CA1160505A - Paper feeding apparatus and method for printing apparatus - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A paper feeding apparatus is disclosed for feeding of individual sheets of paper to a printing device for the printing of matter thereon, the printing device including a print head for printing on a sheet of paper and a paper moving platen for providing relative movement between sheets of paper and the print head to effect printing on the paper. The paper feeding apparatus includes a paper storage tray for storing a plurality of sheets of paper, and a paper drive and guide apparatus for feeding a sheet of paper from the paper storage tray along a paper feed path to the platen of the printing device. A sensor is provided in the paper feed path for sensing when a sheet of paper is in position for being received by the platen, at which time the platen is then actuated to receive the sheet of paper being fed along the paper feed path and to move the sheet of paper relative to the print head to accurately position the sheet of paper in a printing position for the start of printing thereon by the print head. In the preferred embodiment, a second sensor is provided along a paper exit path from the printing sensor is provided along a paper exit path from the printing device which is utilized to indicate that the platen has received a sheet of paper and to position the paper properly in a printing position for the start of printing. Further, apparatus are provided for ejecting the paper from the printing device after printing has been completed on the sheet of paper.

Description

1 ~ ~05~5 The present inven-tion relates to prin-ting apparatus and paper feeding apparatus therefor, and more particularly to a paper feeding apparatus which wil.l automaticall.y feed individual sheets of paper to a printing device, and properly align and position the paper for the start of printing thereon by the printing device.
Tremendous advances have been made in the last few years in automating office procedures. Convention-al typewriters have grown into mini-computers performing word processing, storage and other functions. The speed at which these machines produce words on paper is increas-ing at a rapid rate.
As added speed and sophistication are developed i.nto such machinery, the actua:L putting of words onto paper becomes auxilliary to the main function of collect-ing and organizing the information into a format -to be printed. In order to have flexibility and speed, many systems have been developed where an operator mani.pulates words on a cathode ray tube or other word processing equipment until the final copy is in the format desired. With all of these advances, it has developed that today one of the major bottlenecks in t~rms of time, and thereEore usefulness of this equi.pment, is the rate at which paper can be brought to and moved past a printing head to produce the final hard copy.
Of course it is possible to use continuous shee-ts of perforated papèr, as is commonly done in computer applications, having sprocket holes along tl~e si.de thereof to continuously feed and move the paper through an impact printer. This however requires special paper which is not suited -to the many requirements for which normal typewritirlg is employed.

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i ~ ~0505

2--~ any machines exis-t, both copyin~ rnachines and printin~ machines, which automatically feed paper past a print:ing or reproducing st~tion. These machines are normally run synchronously such that prior to the time that paper is fed, the information to be imparted - to the paper is already organ:ized and the paper is rnoved pas-t the printing head in a continuous fashion.
This is not suitable for impact prin-ting devices since impact printing is accomplished with t,he paper stationary rather than moving, and further the adaption of normal typewriting -type prin-ting requires the moving of paper not only on an intermi-ttant basis but also in the forward and reverse direction in accordance with the information to be typed. Still fur-ther, with such existing equipment, it is general:Ly no-t possible to manually feed separate sheets of paper, which may be of a different size or thickness (such as for example envelopes), without disconnecting the equipment from the printing apparatus.
It is of course possible to radically change the printing equipment to conform with the needs of high-speed paper feeding. However, it is an objec:t of this invention to provide a paper feeding apparatus to conform with the requirements of existin~ impact printing equ:ipment rather than requiring the radical modification thereof`. In particular, it is an object to provide a paper feeding apparatus which is capable of being retrofitted with respec-t to existing printing devices (i.e., distributed as an after market product) as well as being capable of being sold and distributed with or as an integral part of the printing apparatus.
According to the present invention, -there is provided paper f'eeding apparatus for a printing device, which printing device includes a transversely extending platen, a printing head transversely movable relative to t,he transversely ex-tending pla-ten, and a guide member f'or guiding a shee-t of paper in a desired direction, the guide member being associated with the ~ ~ 1 6~5()~

transverse:ly movable pri.nt head and movable -therewith, and the transversely extending pla-ten including paper drive means for providirlg rela-tive longitudinal movement of a sheet of paper relative to the printing head to effect printing on the sheet of paper by transversely moving the printing head relative to the transversely extending platen and by longitudinally moving a sheet of paper rela-tive to the printing head, and wherein the paper feeding apparatus comprises paper storiny means for storing a plurali.-ty of individual sheets of paper, paper feed means for feeding a sheet of paper in a paper feed direction from the paper s-toring means to the platen, the sheet of paper having a longitudinal central portion which extends in the paper feed direction and which is centrally located intermediate the edges of the sheet of paper which extends in the paper feed direction, paper receiving means for receiving a sheet of paper from the platen, the paper receiving means defining a paper exit path having one end arranged adjacent the platen.to recei.ve a sheet of paper therefrom after said printing means has effected printing thereon, and centering means for transversely moving the print head and associated guide member to be in a posi.tion to overlie at least a part of the central portion of the sheet of paper when it is moved therepast upon initial feeding of a sheet of paper to the platen so that the guide member cooperates with the platen to guide the sheet of paper into the paper exit path as the sheet is moved past the guide member.
According to the present inven-tion, there is also provided paper feeding apparatus for a printing device, which printing device includes printing means for printing on a sheet of paper and paper drive means for provid:ing relative movement between a sheet of paper and the pri.nting means to effect printing on the sheet: of paper, and wherein the paper feeding appara-tus cornprises paper storing means for s-toring a plurality 1 ~6~5~

c,~ individucl1 sheets of paper, paper eed means for feeding a sheet of paper from -the paper st~ring means alon~ a paper feed path to the paper drive means, sensor means for sensing when a sheet of paper is in posi-tion for being received by the paper drive means,.and actua-tion means responsive to the sensing means for actuating the paper drive means to receive a sheet of paper and to move it relative to -the printing means to accurately position it in a desired printing position for -the start of printing thereon by the printing means.
According to the present invention, there is also provided a me-thod of feeding an individual sheet of paper to a printing device, which prin-ting device includes prin-ting means for printing on a sheet of paper and paper drive means for providing relative movemen-t between a sheet of paper and the printing means to effect printing on the shee-t of paper, said method comprising the steps of storing a plurali-ty of individual sheets of paper in paper storing means, feeding a sheet of paper from the paper storing means along a paper feed path to the paper drive means, sensing when a sheet of paper is in position along said paper feed path for being received by the paper drive means, and actuating the paper dri.ve means when a sheet of paper is sensed to receive a sheet of paper bei.ng fed along the paper feed path and to thereafter move the sheet of paper relative to the printing means to a printing position for the start of printing thereon by the printing means.
According to the present invention, there is also provided printing apparatus comprising printing means for printing on a sheet of paper, paper drive means for providing relative movement between a sheet of paper and the printing rneans to effect printing on the shee-t of paper, paper storing means for storing a plurality of individual sheets of paper~ paper feed 1 1 BV~

means for feeding a sheet of paper from the paper stori.ng means alon~ a paper feed pa-th to the paper drive means, sensor means -for sensing when a sheet of paper is in posi.-tion for being received by the paper drive means, and actuation means responsive to -the sensing means for actuating -the paper drive means to receive a shee-t of paper and -to move it relative to the prin-ting means to accurately position it in a desired printing position for the start of printing -thereon by the printing means.
According to the present invention, there is also provided printing apparatus comprising a trans-versely extending platen, a prin-ting head transversely movable relative to said transversely extending platen, a guide member for guiding a sheet of paper in a desired direction, the guide member being associated with the printing head and movable therewith, the transversely extending platen including paper drive means for providing relative longitudinal movement of a sheet of paper relative to the printing head to effect printing on the sheet of paper by transverse:ly moving the printing head relative to the platen and by longitudinally moving the sheet of paper relative to the printing head, paper storing means for storing a plurality of indiv:idual sheets oE paper, paper feed means for feeding a sheet of paper in a paper feed direction from the paper storing means to the platen, the sheet of paper having a longitud-i.nal central portion which extends in the paper feed direction and whi ch is centrally located intermedia-te the edges of the sheet of paper which extends in the paper feed direction, paper receiving means for receiving a sheet of paper from the platen, the paper receiving means defining a paper exi.t path having one end arranged adjacent the platen to receive a shee-t of paper -therefrom after the printing means has effec-ted printing thereon, and centering means for transversely moving -the print head and associated guide member to be in a pos;.tion 1 lB~5~S

to overlie at leas-t a part of the central portion of the sheet of paper when it is moved therepast upon initial feeding of a sheet of paper to said platen so that the guide member cooperates with the platen to guide the sheet of paper into the paper exit path as the sheet is moved past the guide member.
The invention will now be descri~ed with reference to the accompanying drawings, in which:
Figure 1 is a perspective view of the paper feeding apparatus embody~ng the present invention mounted on a printing device, portions of the paper feeding apparatus being broken away to illustrate various components thereof.
Figure 2 is a front elevational view of the paper feeding apparatus of Figure l mounted on the printing device, with portions removed to illustrate various components thereof.
Figure 3 is a side elevational view illustrating the paper feeding apparatus mounted on a printing device, showing in full outline the paper feeding apparatus in a raised position for the manual ~eed of sheets into the printing device without utilizing the paper feeding apparatus and showing in dotted outline the paper feeding apparatus in a lowered position for the automatic feeding of sheets of paper to the printing device.
Figure 4 is a rear perspective view of the paper feeding apparatus with the paper trays removed to illustrate various components of the apparatlls.
Figure 5 is a side elevational view of the paper feeding apparatus shown in Figure l with one of the cover plates of the left hand upright housing removed to illustrate the various components therein.

-7_ 11 6~505 Figure 6 is a sectional view taken along lines 6-6 of Figure 2 illustrating how sheets of paper are supported in a paper tray and mounted in the paper feeding apparatus.
F'igure 7 is a plan view of the upper paper tray shown in full outline and of the lower paper tray shown in dotted outline superimposed therebeneath to illustrate different size paper trays for different sizes of paper.
Figure 8 is schematic side elevational view of the paper feeding apparatus and portion of the printing device thereof illustrating the various paper feed and exit paths for sheets of paper.
Figure 9 is side sc~ematic elevational view, similar to that shown in Figure 8, but on a smaller scale, illustrating a sheet of paper being fed from the upper paper tray and moving past the paper inlet sensor.
Figure 10 is a schematic side elevational view, similar to that shown in Figure 9, illustrating a sheet of paper being moved by the platen of the printing device with the leading edge thereof being positioned in front of the outlet sensor in the exit path of movement for the paper.
Figure 11 is a schematic side elevational view, similar to that shown in Figure 9, illustrating a sheet of paper positioned relative to the paper platen with the leading edge aligned with the outlet sensor in the paper exit path of movement.
Figure 12 is a schematic side elevational view, similar to that shown in Figure 9, illustrating a sheet of paper being ejected from the printing device by the paper feeding apparatus.
Figure 13 is a schematic side elevational view, similar to that shown in Figure 9, illustrating sheets of paper stacked on the stacker/deflector plate of the paper feeding apparatus.

Figure 14 is a schernatic side elevational view, similar to that shown in Figure 9, illustrating a sheet of paper being fed from the lower paper tray.
Figure 15 is a schematic side elevational view, similar to that shown in Figure 9, illustrating an envelope being manually fed through a manual input slot of the paper feeding apparatus.
Figures 16a and 16b are schematic flow charts illustrating the algorithm for controlling operation of the paper feeding apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIr~ENT
Referring now to the drawings wherein like reference characters represent like elements, there is shown in Figure l a paper feeding apparatus 10 embody~ng the present invention mounted onto a printing device 12 for operation in conjunction there-with. The printing device 12 generally includes printing means 14 for printing on a sheet of paper 16 and paper drive means 18 for providing relative movement between a sheet of paper 16 and the printing means 14 to effect printing on the sheet of paper 16. For example, in the embodiment shown in Figure 1, the paper moving means comprises a rotatable transversely extending platen 18 which is adapted to rotate abou-t a transversely extending axis, and the printing means comprises a movable print head 14 which is adapted to traverse back and forth across the transverse length of the platen 18. As is conventional, a sheet of paper 16 to be printed on is received between the platen 18 and the paper yuide therefor, which may include appro-priate pressure rollers 19 in engagement with the platen 18 (see Figure 8 for example), and advanced by rotation of the platen 18. The print head or wheel 1~ is carried by a movable carriage which traverses across the trans-verse extent of the platen 18 by means of a suitable -9- 11 60S0~

carriage motor. The print head 14 is arranged to be closely spaced from the platen 18 so that printing in lines is achieved on the paper 16 as the print head 14 traverses between the ends of the platen 18. Alterna-tively, the platen 18 could be carried by a carriageand moved transversely past the print head or means.
During the printing operation, the platen 18 serves to rotate intermittently about the transverse axis to advance the sheet of paper 16 longitudinally relative to the print head 14 for the printing of the next line thereon by virtue of the transverse movement of the print head 14 with respect thereto~
Thus, it is appreciated that in the embodiment shown in Figure 1, printing is accomplished by trans-versely moving the print head or wheel 14 relativeto the paper 16 and then advancing the paper 16 longitud-inally by rotation of the platen 18 to permit the print wheel 14 to traverse thereacross to effect the next line of printing. This printing operation may be as in a conventional typewriter from left to ri~ht, or the printing may be from left to right for one line of print with the next line of print being effected by movement of the printing head from right to left.
This latter means of printing is commonly used in many present day word processing systems.
The paper feeding apparatus 10 is mainly designed for use with printing devices 12 having automatic printing or typing capabilities, i.e., printing systems or devices in which a complete page of print is effected automatical-ly without or with a minimal amount of instructions from the user. In such systems, the text of the matter to be printed may have been previously stored on a disk or other similar recording device, or may be in the memory of a cathode ray tube on which a user has completed work to arrange the matter or information in a desired format. When desired, the system simply prints the stored information onto sheets of paper.

