HAND-HELD ELECTRONIC PRINTER

Abstract: A hand-held and self-contained electronic printing device (10) for printing indicia on a medium (M) includes a housing (12) that can be manually positioned adjacent a surface of the medium (M) and remain stationary against the medium (M) during the printing sequence. The housing (12) has an aperture that generally defines a printing area on the medium (M) when the housing (12) in in position for printing, and a printer for printing indicia in a selectable pattern of dots on the medium (M) within the printing area. The housing (12) also contains an actuator (20) for initiating a printing sequence and electronic control means for controlling the printer to print indicia on the medium (M) during a printing sequence. In one embodiment the print head can be moved to sweep across a printing area by a manual force applied to an actuator (20).

Description: HAND-HELD ELECTRONIC PRINTER BACKGROUND OF THE INVENTION The invention relates generally to methods and apparatus for printing and recording indicia and information on a medium such aε paper, for example. More particularly, the invention relates to fully self contained and hand-held printing apparatus that can be manually actuated by, for example, a hand stamping motion. Mechanically actuated stamping devices are well known and are commonly used for imprinting various types of indicia and information on a medium. Such information can include sequential numbers, dates, text, images and so on. Mechanical hand operated stamping devices, although used for many years, are fairly limited in their flexibility and convenience such as changing the information to be printed. Electronic stampers and hand-held printers known heretofore, including electronic printers that are operated with a sweeping motion across the medium, have required external input functions, such aε from a remote computer, for example, have been limited in the quantity, single line output, type and variety of information that can be printed, and can exhibit considerable image distortion. Additionally, a conventional stationary printing device generally uses an electrically driven print head that traverses the medium parallel to the printed surface. The use of an electric motor or similar drive device increases substantially the power consumption of the apparatus, which iε undesirable for any hand-held and operated unit. The objectives exist, therefore, for better and more reliable and more efficient apparatus and methods for hand-held and operated fully self contained printers. For printing apparatus that will be used in place of conventional mechanical stampers it iε desirable that εuch eviceε mimic the hand stamping motion and feel of a mechanical εtamper, and further utilize a manually driven mechanical actuator to diεplace the print head, thereby reducing the power consumption of the apparatuε. SUMMARY OF THE INVENTION To the accomplishment of the foregoing objectives, the present invention contemplates, in one embodiment, a hand-held and self contained electronic printing device for printing indicia on a medium, comprising a housing that can be manually positioned adjacent a surface of the medium and remain stationary against the medium during a printing sequence; the housing having an aperture that generally defines a printing area on the medium when the housing is in position for printing; a printer disposed in the housing for printing indicia in a selectable pattern of dots on the medium within the printing area,- an actuator for initiating a printing sequence; and electronic control means disposed in the housing for controlling the printer to print indicia on the medium during a printing sequence. These and other aspects and advantages of the present invention will be readily understood and appreciated by those skilled in the art from the following detailed description of the preferred embodiments with the best mode contemplated for practicing the invention in view of the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a simplified schematic perspective of a self contained and hand operated printing apparatus according to the present invention; Fig. 2 is bottom view perspective of the apparatuε of Fig. 1 illustrating use of a movable print head; Figε. 3-5 illustrate alternative embodiments of the apparatus of Fig. 1 which use a stationary print head; Fig. 6 is an electrical schematic diagram of a control circuit suitable for use with the printer apparatuε of Fig. 1; Fig. 7 is a simplified illustration of the use of a manually movable print head in accordance with the invention,- Fig. 8 is a εimplified schematic of a manually operated print head drive mechanism for the apparatus of Figs, l and 2; Fig. 9 is a flow chart for a control sequence of a printing operation in accordance with the invention for embodiments utilizing a manually movable print head; Figε. 10A and 10B are simplified representations of another manually actuated print head drive mechanism,- Fig. ll is a bottom perspective of another embodiment of a printer mechanism suitable for use with the invention,- Fig. 12 is a schematic end view of a print head as used in the embodiment of Fig. 11; Fig. 13 iε a representative illustration of a print area swept by the print head operation of Fig. 12; Figε. 14 and 15 are geometric illustrationε of variouε parameters that influence appearance and distortion of a printed image,- Fig. 16 is an alternative embodiment of the arrangement of Fig. 12, with a non-symmetrical print head rotating about an axis that is non-parallel to the print medium; Figε. 17-25 illustrate an alternative embodiment of a printing mechanism having a print head that rotates on an axis not parallel with the plane of the print medium; Figε. 26-29 illustrate an alternative embodiment of the invention uεing an intermediate tranεfer ink jet printing mechanism; Figε. 30A and 30B are εimplified block diagramε of suitable alternative circuits for implementing voice functions with a printing apparatus, in accordance with the invention,- and Figε. 31A and 31B are εimplified schematics of an embodiment of the invention for use as a postage meter. DETAILED DESCRIPTION OF THE INVENTION With reference to Fig. 1, an embodiment of the invention is illustrated in simplified schematic form for purposes of describing the basic concepts of the invention. In this basic configuration, a hand-held and operated printing apparatus 10 iε illustrated. A significant feature of thiε apparatus is that it is a completely self contained unit that can be manually operated without an external connection. However, as will be explained hereinafter, the apparatus 10 is equipped with interface devices, which can be hardwired connectors or wireless links, to permit external data entry and/or control if so desired for a particular application. In the embodiment of Fig. 1, the apparatus 10 is shown disposed on a medium, M, in this case a paper envelope. Although the invention is described herein with specific reference to printing on a flat web of paper, such as an envelope, sheet paper, and so on, such description is exemplary for purposes of illustration and explanation and should not be construed in a limiting sense. Those skilled in the art will readily appreciate that the invention can be utilized for printing indicia, images, bar codes, text and so on in virtually any color, aε well as black or white, on any medium that iε compatible with the selected printer mechanism used in the apparatus 10. The printer mechanism can be selected from any number of commercially available units, or special made, depending on the particular application. In the exemplary embodiments described herein, the printer mechanism iε an ink jet type printer, sometimes referred to as a bubble jet printer, such printers being generally of the type that emits, projects or ejects ink through a number of nozzles, in