Printer mechanism with vertically displaceable printing means for use with horizontal sheet feed mechanism

Front and rear printers for use with a document transport mechanism. The printers are identical in construction with each having a compact housing in which the associated print head is mounted. The housing has first and second side walls, a front wall which also functions as a guide for guiding documents to be printed upon therepast, and a rear wall which functions as a circuit board which houses the driver electronics assocated with the printer. The print head (ink jet) is mounted on a carriage which is moved within the housing in a first direction which is perpendicular to the direction in which the documents are moved in a document track past the printers. The front and rear printers are detachably mounted on opposed sides of the document track to enable the printing of alphanumerics or graphics on the front or the rear of a document moving thereby.

CROSS REFERENCE TO RELATED APPLICATION 
This application is related to U.S. patent application Ser. No. 07/634,672 
entitled, TABLE TOP IMAGE BASED DOCUMENT PROCESSING MACHINE AND METHODS OF 
PROCESSING DOCUMENTS by Fredrik Kallin et al., said application being 
filed on Dec. 27, 1990 and being assigned to the same assignee as the 
present invention. 
BACKGROUND OF THE INVENTION 
(1) Field of the Invention: 
This invention relates to a printer mechanism which is especially useful 
for printing on documents which are moved in a document track past a 
printing station therein. 
(2) Background Information: 
Some of the problems associated with prior art printers is that they are 
generally, noisy, bulky, and require maintenance, especially when an ink 
jet print head is used in the printer mechanism. Another problem is that 
the usual endorsing of documents, like bank checks, generally utilizes a 
single "Logo" or endorsement stamp which is usually printed or endorsed on 
the back of the bank check as the documents are moved past an endorsing 
station positioned along a document track in which the documents are moved 
past the endorsing station. 
SUMMARY OF THE INVENTION 
The present invention obviates the problems mentioned in the Background in 
that it is compact, quiet, and requires little maintenance. 
The present invention is especially useful in a sheet feeding environment 
like that employed by a teller at a bank, for example, although it may be 
used in other environments, like in the handling of library cards, airline 
boarding passes, and the like. 
In a preferred embodiment of the invention, there is provided an apparatus 
comprising: 
a base having a document track therein, with said document track having a 
bottom surface therein for guiding a document thereon; 
a housing having first, second, third, and fourth walls forming a general 
quadrilateral tubular shape, and a spacer wall for maintaining said first 
and second walls in spaced parallel relationship; 
support means coupled between said spacer wall and said base for supporting 
a carriage; 
a carriage slidably mounted on said support means; 
moving means for moving said carriage bi-directionally on said support 
means along a first line; 
said third side wall being a flexible guide having an elongated slot 
therein; 
securing means for securing said flexible guide to said first and second 
walls; 
a print head; 
mounting means for mounting said print head on said carriage to print 
through said elongated slot along the height of a document in said 
document track and 
transport means for bi-directionally moving said document along a second 
line perpendicular to said first line past said flexible guide in printing 
relationship with said print head. 
In another aspect of the invention, there is provided a compact housing for 
a printer comprising: 
first, second, third, and fourth walls forming a general quadrilateral 
tubular shape, and a spacer wall for maintaining said first and second 
walls in spaced parallel relationship; 
mounting means for mounting a print head in said housing; 
securing means for detachably securing said housing adjacent to a document 
track; 
said third wall being in the shape of a document guide for guiding a 
document in said document track in operative relationship with said print 
head; and 
said fourth wall being in the shape of a circuit board having contacts 
thereon for engagement with a control means when said housing is secured 
adjacent to said document track. 
The above advantages and others will be more readily understood in 
connection with the following description, claims, and drawing.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 is a general isometric view of a machine 10 in which the apparatus 
12 of this invention may be incorporated. The machine 10 may be a document 
processing machine like a bank teller's machine which is used for 
processing financial documents, like checks and deposit slips, for 
example. The apparatus 12 includes a first printer 12-1 and a second 
printer 12-2 depending upon customer requirements. In the embodiment 
described, the printers 12-1 and 12-2 are identical; therefore a 
discussion of only printer 12-1 will be given. 
As an illustration, the printer 12-1 may be used for printing endorsements 
on the back of a document 14, shown entering the machine from the left 
side as viewed in FIG. 1, and the printer 12-2 may be used for printing 
data on the front of the document 14. 
The machine 10 (FIG. 1) includes a transport means 16 for moving the 
document 14 in printing relationship with the printers 12-1 and 12-2. One 
of the features of the machine 10 is that the transport means 16 is 
bi-directional. In this regard, the document 14 is fed into a document 
track 18 from a first or entry side 20 and is moved in a first direction 
towards a second or output side 22, although the document 14 after being 
processed, may be exited from the entry side 20. Having a bi-directional 
transport means 16 enables the machine 10 to have a small footprint or 
enables it to be compact. The bi-directional transport means 16 also 
enables the apparatus 12 to be very versatile in what can be printed. 