1 1 6~50~ 1 .

Generally, in the printing operation, the matter or information is printed one line at a time, with the paper 16 then being automatically advanced for effecting printiny of the next line, and so on until an entire page is printed. Such printing devices 12 are generally of the impact printing type, i.e., the print head impacts the paper 16 against the platen 18 to effect the printing. However, it should be appre-ciated that the paper feeding apparatus 10 could also be used with other types of printing devices, such as for example ink jet printers, line printers, and/or non-impact electro-static printers.
As will be appreciated from the description 5 hereinbelow, the paper feeding apparatus 10 is also particularly well adapted to be retrofitted with such automatic printing devices 12, both in terms of the mechanical mounting on the printing device 12 as well as the electrical connections with the microprocessor or other control equipment for controlling the printing device 12 to print matter on sheets of paper. This is a most important capability as, as was noted above, present day informa-tion and paper handling systems have developed to a s-tage where the limiting factor with respect to the speed of handling and printing is the speed at which the paper can be delivered and positioned for printing thereon by the printing device 12. Consequently, it is desirable that the paper feeding apparatus 10 for accomplishing the paper feeding and removal of the paper from the printing device 12 be capable of being universally adapted, with a minimum amount of changes or modifications, for use with such present day printing devices. In this regard, as automatic printing devices 12 have control capabilities for con-trolling the printing of words in a line and automatic-ally advancing the paper for printing of the next line, the paper feeding apparatus 10 -t 1 6VS05 preferably is capable of connection to the printingdevice 12 so as to use the standard commands gerlerated for movement of the printing head 14 and advancement of sheets of paper 16, thus simplifying the retrofitting of the paper feeding apparatus 10 with an automatic . printing device 12. In this regard, information respecting the standard commands and codes for movement of the platen 18 and the print head 14, as available from the printer interface and as used herein, are set forth in the Interface Manual as published by the printer manufacturer. Accordingly, the paper feeding apparatus 10 . is capable of distribution as an after market product, as well as for distribution with the sale of new printing equipment, in which event the paper feeding apparatus 10 may either be sold as a separate unit or as an integral unit with the printing device 12.
One example of such a typical printing device or system having the capability to automatically print matter, and one with which the preferred embodiment of the paper feeding apparatus 10 is especlally designed for use, is the Lanier Business Products' word processing unit sold under the tradename "No Problem" which includes suitable control commands for effecting an automatic printing of an entire page of type or print on a sheet of paper 16 automatically and which includes paper advance instruct.ions (as by an instruction to rotate the platen 18) and other suitable controls for controlling the margins for the matter to be printed with respect to the paper.
Acco.rdingly, the paper feeding apparatus 10 ~r . - . is operable to feed sheets of paper 16 to the printing device 12, and in particular to the platen 18 thereof, and to control the platen or paper drive means 18 of the printing device 12 to move the paper 16 fed thereto to an appro-1 1 60~05 priate position for printing to begin on the sheetof paper 16. Also, after printing has been completed, the paper feeding appara-tus lO is preferably operable to remove or eject the paper 16 from the printing device 12, to store or stack same in the paper feeding apparatus 10, and to then feed another sheet of paper 16 and move same into position for the beginning of printing thereon.
With the above features and principles in mind, the paper feeding apparatus lO
~ will now be described.
The paper feeding apparatus 10 generally comprises a pair of upstanding generally parallel spaced side housings or covered frames 20, 22 between which sheets of paper 16 will be fed to the printing device 12. The side housings 20, 22 are joined together and supported on a base support member or mounting plate 24 for mounting of the paper feeding apparatus lO onto the pri.nter 12 so as to be in a proper position for feeding sheets of paper 16 to the platen 1~ thereof.
In the preferred embodiment, this mounting plate 24 comprises a generally flat plate member having mounting means or brackets 26, 28 at the front and rear transverse ends thereof, and provides a suitable support surface for supporting the paper feeding apparatus 10 on the printing device 12. The mountiny plate 24 is designed to be attached to the rear top portion or cover 30 of the printer device 12 behind the paper moving platen 18 and the transversely movable printing head 14. The dimensions and configuration of the mounting plate 24 may be varied depending on the particular printing device with which the paper feeding apparatus 10 is to be used, so that the paper feed path of the paper feeding apparatus 10 will be properly aligned with the paper moving platen.l8 of the printing device 12.
As best shown in Figures 3 and 4, the mounting plate 24 is attached in a suitable fashiGn with the mounting means 26, 28 to the upper rear cover 30 of the printing device 12.

ln the preferred embodiment, the mounting pla-te 24 includes a pair of transversely spaced rear hook members 32 (see ~igures 3, 4 and 5) for receiving a transversely extending support or a-ttaching bar 34 which extends between the uprigh-t side housings ~0, 22 at the rear of the paper feeding apparatus lO. A
forward transversely extending support bar 36 (see Figures 3 and 5) is provided at the forward end of the mounting plate 24 which is adapted to be received in appropriate recesses 38 in the upright housings 20, 22 of the paper feeding apparatus 10. The paper feeding apparatus 10 is easily attached to this mounting plate 24 by hooking the attaching bar 34 at the rear bottom of the paper feeding apparatus 10 in the hooks 32 provided at the rear of the mounting plate 24 and then lowering, by rotation abou-t the rear attaching bar 34, the paper feeder apparatus 10 into position on-to the prin-ter 12 so that the forward support bar 36 is received in the recesses 38 in the interior of the side housings 20, 22. It will be appreciat~d that the paper feeder apparatus 10 is rota-table about the attaching bar 34 between a lowered posi.tion (shown in dotted outline in ~igure 3) and an upper position (shown in full outline in Figure 3) for a purpo~e to be described more fully hereinbelow. When in the lowered position, the paper feeding apparatus 10 is held in place relative to the printirlg devi.ce 12 and mounting plate 24 by means of a suitable locking device, which in tile preferred embodiment comprises a spring bi.ased pivotal hook member 40. Actu~tion for effecting locking and unlocking of the spring biased hook mernber 40 is achieved by depressing the locking button 42 on the front of the paper feeding apparatus 10.
Also, in the preferred embodiment, a pair ~-~ of paper trays 44, 46 are provided for storing a first and second plurality of sheets of paper 16 for feeding to the printing device 12. The paper trays 44, 46 are suppor-ted one above the other at the rearward encl of the paper feeding appara-tus lO. As each of the paper -14~ 03~.~

-trays ~4, 46 is similarly constructed and supported be-tween -the housings 20, 22, only the upper paper -tray 44 and the manner of suppor-ting same will be described.
The upper paper -tray 44 comprises a tray shaped box.
member 45 having a paper suppor-t plate 48 pivotally supported i.n the bottom thereof. The dimensions of the tray shaped box member 45 substantially correspond to the dimensions of the paper 16 to be supported therein.
The sheets of paper 16 are placed on the paper support plate 48 and the paper support plate 48 is pivotable upwardly to raise the forward edges of the sheets of paper 16 to be at or just above the forward end of the paper tray 44 and in contact with drive rollers 72 for feeding of the paper (to be described more ful.ly hereinbelow) (see Figure 6). Also, suitable paper reten-tion rneans may be provided for normally retaining thepaper 16 in the paper tray 44, such as for examp].e pivotable tab members 50 arranged at the forward side edges of the paper tray 44. These tab members 50 also serve to separate the sheets of paper 16 so that a si.ngle sheet of paper at a time will be fed by the drive rollers 72 from the paper tray 44.
The paper tray 44 is also provided with a pair of L-shaped brackets 52 each having one leg secured to the sides of the box shaped member 45 and the other leg extending away therefrom. The spacing between the outer ends of the L-shaped brackets 52 substantially corresponds to the spacing between the side hous-;ngs 20, 22 so that the paper l6 in the paper tray 44 may be centered between -the housing sides 20, 22. As can be appreciated, a paper tray for different wi.dth sheets of paper may sim.ilarly be centered between the side housings 20, 22 so that the paper thereof is also centered by simply constructing the paper tray therefor to have ~S5 suitable dimensioned L-shaped brackets 52 secured to the sides thereof so that the outer ends of the L-shape~
brackets 52 are spaced substantially the same distance as the spacing between the uprigh-t side housings 20, 22. This is illustrated :in Figure 7 which shows an -~.5~ 5 ~ ~

upper paper tray 44 for one wid-th of paper 16 in full outline, and a second or lower paper tray 46 superimposed thereunder in clotted ou-tline for a second width of paper. Although -the dimensions of the box shaped por-tions 45, 45' differ from one another, the outer dimensions for the L-shaped brackets 52, 52' are iden-tical, and the cen-ter lines 47, 47' for each of the trays 44, 46 coincide with one another.
A tray support plate 54 is provi~ed between the side housings 20, 22 for supporting the paper -tray 44 (see Figure 4). Each of the side housings 20, 22 is also provided with a bar 56 parallel spaced above the tray support plate 54 to define a space for receipt of -the transversely or laterally extending legs of the L-shaped brackets 52 between the bar 56 and its respective tray support plate 54. A suitable spring biased detent ball 57 may be provided in this space in the side housings 20, 22 for receip-t in a suitable recess 59 (see Figure 7) in the laterally extending legs of the L-shaped brackets 52 to retain the paper tra,v 44 in position when it is inserted between the side housings 20, 22.
I'he tray support plate 54 is provided with a centrally located spring biased pivotable plat~ member 58 having a roller element 60 secured thereto for being received in an appropriate opening or recessed 62 in the bottom of the paper tray 44 for resilien-tly pivoting the paper support plate 48 in the paper tray 44 upwardly to raise the forward edges of sheets of paper 16 suppor-ted thereon. More particularly, the plate member 58 is connected to a rotatable rod 64 journalled in the side housings 20, 22 and connected at one end to a paper tray insertion lever 66 located and moun-ted on the side housing 22. The tray insertion lever 66 is spring biased -to bias the roller element 60 and plate member 5~ towards the raised position, and is operable to pivot the roller element 60 and plate member 58 downwardly to permit insertion and removal of the paper tray 44.

~ 16~5~5 In the downward or lower position, the roller elernent 60 and plate member 58 lie beneath the surface of the tray support plate 54.
Spaced above the upper tray support p:late 54, there is provided a transversely extending drive rod 70 having a first and second pair of spaced rollers 72, 74 secured thereto. The inner pair of rollers 72 are drive rollers which are spaced at equal distances froM the transverse center of the drive rod 70 to engage spaced portions of the upper sheet of paper 16 urged into contact therewith by means o~ the spring biased roller element 60 which forces the paper support plate 4~ upwardly. These inner drive rollers 72 each include a roller clutch mechanism so that the drive rollers 72 wil] be free rol]ing relative to the drive rod 70 in one direction (i.e., the counterclockwise direction relative to the drive rod 70 as viewed in Figure 8) and will be locked with the drive rod 70 in the opposite direction (i.e., the clockwise direction relative to the drive rod 70 as viewed in Fi~ure 8). In this way, when the drive rod 70 is rotated (in a manner to be described hereinbelow) in the counterclockwise direction as viewed in F:igure 8, the drive rollers 72 will be rotated therewith to engage and force a single sheet of paper 16 from the supply tray 44 forwardly thereof.
On the other hand, when the drive rod 70 stops ro-tation and the paper is pulled out of the paper trày (as de-scribed below), the drive rollers 72 will be free to rotate in the counterclockwise direction.
The outer pair of rollers 74 comprise -Ereely rotating idler or support rollers 74 which are adapted to assis-t in feeding a sheet of paper from a paper tray (when inserted between the side housings 20, 22) which is o~ a greater lateral dimension than the paper 35 16 in -the tray 44 (see Figure 7). The support rollers 74 are not driven by -the drive rod, but rather simply provide an addi-tional means for reliable separation and f'eeding of relatively wide sheets of paper from a paper supply tray 44.

