Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
TEC~ICAL FIELD
The present invention relates generally to electronic
measuring units capable of providing a digital indication
representative of a value to be measured while simultaneously
providing a printed representation of such digital indication
upon a record form.
BACKGROUND ART
Recent advances in electronic technology which have
made available low cost but efficient microprocessor systems
have led to the development of improved electronic measuring
systems capable of providing a digital indication
representative of a value to be measured. These microprocessor
controlled systems, such as that disclosed by U.S. Patent No.
3,962,570 to Loshbough, provide automatic zeroing, zero set
functions, tare control, and many other func~ions previously
provided by much more complex logic circuits, such as tha~
disclosed by U.S. Patent No. 3,665,169 to Henderson et al.
Additionally, microprocessor measuring systems may be
programmed to provide a number of calibLation functions and
other program control functions which previously have been
performed by excessively expensive, large and complex
electronic units.
Although microprocessor technology has resulted in the
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development of electronic measuring systems having greatly
enhanced capabilities, such systems are generally still of
substantial size, expensive, and difficult to service. This is
particularly true when the measuring system i5 combined with
both a visual digital indicator and a printer assembly for
providing a record printout of the visual display. Combined
electronic measuring and printer systems, such as ~hose used
for electronic weighing, are generally both large and complsx,
as illustrated by U.S. Patent Nos. 3,623,119, to Orr and
3,701,991 to Livesey. Consequently, there is a demand for a
small, compact, modular electronic measuring unit and printer
system which may be operated from either a battery or a
conventional power supply and which, although adapted to a wide
variety of uses, may be easily and inexpensively serviced and
repaired.
OBJ~CTS OF THE INVENTION
It is the primary object of the present invention to
provide a low cost, compact, modular electronic measuring and
printing unit which is of simple construction and which may be
easily serviced in the field. This unit is constructed for
enclosure within a ~mall, portable housing having at least one
removable wall to provide access to the enclosure within the
housing. The electronic system for the unit is modular with a
power ~upply system being mounted upon a circuit card adjacent
the rear of the housing and the electronic circuitry for -the
mesuring unit being moun-ted with an indicator system therefor
on a circuit card adjacent the front wall of the housing. The
Eront wall of the housing încludes a window to facilitate
visual observation of the indicator.
The present invention further provides a modular,
portable electronic measuring unit mounted within a housing
having a removable front wall section to provide access to the
enclosure within the housing. The measuring system includes a
power supply circuit provided upon a removable circuit card
adjacent the rear of the housing and a measuring and indicator
circuit provided upon a removable circuit card adjacent the
front wall of the housing. The front wall of the housing
carries mechanical control members removable with the front
wall which cooperate with the measuring circuit card to control
the operation of the measuring circuit when the front wall
section is in place on the housing. This unit is designed to
provide convenient access to the measuring circuit card so that
simple calibration adjustment is facilitated.
Another aspect oE the present invention is to provide
a novel and improved modular, portable electronic measuring
unit and printer system which is conveniently mounted within a
small portable compact housing. The power supply circuit for
both the printer and the measuring system is mounted upon a
single circuit card adjustment the rear wall of the housing,
while the measuring circuit and control circuit for the printer
P ~
system is mounted upon a single circuit card adjacent the front
wall of the housiny. This front circuit card also bears an
indicator unit Eor the measuring system which provides a visual
indication through a window in the front wall of the housing.
Control actuators for both the measuring system and the printer
are provided by elements mounted on the housing front wall and
removab]e from the housing with the front wall.
It is another object of the present invention to
provide a printer for use with an electronic measuriny system
which operates to print alpha or numeric characters on a single
or multiple copy pre-printed ticket form. The ticket form is
inserted under a dot marker until a stop is engaged, wherein
the ticket form will then be automatically fed out of ~he
printer as printing occurs. The printer timing and printing
lS are controlled by a microprocessor.