response to electrical control signals, so that each individual ink projection produces a dot on the print medium. In many applications of the invention, other print mechanismε both known and later developed will alεo be suitable for use with the present invention. The apparatuε 10 includeε a houεing 12 which for convenience may be made from metal, plastic, composites or other suitable material. The housing 12 preferably iε a rigid εtructure that iε capable of supporting a printing mechanism therein along with an electronics package and an internal power supply, such as a battery. The housing 12 should also be sturdy enough to withstand manual forces applied to the structure to actuate the apparatus without damage or stresε. The housing 12 should also provide a stable platform so that the apparatuε 10 can be positioned adjacent the medium M, aε illuεtrated in Fig. 1, for example, without sliding or moving on the medium during a printing sequence. Although the embodiment of Fig. 1 (and the detailed Figures associated therewith) are described with respect to a manually actuated apparatus in which a manual force is used t o move a print head, those skilled in the art will appreciate that an electrical or electromechanical drive mechanism could alternatively be used to translate the print head in a desired movement. A particular advantage of the use of a manually driven print head is the substantially reduced electrical power requirements for the overall apparatus 10. Furthermore, in some embodiments it may be desirable for the print head to remain stationary or fixed during a printing operation, rather than moving between first and second positions. Such an embodiment is shown and described, for example, with respect to Fig. 3 herein. The housing 12 holds a key pad device 14, which for convenience can be a conventional push pad or thin membrane type key pad. The housing 12 also holds a display device 16 such as, for example, a conventional LCD or LED display. Internal to the housing 12 (not shown in Fig. 1) is a circuit board or boards which hold the variouε electronic componentε and power supply components for operating the electronic printing apparatuε 10. Part of the control circuitry may include an interface device 18, such as, for example, a conventional transceiver, that transmitε and receiveε data and/or inεtructions from a remote device (not shown) such aε a personal computer, for example. A suitable transceiver device 18 iε an infrared tranεceiver, although other communication linkε could be uεed εuch aε RF, microwave, acoustic and so on. An actuator 20 iε provided on the top of the houεing 12. In this embodiment, the actuator 20 is manually depresεed which cauεes a manually applied force to be exerted against a mechanism within the houεing 12 to cauεe movement or displacement of a print head during a printing operation or sequence, as will be described in detail hereinafter. Preferably, the manual operation of the actuator 20 mimics the feel of a conventional non-electronic stamper. In the case where an electrical or electromechanical print head drive device is used, however, the actuator 20 can be realized simply in the form of an electrical contact switch to provide an input to the control electronics to command a printing operation. Furthermore, in some embodiments it may be desired to have a εtationary print head inside the housing 12. In εuch a caεe, the actuator 20 again could be uεed to provide an electrical control signal to initiate a printing εequence without producing a phyεical diεplacement of the print head. Aε best illustrated in Fig. 2, the bottom of the housing 12 includeε an aperture 22 through which printing iε accompliεhed by a printer mechanism 25 while the apparatuε 10 iε positioned adjacent the medium. Although not shown in the drawings, the houεing 12 can be adapted in a known manner to include a removable cover that protectε the printing mechanism when not in use. A reflective photosensor 24 is mounted near the aperture 22 and provides an output signal that indicates that the apparatus 10 is correctly positioned adjacent the medium. The photosensor 24 output iε used as an inhibit signal to prevent operation of the printer if the apparatuε 10 iε not properly positioned next to the medium, thereby preventing accidental or unintended operation of the printer such aε when the apparatuε is being inεpected or transported, for example. Note in Fig. 2 that the printer mechanism 25 includes a print head 26 which is attached to a support member 28. In this embodiment, the support member iε in the form of a flexible or εpring-like element. The print head 26 in this example consists of a single row of ink jet nozzles 30 which are represented schematically in Fig. 2 by a row of dots. If deεired for a particular application, additional rowε of nozzles can be used, particularly for color printing. Additional print heads can alεo be used. The width of the print head 26 generally defines the height of the printing area on the medium. The spring-like support member 28 is used to move the print head 26 acroεε a length-wise portion of the aperture 22, aε will bε eεcribed more fully hereinafter. Thus, the total printing area for the embodiment of Fig. 2 iε generally delimited by the size of the aperture 22. Alternatively, the print head 26 can be arranged to travel in the width wise direction (using Fig. 2 as a reference), by using a wider print head with more nozzles. In some applications, the advantage of a shorter travel distance may offset the disadvantage of the increased number of nozzles. With reference to Fig. 3, an alternative embodiment iε illustrated which uses a print head 32 that remains εtationary within the houεing during a printing operation. In thiε case, the stationary print head 32 includes a plurality of ink jet nozzles 30 arranged in a series of generally parallel rowε and columns acroεε the aperture 22. A suitable print head configuration iε εhown in U.S. Patent No. 5,325,118 issued to Zybin et al . , the entire disclosure of which iε incorporated herein by reference. The nozzles 30 project ink in generally parallel trajectorieε with reεpect to each other towardε the medium. Beεideε a εingle large area print head 32 aε in Fig. 3, a plurality of smaller individual print heads could be used. As a further alternative illustrated in Fig. 4, the individual print heads 32a and 32b are angled so that each print head projects ink acrosε the entire printing area. Thiε arrangement would facilitate multi-color printing, for example. In the embodiment of Fig. 4, the print headε 32a and 32b can be controlled εo that only one of the print heads is ejecting ink at any given time, thuε eliminating colliεionε between ink dropε emitted by the print hεadε. Aε further illuεtrated in Fig. 5, the εtationary print head 32 can be made smaller than the print area on the medium, with each nozzle 30 dispoεed on the head 32 εuch that it projectε ink toward the medium at a fixed and predetermined angle. Thus, the nozzles will generally project ink on non- parallel diverging trajectories with respect to each other. ith reference next to Fig. 6, there iε shown in εimplified block diagram form a control circuit 40 εuitable for use with all the embodiments of the present invention described herein. Those skilled in the art will readily appreciate that many of the features of this control circuit 40 are optional and can be used or omitted as desired for a particular application. The functions included in the embodiment of Fig. 6 iε not exhauεtive, and the designer can modify the circuit 40 to include additional control functions aε needed for a particular application. Furthermore, although the circuit 40 is deεcribed in terms of a microprocessor based system, the invention can conveniently be practiced with the use of a microcontroller, microcomputer, digital signal