V ~

As can best be seen in F:igures 1, 2 and 5, the ends oI -t~e drive rod 70 are journalled in the opposite upright side housings 20, 22 . In the side housing 20, the drive rod 70 is provided with an integral drive gear 76 thereon which meshes wi-th a suitable gear 78 attached to the drive shaft of a motor 80 also supported in the upright side housing 20. As will be appreciated, actuation of the mot.or 80 to ro-tate in the clockwise direction (as viewed in Figure 5) serves to drive the gear 78 which in turn drives the gear 76 and the drive rod 70 to rotate the drive rollers 72, 74 about the axis of the drive rod 70. In this regard, the rnotor 80 is rotated clockwise and the drive rod 70 is rotated in a counterclockwise direction as shown in Figure 5 so that the drive rollers 72 will engage a sheet of paper 16 and advance same out of the paper tray 44 in a direc-tion substantially parallel to or in the same direction as the direction which the sheets of paper 16 extend, i..e., toward the right and slightly downward as viewed in Figure 5.
A similar set of rollers 72' and 74', drive rod 70', motor 80' and gears 76', 78' are also provided for the lower paper tray 46. Each of these motors S0, 80' are connected with appropriate circuitry so as to be actuated when desired, as more fully descr:ibed hereinbelow.
Positioned adjacen-t the upper paper tray 44 and extending between the upright side housings 20, 22, there is provided an upper paper guide plate.
member 82 having a first upper plate porti.on 84 closely spaced with respect to the forward end of the paper -tray 44 and extending in substantially the same direction as the sheets of paper 16 therein and having a second downwardly inc].ined portion 86 obliquely oriented with respect to the first upper plate portion 84 (see Figures 1, 2 and 8). A similar somewhat shorter lower guide plate member 88 is provided for the lower paper tray -18- t 1 6~0~

46, and also includes an upper plate por-tion 90 posi-tioned so -that the end thereof is closely spaced frorn -the lower paper tray ~6 and ex-tends in substanti,ally the same direction as -the paper sheets 16 therein and a downwardly inclined plate portion 92 obliquely ori.ented with respec-t to the upper plate portion 90 and extending downwardly towards the lower end of the paper ~eeding apparatus 10. Each o:E these guide plate members 82, 88 are supported by suitable fast,eners 94 provided in the opposite lateral ends thereof and which are secured to the inner side walls of the side housings 20, 22. The fasteners 94 protrude slightly beyond the surfaces of the plate portions 86, 92 of the guide plate members 82, 88 at the lateral ends thereof.
These guide plate members 82, 88 together with a removable deflector plate 96 define the paper feed pa-th 100 for the shee-ts of paper 16 which are fed to the paper moving platen 18 of the printi.ng device 12. This paper feed path 100 is shown in dotted outline in Figure 8. More particularly, the paper deflector plate 96 is removably suppor-ted on a transversely extend-ing rod 98 which extends between the side housings 20, 22 at the upper end thereof by means of appropriate hook members 102 provided on the rear surface 104 of the deflector 96. The lower encl of the deflector plate 96 is spaced from the gulde plate members ~2, ~8 by means of the protrudi.ng fasteners 94 of the lowermost guide plate rnember 88.
Thus, it is appreciated, especially from viewing Figures 8-15, which illustrate the various steps in feeding of paper from the paper feeding apparatus 10 to, through and from the printing device 12, that the lower down~Jardly extending portions 86, 92 of the guide plate members 82, 88 and the rear surface 104 of the deflector plate 96 define a main paper feed path 100 along which paper may be fed from either of the paper trays 44, 46 to guide the sheets of paper O ~ V ~

].6 downwar~ly towards the lower end of.the-paper feeding apparatus l.0 toward the paper moving platen 18. In this regard, i-t is to be no-ted that the paper 16, once it is fed i.nto the paper feed path 100 is guided subs-tan-tially in a straigh-t line to the paper receiving or inlet entrance 106 of -the paper moving platen 18 which corresponds with the conventional inlet for inserting paper in-to the platen 18 of the printing device 12.
In other words, the paper feed path 100 for the appara-tus is arranged to d:irectly feed paper 16 into the paper receiving inlet 106 of the printing device 12. It will be appreciated that this paper receiving inlet 106 is conventionally arranged a-t a transverse angle with respect to -the upper surface 30 of -the prin-ting device 12 and in fac-t is capab:le of handling paper shee-ts oriented a-t a wide variety of transverse angles with respect to the upper rear surface 30 of the printing device 12. Thus, the orienta-tion of the paper feed path 100 of the paper feeding appara-tus 10 of the present invention will serve -to prec:isely guide the sheets of paper 16 fed therealong into the paper receiviny inle-t 106 for the printing device 12. :[n this regard, -the positioning of the paper feed pa-th l.00 relative to the paper receiving inlet 106 of the printing device 12 is achieved by proper positioning of the mounting plate 24 on the printing device 12.
It will also be noted from reviewing Fig-lres 8-15, tha-t the shee-ts of paper 16 which are fed from the paper -trays 44, 46 into the paper feed path 100 are initially guided along the respective inlet f`eed paths 108, 110 (defined by the upper plate por-tions 84, 90 of the guide plate members 82, 88) at an oblique angle with respect to the direction of the main paper feed path 100 so that the paper will be deflec-ted by the rear surface 104 of the deflector plate 96 downwardly into and along the paper feed path 100. ~his is true whether a sheet of paper 16 is fed from the upper paper -tray 44 (see Figure 9) or from the l.ower paper tray --20~ V ~ 0 5 46 (see Fi(~ure 14). 'I'hus, i.t will be apprecia-ted that whether the paper is bei.ng fed from the upper paper tray 44 or the lower paper -tray 46, its respective guide plate member 82 ~r 88, together with the deflector plate member 96 serve~, to define t~Jo paper paths along which paper shee-ts 16 may move. One path corresponds to the main paper feed path 100 directing paper 16 to the paper moviny platen 18 and defined by the lower portions 86 or 92 of the guide pla-te members 82 or 88 and the rear surface 104 of the deflector plate 96. This paper feed path has an upper end 100a and a lower end 100b. The other paper pa-ths correspond with the inlet feed paths 108 or 110 for the respec-tive paper trays 44 or 46 for in-troducing paper into the ].5 main paper feed path 100 and are defined by the upper plate portions 84 or 90 of the associated guide p]ate members 82 or 88. These inlet feed paths 108, llO each have a first end 108a, 110a, arranged adjacent -the associated paper trays 44, 46, and drive rollers 72, 72' therefor, and a second end 108b, 110b arranged adjacent the main paper feed path 100 and intermedia-te the upper and lower ends 100a, 110b, thereof.
At the paper receiving inlet 106 of the printin~
device 12, the paper 16 is guided between the paper moving platen 18 and the paper guide 112 therefor ~which generally includes suitable pressure rollers 19) so that upon rotation of the platen 18, the paper 16 will be advanced about the platen 18 and moved past the printing head 1~ so as to be in position for effecting printing thereon bv movement of the printing head 14 transversely across the platen 18 and by rotation of the platen 18 to advance the paper 16 for differerl-t lines of printi.ng. In this regard, it will be noted tha-t the paper 16 is positively fed by -the drive rollers 72, 72' from the associated paper tray 44, 46 i.nto the paper receiving inlet 106 to be received and moved 1 J 6~505 . by the p~.aten 18. Once the paper 16 is received by the platen 18, the rotation of the drive rod 70 or 70' is stopped, and the roller clutch mechanism in the drive rollers 72 or 72~ allows the platen 18 to easily pull the paper from -the paper tray 44 or 46 to advance the paper 16 past the print head 14. In this regard, once the paper 16 is in position for print-ing, the platen 18 may be advanced and moved in accordance with the normal-printing instructions or commands for the printing device 12 for effecting printing on the paper 16.
The paper feeding ~pparatus 10 also includes ejection means for ejecting a sheet of paper 16 from the printing device 12 after printing has been effected thereon. In the preferred embodiment, this ejection means comprises a pair of spaced ejection roller means 114, 116 (best seen in Figure 1 and Figures 8-15) which are supported at the forward end of the paper feeding apparatus 10 between the side housings 20, 22 and arranged so as to receive a sheet of paper 16 as it exits from the printing device 12. In this regard, it is to be noted that the sheet of paper 16 is guided between the ejection roller means 114, 116 while printing is being effected thereon, the spacing of the ejection roller means 114, 116 servin~
to allow the paper 16 to move freely under the control of the platen 18. When it is desired to eject a sheet of paper 16 after the printing has been completed, the forward ejection roller means 114 is moved towards the rear ejection roller means 116 to grippingly engage a sheet of paper 16. The ejection roller means 114, 116 are then rotated to pull the sheet of paper 16 upwardly away from the printing device 12 and to stack same against the front surface 105 of the deflection plate 96.

~ ore pclrticularly, a-t the forward end of -the side housings 20, 22, there is provided an exit guide plate member ll8 having a front surface 120 incline~
downwardly and adap-ted to lie just above -the rotatable pla-ten 18 of the printing device 12 adjacent -the exit end thereof for a sheet of paper 16 and having a rearward-ly inclined V-shaped surface 122 which serves to support the lower edges eJected sheets of paper 16. The forward upper end of -the V-shaped surface 122 is integral wi-t~ the front surface 120 at 124 to provide a smooth transition therebetween, and the rearward end of the V-shaped surface 122 is arranged in close spaced relationship with the lower end of the deflector plate 96, as can best be seen in Figure 8. A curved corner or bend 124 between the V-shaped surface 122 and the front surface 120 of the exit guide plate mernber 118 is provided having transversely extendin~ openings 126 .therein for receipt of a pair of spaced roller me~bers 128 which cornprise the ejector roller means 116. As can best be seen in Figures 1 and 8, these rear ejector rollers 128 are fixedly connected to a transversely extending shaft 130 which is journalled in the upright side housings 20, 22. The other ejector roller means 114 similarly comprise a pai.r of forward spaced roller members 132 affixed to a transversely extending shaft 154 mounted in the side housings 20, 22, the forward roller members 132 being arranged directly opposite from the rear roller members 128 The ends of the forward transversely extending shaft 134 in the side housings 20, 22 are journalled in a plate member 136 supported in the side housin~s 20, 22, for movement to move the forward roller members 132 into en~agement with the rear roller members 128.
As bes-t seen in Figure 5, the movable plate members 136 are sprin~ biased to normally maintain the forward roller members 132 in spaced relationship with respect to the rear roller members 128 in order to provide a space for a sheet of paper 16 to freely move there--2~- 1 16~505 between. 'rhe movable pl.ate members 136 each include a slot 13~ -there:in through which the -trallsversely ex-tend-ing shaf-t 130 for the rear roller members 128 pass.
The rearward end of the movable plate mernbers 136 are each provided wi-th a cable 140 which is connec-ted to retrac-table solenoid members 142 fixedly mounted in brackets i.n each of the uprigh-t side housin~s 20, z2.
These cables 140 connected to the solenoid members 142 and the movab]e plate members 136 each pass about a transversely extending sleeve 144 mounted in the side housings 20, 22. Simultaneous retraction of the solenoid members in -the side housings 20, 22 serves to pull the plate members 136 rearwardly to thereby move the forward ejec-tion roller members 132 into engaye~
ment with the rear ejection roller members 128. Th~ extent of travel of the pla-te member 136 and thus the forward roller members 1.32 may be limited by the length of the longitudinal slot provided in the plate members 136, or alternatively by the engagement of the forward ejection rollers 132 with the rear ejection rollers 128.
The transversely extendirlg rear shaft 130 is provided at one end (the left hand end as viewed in Figure 1) with a ro-tatable gear 146 fixedly mounted thereto and in mesh:ing engagemen-t with a second gear 148 rotatably supported on the wall of the upright side housing 20. This second gear member 148 in turn is in meshing engagement with a gear 150 fixed to the drive shaft of an ejection motor 152 mounted in -the uprigh-t side housing 20. Actua-tion of the ejection motor 152 thus causes the second gear 150 to rotate to in turn rotate the rear ejection shaft 130 to drive the rear ejection rollers 128 in a counterclockwise direction as viewed in Figure 5. As can be appreciated, when the forward ejection rollers 132 are moved into engagement w-ith the rear.ejection rollers 128 and the rear ejection rol:Lers 128 rotated by the ejec-tion motor 152, the forward and rear ejection rollers 132, 128 will -24- 1~ B05~

grippingly engage a shee-t of paper 16 therehetween and rota-te in opposite directions to pull -the paper 16 away from the prin-ting device 12 and move same upwardly (see Fi.gure 12). This upward movement of the shee-t of paper 16 will. continue unti:L the paper 16 is ejected from the rollers 128, 132, a-t which time it will fall backwardly and downwardly (as viewed in Figures 8-15) to rest in a receptacle 168 therefor defined by the lower end of the V-shaped surface 122 of the exi-t guide plate member 118 and the forward surface 105 of the deflector plate 96 (see ~igure 13). As the sheets of paper 16 are ejected from the printing devlce 12, the sheets 16 will thus be stacked against the deflector plate 96 with the lower ends thereof resting in the V-shaped surface 122 of the exit guide plate member 118 (see ~i.gure 13).
The paper feeding apparatus 10 i.s also provided with a removable forward cover member 154 which defines with the forward surface 120 of the exit guide p:l.ate member 118 an exit path of movement 160 (see Figure 8) for guiding the sheets of paper 16 as they leave the platen 18 upwardly between the normally spaced ejection rollers 128, 132.. For this purpose, the cover member 154 inc:Ludes a downwardly extending plate portion 156 which i.s slightly inclined with respect to the forward surface 120 of the exit guide plate member 118 to provide a relatively large en-trance which -taper.s toward the eject:ion rollers 128, 132. The lower front surface 156 of the cover member 154 also serves as a stop or rest for the paper rol.lers 158 of the printing device 12 which normally serve to direct the paper 16 away from the print head 14. The cover 154 also includes a recessed portion 162 for the forward ejection rollers 132 and the mounting shaft 134, and an upper deflection surface 164 for directing the sheet of paper lG rearwardly towards the deflec-tor plate 96. The cover member 154 may also be provided with upwardly extending tab portions 166 extending from the inner surface of -2~ 6V505 the lower forward end portion 156 for ensuring that the paper 16 is guided between the ejector rollers 128, 132 and does not engage the support shaft 134 for the forward ejection rollers 132 (see Figure 1).
The paper f~eding apparatus lo also includes a pair of paper movement sensors 170, 172 for sensing when a sheet of paper 16 is being moved therepast. Each of these sensors 170, 172 is of the photoelectrical reflective type which transmits a beam of light and which includes means for receiving the reflected light to close the sensor 170, 172. Thus, when a sheet of paper 16 is moved in front of each of the sensors ~70, 172, the paper 16 will serve to reflect and direct the projected light back to the sensor 170, 172 which detects same and closes the sensors 170, 172.
The first paper movement sensor 170 is mounted in the lower paper guide plate member 8~ adjacent the lower end of the paper feed path 100. This sensor 170 serves to detect if and when a sheet of paper 16 is moved therepast in order to signal the controller to actuate the platen 18 for rotation to receive a sheet of paper 16 fed from one of the paper trays 44 or 46.
The second paper movement sensor 172 is located in the outlet or exit path 160 of movement of a sheet of paper 16 in the front surface 120 of the exit guide plate member 118 for detecting when a sheet of paper 16 has been picked up by the platen 18 and is being moved thereby in the path 160. This sensor 172 also serves to provide a reference point used in the position-ing of the sheet of paper 16 in a proper print position relative to the printing head 14. Each of the sensors 170, 172 are centrally located with respect to the longitudinal center line of the paper feeding apparatus 10 so that they will be operable with respect to all widths of paper which may be utilized in the paper feeding apparatus 10.