A further aspect of the present invention is to
provide a printer for use with an electronic measuring system
having a print unit which is mounted for movement in a first
plane and a print drive assembly to selectively move the print
unit between spaced points in the first plane. The print unit
marks an adjacent record medium and a record medium drive unit
is provided to move the record medium in a second plane
transverse to the first plane.
~ further object of the presen-t invention is to
provide a modular, electronic measuring and printiny unit
wherein a sinyle microprocessor chip is employed to control
analog to digital conversion, arithmetic and display functions
as well as the operation of a printer unit.
A still further object of the invention is to provide
a modular electronic measuring and printing unit wherein a
printer is employed as the chasis for the electronic circuit
boards for the system. Novel circuit board structures are
provided with sensing units and other components positioned to
cooperate with pcinter components, and ~hese circuit board
structures are uniquely combined with the printer to form an
operative module.
Additional objects, advantages and features of the
invention will be more readily apparent from the following
detailed description of a preferred embodiment of the invention
when taken together with the accompanying drawings.
BRIEF DESCRIP'rION OF TH~ DRAWINGS
FIGURE 1 is a perspective view of the modular
electronic measuring and printing unit of the present invention;
FIGURE 2 is a partially cut away side view of the
modular electronic measuring and prin~ing unit of FIGURE 1 with
the first and second sections of the housing assembly separated;
FIGURE 3 is a diagrammatic plan view of the interior
of the electronic measuring and pri.nting unit of FIGURE 1;
FIGURE 4 is a block diagram o:E the power supply
circuit and circuit for the electronic measuring and indicator
sys-tem for the modular electronic measuring and printinq unit
of FIGURE l;
FIGURE 5 is a block diagram of the elec-tronic circuit
for the printer of FIGURE 3;
FIGURE 6 is an exploded view of the elec~ronic
measuring and printing unit of the present invention; and
FIGU~E 7 is an exploded section of the power circuit
board of FIGURE 6 in combination with the detectors of FIGURE 5.
DETAILED D~SCRTPTION OF INVENTIO~
Referring now to FIGURES 1 to 3, the modular,
portable, electronic measuring system and printing unit of the
present invention indicated generally at 10 includes a housing
12 which is formed from a firs-t housing assembly 14 and a
second housing assembly 16. The housing assembly 14 includes a
top wall 18, a bottom wall 20, a rear wall ~2, and side walls
24 and 26, preferably formed as a unitary unit which deEi.nes an
enclosure 23 having an open front side 30.
The second housing assembly 16 is adapted to be
removably secured to the first housing assembly and operates to
close the open front side 30 of the enclosure 28. This second
housing assembly is formed by a top wall 3Z, a bottom wall 34,
and side walls 36 and 38, all of which are connected together
and substantially coextensive with the top, bottom and side
walls of the f:irs-t housing assembly 1~ when the two housiny
assemblies are connected together. The top, bottom, and side
walls oE the second housing assembly provide a frame for a
recessed face plate 40 which closes the open front side of the
enclosure 28 when the second housing assembly 16 is secured to
the first housing assembly 14. This may be accomplished by
means of an indented, projecting Elange 42 which ex~ends from
the front edge oE the top, bottom, and side walls of ~he first
housing assembly 14 and which is adapted to slide within the
open rear side of the second housing assambly 16 to engage the
inner surface of the walls thereof.
The face plate 40 includes an elongated slot 4~ which
receives a ticket or other record medium and a window 46 which
is position to permit visual obsveration of a digital display
indicator 48 mounted within the enclosure 28. Also mounted
upon the face plate 40 are a print button 50, a zero button 5Z
and a power on/standby button 54 which cooperates with a power
switch 55. These buttons may be depressed relative to the face
plate 40, but are peLmanently mounted upon the face plate and
are removable from the first housing assembly 14 with the
second housing assembly 16.
