Note: Descriptions are shown in the official language in which they were submitted.
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JOURNAL PRINTER PAPER FEED FAULT DETECTION SYSTEM
FOR AUTOMATED TELLER MACHINE
DESCRIPTION
TECHNICAL FIELD
S This invention relates to automated banking machines. Specifically,
this invention relates to a system and method for detecting fault conditions
which occur in the feeding of paper through a journal printer mechanism in
an automated teller machine.
BACKGROUND ART
Automated banking machines are well known in the prior art. In
many types of automated banking machines, including automated teller
machines (ATMs), it is common to include a journal printer inside the
machine. The function of the journal printer is to make a paper record of
each transaction that has been conducted at the ATM. This enables the
institution that operates the ATM to verify its electronic records and to
reconstruct them in the event of a failure.
Journal printers typically involve recording transaction information
on paper that is supplied from a paper roll. The paper from the roll is
passed through the printer where the data is printed on the paper. After
printing, the paper is rewound onto a take-up roll. As transactions are
recorded, blank paper on the supply roll is used and the diameter of the
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supply roll decreases. As paper upon which data has been recorded is
transferred to the take-up roll, the take-up roll increases in diameter.
Eventually, when the amount of paper remaining on the supply roll is nearly
depleted, the supply roll must be replaced and the paper on the take-up roll
removed. The process is then repeated with additional transactions being
recorded on the paper from a new supply roll.
The reliable operation of the journal printer is important to insure
that the institution operating the ATM has a hardcopy record of all the
transactions that have been conducted. It is undesirable for the supply roll
of the journal printer to be depleted, as this results in transactions for
which
there may be no hardcopy record. In some existing ATMs, the need to
replace the supply roll is determined electronically by storing in the memory
of the machine the number of data lines printed by the journal printer since
the last roll change. Such systems require for their operation that all
replacement rolls be identical. This is not always the case. If the roll is
either "too short" or "too long" a paper out condition may arise or excess
paper may be unnecessarily discarded.
A person servicing the ATM to replace the supply roll may forget to
reset the system when the paper is replaced. This can result in the
automated teller machine indicating that it is in a paper low condition when
in fact no such problem exists. Also, a problem such as a paper jam may
occur in the middle of a roll. In this situation the technician must start a
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new roll and reset the machine. This may waste a significant amount of
paper.
Journal printers sometimes experience paper jams. Paper jams
usually result in the paper no longer moving through the printer. The
printer mechanism prints data concerning a multitude of transactions on the
same spot. As a result, the hardcopy record of these transactions is lost.
Only the most severe paper jams that trigger signals indicating a
malfunction in other components are generally detected by existing
automated teller machines. For example, if the paper jam condition is
sufficient to prevent the printer mechanism from moving as required to
produce characters on paper, a printer fault indication may be given.
However in most circumstances, paper jams are not sufficiently severe to
impact the operation of other components. Such paper jams go undetected
until a visual inspection is made by a service technician.
Other types of fault conditions may arise with regard to a journal
printer. A technician may remove a spent roll and forget to put in a new
one even though the machine has been reset. Paper rolls may also have
breaks at splices. In either case the journal printer will become inoperative
and this condition may go undetected for some time.
Problems may also result when a replacement roll has not been
properly installed. The ATM may be run for an extended time before it is
discovered that paper is not feeding through the journal printer.
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Thus there exists a need for a system and method for indicating fault
conditions with paper feeding to a journal printer in an automated banking
machine.
DISCLOSURE OF INVENTION
It is an object of the present invention to provide an apparatus for
indicating a fault condition in a system in which a printer is supplied with
paper from a paper supply.
It is a further object of the present invention to provide an apparatus
for indicating a paper jam condition with a journal printer in an automated
banking machine.
It is a further object of the present invention to provide an apparatus
for indicating a paper low condition for a supply roll supplying a journal
printer in an automated banking machine.
It is a further object of the present invention to provide an apparatus
for indicating fault conditions in a system including a journal printer in an
automated banking machine which is supplied by a paper roll and which
prevents overrunning of the roll.
It is a further object of the present invention to provide an apparatus
for indicating fault conditions in a system including a journal printer in an
automated banking machine which detects the movement of journal printer
paper and which determines that such paper is moving in coordination with
a journal printer.