processing, application specific integrated circuit (ASIC) and discrete logic circuits depending on the overall complexity of the control functions for a particular application. In Fig. 6, a microprocessor 42 iε connected to a number of peripheral circuits, and is used to provide the overall control function for the apparatus 10. A significant feature of the invention iε that the apparatuε 10 iε a wholly self contained and operational hand-held printer that does not require the use of external inputs and controls. Thus, all of the circuits in Fig. 6 are fully contained within the housing 12. However, provision is made for external connection should such a configuration be desired for a specific application. The microprocessor 42 iε programmed in a conventional manner according to the manufacturer' ε instructions, as is well known to those skilled in the art. A suitable microprocessor is part no. MC6800 available from Motorola Incorporated. For embodiments that utilize additional control and processing functions, it may be desirable to use a more powerful microprocessor such as part no. NS486SXF available from National Semiconductor, Inc. A system clock 43 provides timing pulses at regular intervals for the operation of the system, including tracking current time and date information. A replaceable or rechargeable battery type power supply 44 provides system power for the microprocessor 42 and all other circuits within the housing 12. Manual displacement of the print head 26 substantially reduces the power reσuirementε of the apparatuε 10 compared to syεtemε that use an electrically driven print head. The microproceεsor 42 accesses program instructionε and data via a memory circuit 46 which includeε a non-volatile ROM memory 48 and a εuitable volatile temporary memory, such as a RAM memory 50. The ROM is used to store control programs, conversion tables and the like for the microprocessor 42, aε well as fixed information εuch aε commonly printed phrases such as "RECEIVED" or "FAXED", or graphicε imageε including bar code imageε and other indicia. The RAM iε used to store εyεtem data produced during operation such as an activity log, where the log may include, for example, information that was printed, identification of the εource, date and time of the printing. The RAM 50 can also be used to accumulate a running total of the number of dots printed, with the total being reset to zero each time the ink supply associated with the print head 26 is repleniεhed or replaced. By comparing the total number of dotε that can be printed using the ink supply, with the actual number of dotε printed εince the supply was laεt filled, the microprocessor 42 can generate a warning that the ink supply is low, for example, at about 5% capacity. The RAM can further be used to store programs, instructions and data entered manually by the operator through a user interface 52, or received from an external source such as a computer through an I/O device 60, or the results of calculations performed by the microprocessor 42. These calculations may include coordinate conversions, distortion compensation, data used to generate bar codes, and so on. Those skilled in the art will readily appreciate that the volatile memory 50 can also be realized in the form of a FIFO memory, for example. The particular hardware selected for use in realizing the various componentε of thε control circuit 40 will depend on the specific syεte requirementε needed or deεired. A uεer interface circuit 52 includeε the viεual diεplay 16 and the key pad 14. The display 16 is uεed to view the print image prior to printing, as illustrated in an exemplary manner in Fig. l. The display 16 can alεo be uεed to communicate warningε (such as low ink supply or low battery) , εtatuε information or a prompt to request data entry. The key pad 14 iε used, for example, for selecting items to be printed from a menu displayed by the apparatus 10, or for creating indicia to be printed, aε well aε for data entry and command inputs. An actuator εwitch 54 iε provided to initiate a printing εequence or operation. Aε used herein, the terms "printing εequence" and "printing operation" are used interchangeably to simply refer to the steps carried out between actuation of the apparatus 10 and completion of a printing function on the medium. In configurationε where a mechanical force is applied to move the print head 26 acrosε the printing area on the medium, the εwitch 54 can be omitted because a position encoder 56 is used to signal the microprocessor 42 to start a printing operation. In configurations where the print head 32 remains εtationary, or where an electric or electromechanical device is employed to translate the print head 26 across the printing area, the εwitch 54 can be used to signal to the microprocessor 42 that printing is to begin. A plug-in module 58 iε provided so that information, instructionε, or programs may be transferred between the apparatus 10 and an external source such aε, for example, a computer. The module can be, for example, an induεtry standard PCMCIA card. A communication link to an external apparatuε iε accompliεhed by use of an I/O device 60 such aε a serial port 62, a parallel port 64 or a wireless link such aε an RF tranεceiver, or the infrared tranεceiver 18, an acoustic transducer or a modem. The transceiver 18 may be, for example, a Hewlett-Packard HSDL-1000 transceiver. The medium senεor 24 includeε a circuit for producing an output εignal that iε εent to the microproceεεor 42 when the apparatus 10 iε properly positioned adjacent the medium. The apparatuε 10 further includeε the printing mechanism 25, which in the exemplary embodiment includes an ink jet print head 26 and a print head position encoder 56. The encoder 56 can be, for example, Hewlett-Packard devicε HEDR-8000. Thiε εncoder produces two output pulse channels in quadrature relationship εuch that both magnitude and direction of rotation (of the encoder εenεing element) are detected. Because the nozzleε 30 are fixed in the print head 26, position and movement data of the print head 26 can be easily converted into poεition data for each nozzle 30 on a real time basis. Further, with the orientation of each nozzle 30 being a known quantity relative to the medium, the nozzle poεition information can be used to determine the εxact location on thε medium to which each nozzle will project a dot during a printing εequenc . Thoεε εkilled in the art will appreciate that for the embodimentε dεεcribεd hεrεin which uεe a stationary print head, the poεition encoder 56 can conveniently be omitted. In the embodiments herεin that use an ink jet print head, an image iε formεd on thε mεdium by projεcting a sεriεs of dots onto the medium in a εelectεd pattεrn. In onε embodiment, the dotε can be ejected on a line by linε basiε (a "linε" meaning a row or column of dotε) , εo that the net visual effect of a plurality of lines iε the deεirεd imagε. Thε εelection of nozzleε activated for each line of dotε will be dεtεrminεd in part by thε indicia bεing printed. Othεr factorε that affect the dynamic selεction of thε nozzlεs during a printing sεquεncε will be further explained herein. Each printable indicia iε digitally formatted on a line by line basis, in its εimpleεt form aε a εerieε of on/off commands to each nozzle 30 under control of thε microprocessor 42. The digitized representations of the indicia can be sto . rεd in the elεctronic mεmory 46, for example. With reference next to Fig. 7, therε iε illuεtratεd in εimplified elεvation thε motion of thε print head 26 for the embodiment of Fig. 2. In thiε embodiment, a full line (ε.g. a full row or column of no∑zlεε) typε ink jεt print head 26 iε εo disposed aε to sweεp ovεr a εεlεctablε printing area 66 on a surfacε 68 of thε medium M. The printing area 66 iε εεlεcted by the opεrator manually positioning thε apεrturε 22 ovεr thε εεirεd location