The transport means 16 (FIGS. 1 and 2) includes a plurality of drive 
rollers 24, 26, 28, and 30 which are positioned along the document track 
18 as shown, and each of these drive rollers has a pinch roller 24-1, 
26-1, 28-1, and 30-1, respectively, associated therewith to move the 
document 14 positioned therebetween. The drive rollers 24, 26, 28, and 30 
are coupled together to be rotated in the same direction by a timing belt 
32 which is coupled to the output pulley 34 of a stepper motor 36. There 
are sufficient idler rollers like 38, 40, 42, and 44 to enable the timing 
belt 32 to be routed around the printers 12-1 and 12-2, for example, to 
enable the timing belt 32 to be coupled, also, to the drive rollers 28 and 
30. The stepper motor 36 is bi-directional to enable the document 14 to be 
moved in both feeding directions mentioned. The transport means 16 can 
also be used as a staging apparatus to move and hold the document 14 at a 
particular location within the document track 18. A control means 46 
(shown schematically in FIG. 2) for controlling the operation of the 
machine 10 is found on a printed circuit board 48 which is located within 
a chassis 50 of the machine 10. 
The first or rear printer 12-1 is shown in more detail in FIGS. 3 and 4. 
The printer 12-1 includes first, second, third, and fourth walls 52, 54, 
56, and 58 which make up a housing 60 which is generally quadrilateral in 
shape. In the embodiment described, the housing 60 is about two inches 
wide on a side and about six inches tall. 
The first wall 52 and the second wall 54 are held in spaced parallel 
relationship at the top of the housing 60 by a spacer wall 62 (FIG. 3) 
which has tabs, like 64 and 66, to hold these three walls together. The 
printer 12-1 also has support means 68 (FIG. 4) coupled between the spacer 
wall 62 and the base or chassis 50 which is shown only schematically in 
FIG. 4. The support means 68 includes first and second rods 70 and 72 
whose upper ends (as viewed in FIG. 4) are secured to the spacer wall 62 
by suitable molded-in snaps 74. The lower ends of the rods 70 and 72 are 
positioned in locating bushings 76 and 78 (shown schematically in FIG. 4) 
when the printer 12-1 is mounted thereon. The bushings 76 and 78 are 
located in the chassis 50. 
One function of the support means 68 is to locate the printer 12-1 relative 
to the document track 18, and another function is to support a carriage 80 
on which a print head 82 is mounted. The carriage 80 has opposed side 
walls, like 84, which have resilient or expandable slide members, like 86, 
which partially embrace the associated rods 70 and 72 to enable the 
carriage 80 to be moved up and down as viewed in FIG. 4. 
In the-embodiment described, the print head 82 is a THINKJET print head 
#51616A which is manufactured by Hewlett Packard. This print head 82 is a 
thermally driven ink jet printer which includes its own ink supply. When 
the supply of ink is exhausted, the print head 82 is simply thrown away 
and replaced with a new one. This reduces the possibility of service calls 
or maintenance in the field because an operator of the machine 10 can 
easily replace the print head 82 in the case of failure. The print head 82 
is detachably held in place on the carriage 80 by a conventional latch 88 
having an operating lever 90; when this lever is depressed, the print head 
82 is released from the latch 88, permitting it to be removed from the 
printer 12-1. 
A moving means for moving the carriage 80 bi-directionally in a vertical 
direction, as viewed in FIG. 4, includes a drive pulley 92, an idler 
pulley 94, a cable 96, and a stepper motor 98. The drive pulley 92 is 
coupled to the output shaft of the stepper motor 98, with this motor 
having a mounting flange 100 (FIG. 3) which is generally square in shape. 
The first wall 52 of the housing 60 has locking shoulders 102 and 104 
thereon behind which the flange 100 is mounted. The mounting flange 100 
also has apertures therein, like 106, which mate with raised circular 
areas or bosses on the locking shoulders 102 and 104 and first wall 52 
when the mounting flange 100 is rotated to the position shown in FIG. 3 to 
lock the stepper motor 98 in place. A feature of this invention is that 
the parts making up the printer 12-1 are assembled without any fasteners. 
This makes the printer 12-1 inexpensive and reliable to manufacture and 
assemble. The stepper motor 98 is rotated bi-directionally under the 
control of the control means 46 to raise and lower the carriage 80 with 
the print head thereon. 
The cable 96 (FIG. 4) alluded to earlier herein, has one end thereof 
secured to the drive pulley 92 by a special construction to be later 
described herein. There are extra turns of cable wound on the drive pulley 
92 to have sufficient cable to enable the carriage 80 to be moved from the 
topmost position shown in FIG. 4 to its lowermost position. In the 
lowermost position, a lug 108 located on the underside of the carriage 80 
cooperates with an associated sensor 110 to indicate to the control means 
46 that the print head 82 is in a lowermost or home position. When the 
stepper motor 98 is energized to rotate in the opposite direction, the 
carriage 80 is moved upwardly until it contacts a limiting stop 112. In 
the embodiment described, the range of motion of the print head 82 is four 
inches, although the range may be altered to suit different applications. 
The printer 12-1 and chassis 50 are designed so that print head 82 can 
print on a document 14 from the bottom of the document track 18 to the top 
of the document 14 as viewed in FIG. 2. 