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It is a further object of the present invention to provide an apparatus
for indicating fault conditions in a system including a journal printer in an
automated banking machine which detects the movement of a journal printer
supply roll and which determines that such roll is moving in coordination
5 with a journal printer.
It is a further object of the present invention to provide an apparatus
for detecting proper movement of a journal printer paper which enables
readily changing the supply roll.
It is a further object of the present invention to provide an apparatus
for detecting the proper movement of a journal printer supply roll which
apparatus is engaged with said supply roll so as to indicate the movement
thereof but which is readily disengagable from said supply roll to enable the
replacement thereof.
It is a further object of the present invention to provide an apparatus
for indicating fault conditions with a paper feed from a roll to a printer,
which apparatus may be used with rolls of varying size.
It is a further object of the present invention to provide an apparatus
for indicating improper loading or a failure to load, a paper supply to a
printer.
It is a further object of the present invention to provide an apparatus
for detecting severance of paper from a paper supply to a printer.
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It is a further object of the present invention to provide a method for
indicating a fault condition in a system in which a journal printer is
supplied
with paper from a paper supply.
Further objects of the present invention will be made apparent in the
following Best Modes for Carrying Out Invention and the appended claims.
The foregoing objects are accomplished in preferred embodiments of
the present invention by an apparatus for indicating fault conditions in a
transaction recording system within an automated banking machine. The
system includes a journal printer that is supplied with paper from a paper
supply. The printer operates to move paper from the supply and to print
transaction data thereon. The paper with the printed data is rewound on to
a take-up roll.
In a first embodiment the paper supply roll is supported an a spindle.
A wire spring extending from the spindle serves as a connecting member
1S and connects the spindle to the supply roll. As a result, the spindle is
rotatably engaged with the roll so as to move therewith. An encoder
member is supported on one end of the spindle. The encoder member
includes a plurality of uniformly spaced indicia which in the preferred form
of this embodiment is a plurality of slotted openings.
An optical detector is positioned adjacent to the encoder member.
The detector operates to detect rotation of the encoder member which is
indicative of rotation of the paper roll. A drag mechanism is associated
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with the spindle which prevents overrunning of the supply roll as paper is
removed therefrom by the printer.
In a second embodiment of the invention paper is supplied to the
printer from a roll or other type paper supply. The printer includes a
printer drive mechanism which engages the paper and moves it through the
printer in coordination with the printing on the paper. The paper with the
printed data is rewound onto a take-up roll. The take-up roll is moved by a
take-up roll drive mechanism.
Between an area of engagement of the paper with the printer drive
mechanism and the take-up roll the paper passes through a gap. The paper
is movable in the gap both in a direction of paper movement from the
printer to the take-up roll, as well as in a direction that is generally
perpendicular to the direction of paper movement.
The operations of the printer drive mechanism and the take-up roll
drive mechanism are coordinated. The printer drive preferably first moves
the paper towards the take-up roll and a time thereafter the take-up roll
drive mechanism moves the take-up roll to take up the slack in the paper.
This causes the paper to move back and forth in the perpendicular direction
in the gap.
An optical detector is positioned adjacent to the gap. The optical
detector is positioned to detect movement of the paper in the perpendicular
direction. In this manner the detector operates to detect movement of the
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paper in a manner indicative of the proper operation of the printer drive and
take-up roll drive mechanisms.
Both embodiments of the system further include a second detector
adjacent to the paper supply. The second detector serves as a paper low
detector and preferably senses a side face portion of the paper roll, stack or
other form of supply. The second detector is operative to provide a signal
when the diameter or size of the supply has fallen to a predetermined level.
An electronic circuit, which includes a processor, is in operative
connection with the printer and the first and second detectors. The
processor is programmed to provide fault signals when a combination of
certain conditions are detected in accordance with the programming of the
processor.
In operation, a first fault signal representative of a paper jam
condition is generated by the electronic circuit if the second detector senses
sufficient paper, but the first detector has failed to sense movement of the
paper after the printer has operated to print a number of lines. This may be
a failure to sense rotation of the spindle shaft or cyclic movement of the
paper in the perpendicular direction in the gap. This first fault signal is
indicative that the printer is attempting to print several lines of data on
the
paper but that the paper is not moving. The first fault signal is also
generated in conditions where the paper has broken, such as at a splice, or
when a replacement roll or stack has not been properly installed.