on thε mεdium εurfacε 68. Each printing opεration can bε accompliεhεd εithεr during a singlε or a double pass ovεr the printing area 66. It is important to note from Fig. 7 that the print head 26 doεs not maintain a constant diεtancε from thε surfacε 68, nor will thε nozzleε 30 project ink dropletε (rεprεεεnted by the lineε 90 in Fig. 7) at a conεtant angle relative to the εurface 68. Prεfεrably, thε print hεad 26 pivots about a point 70 between a first or home poεition 72 and a εecond or return poεition 74. In gεnεral, the first and sεcond poεitionε dεlimit thε printing arεa 66, although thε nozzlεε 30 can bε individually and angularly diεpoεed in the print head 26 to project ink dropletε laterally beyond the print head 26. Alternatively, a drive mechaniεm can be used that tranεlateε the print head, for example, in a linear manner, rather than along an arc. The poεition encoder 56 provides pulεeε to the microproceεεor 42 aε thε print head 26 εweeps acrosε the printing area 66. Theεe pulεεε can bε timed and counted, with the encoder count bεing εithεr incrεmεnted or decremented depending on direction of movement, to provide both position and velocity information for the print head 26, and in particular the nozzleε 30 disposed on the head 26. The microprocessor 42 software utilizeε the nozzle 30 position and velocity information to determine when to activate each nozzle based on the desired indicia to be printed on the medium for the current printing sequence. The encoder 56 is coupled to the drive εlement that thε print head iε mounted on, in this example the spring-like support member 28 (Fig.- 2) and can be configured, for example, to producε a pulsε for each incremental change in angular displacement of the print head 26. By the convenient use of look-up tables, calculations or approximations, the angular displacement of thε print head 26 can easily be converted to actual position data for each nozzle. In the case of an εlεctrical drivε mεchaniεm for thε print head 26, εuch aε an electric motor, solenoid, voice coil actuator, stepper motor or other available devices, the command signals to the driver can be used for poεition and speed control, aε can any suitable feedback indicators. However, in accordance with another aspect of the invention, in some applications it is desirable to use a manually rivεn print hεad 26. This avoids thε need for a driver that consumes εlεctrical powεr. In thε casε of a manually drivεn print head 26, it is also desirable that the sweep motion be rapid and positivε so that oncε thε swεep motion is initiated it will be completed without further action being required of the operator. With reference to Fig. 8, a mechanical and manually operated actuation arrangemεnt is illustrated in simplified form. One of the general ideaε embodied in the example of Fig. 8 iε to provide a manual actuation that mimicε the feel and operation of a conventional mechanical stamper in which a handle or lever or other membεr is manually actεd on to produce a positive "stamping" εffεct. The housing 12 holds thε print hεad 26 by means of the spring like membεr 28. Thε member 28 is fixedly attached at one end to the housing aε at 76. The attachment at 76 can be accompliεhed by any convenient method εuch aε rivetε, εcrewε, adheεiveε, a retaining bracket and εo on. The actuator 20, in thiε caεε rεalized in the form of a handle that extεndε abovε thε top of the housing 12, includes a post 78 that εxtεndε into the houεing 12 into contact with the member 28. The poεt 78 is provided with a retaining element such as a snap ring (not shown) , for example, to prevent the handle from falling out of thε housing 12. A pεrmanent magnet 80 is mounted in the housing 12 and retains the member 28 in the firεt or home poεition 72 prior to the application of manual force on the actuator 20. With no force applied to the actuator 20, the resilient spring¬ like member 28 acts to move the print head 26 to the first or home poεition 72 εhown in Fig. 8. . In order to initiate a printing operation, the operator presses down on the actuator 20 with enough force to displace the member 28 away from the magnet 80 aε indicated by the directional arrow 82. The εudden releaεe of the magnetic holding force reεultε in the print head 26 fully travelling to the εεcond or return poεition 74. After the operator rεlεases the actuator 20, the member 28 returnε the print hεad 26 to the home poεition 72. The encoder 56 produceε pulεεs from the moment that thε member 28 is released from the magnet 80, thus causing the microprocessor to initiate the desirεd printing εεquence. A rεprεεεntativε εequencε iε illustratεd in the software flow chart of Fig. 9. At step 200 thε syεtem confirmε that the apparatuε 10 iε properly poεitioned adjacent the medium M by confirming the presεncε of thε photosenεor 24 output. At εtep 202 thε εyεtεm tests the encoder count to determine if the print head 26 haε moved to the next print poεition, i.e. if the print head 26 haε advanced to thε initial point whεre printing iε to εtart, or further advanced from the last print poεition by a diεtance corresponding to the pitch between succeεsive lines of dotε. If εo, the data stored in memory representing the next line of dotε forming part of the indicia to bε printed iε retrieved and printed at εtepε 204 and 206. Note that the medium present test at εtep 200 iε repeated throughout a printing operation. When the encodεr 56 count iε dεcremented, aε at step 208, indicating that the print head 26 has reversed direction and is moving back towardε the firεt or homε poεition 72, printing iε tεrminatεd. Note that the actual printing of dotε would have tεrminatεd previouε to thiε εtep, as the last line of image data would correspond to a print head poεition at or before the second or return poεition 74. Alternately, the completion of printing tested at εtep 208 could be determined by the encoder count reaching some predetermined value, or by a determination that all lines of dots comprising a particular image had been printed. Figs. 10A and 10B show an alternative embodiment of the manual drivε mechanism. In this example, the magnεt 80 is omittεd and thε support member 28 is attached at one end to a bi- stable spring 84. In this embodiment, the member 28 need not be a flexible or εpring-like element becauεe of thε usε of thε bi¬ stable spring 84. Fig. 10A εhowε the print hεad 26 in thε homε position 72 and Fig. 10B εhowε the print head in the εecond or return poεition 74. Whεn the actuator 20 iε manually epreεεed, the bi-εtable spring 84 suddεnly concaves aε shown in Fig. 10B and the membεr 28 pivots thus cauεing thε print head 26 to εweep acroεε thε printing area 66. When manual force on the actuator 20 is released, the bi-εtable εpring 84 returns thε mεmber 28 and the print hεad 26 to the home position of Fig. 10A. Printing can be accomplished during eithεr dirεction of travεl or both. Additionally, for all the embodiments described herein, multiple print heads can be attached to the driving mechanism. Fig. li illuεtrateε another embodiment of a printer mechanism 25' equipped with a full line type ink jet print head 26' so disposed as to sweep over a printing area in a single pass upon actuation. (Throughout the variouε alternative embodiments deεcribed and illuεtrated herεin, corresponding structureε and componentε are assigned the same reference numeral followed by a prime (') mark, and a repeatεd dεtailed description of such εtructureε iε not required to underεtand and practice the invention.) The print head 26' iε narrower than the printing area, with εach nozzlε 30' diεposεd such that it projectε ink toward the medium at a εet and predetermined angle εuch that the projected ink droplet reacheε itε intεndεd point on thε mεdium. Notε that thiε εmbodimεnt is similar to thε εmbodimεnt of Figε. 2 and 7 with reεpect to angular diεplacement of the print