Abstract: An ink cartridge detachably mountable to an ink jet recording apparatus, the ink cartridge containing ink to be supplied to a recording head includes an ink container for containing the ink; and an adaptor having a receptor for detachably receiving the ink container and an information medium for storing information relating to the ink, the information being transmitted to the ink jet recording apparatus when the ink cartridge is mounted therein.

Abstract: An ink jet recording apparatus comprises a mounting portion on which an ink jet cartridge is detachably mounted, the cartridge having a connector and a recording head portion for discharging ink to perform image recording. The mounting portion has a body connector associated therewith for electrically connecting the connector of the cartridge to the apparatus. A recording head positioner positions the recording head portion of the cartridge on the mounting portion. An operation device displaces the cartridge and the body connector relative to each other to connect the body connector to the cartridge connector.

Abstract: A connector for enabling a user to selectively couple one of at least a first printhead having a connection member or a second printhead having a set of connection members to a circuit. The circuit comprises first contact means for connecting the first printhead to the circuit and second contact means for connecting the second printhead to the circuit. The connector comprises a body having a first slot for receiving the connection member. The body further comprises a second slot and a third slot for receiving the set of connection members. A first plurality of male conductors is associated with the first slot in order to couple the first printhead to the first contact means of the circuit when the connection member is inserted into the first slot. A second plurality of male conductors is associated with the second and third slots in order to couple the second printhead to the second contact means of the circuit when the set of connection members are inserted into the second and third slots, respectively.

Abstract: A label printer comprises a supporting frame having a pair of side plates facing each other. A platen roller and a head unit having a print head are arranged between the side plates. A supporting shaft extends parallel to the platen roller and has one end fixed to one of the side plates and a free end adjacent to the other side plate. The head unit is supported on the supporting shaft and located in an operative position wherein the print head is opposite to the platen roller. The head unit is slidable from the operative position to the outside of the supporting frame along the supporting shaft. The free end of the shaft and the head unit in the operative position is fixed by a fixing member mounted on the other side plate.

Abstract: In a type disc for typewriters or the like, for locking the hub (1) of the type disc on a drive shaft there is a plurality of catch noses (7) arranged at the ends of cantilever arms (8, 11), of which the rear sides (9), as seen in the axial direction of the type disc, are at a distance from the inner wall (10) of a central hole (2) for receiving the drive shaft. The gaps which the maintained distance brings about allow an economical production of the type disc.

Abstract: A thermal line printer usable as a small output terminal. A printer body has a platen roller rotatably supported by a casing having side plates on either side thereof. A line-printing type thermal head is swingably supported by the printer body while being resiliently urged toward the platen roller. This arrangement allows the thermal head to be easily mounted on and dismounted from the printer body.

Abstract: A print head mounting mechanism for a printer is disclosed by which positioning of a print head in the forward and backward directions, leftward and rightward directions, and upward and downward directions with respect to a carrier can be achieved readily. The mounting mechanism includes a print head mounting plate secured in an integrated relationship to the carrier and having a predetermined thickness. The print head mounting plate has a U-shaped recess having a predetermined width and a predetermined depth. A mounting section for fitting in the U-shaped recess is provided on the print head. The print head is mounted on the carrier in an accurately positioned condition by fitting the print head mounting section into the U-shaped recess and urging the print head in the rearward direction and also in the downward direction by a wire spring.

Abstract: A printing machine having a structure for detachably supporting a cassette housing therein a type wheel is provided. The structure includes a cassette holder which may be pivoted between an operative position where printing may be carried out and an inoperative position where no printing is effected but the cassette may be replaced by another. The structure also includes a motor supporting member for supporting thereon a selection motor which may be engaged with or disengaged from the type wheel, wherein the motor supporting member is also pivoted to the cassette holder in a depending manner and moves between two positions in association with the pivotal movement of the cassette holder. Also provided is a guiding mechanism for guiding the movement of the motor supporting member thereby insuring that the motor is brought into engagement with the type wheel when located at the operative position and the motor is disengaged from the type wheel when located at the inoperative position.

Abstract: A structure for mounting a printing head includes a printing head provided with engaging projections, while a carriage which mounts the printing head is formed with engaging grooves engaging with the projections. Engaging surfaces on the grooves and the projections are subject to the reaction by a platen. The carriage has a lock means for preventing separation of the projections from the grooves, the lock means including a leaf spring, a lock lever and support means.