FIGURE 3 provides a diagrammatic illustration of the
arrangement of components within the enclosure 28. This
arrangement is quite significant, for it not only contributes
to the compactness of the uni-t lO, but also facilitates simple
and economic maintenance. It will be noted from FIGURE 3, that
a printer unit 56 is mounted within the enclosure so as to be
in alignment with the slot 44 and operable by the print button
50. Also occupying the enclosure with the printer unit are a
power supply circuit board 58 and a measuring and indicator
circuit board 60. These two circui~ boards are mounted on the
printer unit 56 to form a sub-assembly that is completely
functional when removed from the enclosure 28 and which may be
conveniently replaced as a single unit. I~ is importan~ to
note that the power supply circuit board is positioned adjacent
the rear wall 2Z of the enclosure while the measuring and
indicator circuit board 60 is positioned adjacent the open
front side 30 of the enclosure and thus adjacent to the
faceplate 40. Since the measuring and indicator circuit board
carries the measuring circuit, the microprocessor unit,
calibration adjustments, and the indicator unit Eor the system,
the position of this board makes calibration simpler.
Consequently, when the second housing assembly 16 is removed
from the first housing assembly 14, the calibration controls
and indicator are then readily accessible for convenient
calibration.
With the power supply circuit board 58 arranged
adjacent to the rear wall 22, convenient access for the input
power line to the housing 12 is provided. This input power
line will carry a power supply conductor 62 directly to the
power supply circuit board 58; the shor-t path thereby
minimi2ing possible interference cause by the power supply
conductor. A measuring signal conductor 64, which provides an
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electrical signal from a suitable measuring ~ransducer to the
measuring and indicator circuit board 60 may be routed through
a separate entry for isolation from the power supply
conductor. The conductor 64 might provide an eleetrical
measurement signal from a load cell unit ~5 when the modular
portable eleetronic measuring and printer unit 10 is employed
for weighing applieations. The rearwar~ positioning of the
power supply eircuit board 58 within the enclosure 28 provides
convenient access to this board for the input power line 62
while also enabling this board to convenien~ly supply power to
the printer 56 and the measuring and indicator circuit board
60. Also, since the power supply eircuit board reguires no
adjustment, it need not be as accessible as the measuring and
indicator circuit board 60.
With reference to FIGURE 4, it will be noted that the
measuring and indicator eireuit board 60 reeeives the input
measurement signal on the line 76~ at an analog input and
adjust eireuit 66. This cireuit may eonstitute any input
eireuit for providing low drit amplifieation while permitting
some analog adjustments to the ineoming measurement signal.
For example, in an eleetronie weighing system, this adjustment
eircuit might include the conventional operational amplifiers,
eomparators, span adjust eireuitry, over capaeity adjust
eireuitry, and dead load adjust circuitry. From the adjust
eireuit 66, the adjusted measurement signal is fed to an analog
to digital eontrol and conversion eireuit 68 where the input
analog measurement signal is converted into a digital signal
for processing in a microprocessor 70. The analog to diyi.tal
control ancl conversion circuit contains the circuitry necessary
to accomplish a digital conversion and is locked into ~he
microprocessor clock to ensure synchroniza~ion.
An auto zero adjust circuit 72, which may be activated
by the control button 52, is connected to the microprocessor 70
which provides conventional automatic zero tracking and push
button zeroing of the system. The microprocessor then controls
the digital display provided by the visual display unit 48.
To this point, ~he components of the electronic
measuring and display system contained on the circuit board 60
perform a measurement and display function in a conventional
manner which is well known in the prior art. However, the
microprocessor 70 is also programmed to control the operation
of the printer 56, and to accomplish this function, the
microprocessor receives an input from a ticket insertion
detector on an input line 74 and a second input from a
synchronization detector on an input line 76. The
microprocessor provides control signals to a print motor driver
78 and also to a print solenoid driver 80.