head 26' (a travel path that iε generally non-parallel to thε medium εurface 68) and alεo can use a mechanical drive mechanism if so desired to provide a rapid and positive sweeping action. As in the previous dεεcribεd εmbodimentε herein, multiple print hεadε may be mounted where one iε εhown and deεcribed, for purpoεeε of printing in more than one color or increaεed resolution. Because the print head 26' is smaller than the actual printing area 66 on the medium, additional consideration should be given to the paths of projection of the ink from thε variouε nozzles 30' . Fig. 12 iε a schematic end view εhowing in a repreεentative manner the divergent angular projection of ink dropletε from the print head 26' to the medium M. Note that each individual ink jet nozzle is oriented at an appropriate angle εuch that its reεpectivε ink droplet or εpray 90' iε projectεd to a dεεired poεition on the medium. The variouε nozzleε project ink at diverging anglεε with rεspεct to onε anothεr. Fig. 13 is a viεw of an uncorrεcted printing area 92 (εhown with daεhed lineε) εwεpt by thε print head 26' in thiε εmbodimεnt. The printing area 92 iε not the dεεirεd rectangle 94, but, rather, exhibitε a broadening at each end, producing an "hour glass" shape, resulting from the angular projection of thε ink droplεts from thε print head 26' , combined with the varying diεtance of the print head 26' (due to the arcuate travel path) from the medium. At the centεr of thε print head'ε εweεp ovεr thε mεdium, thε print hεad 26' iε cloεεεt to thε mεdium and dεpositε dotε 96a with a pitch "a." At εithεr εnd of thε hεad'ε εwεεp, thε diεtancε of thε print hεad 26' from thε mεdium iε at a maximum, and thε εamε noz∑lεε depoεit dotε 96b with a pitch "b" (shown exaggerated for clarity) . Thiε diεtortion may be correctεd by thε control circuitry, εpεcifically by the tεchniquε of mapping, or tranεlating the specified coordinates of a dot to be printεd to a new sεt of coordinatεs which compεnεateε for the diεtortion which would otherwiεε bε producεd. In ordεr to maintain a dεεired print resolution, or dot density, additional ink jet nozzleε can be provided in the print head 26' εo that the deεirεd reεolution iε achieved at the ends of the εweep, where the projected dotε are at a maximum pitch. Thiε process may be best εxplained by way of example. With ref rence to Fig. 14, a print hεad 26' with a lεngth "L" iε εwεεping abovε a medium M at a height "H, " having a printing area with a width "W." Thiε iε an end view, looking in the direction of motion of the print head 26 ' {i . e . the print head moves arcuately through the plane of the drawing) , with the print head 26' at mid sweep, so "H" representε the εhortest distance from the print head 26' to the medium. Each of the two outermost nozzles (one on εach εidε of the print head) projectε ink dropletε at an angle "p" to the perpεndicular aε εhown. Angle "p" may be calculated aε: p = arctan [ ,w"L, 2 /κ] - arctan [ ,W"L, ΛH] . Note that while Fig. 12 εhowε a print head 26' having no∑zleε diεpoεεd about a curvεd εurfacε, Fig. 14 assumεs a flat εurface. Thiε diff rεncε is immatεrial to the calculationε preεεnted here, εo long aε the value of "H" utilized iε that of each particular nozzle in queεtion. Fig. 15 εhowε graphically a εide view of the εa e print hεad 26' which εweepε over a print area of length "S" on the medium. "X" iε the diεplacement of the projected ink dropletε from the center of the swεep. At the farthεst extεnt of thε εwεep, X = S/2 and the print head iε at the poεition deεignated by the numeral 74' . The distance from the point about which the print head sweepε, or thε pivot point 70', to thε print hεad no∑zlεε is "G." Thε sweep angle, "r, " may bε calculated aε: r = arctan (V«* * HJ) The diεtance over which the ink dropletε are projected iε no longer "H, " but "H' , " where H' = ( ,s*H) /«>. r) -G, and print area width iε no longer "W, " but "W , " where W' = L + 2H'*tan p = L + 2* [ ( ,G*H 7co. r) -G] * ( ,W'L, ΛH) ,- or W « = L + [( ICtH, /co. r)-G] <κ - L 7H) For purpoεeε of example, aεεume that the print area iε to be 2" wide by 3" long, or W = 2 and S = 3. Further, aεsume that the print head is 1" wide (L = 1) , G = 3, and H = 0.5. Then: W' = l + [ ( 3 co» r) -3]*2, or At the maximum sweep, X = 1.5 (X = S/2) , so r = 23.2° maximum. Aε r sweeps from 0° to 23.2°, W' varies from 2.00" to 2.62" . Referring again to Fig. 13, asεume for example that the maximum dot pitch deεirεd iε 0.01", for a print rεsolution of 100 dotε pεr inch (dpi), εo that b = .010. Further assume that dot positions are identified as coordinates on a rectilinear grid having 300 points (0 - 299) in the "x" direction and 200 points (0 - 199) in the "y" direction. Dot A is at (0,0) , dot B is at (0,199), dot C is at location (150,199) , and dot D iε at (299,199) . With W' = 2.62", a print head 26' having 262 nozzles iε required. Theεε nozzleε are each deεignated by a poεition number (0 - 261) counting in the "y" direction. In order to print dotε A and B at pointε (0,0) and (0,199) , respεctively, noz∑leε 31 and 230 arε utilized, rather than noz∑leε 0 and 199. Dot C iε printεd uεing nozzlε 261, and dot D iε printεd uεing nozzlε 230. Whilε thε minimum print resolution iε 100 dpi aε requirεd ("b") , rεεolution incrεaεeε to 131 dpi at the center of the print εweep ("a") . While the foregoing diεcuεεion has deεcribed the use of a symmetrical print head sweεping or εcanning about an axis parallεl to thε medium, it iε recognizεd both that a non- symmεtrical print head may be used, and sweeping or scanning may be about an axiε not parallel to the medium. Thiε iε illustrated in Fig. 16, wherein a non-εymmetrical print head 26' ' iε εhown projecting ink dropletε to a medium, while εweeping about a non- parallel axiε 98. Any combination of a εymmetrical or non- εymmetrical print head, εweeping about a parallel or non-parallel axiε, may be uεed, with the appropriate compensation made for the variouε projection angles of ink from the nozzleε aε εet forth abovε. Fig. 17 illuεtratεε a bottom facing perspective of a printer apparatuε 10'' equippεd with an ink jεt print head 99 which rotateε on an axiε not parallεl to, and in thiε caεε pεrpεndicular to, thε mεdium. Shown iε a print hεad 99 of rεduced width, with each no∑zlε diεposεd εuch that it projεctε ink toward the medium at a εεt and predetermined angle εuch that the projected ink droplet reacheε its intended point on the medium. It iε recognized that a print head having a width aε great aε the diagonal of the printing area could also be used. Fig. 18 is a εchematic view showing the angular projection of the ink dropletε 101 from the print head 99 to the medium, where the angle of projection of the ink droplets 101 from each nozzle may be computed using the εame method aε haε been previouεly described with regard to Fig. 14, where "W" is the magnitudε of thε greatest swath to bε covered by the print hεad 99. This will be the diagonal of the printing area when the print head 99 is mounted in the center of the printing area, but may be a lessεr dimension when the print head iε mounted elsewhere as will be later described. It is recognized that while Fig. 18 illustratεs a print head 99 rotating about an axiε 100 perpεndicular to thε medium, thiε iε not a requirement. Fig. 19 illuεtrateε a print head 99a disposed to rotate about an axis 102 not perpendicular to the medium. Fig. 20 is a view of the printing area 104, and threε rowε of dotε 106, 108 and 110 arε shown projected by the print head 99 as it rotates about an axiε centεred at "0" on the print area. It iε apparent from Fig. 20 that thiε embodiment yieldε an array of dots or pixels laid out in a polar, rather than rectilinεar, array, and dot coordinatεε arε thereforε mapped, or tranεlatεd, from a rεctilinεar coordinatε εyεtem aε iε typically used, to polar coordinates. This may be readily