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The electronic circuit provides a paper low signal when the second
detector senses that the paper supply has been reduced to a sufficiently small
size that replacement is warranted. The paper low signal is given if the first
detector is continuing to sense that the paper is still moving. This is
indicative that the journal printer is still operating despite the paper
running
low.
The electronic circuit further provides a paper out signal when the
printer has printed the number of lines during which time movement of the
paper should have been sensed, and if at the same time the second detector
does not sense the presence of paper. This is indicative that the paper
supply has been depleted and that a hardcopy record of transaction data is
not being retained. This second fault signal indicative of a paper out
condition is also given in circumstances when a replacement roll or other
supply was not installed or was improperly installed due to a mistake by a
service technician.
In a further embodiment of the invention, an apparatus is provided for
indicating a fault condition in an automated banking machine, the machine
including a journal printer supplied with paper from a paper roll. The
apparatus
comprises means for extending the paper from the roll through the journal
printer,
means for conducting banking transactions with the machine, means for moving
the paper through the journal printer responsive to each transaction conducted
with the machine, means for sensing that the journal printer ha.s moved the
paper,
and means for generating a first fault signal responsive to the conduct of a
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banking transaction with the machine and the sensing means failing to sense
movement of the paper through the journal printer.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is an isometric view of a journal printer including a first
embodiment of the fault indicating apparatus of the present invention.
Figure 2 is a schematic view of a journal printer including the first
embodiment of the fault indicating apparatus of the present invention.
Figure 3 is a sectional side view of a paper supply roll, spindle and
1 o spindle rotation detector of the first embodiment of the present invention
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with the inside diameter of the paper roll core exaggerated to show the
action of a pair of spring arms connecting the roll and the spindle.
Figure 4 is an isometric view of the spindle of the first embodiment
of the present invention shown with the spring arms extended.
5 Figure 5 is an isometric view showing the spindle partially inserted
into a paper supply roll.
Figure 6 is a flow chart of the computer program executed by the
processor of the electronic circuit used in the fault indicating apparatus of
the present invention.
10 Figure 7 is a schematic view of a journal printer including a second
embodiment of the fault indicating system of the present invention.
Figure 8 is an enlarged cross sectional view of an optical detector of
the second embodiment with paper in a first position adjacent the detector.
Figure 9 is an enlarged cross sectional view similar to Figure $ but
with the paper in a second position disposed from the detector.
BEST MODE FOR CARRYING OUT INVENTION
Referring now to the drawings and particularly to Figure 1, there is
shown therein a first embodiment of the fault indicating apparatus of the
present invention generally indicated 10. The apparatus includes a journal
printer generally indicated 12. Journal printer 12 includes mechanisms
known in the prior art for producing printed data on paper in a conventional
manner.
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Paper generally indicated 14, is fed from a paper supply roll 16 to
printer 12. As schematically indicated in Figure 2, paper that has been
printed on by the journal printer 12 is stored on a take-up roll 18. Printer
12 includes a conventional type drive schematically indicated 20 for moving
the paper 14 therethrough after each line of data has been printed thereon.
Take-up roll 18 is also driven by a conventional mechanism so as to rewind
and store on the take-up roll the paper that has been printed on by journal
printer 12.
Paper supply roll 16 is supported on a spindle generally indicated 22.
The spindle is shown in detail in Figures 4 and 5. Spindle 22 is supported
on a first side by a first vertically extending wall 24. Spindle 22 is
supported at an opposed side by a second vertically extending wall 2b.
First wall 24 includes a first slot 28 therein. First slot 28 includes an open
end and a closed end. The spindle is supported at the closed end of slot 28
when in the operative position as shown in Figure 3. However, the spindle
may be removed from the slot 28 through the open end to enable
replacement of the supply roll and then reinstalled in a manner later
discussed.
Second wall 26 includes a second slot 30. Second slot 30 has open
and closed ends. The spindle is supported at the closed end of the second
slot when in the operative position as shown in Figure 3. Similarly, the
spindle may be removed through the open end of the slot when the supply
roll is depleted and reinstalled after the roll is replenished.
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Spindle 22 is shown in detail in Figure 4. Spindle 22 includes a
spindle shaft portion 32. A flange portion 34 is located at a first end of
spindle shaft portion 32. A flange portion 34 includes a flat circular face
36, the purpose of which is later discussed.
An encoder support shaft portion 38 extends axially outward from
flange portion 34. Encoder support shaft portion 38 supports an encoder
member 40. In the preferred form of the first embodiment of the invention,
encoder member 40 is an encoder wheel with a plurality of radially
extending slotted openings positioned at a plurality of uniformly spaced
radial increments thereon.
