and particularly in telex machines where the platen rotation drive, either a stepping motor or a DC motor, is provided with an incremental control actuated by keyboard keys to advance or counter advance the platen by a small increment of the full line space whereby alignment of the imprinting line with form spaces is facilitated.

Abstract: To more fully utilize the surface area of a typewriter ribbon in a cartridge ribbon receptacle, the cartridge locating plate supporting the receptacle is caused to oscillate with respect to the print head assembly. The ribbon cartridge assembly is a part of a print head and ribbon carrier that is positionable along a line of print by a drive motor through a belt drive engaging a drive pulley rotatably mounted to the carrier. Mounted to rotate with the drive pulley is a cam that engages a cam follower also mounted to the head and ribbon carrier. An upstop forms a part of the cam follower and engages the cartridge locating plate. With the cam follower driven by the cam, an oscillating motion is imparted to the upstop with reference to the head and ribbon carrier which motion is then imparted to the cartridge locating plate. Also fastened to the head and ribbon carrier is a solenoid that when energized spring biases the cartridge locating plate through a leaf spring attached to the plate.