Abstract: An apparatus (500) for mounting a printhead (501) relative to a horizontal surface (508). The apparatus (500) comprises an anchor block (502) mounted on the horizontal surface (508); as well as a bottom clamp member (504) and a top clamp member (506) between which the printhead (54) is sandwiched. The bottom clamp member (504) has a first region pivotally attached to the anchor block (502), a central region (530) for contacting at least a part of the printhead (501), and a distal region. The central region (530) of the bottom clamp member (504) is substantially "V" shaped, extends below a plane of the horizontal surface (508), and has an upperside shaped to receive a bottom of the printhead (54). The first region of the bottom clamp member (504) comprises two yoke legs (512) pivotally connected to the anchor block (502). A pivot rod (522) extends between the two yoke legs (512) of the bottom clamp member (504), and the top clamp member (506) is pivotal about the said pivot rod (522).

Abstract: In a dot matrix print head drive method for controlling head drive signals for driving dot pins in accordance with print pattern signals, a correction factor is set specifically to each dot pin; and the length of time for which the print pattern signals are to remain in effects is varied according to the correction factor, to correct the drive time for each dot pin.

Abstract: An apparatus and method for printing a graphic design on a hard plastic workpiece such as a credit card blank includes a thermal printing element which is supported by a head assembly that has been designed a single link, to have low mechanical compliance in a horizontal plane and yet to allow the print head to align with a print roller. A cleaning assembly is further provided which includes a pair of cleaning rollers having an adhesive coating; and a novel arrangement for stripping particulate matter away from the cleaning rollers after a predetermined number of cards have been cleaned. A number of stepper motors are provided to perform the cleaning and printing functions. The stepper motors are controlled by a local control system which monitors a number of sensors provided on the cleaning and printing stations and is subservient to an overall system controller. The invention further includes a novel method of operation, a cassette for use with the printing station and a novel thermal printing foil.

Abstract: Described is a process for producing information relative to the type of a printer head (18) present in a printer, which head contains at least one printer element (86, 88, 90). The servo component of the printing element (86, 88, 90) has an electrical resistance, which is determined via an electrical evaulation circuit. This resistance is assigned to one of several resistance ranges representing various types of printing head. Depending upon this completed assignment, the evaluation circuit produces a type signal (40a, 40b, 40c) as information. The type signal (40a, 40b, 40c) is made available to a subsequent control, whic can then supply the various types of printing heads (17, 18) with specifically suitable control signals. The invention can be used with practically all types of printing heads, whose printing elements are actuated by electrical or electromechanical servo components and therefore have an electrical resistance.

Abstract: Control parameters necessary for controlling mechanism sections of a printing apparatus are stored in a program ROM. Selection data used for selecting predetermined control parameters stored in the program ROM are stored in a non-volatile memory. When operations of the mechanism sections of the printing apparatus are selectively changed, the selection data stored in the non-volatile memory are changed in accordance with operating states of the mechanism sections. The mechanism sections of the printing apparatus can be controlled upon every change in their operations without replacement of the ROM for storing the control parameters.

Abstract: A type-wheel cassette accommodating a type wheel is mounted on a carriage movable along a printing line on a platen. On the carriage is mounted a holder, on which a printing hammer and a type selection mechanism are mounted. The holder has a pair of first urging pieces extending toward the type-wheel cassette. An ink ribbon guide member intervening between the type-wheel cassette and platen has a pair of second urging pieces extending toward the type-wheel cassette. The first and second urging pieces are in contact with the opposite sides of the type-wheel cassette mounted on the carriage in the neighborhood of the printing position. The second urging pieces urge the type-wheel cassette toward the first urging pieces with the elastic spring force of the ink ribbon guide member, whereby the type-wheel cassette is positioned.

Abstract: A carriage for an electronic typewriter using a 2-row daisy wheel includes a slant bracket pivotally connected to a rail disposed on a main frame, a vibrator movable upward and downward to the main frame, a take-up wheel and a supply wheel around which the correction tape is wound, a print ribbon cartridge coupled to an upper surface of the vibrator, a hammering device utilizing a hammer lever, a print wheel elevation and rotation device, a print ribbon carrying device driven by commonly using a drive motor and a cam gear, a correction tape up/down and carrying device and a sensing device detecting the carrying condition of the print ribbon and correction tape by sensing a rotation of the cam gear, thereby a simple construction and a reduction in cost can be achieved.