A retainer member 42 is movably positioned between flange portion
34 and encoder member 40. Retainer member 42 is a generally hollow
member with an opening (not shown) through which shaft portion 38
extends. The retainer member is enabled to move in an axial direction on
the encoder support shaft portion. 38. Retainer member 42 includes
externally a cylindrical portion 44 and a generally frustoconical portion 46.
Generally frustoconical portion 46 includes the opening therethrough that
enables retainer member 42 to move relative to shaft portion 38.
A compression spring 48 is housed in a generally cylindrical pocket
inside retainer member 42. Compression spring 48 is a coil spring that
extends coaxially with encoder support shaft portion 38. Spring 48 biases
the generally frustoconical portion 46 of the retainer towards face 36 of the
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flange portion 34. However, in response to a separating force, the
frustoconical portion 46 may be moved away from face 36.
A guide shaft portion 50 is positioned at an opposite end of spindle
shaft 32 from flange 34. Guide shaft portion 50 is smaller in diameter than
spindle shaft portion 32. A radially extending step 52 extends between
guide shaft portion 50 and spindle shaft portion 32.
Spindle shaft portion 32 includes a diametrically extending opening
54 therethrough. A second opening 56 in spindle shaft portion 32 is axially
disposed from opening 54 in the direction of flange portion 34. A generally
u-shaped wire spring 58 extends between openings 54 and 56. Spring 58
includes a pair of outwardly biased spring arms 60 which extend from a
spring base 62. Spring base 62 extends through opening 54 in shaft portion
32 as shown in Figure 4. Spring arms 60 each include free ends generally
indicated 64 which each have radially in-turned portions 66. In-turned
portions 66 extend into opening 56 in spindle shaft portion 32.
As shown in Figure 5, when paper supply roll 16 is installed on
spindle 22, spindle shaft portion 32 is inserted into a core 68 at the center
of the paper roll 16. As the spindle shaft is inserted into the core, the
engagement of the core with the spring arms moves the spring arms against
the biasing force of the wire spring so that the in-turned portions 66 are
moved further into opening 56 in the spindle shaft portion. The outward
biasing force of the spring arms maintains engagement between the spindle
22 and the core 68 of the paper roll 16. As a result, the spring arms 60
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serve as connecting members for connecting the spindle to the paper roll so
that the spindle is rotatably engaged therewith. This enables the encoder
member 40 to move in response to movement of the paper roll. This
enables the detection of fault conditions in a manner hereinafter discussed.
The spindle 22 is installed in the roll 16 by movement of the spindle
in the direction of arrow I as shown in Figure S until flange portion 34
engages a side face of the core and paper roll. The spindle 22 is then
installed in supported connection with walls 24 and 26. Installation into
supported connection with the walls is accomplished by engaging guide shaft
portion 50 in second slot 30 and engaging the encoder support shaft portion
38 in the slot 28. Engaging encoder support shaft portion 38 in slot 28
necessitates the movement of retainer member 42 away from flange portion
34 a sufficient distance to enable wall 24 to extend therebetween. This is
accomplished by engaging the tapered generally frustoconical portion 46 of
the retainer in the open end of slot 28 and moving spindle 22 downward.
This downward movement biases the retainer member 42 axially outward
against the biasing force of compression spring 48. This enables spindle 22
to be moved so that shaft portion 38 is supported at the closed end of slot
28 as shown in Figure 3.
When the spindle 22 is supported in slots 28 and 30 as shown in
Figure 3, retainer member 42 applies a biasing force against the outer
surface of first wall 24. This biasing force causes wall 24 to be in
compressed sandwiched relation between flange portion 34 and retainer
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member 42. The frictional forces that are applied by face 36 of flange
portion 34 on the inside of wall 24 combined with the frictional force of the
retainer member 42 engaging the outer surface of wall 24, act to resist
rotation of spindle 22. Because spindle 22 is connected to paper roll 16
5 through the spring arms 60, these structures act as a drag mechanism to
prevent spindle 22 from freely rolling in response to forces applied thereto.
As a result, when roll 16 is moved in response to printing operations being
conducted by journal printer 12, roll 16 is prevented from overrunning by
the drag mechanism.