accomplished by the use of a look-up table, or by calculation, for example. A completε sweep of the print area uses a 180° rotation of the print head 99. The print head 99 may be rotated in the opposite direction, b ack to the starting position, at the conclusion of εach printing, or, alternately, it may print bi-directionally such that it rotates clockwise for one printing, then counter- clockwise for the next printing, and εo forth. Fig. 21 iε a view of the print area 104, and thε thrεε rowε of dotε 106, 108 and 110 projected by the print head 99 aε it rotatεε about an axiε 0' cεntered on one εide of thε printing area 104. A εecond print head (not εhown) , printing for example a εecond color, can be located on the oppoεite εidε of thε printing area 104 if εo deεired, on an axiε 112. Thiε configuration likewiεε uεeε a 180° rotation of the print head(ε) 99. The print head 99 axeε may bε diεplaced towardε onε end of the print area, to allow for the introduction of two additional print headε on axeε 114 and 116 aε εhown. Thiε will allow printing with up to four separate print headε, and four colorε. Fig. 22 iε a view of the printing area 104, and three rowε of .dotε 106, 108 and 110 projected by a print head 99 aε it rotateε about an axiε located at a corner 118 of the printing area 104. Additional print headε may be located at the other corners of the print area if εo desired. In this configuration, print head rotation of juεt 90° can be uεed to εcan the entire printing area. With thiε embodiment it iε recognized that any number of poεitions may be selεctεd for thε placement of the print head relative to the medium in addition to thoεe deεcribed. Conεiderationε includε thε number of nozzleε required, the angle of rotation required, and the maximum diεtance over which ink droplets muεt bε projεcted. Similarly, it iε recognized that a number of meanε are available to achievε rotation of thε print hεad(ε) as dεεcribed. Such meanε include elεctric motorε, voicε coil actuatorε, εolenoidε, and the like, aε well aε variouε mechanical linkageε and mεchaniεmε. A biεtablε εpring apparatuε aε shown in Figε. 10A and 10B may, for example, be adapted to produce rotary motion. Thiε iε εhown schematically in Fig. 23, where a rotary ink jet print head 99 is supported by bearing 120. A spiral groovε 122 in thε body 124 of thε print head 99 slidably receives a guide pin 126 protruding from a rod 128, which iε constrained to move vertically by a bushing 130 attached to the housing 12 (houεing 12 not εhown in Fig. 23 for clarity) . The rod 128 iε attached to a biεtable εpring 132, which may be εimilar to the biεtable εpring 84 deεcribεd hereinabove with reεpect to Figε. 10A and 10B. When the actuator handlε 20 iε depressεd by the operator, bistablε εpring 132 εnapε abruptly into an altεrnatε poεitiσn, aε previouεly deεcribεd with rεgard to Fig. 10B. Thε rod 128 and pin 126 are driven down, reεulting in a rotation of print hεad 99. When actuator handle 20 iε releaεed, the biεtable spring 132 returns to itε initial position, pulling up the rod 128 and pin 126, thereby rotating print head 99 back to itε initial or home poεition. It iε of further note that the ink jet print head 99 noz∑leε 30 need not be linearly disposed along the print head, but may, if so deεired for ease of manufacture or any other purpose, be distributed in some useful pattern as shown in Figs. 24 or Fig. 25. Multiple identical setε of nozzleε may be uεed to reduce the angle of rotation required for full coverage of the print area. Two identical sets of nozzles, for example, would reduce thε required print head rotation in half. With reference next to Fig. 26, the printer mechaniεm can also be realized in the form of a printer equipped with a flat plate type intermediate transfer ink jet printing device. In this embodiment an ink jet print head doeε not print directly on the print medium, but rather printε on an intermediate tranεfer medium. Thiε tranεfer medium iε then brought into contact with the print medium to effect the tranεfer of the image. A print head capable of printing the full width of the print area iε uεεd. In Fig. 26, thε printεr iε shown with thε εxe plary display 16 reading "PAID, " indicating that as thε imagε which is about to bε transfεrrεd to the print medium, and the same imagε iε εhown on thε transfεr platε 140, already in thε print poεition. Note that printing on the tranεfer medium will be invertεd, bεcauεε it will bε reversed (and thus read properly) whεn tranεferred to the print mεdium. Fig. 27 iε a schematic view showing a print head 142, an intermεdiate tranεfer plate 140 and the print medium M. In operation, the tranεfer plate 140 iε pushed down vertically past the print head 142 aε εhown. Further motion tipε the plate down into a horizontal poεition, and then into contact with the print medium. A cleaning pad 144 wipeε any exceεε ink from the transfer plate 140 on itε upward return, and again on itε down stroke for the next printing. This cleaning pad 144 can bε an absorbεnt matεrial εuch aε cotton, and εhould bε changed periodically. This is accomplished by changing thiε pad when the ink εupply iε renεwεd. Thiε can bε facilitatεd by incorporating thε ciεaning pad 144 into an ink cartridge/print head aεεembly εo that thε ink εupply, print head, and cleaning pad arε all renewed at the εame timε. Tranεfer plate 140 iε made of a non-abεorbent material. Excellent reεultε have been obtained with both metal and vinyl εurfaceε, with nearly complete transfer of ink to the print medium, with very little reεidue left to bε removed by the cleaning pad 144. Fig. 28 iε a bottom facing perspεctivε viεw of a printεr εσuippεd with a roller type intermediate transfer ink jet printer mechanism 150. Thiε iε similar to the flat platε type juεt εscribed, but here the transfεr mεchanism iε a roller 150, rather than a flat plate. Transfer is effεcted by a rolling action against the print medium. In still a further alternative, Fig. 29 illustrates a printer apparatus 10 εσuippεd with a hεlical scanning rollεr typε interme iatε transfεr ink jet print mechanism. This iε εimilar to the roller tranεfer typε juεt dεεcribεd, but hεrε the ink jet print head iε not capable of printing the full width of the print area, but rather juεt a εmall εwath εuch as 1/8" or so, as is typical of ink jεt print headε manufactured for inεxpεnεivε printεrε. Such a print head iε, for example, Hewlεtt-Packard part number 51604A. By meanε of helical εcanning as herein deεcribed such a narrow εwath print head can print the full area of the tranεfer roller. Thiε embodiment utilizeε a tranεfer rollεr that iε largε εnough εo aε to bε ablε to rεcεivε thε εntirε matter to be printed prior to tranεfer to thε print medium. If the print area iε 2" x 3", for examplε, thε tranεfer roller may be 2" long and with a circumferεncε of at leaεt 3", correεponding to a diameter of at leaεt 0.955" . Fig. 29 is a schematic view from the top of such a hεlical scan printing mεchanism showing a print head 152 and a transfer roller 154. Aε the transfer roller 154 rotates about an axis 156 aε εhown, the print head 152 traverεeε thε width of thε roller. The print head 152 haε a plurality of noz∑leε capable of printing a narrow swath as indicated by the projected ink droplets 158. This traverse of the print head 152 in conjunction with the rotation of the transfer roller 154 results in helical εcanning of the roller 154 aε shown. The print head 152 can be moved or translated adjacent the transfer roller 154 by any convenient means such as a conventional motor drive as is well known, or the print head 152 may sweep over the transfer roller εurface uεing a mechanical sweep mechanism aε deεcribed with regard to Figε. 8 and 10A, 10B herein. Whatever traverεe meanε iε used, the traverse of the print head 152 is synchronized with the rotation of the tranεfεr roller 154 such that the print