Abstract: A structure for detachably supporting a cassette housing therein a type wheel is provided. The structure includes a cassette holder which may be pivoted between an operative position where printing may be carried out and an inoperative position where no printing is effected but the cassette may be replaced by another. The structure also includes a motor supporting member for supporting thereon a selection motor which may be engaged with or disengaged from the type wheel, wherein the motor supporting member is also pivoted to the cassette holder in a depending manner and moves between two positions in association with the pivotal movement of the cassette holder. Also provided is a guiding mechanism for guiding the movement of the motor supporting member thereby insuring that the motor is brought into engagement with the type wheel when located at the operative position and the motor is disengaged from the type wheel when located at the inoperative position.

Abstract: A printer includes identification circuitry disposed in a print head for identifying the type of the print head loaded on a carriage portion for printing characters on a print paper, and head connectors disposed on the carriage portion for enabling a plurality of different types of print heads to be commonly connected with a drive circuit and a control portion. The control portion is operative to identify the type of the loaded print head on the basis of the content of the identification circuitry, and also to perform controlling of the drive circuit under certain controlling conditions corresponding to the type of thus identified print head.

Abstract: A printhead cartridge and carriage assembly (10) is provided comprising: a carriage (12); a snap-spring (62) for securing a printing cartridge (14) in postion on the carriage; and an interconnect strip (16) for supplying electrical signals to the cartridge, including a force loading spring pad (24) for urging a portion of the interconnect strip against a portion of the cartridge. The cartridge has top (32), bottom (34), sides (36, 38), front (40) and rear (42) surfaces and includes a printhead (44) on the bottom surface, an electrical contact strip (46) on the back surface connected to the printhead, referencing pads (56) on the side surface, and a lip (64) on the back surface for accepting the snap-spring. Referencing surface (60) are provided for receiving the referencing pads on the cartridge. The spring pad urges the interconnect strip against the electrical contact of the cartridge.

Abstract: A printing wheel discriminating apparatus comprises a driving device for driving a printing wheel in units of predetermined angles, a detecting device for detecting identification data attached to a specific position of the printing wheel, and a storing device for storing presence/absence data of the identification data corresponding to the specific position of the printing wheel based on the output from the detecting device, thereby discriminating the type of printing wheel.

Abstract: A novel ink-jet printer (10) is provided. The print provides both paper supply tray (12) and paper collection tray (18) in the front (14) of the printer for ease of paper handling and reduced footprint. The paper collection tray is provided with a pair of opposed output rails (22) which support a sheet of paper (16c) during printing to permit ink on a sheet of paper (16b) previously printed to dry. A paper handling mechanism is provided which eliminates a sheet pickup motor and associated elements. The paper handling mechanism is configured to pick off a sheet of paper from a stack of input paper, bring it around paper drive rollers (24) onto a platen (26), where the printing operation, employing a printhead cartridge (32), occurs. The printer further includes a service station (230) for clearing clogged nozzles in the printhead (33) and removing bubbles therefrom, for covering the nozzles with a protective cap (266), and for wiping contaminants off the nozzles.

Abstract: A dot-matrix printer is provided with different types of printheads which are interchangeably attachable to the printer carriage. The heads are provided with individual codes which are read by the printer control system and used to reconfigure its control function to suit the control requirements of the identified head. Such a system may include a microprocessor responsive to individual sets of instructions or programs providing new and different processing capabilities for printing control in response to the insertion of a new printhead.

Abstract: A printer, and in particular a matrix printer, is provided with a carriage guide running parallel in front of a print-surface support for a print-head carriage (3). The print-head carriage (3) supports a print head (4) and an ink-ribbon guide (8), disposed on the print-head carriage (3). The print head (4) can be exchanged even by the operating personnel of the matrix printer by using a print head (4) which is exchangeable in a mechanical guide (6) and which is connected with an electric plug connection (7) and is thus removable and again insertable into the print-head carriage (3). At least one tiltable ink-ribbon guide (8) is disposed on the print-head carriage (3) and serves as a locking means (9) for the inserted print head (4) on the print-head carriage (3).