10 The apparatus of the first embodiment of the present invention
further includes a detector 70. In the preferred form of the invention
detector 70 is an opto-interrupter sensor. Detector 70 is operable to detect
the passage of a beam of light through the openings 72 in the encoder
member 40 as the openings are aligned with the sensor. As spindle 22
15 rotates, detector 70 sequentially senses the passage and blockage of light
as
openings 72 are aligned in the sensor.
As schematically shown in Figure 2, detector 70 is electrically
connected through an appropriate interface to an electronic circuit
schematically indicated 74. Electronic circuit 74 includes a processor 76
which operates in accordance with the steps of a computer program
hereinafter described. Electronic circuit 74 is also connected to journal
printer 12 for purposes that are later discussed.
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The apparatus of the present invention further includes a second
detector 78. Second detector 78 is also preferably an opto-electric detector.
Second detector 78 is positioned between the spindle and the journal printer.
Second detector 78 preferably operates to direct a light beam against a side
face portion of paper supply roll 16 and to detect the light reflected from
such surface. As a result, when the diameter of roll 16 has decreased so
that the side face surface is no longer present in the area adjacent second
detector 78, this condition may be sensed as shown in Figure 2. In other
embodiments other types of detectors may be used instead of electro-optical
detectors. Second detector 78 is electrically connected through an
appropriate interface to the electronic circuit 74. Electronic circuit 74
operates as schematically indicated in Figure 2 to output electrical signals
on
a line schematically indicated 80.
Electronic circuit 74 operates to output fault indication signals in
response to a determination that there is a paper jam or a comparable
condition, that the paper on the supply roll is low, or that the paper on the
supply roll is out or a comparable condition. These signals are given in
response to processor 76 which executes generally the computer program
steps indicated in Figure 6.
It will be understood by those skilled in the art that because the
diameter of paper supply roll 16 varies as paper is used, the amount that the
spindle will rotate in response to printer 12 removing a predetermined
amount of paper from the roll will vary. The spindle will rotate a lesser
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amount for a given length of paper when the roll is new. The roll will
gradually increase the angular displacement for a given amount of paper as
the roll approaches depletion.
Printer mechanisms are generally set up such that each line of
printed data occupies a predetermined width on the paper. This width
extends in a transverse band. Each time the printer is instructed by the
printer driver control to move to the position to print the next line of data,
the drive 20 of the printer operates to attempt to move the paper forward a
predetermined distance. Because the printer advance for each line of data is
constant, but the amount of associated rotation of the spindle and the
attached encoder member 40 varies, the processor of the present invention is
programmed so as to prevent the generation of fault signals in circumstances
where the encoder member has only moved slightly due to the large
diameter of the roll.
As shown in Figure 6, the processor 76 is connected to printer 12 so
as to enable the printing of a line of data on the paper at a step 82. A
counter is then incremented at a step 84 to note that an additional line has
been printed. At a step 86, the counter is checked to determine if the
number of lines that have been printed is equal to a set number. This set
number is preprogrammed so that for the largest roll to be installed on
spindle 22 the encoder member must have moved sufficiently so as to
produce a change in signal at detector 70 after the preset number of lines is
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printed. If the counter has not yet reached this preset limit, the program
returns to print the next line. If it has, the program moves on.
At a step 88, the processor checks to determine if there has been a
change in signal from detector 70. This would indicate that the spindle has
rotated enough to indicate at least one change from "dark" to "light" or vice
versa. At a step 90, a decision is made as to whether such a change in
signal from detector 70 has occurred. If at least one change in signal has
occurred, the counter is reset at a step 92. A step 94 is then executed to
check if paper is sensed by second detector 78. If paper is present adjacent
the second detector, then the processor enables the program to return. The
printer will then print the next line. However if paper is not sensed
adjacent to second detector 78, a "paper low" signal is generated at step 96.
Because it is desirable to operate the journal printer as long as possible,
even if the paper is low, the processor continues to operate the printer.
If in executing the computer program, it is determined in step 90 that
the encoder has not changed condition since the last check, this is
representative of a problem. The processor then executes step 98 wherein
the processor seeks to determine if paper is sensed adjacent to second
detector 78. If paper is present, but the spindle is not moving, the
processor indicates a first fault detection signal representative of a paper
jam or a comparable fault condition at a step 100. As it is often not
desirable to operate the ATM without a journal printer, in addition to giving
a paper jam signal, the processor or the paper jam signal may also operate
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to stop further operation of the ATM after it has completed the pending
transaction.