head iε advancεd by the width of one print swath for each revolution of thε transf r rollεr. If, for εxamplε, thε print swath iε 1/8", and thε width of thε print area (and thus the roller) iε 2", then the print head traverεεε 1/8" for each rεvolution of thε rollεr, and thε roller makeε 16 rεvolutionε for complεtε printing. Only after the tranεfer roller is completely printed does tranεfer to the print medium take place, hencε thiε εmbodimεnt essentially involves a two εtep printing proceεs. Firεt, thε transfεr roller iε rotated and the print head traversed to complete the process of printing the information on thε transfεr roller. Next, the tranεfer roller iε brought into contact with the print medium and rolled through one complete revolution to effεct tranεfer to εaid print medium. Aε further enhancementε to the utility and flexibility of the εelf-contained hand-held printing apparatuε described herεinabovε, those skilled in the art will appreciate that the use of an internal control circuit, such as thε circuit 40 herein that useε a microproceεεor 42 and memory circuit 46, facilitateε incorporating additional uεer functionε with the hand-held printer apparatuε 10. Such additional features will now be described in terms of additional exemplary embodiments of the invention, including a calculator, personal organizer functionε, voice recording and play back, voice recognition and εyntheεiε and poεtage meter functionε. The hand-held printer apparatuε 10 aε previouεly diεcloεed hereinabove permitε implementation of a calculator, with the use of appropriate software for the microprocessor 42. Similarly, implementation of a personal organizer is available with thε usε of appropriatε εoftwarε well known to thoεe εkilled in the art. Thε device may, for examplε, function aε a printing calculator. In a further example, uεing the personal organizer capabilitieε, nameε and addreεses can be retrieved from a data base stored in the memory 46, sorted, selected and then printed on envelopes. Referring to Fig. 30A, with the addition of a suitable transducer 170, amplifiers 172, 178, an analog to digital convertεr (A/D convεrtεr) 174, and a digital to analog convεrtεr (D/A converter) 176, the hand-held printer 10 gains the capability to serve as an audio recording and playback devicε. The recording time available will be limited only by the amount of memory available. A εuitable tranεducer 170 iε a εimple elεctromagnεtic εpεakεr or microphonε, or a ceramic or cryεtal piezoεlεctric εlement, or any of variouε other deviceε commercially available, εuch aε model WM-70S1 available from Panaεonic. A εingle transducεr may sεrvε aε both εpeaker and microphone, or two separate transducers may be used. When recording, the transducer 170 functions as a microphone, whosε signal may bε boosted to an appropriate level by the amplifier 172, the output of which is applied to the A/D converter 174. The A/D converter 174 convertε the analog εignal into digital form which can be εtored in memory 46 by the microproceεεor 42. At playback, the opposite procesε takeε placε, with thε microprocεεεor 42 reading the εtored digital meεεage from memory, and applying the digital signal to the D/A converter 176. The output of the D/A convertεr 176 iε an analog signal which iε then amplified by an amplifier 178 to an appropriate level and applied to the tranεducer 170, which now functionε aε a εpeaker. The amplifierε 172, 178 may be εelectεd from any of a εuitablε εolid-εtatε integrated circuit deviceε made for εuch purpoεeε, and may, in fact, be integrated with their respective converters. Similarly, the A/D and D/A converters may be standard devices readily available and well- known. Some microprocessors contain such converters aε an integral part, in which case separate devices are not needed. With reference to Fig. 30B, a delta-modulation technique provides an alternative and efficient method for audio signal digitization with reduced data rate and memory size requirements. An integrated circuit continuously variable εlope delta-modulator 180 performε the A/D and D/A converεion functionε with delta modulation, aε well aε automatic gain control. A suitable device for the circuit 180 iε part no. HC-55564 available from Harriε Corporation. Further, with appropriate voice recognition εoftware, the apparatuε 10 can be made reεponεivε to voicε commands. For εxamplε, thε spoken phrase "print confidεntial" would causε the device to retrieve the word CONFIDENTIAL from its mεmory and set itεelf to print that word. Similarly, voice εyntheεiε εoftware could be uεed to provide εpokεn communicationε from thε printεr to thε uεer, εuch aε, for example, "ink εupply iε low." The hand-held printer 10 aε deεcribed can further be provided with additional featureε εo aε to function aε a poεtage meter. With reference to Figε. 31A and 31B, in performing the function of a poεtage meter, the printer apparatuε 10 printε a poεtage indicia in an appropriate amount, and deductε thε amount of poεtagε from a mεmory regiεter which haε previously beεn loadεd with a purchased amount of postage. The postage meter imprint may include a logo and/or advertising message as may be permitted by postal regulations, with the logo or advertising meεεage having been εtored in memory 46 uεing the printer' ε interfacε or I/O interconnection circuitε aε haε beεn dεεcribεd herein. Appropriate devicεε and circuitε can be included to load the memory regiεtεr with postagε in a secure manner, such that postage can bε added to the register only when it haε been properly purchaεed, aε iε known. The amount of poεtage required to be imprinted on a particular item may be manually entered via the key pad, or, alternatεly, may bε determined directly by the printer devicε when it iε equipped with a suitable wεighing mechanism. A suitable weighing mechanism is a load cell as is well-known, or a calibrated spring as iε well-known. Where a calibrated spring iε utilized, any weight will result in a displacement of a εpecific amount, where the diεplacement can be meaεured by an optical encoder, a linear variable diεplacement transducer (LVDT) , a potentiometer or other device aε are well-known. The weighing mechanism supports an article 194 to be weighed, such that the weight can be determined. Thiε εupport function may take many formε, εuch aε, for examplε, a platform 184 which foldε out from the back of the printer 10, aε εhown in Figε. 31A and 31B. When not in uεe, thε platform 184 iε held in the εtowed poεition aε in Fig. 31A by a latch or other convenient dεvicε (not εhown) . In use, the platform 184 is eployεd aε illuεtrated in Fig. 31B, with the printer 10 placed on a εurface aε εhown, and the article to be weighed placed upon the flat εurfacε 186 provided on the platform 184. A torεion spring 190 is attached at one end to the housing 12, and at itε other end to the platform 184. The torεion εpring 190 reactε to the weight of the article, and the platform 184 iε dεprεεεed by an amount which iε a function of the weight of the article. Thiε movemεnt iε mεasured or detected by an encoder 192 at the platform's pivot point 188 and input to the microprocesεor 42 which then computeε or othεrwiεe determineε the weight and the required postage by referring to postal rate data εtored in the memory 46 or other memory device. The platform 184 iε then stowed aε in Fig. 31A, and the printer 10 can be actuated in the manner described in the exεmplary embodiments herεin, to print thε postagε indicia on thε mεdium. While the invention has been shown and described with respect to specific embodiments thereof, this is for the purpose of illustration rather than limitation, and other variationε and modifications of the εpecific embodimentε hεrεin εhown and dεεcribεd will bε apparent to thoεe skilled in the art within the intended spirit and scope of the invention aε εet forth in thε appended claimε.