The power supply circuit board includes a power supply
circuit 82 to provide power to both the components on the
measuring and indicator circuit board 60 as well as to
components for the printer 56. For example, ~he power supply
circuit provides power on a ticket detector output line 84 and
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also on a synchLonization detector output line 86.
Additionally, power is supplied to other miscellaneous
components of the system on a miscellaneous line 88. For
example, the line 8~ could provide power to an optional heater
for the modular electronic measur:ing and printing unit 10.
The control circuit for the printer 56 may best be
understood with reference ~o FIGURE 5. Here, it will be noted
that the printer timing and character generation functions are
controlled by a microprocessor, which may be the same
microprocessor 7G employed with ~he measuring circuit on the
measuring circuit and indicator card ~0. This microprocessor
may constitute an 8048 or 8748 single chip microprocessor
manufactured by Intel Corporation and programmed for both
measurement and print control functions. On the other hand,
the microprocessor for the printer 56 may be self-contained
microprocessor constituting a portion of the printer proper,
and in this case the microprocessor might receive data at a
data input from a measuring circuit microprocessor such as the
microprocessor 70 or from some other data source. In instances
where the main measuring unit microprocessor is not employed in
the printer and the printer is provided with a self~con~ained
microprocessor, the printer microprocessor could still
constitute a single chip microprocesso.r having character matrix
dot patterns stored in a non-volatile memory. Otherwise the
measuring circuit microprocessor is programmed and designed to
control ~he printer 56.
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Before the microprocessor initiates charac~er
printing, it must Eirst determine whether a ticket or other
record medium has been inserted into the printer 56 through ~he
slot 4~. This information is provided to the microprocessor by
a ticket insertion detector 15B and a synchronizalion detector
160. The ticket insertion detector 158 includes a ligh~
source, such as a light emitting diode 162, which transmits
light across a slot 1~4 in a sensing block 1~6 to a light
sensitive transistor or similar solid state device 168. I'he
sensing block is mounted on the po~er supply circuit board 58
and is directly aligned with a blade 170 extending from the
rear side of the carriage. When the push button is pressed,
the blade 170 enters the slot 16~ and prevents light from the
light emitting diode 162 from reaching the ligh~ sensitive
transitor 168. This provides a ticket insertion signal on the
line 74 to the microprocessor 70.
Similarly, the synchronization detector 160 includes a
sensing block 17Z which is suitably mounted upon the power
supply circuit board 58 to sense the position of the cam 112.
The synchronization detector includes a light emitting element,
such as a light emitting diode 174, positioned by the sensing
block 172, and a light sensitive transistor 1-/6 positioned by
the sensing block 172 opposite to the light emitting diode
174. With the slot 173, the light from the light emitting
diode 174 will strike the transistor 176 and provide a proper
position signal on the line 76 ~o the microprocessor 70.
To activate ~he printer 56, ~he print button 52 is
depressed -to rotate -the carriage 118, and a ti.cket or other
record medium is inserted. When the print button is then
released, the blade 170 leaves the slot 164 and a signal is
sent to the microprocessor 70 to indicate that a ticket is in a
position for printing. When ~he microprocessor program
recogniæes that a ticket has been inserted, that input data has
been stored, and that the printer is in the proper start
position, printing will begin. If, however, the printer is not
in the proper start position, the microprocessor will cause
adjustments until the printer is in the proper start position
and a start signal i6 received from ~he synchronization
detector 160.
Referring to FIGURE 6, it will be noted that the
printing unit are provided with outwardly facing threaded
apertures 196 and 198 that are adapted to align with holes ~00
and Z02 formed in the power circuit board 5~ and the measuring
and indicator circuit board 60 respec~ively. Threaded screws
or other suitble fasteners may then be inserted through the
holes 200 and 202 and threaded into the apertures 196 and 198
to attach the circuit boards 58 and 60 to the printer 56. It
is imperative that the power circuit board be carefully aligned
with the printer, as the power circuit board carries the
sensing blocks 166 and 172 (FIGURE 7). Since the slot 164 in
the sensing block 166 must be aligned with the blade 170 on the
cariage 118 while the slot 175 in the sensing block 172 must be
aligned to receive the flange 106, the power circuit board 58
must be carefully positioned with respec~ -to the printer 56.