The first fault detection signal may be generated in response to
conditions other than paper jams. For example, the signal will also be
given if the paper is severed or broken. This may be due to a break at a
splice in the roll. The first fault detection signal will also be generated if
the supply roll has not been properly installed and seated in the slots in the
side walls. This will cause the roll to bind and not unwind. In each case
the first fault detection signal indicates that ample paper is present but
paper
is not being fed in response to the printer.
Alternatively, if at step 98 it is determined that no paper is present
adjacent to second sensor 78 and the encoder is not moving, then a "paper
out" signal is generated at a step 102. Further, as previously discussed, in
addition to generating the paper out signal, which is a second fault signal,
the processor or the fault signal may operate to discontinue operation of the
ATM after completing the then pending transaction.
The "paper out" signal may also be given in other comparable
situations. These would include situations in which a technician has taken
out a spent roll and forgotten to put in a new roll, or when a new roll has
been installed so improperly that its presence cannot be sensed. In these
situations, the transaction information is not being recorded due to absence
of paper.
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The force applied by the drag mechanism on the spindle insures that
the encoder member accurately reflects the movement of paper through the
journal printer. In the event of even a minor paper jam or paper feeding
problem which prevents the proper operation of the printer, a fault
5 indication signal is given. in addition, the present invention enables
giving
accurate signals representative of paper low and paper out conditions. This
is superior to basing replacement of the paper supply roll on estimates on
the amount of paper remaining. It is also not necessary to replace the roll
and reset a paper counter after a paper or printer problem is corrected.
10 An additional advantage is that while the apparatus of the present
invention is highly reliable, it does not interfere with the replacement of
the
paper rolls or complicate the threading of the paper through the journal
printer.
It will be understood by those skilled in the art that while an opto-
15 interrupter type sensor has been used as the detector for detecting
rotation
of the spindle in the preferred form of the first embodiment of the
invention, other rotation sensors may be successfully used in other
embodiments. These include those detectors that sense other types of
indicia or features on a member that is in connection with the spindle.
20 While the spring arms of the wire spring serve as the connecting
members in the preferred form of the first embodiment, other types of
connecting members may be used to connect the paper roll and the spindle
shaft. These include other types of spring members as well as ridges or
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other contours which serve to provide a rigid rotational connection between
the spindle and the roll.
While a reflective type detector is used for the second detector in the
preferred embodiment, other types of detectors may be used. These other
detectors include detectors which sense the paper between the spindle and
the journal printer by way of sensing the side surface of the supply roll or
other paper feature.
An alternative embodiment of a fault indicating apparatus generally
indicated 104 is shown in Figure 7. The second embodiment is similar to
the first embodiment and includes a journal printer 106. Printer 106
includes a printer drive mechanism schematically indicated 108. The printer
drive mechanism 108 moves paper 110 through the printer in coordination
with the printing of lines of characters thereon.
As in the first described embodiment the printer drive mechanism
108 causes paper to be pulled from a paper supply roll 112. Roll 1I2
rotates in the direction indicated by Arrow F responsive to movement of the
paper by the printer drive mechanism. In this second embodiment the paper
supply roll may be rotatably supported on a spindle or in another suitable
manner. Alternatively in this second embodiment another form of paper
supply such as a stack of fanfold paper may be used instead of a supply
roll.
Paper 110 that is moved by the printer drive mechanism is rewound
on a take-up roll 114. The take-up roll is moved in the direction indicated
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by the Arrow T by a take-up roll drive mechanism schematically indicated
116.
As in the first described embodiment, the second described
embodiment includes an electronic circuit 118 similar to electronic circuit
74 except as otherwise described. Electronic circuit 118 includes a
processor 120. The second embodiment also includes a second detector 122
similar to detector 78, which is positioned adjacent the paper supply and is
in communication with the electronic circuit 118.
Unlike the first embodiment a detector 124 is positioned between an
area where said printer drive mechanism 108 engages the paper and where
the paper engages the take-up roll. The detector 124 is mounted adjacent to
a gap 126. The paper 110 extends in the gap and is freely movable therein
between the printer drive mechanism and the take-up roll. Gap 126 is
preferably sized so that the paper is movable in the gap in a direction that
is
generally perpendicular to a plane of the paper and the direction of
movement of the paper through the gap toward the take-up roll.