-26~ 5 0 ~

The paper feeding appara-tus 10 further includes paper tray sensors 17~i, 176 for sensing w~len the paper trays 44, 46 are out of paper. These sensors, 174, 176, one for the upper tray 44 and one for the lower tray 46, are mounted on the underside of either the top suppor-t pla-te 167 or the upper paper tray plate member 5~. Each of these tray sensors 174, 176 includes a cantilevered movable switch actua-tor 178 which is directed towards its respective paper tray 44, 46 and engages a sheet of paper 16 when paper is in -the tray 44, 46. The paper support plates 48 in the paper trays 44, 46 are each provided with a slot 180 therein in alignment with the switch actuators 178 of the respective sensors 174, 176. Each of the tray sensors 174, 176 are open when the switch actuators 178 are raised and are closed when the switch actuators 178 are lowered, the actuators 178 being biased toward the lowered posi-tion. As long as a sheet of paper 16 is in the paper tray 44 or 46 on top of the paper support plate 48 (which is bi.ased upwardly by the roller elements 60) the actuators 178 will be i.n t;}!e raised posi-tion. However, when the last sheet of paper 16 is removed from the paper tray, 44 or 46, or when the paper tray rele~se lever 66 is depressed or the paper tray 44, 46 ha.~
been removed, there will be no sheet of paper or l)ther means for rnaintaining the swi.tch actuators 178 in the raised position and the actuators 178 will thus move into its lower position, thereby providing an indication that no paper is available for feeding to the prin-ting device 12.
The opera-tion of the paper feeding apparatus 10 will now be described.
Initial.ly, the paper feeding apparatus lO
is rnounted to the upper rear surface 30 of a printing device 12 with the paper feed path 100 being ali(Jned with the inlet 106 -to the paper platen 18 and wit7~

-27~ VS0 -the paper exi.t path 160 being aligned wi.th ~he e~i-t en~ o~
the platen 18. I~ a conventionally used cylindric~1 platen 18 is provided in the printing device 12, the spacing between the paper feed path 100 and the paper exi-t path 100 in the paper feedin~ apparatus 10 will substantially correspond to the diameter of the platen 18. This mounting of the paper feeding appara-tus 10 is accomplished by inserti.n~ the rear transversely extending bar 34 into the hook members ~2 of the mounting plate 24, previously mounted to the prin-ter device 12, and then -tilting the paper feeding apparatus 10 downwardly while depressing the loc~ing button 42 to receive the ~orward transverse bar 36 on the mountin~ plate 24. The locking button ~2 is then released to secure and lock the paper feeding apparatus 10 in place on the mounting plate 24. The paper ~eeding apparatus 10 is then connected electronically to the printer device 12 via a suitable electrical connection device and cable 182. 'I'he electrical section of the paper feeding apparatus lO includes a microprocessor, an interface and a cable 182. The microprocessor essentially serves to control the operation of the paper feeding apparatus l.0 during feeding as well as to cooperatively control movement of the platen 18 and printin~ head 14 to the extent necessary for proper feeding of sheets of paper 16 and moving the same into proper po~itioning for printing. In this regard, to the extent that the paper feeding apparatus 10 controls operation of -the platen 18 and prin-t head 14 of the printer device 12, the paper feeding apparatus 10 uses the conventional codes or commands used by a printing device 12 via the control circuitry therefor. The information respecting these codes or commands, as available from the printer interface and as used herein, are set forth in the Interface Manual which, in -the instance of the exemplary embodiment which is used on conjunction with a Lanier "No Problem" word processing unit, is pu~lished by Lani.er Bus.iness Products.

-2~- 1 1 6~0$
The paper feeding apparatus 10 permits the automatic ]oading o-f sheets of paper 16 into the printing device 12 for prin-ting thereon either -from commands loca-ted in the text being processed by the prin-ting device 12 or by operator selection through a control panel 184 located in -the fron-t of the paper feedin~
apparatus 10. Thus, in this latter regard, the paper feeding appara-tus 10 may be used to feed shee-ts 16 automatically to the printing device 12 and print any previously crea-ted text that is stored on a disk or in the word processing unit without any additional commands for controlling operation of the paper feeding apparatus 10 being made to the text.
The control panel 184 in the preferred embodi-ment consists of four switches 186a-d and five lights 188a-e. Four of the lights 188a-d are moun-ted on the switches 186a-d and the remaining light 188e is located on the top of the panel 184 to provide an indication that the power is on for the printing device 12. In this regard, this power on light 188e indicates that the paper feeding apparatus 10 is connec-ted to the printer device 12 and has power. Under normal operation, only the power light 188e will be on and the other four lights 188a-d will be oEf. One of the switches and lic3hts, for example, -the upper switch 186a and light 188a, are for resetting the operating of the paper feeding apparatus 10 and to indicate that there ls a fault. The second switch 186b may for example control feeding of paper 16 from the upper paper tray 44 and, when the light 188b is lit, to indica-te that the tray 44 is empty. Similarly, the third switch 186c is for controlling feeding from the lower paper tray 46 and the light 188c serves to indicate when the lower -tray 44 is empty. The fourth switch 186d may provide control of the mode of operation of -the paper feeding apparatus 10, to be described more fully hereinbelow, with the light 188d indicating that the feeding apparatus 10 is in the manual mode of operation.

11~05Q~

The actual processing which takes place during operation of the paper feeding apparatus 10 may best be appreciated upon a detailed review of the annotated program listing attached hereto as Appendix A; however, in order to provide the reader with an overall view of the processing which takes place under program control, -the flow charts set forth in Figures l~a and 16b are provided and will be hereinafter discussed so that the manner in which the paper feeding apparatus 10 operates and implements basic functions may be readily.understood. It should be noted however, that the flow charts which are herein-after discussed are simplified to a great degree, consis-tent with the usage of flow charts as relied upon by those of ordinary skill in the art, and hence, reference to Appendix A should be made for precise details ofthe particular program described or otherwise employed.
In essence, the flow charts of Figures 16a and 16b illustrate the implementation of the basic algorithm for the microprocessor in the control vicinity of the paper feeding apparatus 10. The operation of the paper feeding apparatus 10, by means of operator selection through the control panel 184j will now be described with reference to Figures 16a and 16b.
When it is desired to print stored -text onto a sheet of paper 16, the paper feeding apparatus 10 is activated to enter the Feeder Control Routine A
(as indicated by the circular flag 200 and labeled "Feeder Control Routine" in Figure 16a) by depressing the appropriate paper tray switch 186b or 186c for either the upper or lower paper trays 44, 46 to select the appropriate size of the paper 16 upon which printing will occur. The paper feeding apparatus 10 initially tests to ascertain which switch 186b or 186c is de-pressed. Assuming that only one of the tray switches186a or 186b is depressed (the other operations depicted in Figure 16a will be described later), the paper feeding apparatus 10 enters the Reset, Fj ect and Feed Routine B (illustrated in Figure 16b, labeled as circular flag 224) for the selected tray 44, 46.

30_ t ~ 5~5 ~ ore specifically, the paper feeding apparatus 10 initially tests to de-termine if the upper tray switch 186b is depressed as indicated by the diamond 202.
This :is done by testing -the open or closed condition S of swltch 186b. If the tray switch 186b is depressed, the state of -the lower -tray sw.itch 186c is tested to determine if the lower tray sw:itch 186c is also depressed, as indicated by the arrow 204 and diamond 206. (The operation of the system when both tray switches 186b and 186c are depressed to~ether will be described herein-below; at the present time, it is assumed that only the upper tray switch 186b is depressed.) If the test of the lower tray switch 186c (as indicated by the diamond 206) is negative, the Reset, Eject, and Feed Routine B is entered for the upper tray 44, as i.ndicated by the arrow 208 and the circu:Lar flag 210. If the upper tray switch 186b is not depressed, the~ lower tray switch 186c is then checked, as indicated by the arrow 212 and diamond 214. If the lower tray switch 186c is depressed, the Reset, Eject and Feed Routine B is entered for the lower paper tray 46 (as indicated by the arrow 216 and circular flag 218). If the lower tray switch 186c is not depressed, the paper feeding apparatus 10 then tests whether the reset switch 186a has been depressed, or whether the mode switch 186d has been depressed, as indicated by the diamonds 220 and 222. These tests and the operation effected as a result thereof wlll be described more fully hereinbelow.
Although not shown, the depressing of the upper or 30 lower paper tray switches 186b or 186c also sets a tray flag, which may typically comprise a flip-flop, to indicate which tray has been selected so -that during the Rese-t, Eject and-Feed Routine, paper will be fed from the appropriate paper s-torage tray 44, 46. Thus, it.will be appreciated that the paper feeding apparatus 10 may be activated by depressing either of the switches 186b or 186c -to set the appropriate flag and enter the Rese-t, Eject and Feed Rou-tine for either the upper paper tray 44 or the lower paper tray 46.

-31- 11 6~0~

~ s the Reset, Eject and Feed Routine is essen-tially the same whether the upper tray swi~ch 186b is depressed or the lower tray switch 186c is depressed, the flow diagram of Figure 16b will be described l~ith reference to -the upper tray switch 186b having been depressed.
When the Reset, Eject and Feed Rou-tine B
(indicated by the circular flag 224, in Fi~ure 16b) is ini-tially entered for the paper tray 44, -the paper feeding apparatus lo automatically checks to determine if any paper 16 is left in the printing device 12.
This is accomplished as indica-ted by the diamond 226 and is implemented by checking whether or not the paper inlet sensor Sin is in an open or closed condition.
The inlet sensor Sin corresponds to paper movement sensor 170, and thus the determination of whether the inlet sensor Sin is closed or open corresponds to a detection of an output from the receptor portion of the sensor 170 corresponding to the receipt of light as reflected by a sheet of paper 16 on the back of the paper movement sensor 170 (in which case the inlet sensor Sin is closed) or whether no light is received (in which case the lnlet sensor Sin is open). If the paper inlet sensor Sin is closed, as `indicated by -the 25 arrow 228 and the rec-tangle 230, the print head 14 and its associated guide member 15 are centered trans-versely with respect to the platen 18, a platen flag is set, and then a Sin timer is started. The print head 14 and guide member 15 are centered to ensure -that the sheet of paper 16 in the printer device 12 will be guided along -the exit path of movement 160, as more fully described hereinbelow. The setting of the platen flag and the star-t of the Sin timer are for the purpose, respectively, of indicating that the inlet sensor Sin was initially closed (i.e., paper was initially in front of the inlet sensor Sin (170 ?

~ 1 6~S~

when a nel~ sheet of paper was called for), and to s-tart a -timer which wi].l serve to actuate an alarm wi-thin a predetermined time if the inlet sensor Sj is not cleared. ~he platen :~lag may typically comprise a flip-flop and -the Sin timer may typically comprise a counter driven from the sys-tem clock or divisions thereof.
After centering of the print head 14 has been initiated t.ogether with a setting of the platen flag and a starting of the Sin t-mer, the pla-ten 18 is actuated (as indicated by the rectangle 232) to drive paper 16 in -the forward paper feed direction for a prede-termined number of increments, corresponding for example to a distance of 2 inch per step.
The centering of the print head l~ and its associa-ted guide member 15, as well as the advance of the platen 18 is accomplished in the preferred embodi-ment by utilizing the conventional printing device 12 commands as normall.y provided by the system to the printer. For example, this can be accomplished by genera--ti.on of an appropriate signal which corresponds tothe signal used by the prin-ting device 12 for actuating the platen advance motor and the print head ~arriage motor. In this regard, it is to be noted that -these conventional commands can be utilized since the paper feeding apparatus lO is electrically connected and coupled with the control unit for the printing device 12.
After the platen 18 has advanced the predeter-mined number of increments, the paper feeding apparatus lO again tests to determine whether the inlet sensor Sin (170) is still closed, as indicated by the diamond 23~. If the inlet sensor Sjn is still closed, the S i timer is then checked to determine if it has -timed out, as indicated by the arrow 236 and -the diamond 238. If the Sin timer has timed out, an appropriate alarm is actuated and returns to the Feeder Control _33_ ~1 6~Q~