To achieve this position, the upper and lower spacing bars 94
and 96 which engage the power circui~ board 58 are each
provided with rearwardly projecting locator pins 204 which
project into locator holes 206 ~provided in the power circuit
board between the holes 200. This insures alignment of the
power circuit board and the sensing blocks 166 and 172 with
corresponding components of the printer.
After the power circuit board 58 and ~he measuring and
indicator circuit board 60 are secured to the printer 56, a
tubular spacer 208 having a threaded aperture at each end may
be positioned between the free ends of the power circuit board
and the measuring and indicator circuit board in alignment with
holes 210 and 21Z the.rein. This spacer may then be secured by
threaded screws or other fasteners inserted through the holes
210 and 212 and into the spacers, thereby creating a very rigid
assembly. Now a flat belt type connector 214 which is secured
to the power circuit board 58 may be passed beneath the prin~er
56 and secured to a proper socket (not shown), on the measuring
and indicator circuit board 60 to comple~e the power and other
connections thereto.
The operational module formed by the printer 56, the
power circuit board 58, and the measuring and indicator circuit
board 60 may easily be inserted within the enclosure 28 in the
first housing assembly 14 and is positioned and supported
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therein by locator bars 216 formed in the first housing
assembly. It will now become apparent that when the second
housing asseïnbly 16 is secured to the first housing assembly,
the slot 44 will align with a 610-t 218 in the measuring and
indicator circuit board 60.
As previously stated, th~e print button 50, zero button
52, and power on/standby button 54 are removed from the first
housing assembly l~ wi~h the second housing assembly 1~. One
method for accomplishing this may be to provide the second
housing assembly with a face plate 220 provided with apertures
2Z2 which are dimensioned to permit only a portion of the
buttons 50, 52 and 54 to project therethrough. Each of these
buttons may be provided with a flange 224 which contacts the
face plate 220 and limits the outward projection of the buttons
through the apertures 222. Biasing springs 226 for biasing
these buttons outwardly may be retained between the face plate
220 and a rear wall 228 on the second housing assembly which
cooperates with the face plate to form the recessed face plate
40. The face plate 220 and rear wall 228 are arranged to
permit limited inward movement of the buttons SO, 52 and 54.
The print button 50 includes an extension rod 140
which operates, when the p.rint button is depressed, to make
contact on the printer. This extension rod extends -through an
aperture 230 in the rear wall 228 and an aperture 232 in the
measuring and indicator circuit board 60 ~o reach the printer
56.
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Jr~ t, ;~
Similarly, the ~ero but-ton 52 is provided with a short
extension rod 234 which ex~ends through an aperture 236 in the
rear wall 228 and which contacts a zero control but-ton 238 on
the measuring and indicator circuit board.
Finally, the power on/standby hutton 54 is provided
with an extension rod 240 which extends through an aperture 242
in the rear wall 2Z8 and an aperture 2~ in the measuring and
indicator circuit board 60 to the power switch 55 mounted upon
the power circuit board 58.
To achieve effective operation of the modular,
portable, electronic measuring system and printing unit 10 in
the manner described, the single chip microprocessor 70 may be
programmed in accordance with the following program. If the
printing unit 56 includes a self-contained microprocessor 70
and is employed as a separate unit, this microprocessor pro~ram
would then begin at line 776 of the followlng program.
When the printing unit 56 is combined in the modular
system lO of FIGURE l, an extremely compact and efficient
measuring and printing unit i6 provided. Other aspects and
advantages of the presant invention will be readily apparen-t
from a consideration of the specification and the appended
drawings.
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