Gap 126 is bounded at a first side by a first guide 128. Guide 128
includes a paper engaging surface that is preferably angled in a direction
generally toward the take-up roll 114 as shown. The relative orientation of
take-up roll 114 and guide 128 is such that the paper will generally be
positioned adjacent to guide 128 when the paper is relatively taut between
the printer drive mechanism and the take-up roll. This is preferably true for
all diameters of the take-up roll. However, in other embodiments other
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paper guiding mechanisms may be positioned between guide 128 and the
take-up roll to maintain the paper generally adjacent thereto when the paper
is taut.
Gap 126 is bounded at a side opposed from guide 128 by a guide
130. Guide 130 has a paper engaging surface that is preferably angled
similar to guide 128. Guide 130 in the preferred embodiment is a tear bar
which includes a serrated edge 132 at its upper surface (see Figure 8J.
Edge 132 facilitates cutting the paper when that is desirable, such as when
manually preparing a free end of the paper to engage take-up roll 114.
Detector 124 preferably extends in an opening in guide 130. In this
embodiment detector 124 is preferably of the electro-optical detector type
previously discussed. In other embodiments other types of suitable
detectors may be used.
The apparatus of the second embodiment operates in a manner
similar to the first embodiment except as otherwise explained. The printer
106 operates under the control of circuit 118 and 'processor 120 to print
lines of characters on the paper 110. The printer drive mechanism 108
moves the paper, generally one line width at a time, as printing is
conducted.
The take-up roll drive mechanism 116 is also operated responsive to
the control of the electronic circuit 118 and the processor. In the second
embodiment the operations of the printer drive mechanism 108 and the take-
up roll drive mechanism 116 are coordinated so they operate in sequence.
CA 02427875 2003-05-08
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Specifically, the drive mechanisms are operated so that the printer drive
mechanism moves the paper toward the gap 126 and the take-up roll 114,
while the take-up roll remains stationary. This results in slack in the paper
between the area where the printer drive mechanism engages the paper and
the take-up roll. After the printer drive has moved the paper, the take-up
roll drive mechanism 116 moves the take-up roll 114 to remove the slack
from the paper in the area between the printer drive mechanism and the
take-up roll.
The coordinated movement of the printer drive mechanism 108 and
the take-up roll drive mechanism 116 causes the paper 110 to move in the
gap 126 between the positions shown in Figures 8 and 9. In the preferred
form of the second embodiment, when the printer drive mechanism 108 has
moved the paper 110, and the take-up roll drive mechanism 116 has not yet
moved, the paper extends in the gap generally as shown in Figure 8. The
13 slack in the paper and the orientation of guides 128 and 130 causes the
paper to move adjacent to guide 130 and detector 124.
When the take-up roll drive mechanism 116 moves the paper a time
increment after the printer drive mechanism, the paper moves in the
perpendicular direction in gap 126. As the take-up roll drive mechanism
takes the slack out of the paper, the paper moves adjacent to guide 128 as
shown in Figure 9. The paper remains in this position until the printer
drive mechanism 108 again moves the paper to the position shown in Figure
8.
CA 02427875 2003-05-08
The cyclical sequential back and forth movement of the paper in the
gap is sensed by detector 124. The detector 124 is operative to output
signals in a manner similar to detector 70 of the first embodiment
responsive to paper movement. These signals from detector 124 are
5 delivered to circuit 118.
In the preferred form of this embodiment, circuit 118 includes a self
calibrating triggering sub-circuit 134. Sub-circuit 134 is operative to
provide a trigger signal to circuit 118 each time the paper moves between
generally the positions shown in Figures 9 and 8.
10 Sub-circuit 134 is operative to compensate for changes in signals
from detector 124 due to changes in conditions such as paper color, paper
weight, the diameter of the take-up roll, accumulation of dirt and other
factors which may affect the level of sensed reflectance as the paper moves
or the amount of paper movement. In an embodiment of the invention, sub-
15 circuit 134 is operative to adjust how much light must be sensed as
reflected
from the paper before it generates its signal during each cycle. This is
accomplished based on the amount of light that is reflected from the paper
in the area adjacent the detector.