Routine A so the alarm may be deactivated ~as des~ribed hereinbelow), as indicated by the arrow 2~0 and the rectangle 242. The alarln for example may comprise a swi-tchable buz~er or bell and/or a li.ght. In -the preferred embodlment, this alarm compri.ses both a bell (not shown) and a light 188a. The tirning period for -the Si timer should be chosen to be sufEiciently long to permit a sheet of paper 16 blocking the sensor Si to be cleared from the sensor Sin by movement of the paper 16 by the pla-ten 18. If the Sin timer has not timed out, the platen 18 is again advanced, as indicated by the arrow 244 and rectangle 232. This operation of advancing the platen 18, checking the inlet sensor Si and the timer Sin .is continually repeated until the inlet sensor Sin opens to indicate that paper 16 has been cleared from in front of the inlet sensor Sin, or the Sin timer times out. Assuming that the inlet sensor Sin opens before the Sin timer times out, (as indicated by the arrow 246), the paper feeding apparatus 10 then proceeds to determine whether the outlet sensor SOUt, corresponding to the paper movement sensor 172, is closed or open as indica~ed by the diamond 248. Similarly, if the inlet sensor Sin is initially opened (corresponding to no paper being in front of the input sensor Sin (170~), the outlet sensor SOUt will then be tested, as indicated by the arrows 250, 246 and diamond 248.
I:E the outlet sensor S ut is ~losed (correspond-ing to the paper 16 being in Eront of the paper movemen-t sensor l.72) as indica-ted by the arrow 252, the paper feeding apparatus 10 is operated to eject paper 16 from the pr:i.nting device 12. More specifically, after the outlet S t is sensed as being closed, the print heac1 14 is centered and the platen 18 is actuated a predet.ermined number increments to ensure that the paper 16 in the pr nting device 12 is free from the platen 18, c~s indicated by the rectangle 254. In this regard, if the p~:n.rlt head 14 has already been centered _3~ ll 60505 (in the opera~ion serving to clear -the inle-t sensor Sin, indica-ted by the rectan~le 230), the signal for centering -the print head 14 would not cause any additional motion. The operation of advancing the pla-ten 18, indi-cated by the rectangle 254, is again accomplished bygenerating a signal uti:lizing -the conventional commands for t;he printing device 12 to rotate the platen 18 a sufficient number of increments to move the trailing eclge of the paper 16 to the exit end of the platen 18. The number of increments for example would correspond to the distance from the inlet sensor Sin (170) to the exit from the platen 18 (since it is known that pri.or to this advance of the platen ].8 the trailing edge of the paper 16 is clear of the inlet sensor Sin).
Nex-t, as indicated by the rectangle 256, the ejection solenoids 142 are actuated to ~.ove the ejection rollers 128, 132 into engagement ~ith one another, and then the ejection motor 152 actuated to drive the ejection rollers 128, 132 to pull the sheet of paper 16 out of the printing device 12 and to stack the same i.n the paper outlet hopper or receptacle 168. The ejection motor 152 typically may comprise a stepping motor which is actuated for a specified number of steps and is then turned off. The number of steps should be sufficient to move the trailing edye of the sheet of paper 16 through the ejection rollers 128, 132. This would corres-pond to movin~ the paper 16 a distance at least as great as the distance from the exit of the platen 18 to the ejection rollers 128, 132, as the platen 18 was previously advanced -(as indicated by the rec-tangle 254) to move the trailing edge of the paper 16 to the exi.t for the platen 18. After the ejection motor 152 is actuated, the ou-tlet sensor S0ut (172) i5 again tested as indicated by the diamond 258. If the outlet serlsor S0ut is closed, an alarm is sounded and the light 188a is lit, as indicated by the arrow 260 and rectangle 262, and then returns to the Feeder Control 1 1 S~50`~

Routine A (200). Ihis condition would correspond to a paper jam since actua-tion of the ejection mo-tor 152 for -the predetermined number of steps should have cleared the outlet sensor S
out If the output sensor S ut is open, the ejectior~
solenoids 142 are deactivated to open the space between the ejection rollers 128, 132, as indicated by the arrow 264 and rectangle 266. After this operation, the paper feeding apparatus 10 proceeds to the line 268 to eventually check whether the upper paper tray 44 is empty (since the upper paper tray 44 was initially selected from which to feed paper 16), as indicated by the arrow 270 and diamond 272.
Alternatively, if the outlet sensor SOUt was opened when it was initially tested, as indicated by the diamond 248 (i.e., no paper 16 was in front of the sensor 172), the paper feeding apparatus 10 will test whether the platen flag was set, as indicated by the arrow 274 and diamond 276. This test serves to determine whether t~le inlet sensor Sin w~s initially closed or opened when the Reset, Eject and Feed Routine was entered. If -the platen flag was not set ~correspond-ing to the condition of the inlet sensor Si having been initially open) the paper feediny apparatus lO
proceeds, as indicated by the arrow 278, to the line 268 to subsequently -test whether the upper paper tray 44 is empty, as indicated by the arrow 270 and diamond 272. On the other hand, if the platen flag was se-t (indicating that paper 16 was in front of the inlet sensor S initially), an alarm is sounded and the ln light 186a lit, as indicated by the arrow 280 and rect~ng-le 282, and returns to the ~eeder Control Routine A
(200). Here i-t should be noted that the test oE whether the platen flag was set (at the diamond 276) would only be made if the outle-t sensor SOUt were initially operl when tested at the diamond 248. Thus, it will -~t,-0 ~

be appreciated tha-t an alarm would be ac-tua-ted only if the inlet sensor Sin were initially closed and, after Sin is opened, the outlet sensor S t is initially open. This would indicate that the paper initially blocking -the inlet sensor Si jammed in the printer 12 before reaching the outlet sensor S t. Conversely, if the :inlet sensor Si was initially open (i.e., no paper 16 in the paper feed path 100) the paper feeding apparatus 10 would proceed along arrow 250 to test the condition of the outlet sensor SOUt and the platen flag wou:Ld not be set. If the outlet sensor SOUt is also open initially (indicating that no paper is in the exit path 160), the test for the platen flag, at the diamond 276 would be negative, as indicated by the arrow 278, and the paper feeding apparatus lO would proceed to test the upper paper tray 44 for paper, as indicated by the line 268, the arrow 270 and the diamond 272.
If the paper feeding apparatus lO has not jammed and the printer 12 is clear oE paper, the paper feedlny apparatus lO proceeds to test whether the selected paper tray (i.e., the upper tray 44 in this example) is empty, as indicated by the diamond 272. In this determination, if the selected paper tray 44 is empty, an appropr:iate alarm is actuated, as indicated by the arrow 284 and the rectangle 286, and the paper feeding apparatus lO returns to the Routine A (200). In the preferred embodiment this alarm comprises lighting the paper tray empty light 188b and sounding a ~ell or buzzer to alert the operator. If the paper tray 44 is not empty, as indicated by the arrow 288, the paper feeding apparatus 10 then generates a signal to center the print head 14 transversely with respect to the platen 18, again by utilizing the conventional O~05 .commands for the pri.nting device 12 for movemen-t of the prin~ head carriage, as indicated by the rectangle 290. If the print head 14 has already been centered as in the ejecting part of the Routine B as indicated by the rectangle 230 or the rectangle 254), this si~nal will simply be ignored. Also, at this time, as indica-ted by the rectangle 290, the appropria-te tray drive rollers 72 are ac-tivated by actuation of the associated drive motor 80 to feed a single sheet of paper 16 from the lO . paper tray 44 forward along the paper inlet path 108 into the main paper feed path lO0. When the associated drive motor 80 is actuated, a first drive roller in-terval timer is also started, as indicated by -the rectangle 290. This timer may be similar to the Sin timer and performs a si.milar function wi.th respect to the time of operation of the tray drlve rollers 72. As the sheet of paer 16 is fed from the paper tray 44 along the paper inlet path 108 into the main paper feed path 100, the leading edge of the paper 16 strikes the deflect-or plate 96 and is directed downwardly along the main paper feed path 100. The paper travels in a relatively straight line path towards the platen lB and past the paper input sensor 170 (see also F'igure 9).
The next operation is to tes-t the inlet sensor Sin (170) to determine if it is closed. If the paper i.nlet sensor Sin (170) does not close within a predeter-mined time after actuation of the tray drive motor 80, a fault alarm is sounded and the fault light 188a is lit on the paper feeding apparatus 10, to indicate that -the paper 16 has not been fed from the paper tray 44, or that the paper 16 has jammed in the inlet feed path 108 or in the main paper feed path 100. This is acGom-plished by testing the inlet sensor Sin to determine whether or not it is clo~ed, ac -.rldi.c~-ted by the diamond 292. If the inlet sensor Sin is not closed, a test is made 1 1 6~0 ~

as to whether the first drive rol:Ler t-imer has timed o~Jt, as indicated hy the arrow 29~ and diamond Zg6. If the firs-t drive roller -timer h~s ti.med out, the alarms are actuated, as indicated b~J -t.he ~Irrow 298 and rectangle 300, S and the paper feeding apparatus 10 returns to the Routine A (200). If the first drive roller timer has no-t timed out, the paper *eeding apparatus 10 again tests the inlet sensor Sin to determine whether it is closed, as indicated by the arrow 302 and the diamond 292. This loop is continued until either the inle-t sensor Sin is closed or the first drive roller timer has timed out. The interval or timing period for the fi.rst drive roller timer is chosen to allow a sufficient time for paper 16 -to be fed from the tray 44 past the inlet sensor Sin (170) if the paper has not jammed.
If the inlet sensor Sin (170) closes within the predetermined period of time alot-ted by the firs-t drive roller timer, the platen drive motor is actuated to begin driving the platen 18 for receipt of the sheet of paper 16 being fed along the main paper feed path 100, as indicated by the arrow 304 and the rectangle 306. This actuation of the platen 18 takes pl.ace a predetermined time after the leading edge of the shee-t of paper 16 being fed passes the paper inlet sensor 170. In this regard, it should be noted that the platen 18 is driven at a slower rate of speed than the speed at which the paper 16 is fed by the tray drive motor 80 to ensure a posi.-tive feeding of the sheet of paper 16 into the platen 18. ~lso, when the pla-ten 18 is actuated, an outlet sensor counter (S0ut counter) and a second drive roller timer are started, as indicated by the rectangle 306. The SOUt counter is decremented each time the platen 18 is advanced and should be set at an initial s-tate corresponding to the number of discrete steps of the platen 18 with which the outlet -39~ 5 0 5 sensor SOut shoulcl c'Lose if the paper 16 is being properly moved by the platen 18. ~'he second drive roller timer is similar to the Si , and first drive roller timers, and serves to define a predetermined period of time after which the drive rollers 72 should be turned off.
This timing interval should provide a sufficient time or number of steps to permit the leading edges o-f the paper 16 to advance from the inlet sensor Sin into t,he inlet 106 for the platen 18.
Next, the paper feeding apparatus 10 de-termined whether the second drive roller timer has timed out, as indi.cated by the arrow 307 and the diamond 308.
This test is continually repeated, as indicated by the arrow 310, until the second drive roller timer has timed out. When the second drive roller timer has timed out, as indicated by the arrow 312, the tray drive rollers 72 are turned off, as indicated b~ the rectangle 314. When the tray dri.ve rol].ers 72 have been turned off, the paper 16 will be advanced solely by means of the platen 18. In thls regard, it will be noted that the drive rollers 72 are provided with a roller clutch so that the drive rollers 72 may Ereely rotate in the counterclockwise direction relative to the drive shaft 70, as viewed in Figures 8-15.
Once the paper 16 is fed into the platen 18, it will be advanced around the platen 18 to move past the print head 14 and associated guide member 15 of the printing device 12 and be directed along the paper exit path 160. In this regard, it will be recalled that the print head 14 and associated guide member 15 thereon were previously centered with respect to the transverse center of -the platen 18 (see rectangles 230, 254, 290), and thus with respect to the longitudinal center line of the paper 16 being advanced. The paper guide member 15 serves to deflect a sheet of paper 16 being advanced therepast directly into alignment -40~ 0~0~

with the paper exi-t pa-th 160 be-tween the lower pla-te port:i.on ~56 of the cover 154 and the lower front surface 120 as the exit guide plate member 118. The paper guide member 15 is a conventional element of typewriters and printers, and has a -transverse width which normall.y serves to deflect the paper being fed therepas-t in the rearward direc-tion on the platen 18 so that the paper will not fall back over the print head 1~. Tl~e alignment of the print head 14 and guide member 15 in the center of the platen 18 is preferably accomplished before the tray drive rollers 72 are actuated (see rectangle 290), although it may be accomplished any time prior to a sheet of paper 16 being received by the platen 18.
' Thus, it will be appreciated that in -this manner, the guide member 15 and the printing head 14 are employed as a deflection member to ensure prope~
f'eeding of the paper 16 along the desired exi.t pat~
160. More specifical.ly, the centering of the guide member 15 with.respect to the platen 18 serves to properly direct and guide the paper 16 a:long the exit paper path 160, which might not otherwise be the case if the print head 14 and paper gu:ide member 15 were located at one of the margins of the paper 16 of if no guide 5 member 15 were provided.
l'he pl.ate~n 18 is cont:inued to be driven -to advance the leading edge of the paper 16 in the ex:it path 160 and past the paper outlet sensor 172 (see Figure 10). In this regard, it is to be noted that the platen 18 is driven by using conventional commands of the printing device 12 for advancing the platen 18. Thus, in terms of an impact printing device 12 which incrementally advances paper, a sheet of paper 16 is advanced incrementally during this feeding opera-tion by simply directing the printing device 12 toadvance the platen 18 a specified number of increments.