Claims: CLAIMS 1. A hand-held and self contained electronic printing device for printing indicia on a medium, comprising: a housing that can be manually positioned adjacent a surface of the medium and remain stationary against the medium during a print sequence,- a printer disposed in the housing for printing indicia on the medium, the printer comprising a print head movable between first and second positions within the housing; an actuator for controlling application of a force that moves the print head from said first position to said second position; a spring operatively connected to the print head to move the print head from said first position to said second position in response to the actuator; and electronic control means disposed in the housing for controlling the printer to print indicia on the medium during at leaεt part of the movement of the print head from the firεt to the second position. 2. The apparatus of claim 1 wherein said print head scans a print area on said surface of the medium during movement thereof between said first and second positions. 3. The apparatus of claim 2 wherein said print head is moved along an arcuate path between said first and second positions. 4. The apparatus of claim 2 wherein said print head is rotated about an axis between said first and second position. 5. The apparatus of claim 3 wherein said actuator comprises a handle with said spring attached at one end to said print head and at another end to the housing, said handle displacing the spring to move εaid print head from said first to said second position when said handle is manually pressed down in a stamping- like motion. 6. The apparatus of claim 5 further comprising a magnet in said housing, said magnet holding said spring at said first position, said handle disengaging said spring from said magnet when manually actuated. 7. The apparatus of claim 1 further comprising user interface means for inputting print and indicia commands to a memory disposed in said housing. 8. The apparatus of claim 1 wherein print head comprises a number of ink jet nozzles. 9. The apparatus of claim 1 further comprising means for sensing and indicating correct position of said print head with respεct to thε medium to εnable a print sequence. 10. The apparatus of claim 8 wherein said nozzles are disposed to project ink droplets on divergent trajectories with respect to each other. 11. The apparatus of claim 10 wherein said electronic control means compensates to reduce distortion in a printed indicia caused by said divergent trajectories. 12. The apparatus of claim 1 whεrein said electronic control means compensates to reduce distortion in a printed indicia caused by movement of said print head along a path that is other than parallεl to said surface of the medium. 13. A hand-held and self contained electronic printing device for printing indicia on a medium, comprising: a single housing that is manually held stationary against a surface of the medium during a printing sequence; a printer disposed in said single housing for printing indicia in any selectable pattern on the medium during said printing sequence,- an actuator for initiating said printing sequence,- and electronic control means disposed in said single housing and responsive to said actuator for controlling the printer to print selected indicia on the medium during said printing sequence; the printing device autonomously executing each entire printing sequence after each printing sequence is initiated. 14. The apparatus of claim 13 wherein said control means comprises a memory that electronically stores a plurality of selεctablε indicia that can be selected for printing during a printing sequence. 15. The apparatus of claim 14 further comprising input means disposed in the housing for an operator to select a number of said stored indicia for printing. 16. The apparatus of claim 15 wherein said input means compriseε a keypad and visual display devices that are used by the operator to create an indicia pattern to be printed. 17. The apparatus of claim 14 wherein said memory stores a control program and instructions such that the apparatus is manually operational in a stand alone configuration independent of electronic input controls from an external source. 18. Thε apparatus of claim 13 further comprising communications means disposed in the housing for transmitting instructions, commands and data between said apparatus and an external control device. 19. The apparatus of claim 18 wherein the external devicε comprises a personal computer. 20. The apparatus of claim 18 wherein said communication means comprises a wirelεss link between said apparatus and the εxtεrna1 device. 21. The apparatus of claim 18 wherein said communication means includes a device selected from the group consisting of: an RF transceiver, acoustic transceiver, optical transceiver, modem, serial port and parallel port. 22. The apparatus of claim 13 wherein said printer comprises an ink jet printer that remains stationary during a print sequεnce. 23. The apparatus of claim 13 wherein said printer comprises a print head having a number of nozzles, said print head being movable between first and second positions along a path that is generally not parallel to a plane of the printing area. 24. The apparatus of claim 23 wherein said nozzles are disposed on said print head to project ink at diverging angles with respect to each other. 25. The apparatus of claim 23 further comprising means for compensating distortion caused by movement of the nozzles along εaid non-parallel path. 26. The apparatus of claim 23 further comprising electric means for moving said print head. 27. The apparatuε of claim 23 further comprising means for applying a manual force to said print head to move said hεad from said first to said second position. 28. The apparatus of claim 13 wherein said printer comprises a print head having a number of nozzles disposed to print on an intermediate transfer medium. 29. The apparatus of claim 13 wherein said printer comprises a print head that rotates about an axis. 30. The apparatus of claim 13 wherein said control means accumulates a total count of dots printed by said printer and produces an output indicating low ink supply based on said accumulated total coun . 31. The apparatus of claim 13 wherein said control means accepts a plug-in module for transferring information between the apparatus and an εxternal source. 32. The apparatus of claim 13 further comprising a sensor that enables a print sequence when the apparatus is correctly positioned with respect to the medium. 33. The apparatus of claim 13 wherein said printer includes means for printing indicia in a number of colors. 34. The apparatus of claim 24 further comprising means for compensating distortion caused by projection of ink by nozzles disposed at diverging angles with respect to each other. 35. The apparatus of claim 24 further comprising compensation for distortion caused by projection of ink by nozzles disposed at diverging angles with respect to each other. 36. The apparatus of claim 29 further comprising means for compensating distortion caused by polar coordinate projection of ink by nozzles disposed at diverging angles with respect to each other. 37. The apparatus of claim 13 further comprising a weight devicε stowεd in said housing for weighing an article, wherεin said control means computes a postage value based on said measured weight for printing on said medium. 38. The apparatus of claim 37 wherein said weight devicε includes a platform pivotally retractable from said housing that supports an article to be weighed. 39. The apparatus of claim 38 further comprising displacement means for detεrmining weight of an article as a function of displacement of said platform when the article is placed thereon. 40. The apparatus of claim 13 further comprising means for audio input, audio storage and audio output. 41. The apparatus of claim 13 wherein said printer is entirely disposed in said single housing and comprises a linear array of nozzles. 42. The apparatus of claim 41 wherein said linear array of nozzles comprises a single line of a plurality of ink jet nozzles. 43. The apparatus of claim 13 wherein said printer is entirely disposed in said single housing and comprises a plurality of ink jet nozzles wherein each nozzle projects an ink dot onto the medium, within a printing area defined by the housing, along a trajectory that is fixed by the position of the nozzle within the housing when the nozzle is activated by the electronic control means. 44. The apparatus of claim 13 wherein said printer comprises an areal array of ink jet nozzles positionally fixed within said housing during a printing sequence, wherein each ink jet nozzle projects an ink dot to a predetermined dot position in a printing area defined by the housing. 45. The apparatus of claim 43 wherein said printer comprises a print head that moves from a first position to a second position during a printing sequence, the print head comprising said nozzles, the apparatus further comprising means for determining position of each nozzle during a printing sequence and means for dynamically selecting said nozzles for printing a dot pattern on the medium as a function of said detected positions and the image to be printed. 46. The apparatus of claim 43 wherein said nozzles project ink at diverging angles with rεspect to each other. 47. The apparatus of claim 45 wherein distance between said print head and the medium varies during a printing sequence. 48. The apparatus of claim 45 wherein an angular relationship between said print head and the medium varies during a printing sequence. 49. The apparatus of claim 45 wherεin thε print hεad moves in an arcuate path from said firεt to εaid second position. 50. The apparatus of claim 13 wherein the indicia to be printed is stored in a memory within said housing, said electronic control means controlling the printer using an algorithm to compensate for printed image distortion caused by movement of the printer within the housing during a printing sequencε. 51. The apparatus of claim 50 wherein said printer comprisεs a plurality of printing elements each of which ejects ink at diverging angles with respect to the others, and wherein the control means algorithm includes the step of controlling which printing elements are activated to position a dot at a selected position in the printing area based on the detεcted positions of the printing elements during a printing sequencε. 52. Thε apparatus of claim 13 whεrεin said printεr comprisεs a numbεr of print εlements each of which operatεs to print a portion of a respective fixed pattern on thε medium during a printing sequence. 53. Thε apparatus of claim 28 wherein said intermediate transfer medium is a flat plate. 54. The apparatus of claim 28 wherein said intermediate transfer medium is a roller. 55. The apparatus of claim 54 wherein said roller is helically scanned.

Inventors: BOBRY HOWARD H, BOBRY, HOWARD, H.
Applicants: BOBRY HOWARD H, BOBRY, HOWARD, H.
Application year: 1996
Main classification: B41J3
IPC codes: B41J3