As stated earlier herein, the housing 60 is generally comprised of first, 
second, third, and fourth walls 52, 54, 56, and 58 which make up a general 
quadrilaterally shaped housing. The walls 52 and 54 have already been 
discussed. One of the features of this invention is that the walls 56 and 
58 perform functions in addition to that of simply being part of the 
housing 60. For example wall 56 (FIG. 3) forms a "shim" or document guide, 
while wall 58 supports a printed circuit board 59 (FIG. 4) which houses 
some of the processing circuitry associated with the first printer 12-1, 
for example. 
The guide or wall 56 (FIG. 3) also performs the function of guiding 
documents, like 14, in printing relationship with the printers 12-1 and 
12-2. In order to have precise printing, it is desirable to have the 
document to be printed upon remain at a predetermined distance from the 
print head 82. When both printers 12-1 and 12-2 are placed along the 
document track 14, the associated guides or walls 56 face each other and 
provide sufficient clearance for the width of the document 14 to pass 
therebetween. In the embodiment described, the guide or wall 56 is made of 
blue tempered #1095 steel which is 0.005 of an inch thick; this provides 
sufficient resilience or robustness to prevent damage thereto by an 
operator of the machine 10. The guide or wall 56 has a slot 114 therein 
which extends vertically as viewed in FIG. 3. This slot is over four 
inches long in the embodiment described to enable the print head 82 to 
print on a document 14 which is up to four inches high. Because the 
document 14 may be fed bi-directionally within the document track 18, the 
guide or wall 56 is provided with ramps 116 and 118 which are located on 
the sides of the slot 114 so as to prevent the leading edge of the 
document 14 from being caught by the slot 114. The guide or wall 56 also 
is shaped to provide chamfered edges 120 and 122 which project slightly 
into the document track 18 when the printers 12-1 and 12-2 are positioned 
at the document track 18 as will be described hereinafter. 
The guide or wall 56 (FIG. 3) is held in place in the housing 60 in the 
following manner. The first and second walls 52 and 54 have slotted edges 
or recesses 124 and 126, respectively, formed therein to slidably receive 
flanges on the guide or wall 56. The guide or wall 56 is inserted in the 
housing 60 by pushing the guide or wall 56 downwardly, as viewed in FIG. 
3, until a raised projection or boss 128 on the spacer wall 62 engages an 
aligned hole in the guide or wall 56 to retain it in place. 
Another feature of this invention is that the fourth wall 58 (FIG. 4) also 
functions as a support for the circuit board 59 which handles the driver 
electronics associated with the print head 82. The wall 52 has a slot in 
the area 129 (FIG. 4) to slidably receive one side of the wall 58, and the 
wall 58 has hook-type extensions 130 and 132 on the opposed side thereof 
to be inserted through slots 134 and 136 (FIG. 1). After insertion through 
the slots 134 and 136, the wall 58 is pushed downwardly, as viewed in FIG. 
1, to secure the wall 58 to the housing. The circuit board 59 has plug-in 
contacts 140 to couple the circuit board 59 on the wall 58 to the P.C. 
board 48. There is some looseness in the mounting between the circuit 
board 59 and the wall 58 to allow for some minor movement between the 
circuit board 59 and the P.C. board 48 (due to a misalignment 
therebetween) to enable the circuit board 59 to be plugged into the P.C. 
board 48. The connection cables associated with the stepper motor 96 and 
the print head 82 are coupled to the circuit board 59 on the wall 58. 
When the housing 60 (FIG. 4) is assembled as described, the rods 70 and 72 
extending from the housing are inserted in the bushings 76 and 78 to align 
the housing 60 and the print head 82 therein relative to the document 
track 18. As the housing 60 is pushed downwardly as viewed in FIG. 4, a 
hold-down snap member 142 engages a portion of the chassis 50 to 
detachably retain the housing 60 thereon. At the same time, the plug-in 
contacts 140 associated with the printed circuit board 59 on wall 58 are 
coupled to the P.C. board 48 which is part of the control means 46. The 
printers 12-1 and 12-2 may be controlled by the control means 46 in a 
conventional manner. 
As alluded to earlier herein, the pulley 94 (FIG. 4) is mounted in the 
housing 60 to place some tension on the cable 96 in the following manner. 
The idler pulley 94 has a shaft 144 extending therefrom as shown in FIG. 
5. The housing 60 has recesses 146 and 148 therein to receive the ends of 
the shaft 144 to rotatably support it. Two cantilever type members 150 and 
152 which are molded in the housing 60 are used to maintain a downward 
bias (as viewed in FIG. 5) on the idler pulley 94 to tension the cable 96. 
The ends of the cable 96 are secured to the drive pulley 92 as shown in 
FIG. 6. A split metal ball 154, for example, having one end of the cable 
96 crimped between the split portions is pushed into the hole 158, and 
similarly, a split metal ball 156 having the remaining end of the cable 96 
crimped between the split portions is pushed into the hole 160. The cable 
96 is secured to the carriage 80 by a ball and hole construction similar 
to ball 154 and hole 158, for example. This construction provides an easy 
to assemble means for securing the cable 96 to the drive pulley 92.