-4~-$ 0 ~.) In the preferred embodiment, the p1aten 18 is advanced to move the paper 16 in 2 inch steps. For example, if e~ch platen increment corresponds -to 1/~8 inch of movement of the paper 16, the platen 18 would be advanced 24 increments at a time in this operation.
After a predetermined number of increments of pla-ten rota-tion (corresponding to the distance from the inle-t 106 to the platen 18 to the outlet sensor 172), the paper 16 should be moved past the paper-outlet sensor 172. If the outle-t sensor 17~ does not close within a predetermined number of increments of the platen rotation (corresponding to the initial state of the S0ut counter), an alarm and fault signal 188a are generated to alert the operator to a possible paper jam. This is accomplished by testing of the outlet sensor SOUt, as indicated by the diamond 316, after the tray drive rollers 72 have been turned off. If the outlet sensor S has not closed, a test is made out as to whether the S0ut counter i5 zero, as indicated by the arrow 318 and the diamond 320. If the SOUt counter is zero, an alarm is actuated as indicated by the arrow 322 and the rectangle 324, and the paper feeding apparatus 10 returns to the Routine A (200). In the preferred embodiment, the actuat:ion of this alarm comprises sounding an alarm and lighting the light 188a. If the SOUt counter is not zero, the outlet sensor SOUt is again tested to determine whether it has closed, as indica-ted by the arrow 326 and diamond 316. This loop is continued until either the SOUt counter is zero, in which event an alarm is actuated, or until S0ut has closed.
Once the paper outlet sensor SOUt (172) detects or senses the leading edge of the paper 16, the platen 18 is controlled to move in the reverse direction to move the leading edge of the sheet 16 slowly back until the paper outlet sensor 172 opens. At this moment, the movement of the platen 18 is stopped (see Figure llj, -42~ 050~

with the leading edge of -the paper 16 being aligned with the paper outlet sensor SOUt (172). This prov:ides a fixed or known reference point for the purposes of aligning the sheet of paper 16 relative to the print head 14 for the beginning of printing. Specifically, by knowing the distance of the paper sensor 172 from the print head 14, and -the distance the paper moves for each increment of the platen 18 advance or reverse, conventional printing commands can cause the paper 16 to be moved to the proper print position for the first line of print by advancing or re~ersing the platen 18 the required number of increments. For example, if the paper movement sensor 172 is located three inches from the pr:int head 14 and a one inch margin is desi.red at the top edge of the paper, -the p]aten 18 can be reversed to move the paper 16 two inches in the reverse direction. This operation of moving the platen 18 forward to move the leading edge of a sheet of paper 16 past the sensor 172, and then reversing the platen 18 movement is made in order to be able to move the platen 18 forward in rela-tively large increments (for example 2 inch steps) to achieve a relative fast speed of operation to align the paper 16.
More particularly, this operation for aligning the paper 16 for the start of printing is accompli.shed by reversi.ng the platen 18 once the outlet sensor SO t (172) closes, as indicated by the arrow 328 and rectangle 330. The platen 18 is then reversed slowly, for example in one step increments, and the outlet sensor SO t is again sensed to determine whether it is still closed, as indicated by the diamond 332. If the outlet, sensor SOUt remains closed, the platen 18 is again reversed one step, as indicated by the arrow 334 and rectangle 330. This operation is continued until the outlet sensor S opens. At that moment, the platen 18 is stopped out --4~

and the paper is -then repositioned re].ative to the print head 14 by movement of the platen 18, as indicated by the arrow 336 and rectangle 338. Finally, the print head 14 is moved to the adjusted left margin of the paper 16, as indicated by the rectangle 338.
In this regard, since the paper 16 is not aligned with the lef-t hand end or zero position of the printing device 12 when i-t is fed thereinto, but rather is inserted so that the center of the paper 16 is aligned with the center of the printing device 12 (i.e., since the paper 16 was fed with the lon~itudinal central portion being aligned with the longitudinal centerline of the paper feecl path 100 and the center of the pla-ten 18), margin adjust information is re_eived or programmed in the paper feedin~ apparatus 10 to adjust the margin control information in the printing device 12 to provide the desired margins for- printing.
More speci~ically, before any printing operation is undertaken, the printing device 12 generally will generate a restore command which move.s the pri.nt head 14 to the left hand end or zero position of the platen 18.
The host program or processor for -the prestored text contains appropriate margin information or commands for adjust.in~ the print head 1~ to pr~ a desired margin for the matter to be printed. Thi.s yenerally invo:lves a command to move the print head 14 a specified distance from the left end or zero position of the platen 18 which would provide the desired margins on the printed sheet of paper if the paper 16 were aligned with the left hand end of the platen 18. Since the shee-t of paper 16 is centrally fed by the paper feeding apparatus 10 in the present invention, by which it is known that the left hand edge of the sheet of paper is displaced a specified distance in from the left hand end of the platen 18, the margin adjust information simply adds a constant distance (corresponding -to this -44- 1 160~0~

known displacement of the left hand edge of the paper 16 from the lef-t hand end of the platen 18) -to the margin informa-tion in -the hC~Ct program or processor for the prestored tex-t of materials to be printed.
For example, if -the ma-terial to be printed is to have a one inch margin along the lef-t hand edge of -the paper 16, and if the left hand edge of the paper is displaced three inches from the left hand end or zero pos~ti.on of the platen 18, the margin information in the ~rintin~
device 12 (which would normally generate command to displace the print head 14 one inch in from the lef-t or zero position of the platen 18) would be adjusted to displace the print head four inches (one inch margin and three inches because the paper 16 is centered on the platen 18) in from the left or zero position of the pla-ten 18. This margin adjus-t informatiori can be preprogrammed into microprocessor for-the paper ~`eeding apparatus 10 for each of the different paper trays 44, 46 if standard paper trays are used.
After the paper 16 has been moved to the proper prin-t position for the beginning oE printing and the prin-t head 14 has been moved to the adjusted left margin of the paper, as indica-ted by the rectangle 338, the print mode is then entered, as indicated by the circular flag 340, and the prin-ting device 12 proceeds in accordance with i-ts program to prin-t the material on the sheet of paper 16.
When the printing has been completed on the sheet of paper lG, the printing device 12 is stopped, such as for example by appropria-te stop codes in the printing device 12. The paper feeding apparatus 10 will then automatically eject the paper 16 when the next sheet of paper is called for by the operator depressing one of the paper tray control switches 186b or 186c in which event the Reset, Eject and Feed Routine B
will again be entered, as indicated by either o~ -the circular flags 210, 218 in the flow chart of Figure -~5- ~ I G~ ~0 ~

16a. At tll-is tim~, the shee-t of paper 16 wilI be ejected frc>m the printi.ng device 12 (see ~igure 12) and store~
in the output hopper cr receptacle 16~ (see Figure 13).
It will be appreciated that duri~g the printing operations, the -trail:ing edge of the paper 16, which is some instances may be in the paper feed path 100, is free to move back and forth along this path 100 without interference from the paper storing -trays 44, 46 or drive rollers 72, 72' which are located transversely in the paper inle-t feed paths 108, ]10. This is a most important feature, since in impact type pri.nting opera-tions, the paper 16 must be capable of being moved back and for-th by the platen 18 for the printing of`
subscripts, superscrip-ts, charts or other special opera-tions. Also, with the paper feeding apparatus 10, the paper is moved backwards to align the leading edge with the paper outlet sensor 172 and then Eurther to set the desired top margin. More particularly, as can be seen from Figures 8-11, the paper 16, once it is released from the paper trays 44, 46 and drive rollers 72, 72' rnay be freely moved along the paper feed path 100 past the ends 108b, llOb, of the inlet feed paths 108, 110 for the upper and lower paper trays 44, 46.
The paper feeding apparatus 10 is also capable of being used in conjunction with a stored text or material which includes appropriate codes for automatical-ly feeding the paper 16 from the upper or lower trays 44, 46 and which are coded to indicate the en~ of a page of text or material to be printed. In this instance, the text or material is stored on the disk or other recording device may be modified to include automatic feed and ejec-t operation codes which would thus serve to allow the printing of a plurality of pages of text au-tomatically with the user only having to initially 46 ~ IB05~5 turn on the device. In -this operation, the paper feeding appara-tus 10 would aulomatically eject the paper 16 into the output receptacle 168 and feed a new sheet 16 into the prin-ter 12 without any additional opera-tion to be performed by the user. For example, such codes may include a code or command for indicating the proper paper tray 44, 46 to be used, such as an upper tray code or command, and a lower tray code or command, as well as an eject paper code command for ejecting paper when the prin-t head 14 has completed printing on the sheet of paper 16. The eject code, depending on the type of word processing unit and printer 12 wi-th which it i.s used, may include an eject code for the right hand margin of the printed matter when printing is always from the left to the right, or may include both left margin and right margin eject codes for use with a bi-directional printing technique where the print head 14 moved from the left to the right for one line of print, and, for the next or subsequent line, moves from the right to the left relative to the platen 1~. In this type of automatic operation, when the print command is given, the paper feeder appara-tus 10 will feed a paper from one of the two trays 44, 46, which command i.s programmed as the ~irst text 2S line of the page, with all subsequent paper feedings being from the selected tray or, if the opposite tray is selected, from the opposite tray, in which case all subsequent paper feedings will be from that tray.
At the completion of each page of print, by properly programming appropriate-eject codes into the text of the ma-terial, the system will au-tomatically eject the paper 16 and feed a new sheet of paper 16 into proper printing position in the manner as described above.

~ 16~505 In this regard, the codes appearing in the text of -the material in essence serve to yenera-te signals which are similar to the signa:ls genera-ted by either the upper or lower tray switches 186b or 186c being depressed (i.e., signals corresponding to the arrows 208 or 216) and the eject codes or commands are e~uivalent to generating a signal similar to the reset switch being depressed (to be described hereinbelow), so that the paper feeding apparatus will enter the Reset, Eject and Feed Routines and operate in the same manner as described above, as if the operator had selected one of the tray switches.
Of course, it should be appreciated -that this is only one way of automatically feeding, printing and ejecting paper, and that there are numerous other ways that such operations could be performed, as will be appreciated by those skilled in the art.
During operation of the paper feeding apparatus 10, the upper and lower tray switches 186b and 186c (if they have been depressed), are cleared (such as for example by providing spring biased switches normally biasing the switches 186b and 186c to an undepressed state). Thus, upon return to the Feeder Control Routine A (200), the paper feeding apparatus 10 may again sense whether any switches have been depressed. This is a continuous routine, as indicated by the return arrow 372, until and if further switches are depressed.
If an alarm has been actuated during the Reset, Eject and Feed Route B, the alarm may be turned off by depressing the Reset Switch 186a. This is accom-plished by returning to the Feeder Control Routine200 and testing the condition of the Reset Switch 186a.
More specifically, as noted above in the description of the Reset, Eject and Feed Routine B, after any alarm is actuated, the paper feeding apparatus 10 returns to A, the Feeder Control Routine 200. Since the upper 1 1 6~505 and lower -tray switches 186b, 186c have previously been cleared (and -thus -the tests of these switches, indicated by the diamoncls 202, 214, are negative, as indicated by the arrows 212, 342), the paper feeding apparatus 10 will proceed to tes-t whether the reset switch 186a is depressed, as indicated by the diamond 220. If the reset switch 186a is depressed, the paper feeding apparatus 10 wi.ll proceed to test whether an error condition exists, as indicated by the arrow 344 and diamond 346. This error condition would correspond to one of the alarms being actuated, and could typically be indicated by se-tting of an alarm flag whenever an alarm is actuated and testiny whether an alarm flag has been set. If an error condltion does exist, the alarm is turned off (in particular the sound alarm), as indicated by -the arrow 348 and the rectangle 350.
Then, the reset switch 186a is again tested, as indicated by the diamond 352. If the reset switch 186a has been depressed again, a restore command is generated for the printing device 12, as indicated by the arrow 356 and rectangle 35~. It should be noted here that the reset switch 186a, when an alarm is actuated, is simply pressed once and released to turn off the alarm. It is thereafter pushed a second time to.generate the reset command and clear any alarm flags. The paper feeding apparatus 10 then returns to the Feeder Control Routine A, as indicated by the circular flag 360. If the reset switch 186a has no-t been depressed, -the paper feeder simply returns to check the reset swi.tch 186a until it is depressed again, as indicated by the arrow 354 and the diamond 352.- Once an error condition has been detected, the reset switch 186a must be depressed a second time before any printing or further feeding operations are continued.