Abstract: A dot matrix print head has a heat sink substantially surrounding the head for dissipating heat therefrom. A print head carriage includes a pivot or bearing assembly on one side of the print head and includes a bail type clamp pivoted on the carriage on the other side of the print head. The arrangement allows the heat sink to swing from a covered print head operating position to an uncovered position for servicing or for removing the print head.

Abstract: Disclosed is a printing mechanism having a printing head mounted on a carriage frame so as to linearly move the printing head toward a platen.

Abstract: A printer comprises print means for printing on a print medium in accordance with a print command; guide and hold means for guiding the print means toward a print surface of the print medium with a print surface of the print means facing the print surface of the print medium and for holding the print means at the guided position; and actuation means for pressing the print means substantially normally to the guide direction of the guide and hold means to resiliently fit to a positioning area formed on the print means and fix the print means at a print position.

Abstract: A printing apparatus system includes a plurality of type units each having a plurality of type elements and each being different from the others. Each type unit may be mounted in the apparatus. A detector detects which of the type units is so mounted and produces a detection signal representative thereof. The printing pressure with which each type element is imprinted on a print medium is determined in accordance with the particular type wheel mounted in the apparatus as indicated by the detection signal. Additionally, the amount of advance of an ink ribbon for imprinting a type element on a type unit is determined in accordance with the particular type unit mounted in the apparatus, again as indicated by the detection signal.

Abstract: Improved rotary-type printing wheels, components thereof and mechanisms for mounting the printing wheels to a drive are disclosed. The disclosed printing wheels have a reduced rotary moment of inertia. As compared to all plastic printing wheels, they have improved print characteristics and service life while still having a reduced rotary moment of inertia. The printing wheels include a central hub having teeth extending along its periphery which are engaged by a drive. Alignment apparatus is provided for aligning the hub and drive, but rotary torque need only be applied to the printing wheel hub through the peripherally disposed teeth. The spoke elements of the printing wheel are made of metal and can be formed as one piece with the hub or separately. The tips of the spoke elements have a configuration which facilitates and improves attachment of a character element thereto while reducing the rotary moment of inertia of the print wheel.

Abstract: An alterable storage unit is included in a control apparatus to store code conversion tables for transforming type data or type position data into various control data such as a hammer pressure, an amount of ribbon feed and an amount of proportional space. When a type element is replaced with another, code conversion tables concerned with the new type element are stored in the storage unit. This permits the code conversion tables to be altered or renewed concentratedly in the event of type element replacement.

Abstract: A hand held thermal printer has a hingedly mounted bottom cover which can be opened to provide comfortable access into the printer and therefore substantially simplified loading of a roll of labels into the printer. The platen roller of the printer which normally abuts the print head of the printer is supported on a pivotable platen arm. The platen arm, like the bottom cover can be pivoted to an open position to provided direct access to the print head. The print head is held in place by a retainer plate which is held by screws and the screws can be simply loosened to permit the print head to be easily replaced. In the open position of the platen arm a wide and straight label passage is created through which the leading end of the backing sheet on which the labels are located could be easily threaded into the printer.

Abstract: A print wheel for serial printing devices of the type wherein print fonts are arranged upon a disc print wheel member. The print wheel has both coarse alignment and fine alignment means formed therein; the coarse alignment means for driving the print wheel, and the fine alignment means for accurately positioning the wheel during hammer impact.

Abstract: A print unit for an electronic typewriter comprising a removable character-carrying disc with flexible spokes which is operated by a selector motor which in turn is controlled by a control circuit. The character-carrying disc is provided with a plurality of reflective identification plates and a recognition circuit detects the pattern of the reflective plates present in selected ones of a series of predetermined angular sectors of the disc to identify some characteristics of the disc, e.g. typing pitch and character set. The angular position of the disc is detected by a position transducer which generates a position signal for the control circuit having a period which is double the angular distance between two contiguous character-carrying spokes discriminating the spokes at even positions from those at odd positions.

Abstract: A dot printer comprising a printer head freely detachably attached to a carriage in the printer and a system cartridge also freely detachably attached to the printer, said system cartridge having stored a character front and a firmwear program therein, wherein the number of dots printed can be changed by exchanging the printer head and the system cartridge with those which are different in number of pins used. Printing can be thus done with any desired numbers of dots which meet various purposes and one dot printer can be used for various purposes with extremely high economy.