The detector 124 is preferably oriented so that when the paper moves
20 in each cycle from generally the position shown in Figure 9 to generally
the
position shown in Figure 8, the area of the paper sensed by the detector
when the paper was disposed from the detector is generally the same area
that is sensed when the paper is moved closer to the detector. As a result,
CA 02427875 2003-05-08
26
the generation of the trigger signal from sub-circuit 134 is based on a
difference in the signals from detector 124 as generally the same area of the
paper is moved between the two positions. Sub-circuit 134 operates so that
the threshold level at which the sub-circuit will trigger is appropriately
adjusted each time the paper drives move the paper to the position shown in
Figure 9. The threshold level for generating the signal is determined as a
function of the delta or change in reflectance detected from the paper when
the paper is disposed away from the detector. In various embodiments the
threshold may be established as a percentage change in reflectance.
However in other embodiments it may be a complex function. This depends
on the printing and paper types used in the particular system. Of course
while in this embodiment the threshold level for generating a signal is
adjusted based on reflectance when the paper is disposed the extreme
distances from the detector, in alternative embodiments the adjustment to
the level may be based on the signals from the detector when the paper is in
other positions.
Through the use of self calibrating sub-circuit 134 a signal is more
reliably provided each time paper moves between generally the positions
shown in Figures 9 and 8. This enables detector 124 to be positioned
adjacent areas where the reflectance of the paper varies due to printing
thereon. The sub-circuit also compensates for differences in reflectance
during paper movement cycles due to paper color, weight and other factors,
while indicating a failure condition through lack of a paper movement signal
CA 02427875 2003-05-08
27
when the drives operate in a manner which should cause the paper to move
in the gap but no movement occurs.
In operation of this embodiment signals are generated by sub-circuit
i 34 responsive to the cyclical paper movement in coordination with
movement of the printer and take-up roll drive mechanisms. These signals
are indicative of proper paper movement like those produced by detector 70
and encoder 40 of the first embodiment
The processor 120 executes a computer program which includes the
steps described in connection with Figure 6 to detect and indicate fault
conditions generally in the manner previously discussed. It should be
understood however that the set number used for comparison in step 86 is
set to a number of lines that would be printed to produce at least one
change of condition of the paper in the gap.
The second embodiment of the invention avoids the need to employ a
spindle in connection with the supply roll 112. Rather a supply roll can be
supported in a cradle or other manner. Further, the second embodiment
may be used with fanfold paper or another type of paper supply other than a
roll. Of course when an alternative form of paper supply is used, detector
122 must be appropriately positioned to detect when the paper supply is
low.
Although the take-up roll drive mechanism 116 is schematically
shown in Figure 7 as electrically operated by the electronic circuit, it
should
be understood that in embodiments of the invention it may be mechanically
CA 02427875 2003-05-08
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operated. For example, the take-up roll drive may be mechanically
connected with the printer drive mechanism. Such connection may include
mechanical linkages which provide the coordinated operation of the printer
drive and the take-up roll previously described. In this manner the take-up
roll drive operates responsive to the signals by the control circuit to the
printer drive.
While the preferred form of the second embodiment provides for
moving the paper in the gap adjacent to a detector in response to paper
being fed, and away from the detector when slack is removed, alternative
embodiments may work in a different manner. For example, the signals
indicative of paper movement could be based on movement away from a
detector or a detector may be placed in connection with guide 128.
Alternatively, the detector could be positioned adjacent a location of the
paper where no printing occurs to simplify or eliminate the need for the
self-calibrating sub-circuit. Alternatively, other paper guiding mechanisms
may be used for positioning the paper in a manner which conf'ums proper
paper movement. Those skilled in the art may devise numerous
embodiments employing the teachings of the present invention.
Thus the new fault indicating apparatus of the present invention
achieves the above stated objectives, eliminates difficulties encountered in
the use of prior devices and systems, solves problems and attains the
desirable results described herein.
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29
In the foregoing description, certain terms have been used for
brevity, clarity and understanding. However no unnecessary limitations are
to be implied therefrom because such terms are for descriptive purposes and
are intended to be broadly construed. Moreover, the descriptions and
illustrations herein are by way of examples and the invention is not limited
to the details shown and described.
In the following claims, any feature described as a means for
performing a function shall be construed as encompassing any means
capable of performing the recited function, and shall not be limited to the
particular means used for performing the function in the foregoing
description, or mere equivalents.
Having described the features, discoveries and principles of the
invention, the manner in which it is constructed and operated and the
advantages and useful results attained; the new and useful structures,
devices, elements, arrangements, parts, combinations, systems, equipment,
operations, methods, processes and relationships are set forth in the
appended claims.