. ~49~ 1 16~05 The reset swi.tch l~a mcly ai.~.o be utilized to eject paper 16 from the printin~ device 12. More specifically, if the test of the reset switch 186a, as indicated by the diamond 220, is positive, and there is no error condition, the paper feeding apparatus 10 will enter the Reset, Eject and Feed Routine B for the reset mode, as indicated by the arrow 362 and the circular flag 364. Also, similar to the situation where the upper or lower tray switches 186b, 186c are ~epressed, a reset flag will be set before the Reset, Eject and Feed Routine B is entered so that the ~eset, Eject and Feed Routine B may be exited at the appropriate time.
When the Reset, Eject and Feed Routine B
224 is entered for the reset mode, the same set of operations as were initially performed upon depressing of the upper or lower tray switches 186b or 186c are performed to clear the printing device 12 of ary paper 16 which may be therein. The only difference is that once the inlet and outlet sensors S. and S are ln out both cleared or opened, as indicated by the arrow 27 and 264 (assuming no jam which would cause actuation of an alarm indicated by the rectangle 282), the paper feeding apparatus 10 exits from the reset mode and returns to the paper feeding routine A, as indicated by the line 268, the arrow 270 and the circular flag 365, prior to determining whether paper is in any tray 44, 46.
A further feature of the paper feeding apparatus is the provision that individ-ual sheets of paper 16 may be inserted into the printer platen 18 without removal of the paper feeding apparatus 10 from the printer 12. This is accomplished by moving or depressing the mode switch 186d to manual operation which will leave the paper feeding apparatus 10 electrical-ly connected to the printing device 12 but transparent 1 1 ~0~0~ ' to the system (i.e., the paper feeding apparatus 10 appears not to be connected to the system). The paper feeding apparatus 10 may then be tilted upwardly to its raised position (see Figure 3) by depressing of the locking switch 42 to thereby provide access to the printer platen 18 without interference from the paper feeding apparatus 10. The paper feeding apparatus 10 may either be supported on the printer 12 in the raised position or can be removed from the printer 12. In this manual mode of operation, the printer device 12 would operate as if the paper feeding apparatus 10 did not exist so that the user may simply insert the sheet of paper 16 into the platen 18 and manually align same.
In terms of the flow diagram of ~igure 16a, the mode switch 186d is tested during the Feeder Control Routine (200) as indicated by the diamond 222. If the mode switch 186d is depressed, the print mode of the printing device 12 is entered as indicated by the arrow 368 and the circular flag 370. If the mode switch 186d is not depressed, as indicated by the arrow 372, the Feeder Control Routine 200 proceeds with testing of the other switches 186b, 18hc, 18fia on the control panel 184, as indicated by the diamonds 202, 214, 220.
A still further feature of the paper feeder apparatus 10 is the provision for envelope or single sheet feeding without having to remove the paper feeding apparatus 10 from the printer 12. In this mode of operation, envelopes or other non-standard sheets of paper 16' can be fed manually through the paper feeding apparatus 10 to the printer platen 18. In this instance, a special input slot 190 in the output hopper or receptacle 168 of the paper feeding apparatus 10 is provided. More particularly, as best -51- 11 6~5~5 seen in Figures 8-15, the V-shaped surface 122 of the exi-t guide pla-te member 118 is spaced from the deflector pla-te 96, thus defining the inpu-t slo-t 190 which comm~ni-ca-tes with the paper feed pa-th 100 -to -the platen 18 a-t a position in the paper inlet feed path lO0 below the lower paper -tray 46. The envelope or other non-standard size of paper 16' can -thus be fed directly in-to the paper receiving inle-t 106 for the paper platen 18.
To utilize this feature, all the paper 16 in the outpu-t hopper 168 must be removed and the reset switch 186a pushed to eject any paper 16 which may be in the printer 12 and paper feed and exit paths 100, 160, and to move the print wheel 14 to the left most printing position. Then, the upper and :Lower paper tray swi-tches 186b, 186c are depressed simultaneously which will position -the prin-t wheel or prin-t head 14 in the center of the printer 12 and place the paper feediny appara-tus 10 in the envelope/ single sheet mode. The envelope or shee-t of paper 16' is then placed in the :input slot 190 therefor and -the paper 16' is posi-tioned or aligned with the printer device 12 by manual opera-tion of the platen ~nob. 1`he paper 16' is now in position for prirlting the page directly with 2~ the use of the word processinc~ printing comrnands.
In terms of the F'eeder Control Routine shown in Fiyure 16a, -the paper feeder apparatus 10 tests whether both of the upper and lower tray swi-tches 186b, 186c have been depressed -together. This is accomplished with the tes-t of whether the upper tray switch 186b is depressed as indicated by -the diamond 202, previously described.
As noted above, if the upper paper switch 186b is depressed, the state of -the lower -tray switch 186c is then tested, as indicatecl by -the arrow 204 and the diamond 206. (As noted above, if the -test is negative, as indicated by the arrow 208, the paper feeding apparatus lo enters the Reset, Eject and Feed Routine B for the upper paper tray 44.) If the lower tray switch 186c is also depressed, the print head 14 is centered, as indicated by the arrow 374 and the rectangle 376, and the print mode is entered, as indicated by the circular flag 378, and printing may be commenced.
In the preferred embodiment, when the system has been placed in the envelope mode, depression of either of 10 the upper or lower switches 186b, 186c will feed a sheet of paper 16 from the selected paper tray 44, 46 with the system still remaining in the envelope mode.
The electrical connections of the paper feeding lS apparatus 10 are made with the control circuitry or uni.t for the printing device 12 which for example may include a microprocessor for processing the data stream from the word processing system, or the host processor of the data processing system controlling the printing device 12. In this regard, the electrical circuitry or connection 182 of the paper feeder apparatus 10 serves to interrupt receipt of information respecting the text when a new sheet of paper 16 is to be fed into the printing device 12 to allow the paper feeder apparatus 10 to feed and align a sheet of paper 16 in the printing device 12. In this instance, the paper feeding apparatus 10 generates a command to the host processor to delay feeding of the information respecting the text to be printed as well as other commands to permit the paper 16 to be fed into the device 12 and aligned. Once the feeding of the paper 16 into the device 12 has been accomplished and is aligned for the beginning of printing, the conventional control unit of the printing device 12 takes over and the page is printed on. It will be appreciated that one of the features of simplicity of the present e~odiment, and 1 ~ 6~505 which is particularly aclapted for retrofit-ting oF the paper feeding apparatus 10 on exis-ti.ng printi.ng de~i.ces 12, is the fact that the paper feeding apparatus 10 uses the conven-tional codes or commands or positioning of the printi.ng head 14 and advancing and reversing of the platen 18.
While the preferred embodiment of the present invention has been shown and described, it will be understood that such is merely illustrative and -that changes may be made without departing from the scope of the invention as cl.aimed.

Claims (59)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Paper feeding apparatus for a printing device, said printing device including a transversely extending platen, a printing head transversely movable relative to said transversely extending platen, and a guide member for guiding a sheet of paper in a desired direction, said guide member being associated with said transversely movable print head and movable there-with, said transversely extending platen including paper drive means for providing relative longitudinal movement of a sheet of paper relative to said printing head to effect printing on said sheet of paper by trans-versely moving said printing head relative to said transversely extending platen and by longitudinally moving a sheet of paper relative to said printing head, said paper feeding apparatus comprising:
paper storing means for storing a plurality of individual sheets of paper;
paper feed means for feeding a sheet of paper in a paper feed direction from said paper storing means to said platen, said sheet of paper having a longitudinal central portion which extends in the paper feed direction and which is centrally located intermediate the edges of said sheet of paper which extends in the paper feed direction;
paper receiving means for receiving a sheet of paper from said platen, said paper receiving means defining a paper exit path having one end arranged adjacent said platen to receive a sheet of paper therefrom after said printing means has effected printing thereon;
and centering means for transversely moving said print head and associated guide member to be in a position to overlie at least a part of the central portion of said sheet of paper when it is moved therepast upon initial feeding of a sheet of paper to said platen so that said guide member cooperates with said platen to guide said sheet of paper into said paper exit path as said sheet is moved past said guide member.

2. The paper feeding apparatus of Claim 1 wherein said paper feeding means feeds a sheet of paper from said paper storing means to align the longitudinal central portion of said sheet of paper with the transverse center of said platen, and wherein said centering means transversely centers said print head and associated guide member relative to said transverse center of said platen upon initial feeding of a sheet of paper to said platen.

3. The paper feeding apparatus of Claim 2 wherein said paper feed path has a longitudinal center line extending in the paper feed direction and aligned with the transverse center of said platen; wherein said paper storing means is positioned relative to said paper feed path so that the longitudinal center line of said paper feed path is aligned in the longitudi-nal central portion of said sheets of paper in said paper storing means, wherein said paper feeding means comprises transversely extending roller means rotatably supported for rotation about an axis extending perpendi-cular to the longitudinal central portion of said sheets of paper and adjacent to said paper storing means for engaging a sheet of paper in said paper storing means and for introducing a sheet of paper into said paper feed path whereby the sheet of paper is fed into said platen with the longitudinal center line of said paper feed path overlying the longitudinal central portion of said sheet of paper.

4. The paper feeding apparatus of Claim 2 wherein said paper receiving means further includes receptacle means for receiving sheets of paper moved along said paper exit path.

5. The paper feeding apparatus of Claim 4 wherein said receptacle means is at least partially defined by one side of a deflector plate arranged to receive sheets of paper moved along said paper exit path, the other side of said deflector plate at least partially defining said paper feed path.

6. Paper feeding apparatus for a printing device, said printing device including printing means for printing on a sheet of paper and paper drive means for providing relative movement between a sheet of paper and the printing means to effect printing on the sheet of paper, said paper feeding apparatus compris-ing:
paper storing means for storing a plurality of individual sheets of paper;
paper feed means for feeding a sheet of paper from said paper storing means along a paper feed path to said paper drive means;
sensor means for sensing when a sheet of paper is in position for being received by said paper drive means; and actuation means responsive to said sensing means for actuating said paper drive means to receive a sheet of paper and to move said sheet of paper relative to said printing means to accurately position said sheet of paper in a desired printing position for the start of printing thereon by said printing means.

7. The paper feeding apparatus of Claim 6 wherein said sensing means comprises first detecting means for detecting the leading edge of a sheet of paper being fed along said paper feed path; and wherein said actuation means comprises drive start means for actuating said paper drive means at a first predetermined time after said first detecting means detects the leading edge of said sheet of paper to receive said sheet of paper and to drive said sheet of paper to move the leading edge of said sheet of paper past said printing means, and stop means for stopping said paper drive means when the leading edge of said sheet of paper has moved a first predetermined distance past said printing means.

8. The paper feeding apparatus of Claim 7 in which said printing device includes guide means for directing the sheet of paper toward a paper exit path of movement after the paper has been moved past said printing means; wherein said actuation means further includes second detecting means for detecting the leading edge of said sheet of paper after passing said printing means, said second detecting means being arranged down-stream of said printing means along said paper exit path of movement; and wherein said top means is responsive to said second detecting means detecting the leading edge of said sheet of paper.

9. The paper feeding apparatus of Claim 8 wherein said drive start means operates said paper drive means to move the leading edge of said sheet of paper in a paper feed direction past said second detecting means; and wherein said stop means comprises reverse feed means responsive to said second detecting means for reversing the direction of feed of said sheet of paper to move said sheet of paper in the opposite direction from said paper feed direction and for stopping the reverse feed means when said second detecting means detects the leading edge of said sheet of paper being in alignment therewith to thereby align said sheet of paper at a precise position in reference to a desired position for the beginning of printing thereon by said printing means.

10. The paper feeding apparatus of Claim 9 wherein said reverse feed means comprises means for operating said paper drive means to feed said sheet of paper in said opposite direction.

11. The paper feeding apparatus of Claim 8 further including first alarm means associated with said first detecting means for generating a first alarm signal a second predetermined time after said paper feeding means is actuated to feed a sheet of paper from said paper storing means if said first detecting means fails to detect the leading edge of a sheet of paper within said second predetermined time.

12. The paper feeding apparatus of Claim 11 further including second alarm means associated with said second detecting means for generating a second alarm signal a third predetermined time after said first detecting means detects the leading edge of a sheet of paper if said second detecting means fails to detect the leading edge of a sheet of paper with said third predetermined time.

13. The paper feeding apparatus of Claim 12 further including ejector drive means for engaging a sheet of paper after printing has been effected thereon and removing said engaged sheet of paper from said printing device.

14. The paper feeding apparatus of Claim 13 wherein said second alarm means is operable to generate said second alarm signal a fourth predetermined time after said ejector drive means is actuated if said second detecting means fails to detect the trailing edge of a sheet of paper being moved therepast within said fourth predetermined time.

15. The paper feeding apparatus of Claim 14 further including feed start means for actuating said paper feed means to begin operation to feed a sheet of paper to said paper drive means; and means responsive to actuation of said feed start means for actuating said ejection drive means if one of said first and second detecting means detects a sheet of paper in said paper feed path or said exit paper path of movement and for disabling operation of said paper feeding means until said first and second detecting means detect the absence of a sheet of paper in said paper feed path and in said paper exit path.

16. The paper feeding apparatus of Claim 8 wherein said paper storing means comprises a first paper tray having a plurality of individual sheets of paper therein, said first paper tray being arranged adjacent to said paper feed path upstream of said first detecting means, and further including paper tray sensing means for generating a signal in the absence of a sheet of paper being in said paper tray being in position for feeding to said paper drive means.

17. The paper feeding apparatus of Claim 16 further including disabling means responsive to said signal generated by said paper tray sensing means for disabling said paper feeding means from operating.

18. The paper feeding apparatus of Claim 16 further including a second paper tray having a plural-ity of individual sheets of paper therein, said second paper tray being spaced from said first paper tray and arranged adjacent to said paper feed path upstream of said first detecting means.

19. The paper feeding apparatus of Claim 8 further including ejection means arranged along said exit path of movement for removing said sheet of paper from said printing device after printing has been effected on said sheet of paper.

20. The paper feeding apparatus of Claim 19 further including receptacle means for receiving and storing said sheet of paper ejected by said ejection means, said receptacle means comprising a plate member arranged adjacent said exit path of movement and against one side of which sheets of paper are stacked after ejection by said ejection means.

21. The paper feeding apparatus of Claim 20 wherein the side of said plate member opposite from said one side defines a portion of said paper feed path.

22. The paper feeding apparatus of Claim 19 wherein said ejection means comprises a pair of spaced rotatable ejection drive rollers defining a portion of said paper exit path therebetween, and means for moving said pair of spaced ejection drive rollers toward one another to engage each sheet of paper there-between and to rotate said ejection drive rollers to eject a sheet of paper from said printing device after printing has been effected on said sheet of paper, said ejection drive rollers being normally spaced from one another a distance to permit said sheet of paper to be guided therebetween and be freely moved therebetween during printing on said sheet of paper by said printing means.

23. The paper feeding apparatus of Claim 6 wherein said paper feed path comprises a first paper feed path, and further including means defining a second paper feed path communicating with a portion of said first paper feed path for manually introducing a sheet of paper to said paper drive means.

24. The paper feeding apparatus of Claim 23 further including a paper guide plate member having a first side defining said first paper feed path and a second side defining said second paper feed path, said paper guide plate member including an edge portion providing communication between said first and second paper feed paths, said edge portion being spaced from and adjacent said paper drive means.