Abstract: A document processing system has a pitch key for generating character pitch information, an MPU for counting the character pitch information to set auto mode data in an auto mode selection memory RAM, a wheel sort memory RAM for storing printing pitch information of a printing wheel loaded in the system, a display unit for displaying the auto printing pitch setting mode and the detected printing pitch in a combination of different display patterns, and a display controller for controlling the display unit in response to the data read out from the RAMs under the control of the MPU.

Abstract: A printhead cartridge and carriage assembly (10) for use with ink-jet printers is disclosed. The assembly is provided with means (56) for ensuring that an ink-jet cartridge (20) is securely locked in place in a cartridge carrier (12), means (78, 78a, 80, 80a, 82, 82a) for ensuring that cartridge is registered in a given, fixed, repeatable position each time, means (128) for ensuring that the cartridge is spaced from the printing medium (40) a minimum, fixed distance, means (100) on the carriage for maintaining this fixed distance, and interconnect means (84) for connecting a printhead assembly (34) on the cartridge with a microprocessor for controlling the pattern of ink drop ejection. The assembly further includes a preloader assembly (106) for preventing backward rotational pivoting of the carriage about a slider rod (44) associated with a platen (46) of the printer and for urging the carriage toward the medium on the platen.

Abstract: A type wheel cassette to be loaded in a carriage of a printer, typewriter or like printing apparatus and holding a type wheel in a case thereof, and a type wheel cassette loading mechanism for removably loading the cassette in the carriage. The type wheel and the cassette can be assembled with ease, while the cassette can be readily loaded and unloaded into and out of the carriage.

Abstract: This invention provides a printer capable of regulating the displacement of printing head according to the kind of characters to be printed. The printer has a printing head, an identifying device for identifying the print size of the printing head, and a drive mechanism for driving the printing head according to the print size identified by the identifying device.

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: Ink jet printing apparatus of the type having feed means for advancing successive line portions of a print medium past a linear print zone includes a plurality of carriages constructed to traverse the print zone in a predetermined direction and removably support a plurality of print/cartridges. Each of the carriages includes referencing edges that are substantially parallel to the direction of the carriages traverse and indexing means for moving supported print/cartridges into a precise detent relation with respective referencing surfaces of their carriage unit.

Abstract: For use in ink jet printing apparatus, an insertable print/cartridge having an ink reservoir, at least two linear arrays of drop generating elements located in a parrallel relation, a support for coupling the ink reservoir and driver arrays and an orifice plate comprising a plurality of linear orifice arrays aligned in spaced relation over respective drop generating arrays. The orifice plate is an integral photofabricated element wherein the linear patterns formed by the orifice arrays are precisely parallel and have a precise predetermined spacing therebetween.

Abstract: The device comprises a flange (14) which is fixed to the shaft (12) of the motor and which is provided on its front face with a plurality of radial teeth (28) spaced by recesses each having their active side surfaces parallel to each other and to the radial line through the recess. Removably connected to the character-carrying disc (11) coaxially therewith is another disc (35) of smaller diameter which is provided on its outward front surface with radial teeth (48) having their active side surfaces (50) parallel to each other and capable of being coupled to the radial recesses of the flange which is fixed to the motor shaft. On the other front surface, hooks (38, 39) engage in holes (21, 23) in the disc. In an alternative embodiment the teeth (48) are integral with the hub (16) of the disc (11) itself.

Abstract: A character-carrying disc comprises, arranged on its front face, a circular arc-shaped wire spring ended by two branches, which are rectilinear and bent inwardly constituting a small fork adapted to grip the shaft of a printing machine in which the disc is used and to engage an annular groove of this shaft. This disc carries a slidable pin on a shoulder of which the central portion of the arc-shaped part of the spring bears so as to maintain the pin in an axial position in which it co-operates with a member of the machine to provide a drive connection for rotation of the disc. Thus, the spring performs a double function, ensuring on the one hand the return of the pin to its working position and on the other hand the securing of the disc on the shaft of the machine.

Abstract: A system for printing with a plurality of removable print/cartridges includes a carriage constructed to traverse a linear print zone and removably support such print/cartridges. A plurality of referencing surfaces are located respectively on each of the carriages, parallel to the direction of the carriages traverse. The carriage includes fastening mechanisms for moving supported print/cartridges into a precise detent relation with respective referencing surfaces of the carriages. The referencing surface portions of the system are adjustable to allow selective physical indexing of print/cartridges, either in registered or interlaced printing positions. A transverse location detection system detects and stores the relative transverse locations of the print/cartridges in either position so that print control electronics can coordinate the output of the print/cartridges transversely.