25. The paper feeding apparatus of Claim 6 in which said paper drive means includes a transversely extending platen, and in which said printing means includes a movable print head transversely movable relative to said transversely extending platen, and a guide member for guiding a sheet of paper in a desired direction; wherein said paper feed means is operable to longitudinally feed a sheet of paper in a paper feed direction along said paper feed path, said sheet of paper having a pair of spaced edges extending longitud-inally in said paper feed direction, and having a longitud-inal central portion centered between said longitudinally extending spaced edges of said sheet of paper; and said paper feeding apparatus further including paper receiving means for receiving a sheet of paper as it leaves said guide means, said paper receiving means defining a paper exit path having one end arranged adjacent said transversely extending platen and downstream in said paper feed direction of said transversely movable print head and said guide member to receive a sheet of paper therefrom after said transversely movable print head has effected printing on said sheet of paper, and centering means for centering said guide member relative to the longitudinal central portion of said sheet of paper so that said guide member cooperates with said transversely extending platen to feed said sheet of paper to said paper receiving means.

26. The paper feeding apparatus of Claim 25 wherein said paper receiving means includes receptacle means for receiving and storing sheets of paper received by said receiving means.

27. The paper feeding apparatus of Claim 26 wherein said paper feed means is operable to longitudin-ally feed a sheet of paper to said transversely extending platen with the longitudinal central portion of said sheet of paper aligned with the transverse center of said transversely extending platen, and wherein said centering means comprises means for transversely centering said guide member relative to said transversely extending platen.

28. The paper feeding apparatus of Claim 6 wherein said paper feed means feeds a sheet of paper in a paper feed direction along said paper feed path, said paper feed means being adapted to release a sheet of paper when it is received by and initially moved by said paper drive means in said paper feed direction, said paper feed means further being so positioned that said paper feed means is out of the path of movement of a released sheet of paper when thereafter moved by said paper drive means so that said released sheet of paper may be moved freely by said paper drive means in said paper feed path without interference from said paper feed means.

29. The paper feeding apparatus of Claim 28 wherein said paper storing means is positioned adjacent said paper feed path and oriented with respect thereto so that said individual sheets of paper therein are arranged to extend transversely of the longitudinal direction of said paper feed path.

30. The paper feeding apparatus of Claim 6 wherein said paper feed means comprises guide means defining said paper feed path between said paper storing means and said paper drive means, and a pair of transverse-ly spaced drive rollers for driving a sheet of paper from said paper storing means in a paper feed direction, said transversely spaced drive rollers being positioned adjacent said paper storing means and spaced from said guide means for directing a sheet of paper from said paper storing means into said paper feed path.

31. The paper feeding apparatus of Claim 30 wherein said paper feed means further includes a pair of idler rollers, said pair of idler rollers being spaced transversely from said pair of drive rollers with said pair of drive rollers being located therebetween for guiding a sheet of paper having a transverse width greater than the spacing between said first pair of drive rollers.

32. A method of feeding an individual sheet of paper to a printing device, which printing device includes printing means for printing on a sheet of paper and paper drive means for providing relative movement between a sheet of paper and the printing means to effect printing on the sheet of paper, said method comprising the steps of:
storing a plurality of individual sheets of paper in paper storing means;
feeding a sheet of paper from the paper storing means along a paper feed path to the paper drive means;
sensing when a sheet of paper is in position along said paper feed path for being received by the paper drive means; and actuating the paper drive means when a sheet of paper is sensed to receive a sheet of paper being fed along the paper feed path and to thereafter move the sheet of paper relative to said printing means to a printing position for the start of printing thereon by said printing means.

33. The method of feeding paper of Claim 32 wherein said step of sensing comprises detecting at a first position in said paper feed path the leading edge of a sheet of paper being fed along said paper feed path, and wherein said step of actuating comprises actuating said paper drive means at a first predetermined time after the leading edge of said sheet of paper is detected at said first position in said paper feed path.

34. The method of feeding paper of Claim 33 wherein said step of actuating comprises operating said paper drive means to receive the sheet of paper and to move the leading edge of the sheet of paper past said printing means, and stopping said paper drive means when the leading edge of said sheet of paper has moved a first predetermined distance past said printing means.

35. The method of feeding paper of Claim 34 further including the steps of guiding the sheet of paper toward and along a paper exit path of movement after the sheet of paper has been moved past said printing means, and detecting at a second position in said paper exit path the leading edge of said sheet of paper after passing said printing means, said second position in said paper exit path being located at said first pre-determined distance downstream of said printing means.

36. The method of feeding paper of Claim 35 wherein said step of operating comprises operating said paper drive means to move the leading edge of said sheet of paper in a paper feed direction past said second position in said paper exit path and then reversing said paper drive means to move said sheet of paper in the opposite direction from said paper feed direction; and wherein said step of stopping com-prises stopping operation of said paper drive means when the leading edge of said sheet of paper is detected at said second position in said paper exit path.

37. The method of feeding paper of Claim 36 further including the step of generating a first alarm signal a second predetermined time after the start of said step of feeding a sheet of paper from said paper storing means if the leading edge of said sheet of paper is not detected at said first position in said paper feed path within said second predetermined time.

38. The method of feeding paper of Claim 37 further including the step of generating a second alarm signal a third predetermined time after the leading edge of said sheet of paper is detected at said first position in said paper feed path if the leading edge of said sheet of paper is not detected at said second position in said paper exit path within said third predetermined time.

39. The method of feeding paper of Claim 38 further including the step of ejecting a sheet of paper from said printing device after printing has been effected thereon.

40. The method of feeding paper of Claim 39 further including the step of generating a third alarm signal a fourth predetermined time after the step of ejecting has commenced if the trailing edge of said sheet of paper is not detected at said second position in said paper exit path within said fourth predetermined time.

41. The method of feeding paper of Claim 32 further including the steps of ejecting a sheet of paper from said printing device after printing has been effected on said sheet of paper, and of repeating said steps of feeding, sensing, actuating and ejecting for a plurality of succeeding sheets of paper after said printing device has effected printing on said sheet of paper to feed successive sheets of paper, one at a time, to said printing device for subsequent printing thereon.

42. The method of feeding paper of Claim 41 wherein the step of ejecting a sheet of paper from said printing device is performed prior to the step of feeding the next succeeding sheet of paper from said paper storing means.

43. The method of feeding paper of Claim 42 further including the step of generating an empty signal when said paper storying means is empty and for preventing, in response to said empty signal, performance of said steps of feeding, sensing and actuating.

44. The method of feeding paper of Claim 42 further including the step of storing ejected sheets of paper in a receptacle therefor.

45. The method of feeding paper of Claim 32 in which said sheet of paper has a pair of spaced edges extending in a longitudinal direction, and a central portion centered between said pair of spaced edges; and wherein said step of feeding a paper from said paper storing means comprises longitudinally feeding of a sheet of paper in a paper feed direction along said paper feed path so that during movement of said sheet of paper, the center line of said paper feed path is aligned with said central portion of said sheet of paper.

46. The method of feeding paper of Claim 45 in which said paper drive means comprises a transverse-ly extending platen, and in which said printing means includes a movable print head transversely movable relative to said transversely extending platen and an associated guide member for guiding a sheet of paper in a desired direction, said guide member being transverse-ly movable with said print head; and said method further including the step of moving said print head with said associated guide member to a transverse position relative to said platen to overlie said central portion of said sheet of paper as said sheet of paper is fed past said print head to guide said paper along an exit path of movement.

47. The method of feeding paper of Claim 32 wherein said paper feed path comprises a first paper feed path having a first end and a second end; wherein said step of feeding comprises feeding of a sheet of paper from said paper storing means along a second paper feed path into said first paper feed path, said second paper feed path being positioned intermediate said first and second ends of said first paper feed path and transversely oriented with respect to said first paper feed path so that paper in said first paper feed path may move between said first and second ends of said first paper feed path without entering said second paper feed path.

48. Printing apparatus comprising:
printing means for printing on a sheet of paper;
paper drive means for providing relative movement between a sheet of paper and said printing means to effect printing on the sheet of paper;
paper storing means for storing a plurality of individual sheets of paper;
paper feed means for feeding a sheet of paper from said paper storing means along a paper feed path to said paper drive means;
sensor means for sensing when a sheet of paper is in position for being received by said paper drive means; and actuation means responsive to said sensing means for actuating said paper drive means to receive a sheet of paper and to move said sheet of paper relative to said printing means to accurately position said sheet of paper in a desired printing position for the start of printing thereon by said printing means.

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49. The printing apparatus of Claim 48 wherein said sensing means comprises first detecting means for detecting the leading edge of a sheet of paper being fed along said paper feed path; and wherein said actuation means comprises drive start means for actuating said paper drive means at a first predetermined time after said first detecting means detects the leading edge of said sheet of paper to receive said sheet of paper and to drive said sheet of paper to move the leading edge of said sheet of paper past said printing means, and stop means for stopping said paper drive means when the leading edge of said sheet of paper has moved a first predetermined distance past said printing means.

50. The printing apparatus of Claim 49 further including guide means associated with said printing means for directing a sheet of paper toward a paper exit path of movement after the paper has been moved past said printing means; wherein said actuation means further includes second detecting means for detecting the leading edge of said sheet of paper after passing said printing means, said second detecting means being arranged downstream of said printing means along said paper exit path of movement; and wherein said stop means is responsive to said second detecting means detecting the leading edge of said sheet of paper.

51. The printing apparatus of Claim 50 wherein said drive start means operates said paper drive means to move the leading edge of said sheet of paper in a paper feed direction past said detecting means; and wherein said stop means comprises reverse feed means responsive to said second detecting means for reversing the direction of feed of said sheet of paper to move said sheet of paper in the opposite direction from said paper feed direction and for stopping said reverse feed means when said second detecting means detects the leading edge of said sheet of paper being in alignment therewith to thereby align said sheet of paper at a precise position in reference to a desired position for the beginning of printing thereon by said printing means.

52. The printing apparatus of Claim 51 further including ejection means arranged along said exit path of movement for removing said sheet of paper from said printing device after printing has been effected on said sheet of paper.

53. The printing apparatus of Claim 52 further including receptacle means for receiving and storing said sheet of paper ejected by said ejection means.

54. The printing apparatus of Claim 4 wherein said paper drive means includes a transversely extending platen; wherein said printing means includes a movable print head transversely movable relative to said platen, and a guide member movable with said print head for guiding a sheet of paper in a desired direction after said sheet of paper is moved past said print head;
wherein said paper feed means is operable to longitudinal-ly feed a sheet of paper in a paper feed direction along said paper feed path, said sheet of paper having a pair of spaced edges extending longitudinally in said paper feed direction, and having a longitudinal central portion centered between said longitudinally extending spaced edges of said sheet of paper; and further including paper receiving means for receiving a sheet of paper as it leaves said guide means, said paper receiving means defining a paper exit path having one end arranged adjacent said transversely extending platen and downstream in said paper feed direction of said transversely movable print head and said guide member to receive a sheet of paper therefrom after said transversely movable print head has effected printing on said sheet of paper, and centering means for centering said guide member relative to the longitudinal central portion of said sheet of paper so that said guide member cooperates with said transversely extending platen to feed said sheet of paper to said paper receiving means.

55. The printing apparatus of Claim 5, wherein said paper feed means is operable to longitudinally feed a sheet of paper to said transversely extending platen with the longitudinal central portion of said sheet of paper aligned with the transverse center of said transversely extending platen, and wherein said centering means comprises means for transversely centering said guide member relative to said transversely extending platen.

56. The printing apparatus of Claim 48 wherein said paper feed means feeds a sheet of paper in a paper feed direction along said paper feed path, said paper feed means being adapted to release a sheet of paper when it is received by and initially moved by said paper drive means in said paper feed direction, said paper feed means further being so positioned that said paper feed means is out of the path of movement of a released sheet of paper when thereafter moved by said paper drive means so that said released sheet of paper may be moved freely by said paper drive means in said paper feed path without interference from said paper feed means.

57. The printing apparatus of Claim 48 wherein said paper feed means comprises guide means defining said paper feed path between said paper storing means and said paper drive means, and a pair of transversely spaced drive rollers for driving a sheet of paper from said paper storing means in a paper feed direction, said transversely spaced drive rollers being positioned adjacent said paper storing means and spaced from said guide means for directing a sheet of paper from said paper storing means into said paper feed path.

58. The printing apparatus of Claim 57 wherein said sheet of paper has a longitudinal center line which extends in the paper feed direction and which is centered intermediate the edges of said sheet of paper which extend in the paper feed direction, and wherein said spaced apart drive rollers are positioned to engage a sheet of paper at positions which are of equal distances from and on opposite sides of the longitu-dinal center line of a sheet of paper regardless of its width.

59. Printing apparatus comprising:
a transversely extending platen;
a printing head transversely movable relative to said transversely extending platen;
a guide member for guiding a sheet of paper in a desired direction, said guide member being associated with said printing head and movable therewith;
said transversely extending platen including paper drive means for providing relative longitudinal movement of a sheet of paper relative to said printing head to effect printing on said sheet of paper by trans-versely moving said printing head relative to said platen and by longitudinally moving a sheet of paper relative to said printing head;
paper storing means for storing a plurality of individual sheets of paper;

paper feed means for feeding a sheet of paper in a paper feed direction from said paper storing means to said platen, said sheet of paper having a longitudinal central portion which extends in the paper feed direction and which is centrally located intermediate the edges of said sheet of paper which extends in the paper feed direction;
paper receiving means for receiving a sheet of paper from said platen, said paper receiving means defining a paper exit path having one end arranged adjacent said platen to receive a sheet of paper therefrom after said printing means has effected printing thereon;
and centering means for transversely moving said print head and associated guide member to be in a position to overlie at least a part of the central portion of said sheet of paper when it is moved therepast upon initial feeding of a sheet of paper to said platen so that said guide member cooperates with said platen to guide said sheet of paper into said paper exit path as said sheet is moved past said guide member.