Abstract: A high resolution ink jet printing system includes a plurality of substantially identical print/cartridges each having an orifice plate comprising: (i) an array of orifices located in a precisely interspaced relation and (ii) a detent means precisely located with respect to the orifice array. The system provides a carriage for insertably supporting such print/cartridges and for traversing them along a linear print zone in a direction substantially perpendicular to the direction of print medium feed. The carriage has reference surfaces for respectively positioning the detent means of inserted print/cartridges at predetermined locations that are precisely vertically offset relative to the direction of carriage traverse. In such system the printing droplets from the vertically offset orifice arrays of inserted and indexed print/cartridges will be vertically interlaced in each printing traverse of the carriage.

Abstract: A mounting mechanism for releaseably mounting a print head to the carriage of a printer includes a pair of pivotable levers respectively located on opposite sides of the print head. A spring member biases the levers in a predetermined direction. The levers are pivotable between a first position where the print head is secured to the carriage and a second position where the print head is released.

Abstract: Ink jet printing apparatus, for cooperative printing along a common linear print zone with a plurality of disposable print/cartridges having linear orifice arrays, utilizes a carriage which traverses adjacent and parallel to the print zone and includes positioning structure for insertably receiving and releasably constraining a plurality of print/cartridges in transversely spaced relation with the line of their orifice arrays precisely perpendicular to the direction of carriage traverse and vertically indexed to the direction of carriage traverse. The printer has a detector for sensing and storing the relative-transverse locations of the orifice arrays of the positioned print/cartridges. A printing controller regulates actuation of each positioned print/cartridge in accordance with its detected relative-transverse location to achieve proper horizontal drop placements.

Abstract: Ink jet printing apparatus of the type having a carriage that traverses a printing zone with a plurality of insertable print/cartridges includes a system for use in coordinating the transverse printing of such print/cartridges to compensate for variable transverse print/cartridge locations. The system employs an electrooptical scanner located along the transverse path of the carriage for signalling the passage of a print/cartridge feature(s) that are indicative precisely of an instantaneous horizontal position, vis-a-vis the scanner, of the orifice array of a passing print/cartridge; a carriage detector for periodically sensing and signalling the successive instantaneous positions of the carriage during its traversing movement; and means, responsive to signal inputs from the scanner and the carriage detector, for computing and storing horizontal location data for each print/cartridge orifice array.

Abstract: Ink jet printer for printing along a linear print zone with a plurality of insertable print/cartridges employs a carriage for traversing the print zone and supporting the print/cartridges with their orifice arrays mutually indexed to a carriage reference that is parallel to the direction of carriage traverse; detecting and storing the relative transverse locations of the indexed orifice arrays; and controlling the actuations of the supported print/cartridges in accordance with their detected transverse locations. A detecting and storing sub-system detects and stores inter-array spacings in the form of encoder mark-count plus intra-mark phase information. A control sub-system: (1) outputs printing information signals for the print/cartridges on the basis of the stored mark-count information; and (2) enables print/cartridge actuations in sequential orders based on the stored intra-mark phase information. These orders differ in forward and retrace printing.

Abstract: In a system including a cassette containing a print wheel arranged to cooperate with holding devices provided in an impact printer having a rotatable setting shaft to which the print wheel can be releasably fastened for rotation therewith, the cassette is formed to enclose the print wheel on all sides except the region where it is to be acted upon by a printing hammer, and the cassette and printing wheel can be provided with elements which cooperate to hold the printing wheel in a predetermined angular position in the cassette when the printing wheel is disconnected from the setting shaft. The printer can be provided with a detent mechanism cooperating with countendetent elements in the cassette to hold the cassette in a fully inserted position in the printer.

Abstract: A dot printer wherein a bearing member is movably attached to each of two shafts disposed in parallel with a platen, and a plurality of electromagnets are secured to the bearing members together with a head which houses therein a plurality of needles driven by the electromagnets. In this arrangement, the necessity of employing a carrier can be eliminated to simplify the structure as well as to reduce both the dimensions and the weight of the whole while ensuring a high-speed printing operation with another advantage of facilitating the assembling process.