EP0015954B1 - Ink level control apparatus - Google Patents

Ink level control apparatus Download PDF

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Publication number
EP0015954B1
EP0015954B1 EP79900421A EP79900421A EP0015954B1 EP 0015954 B1 EP0015954 B1 EP 0015954B1 EP 79900421 A EP79900421 A EP 79900421A EP 79900421 A EP79900421 A EP 79900421A EP 0015954 B1 EP0015954 B1 EP 0015954B1
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EP
European Patent Office
Prior art keywords
ink
level
signal
fountain
echo
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP79900421A
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German (de)
English (en)
French (fr)
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EP0015954A1 (en
Inventor
John Macphee
Peter Van Raalte
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Baldwin Gegenheimer Corp
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Baldwin Gegenheimer Corp
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Publication of EP0015954A1 publication Critical patent/EP0015954A1/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41F—PRINTING MACHINES OR PRESSES
    • B41F31/00—Inking arrangements or devices
    • B41F31/02—Ducts, containers, supply or metering devices
    • B41F31/022—Ink level control devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41F—PRINTING MACHINES OR PRESSES
    • B41F33/00—Indicating, counting, warning, control or safety devices

Definitions

  • This invention relates to an apparatus for controlling the ink level in an ink fountain used in a printing press such as the viscous ink in an offset lithographic press.
  • Ink generally is considered an active substance in the sense that the ink sets when allowed to stand and dries when exposed to air.
  • ink is sticky and readily adheres to all commonly used materials. These properties pose a difficulty in sensing ink level since the ink has a tendency to accumulate or build up on any sensing member or component with which the ink comes into contact.
  • the ink fountain or reservoir in an offset printing press is constructed in the form of a trough such as shown in U.S. Patent 3,848,529 to Gegenheimer et al., which is assigned to the present applicant.
  • the ink trough is formed by a flat blade which forms a nip with a fountain roller.
  • a feature of such reservoir is that the surface of the ink contained therein is not flat, but usually undulates while the press is in operation at a frequency in the range from 0.25 to once a second. This undulation is produced by a ratchet action of a fountain roller and makes it difficult to sense the ink level.
  • Ink fountains in many printing presses are commonly equipped with ink agitators which improve ink distribution, prevent the formation of surface skin and improve feeding of the ink to the nip between the flat blade and the fountain roller.
  • the main element of an ink agitator may be in the form of a conically shaped roller which is caused to rotate while traveling to and fro the length of the ink fountain. Such roller is illustrated in the aforementioned Gegenheimer et al. patent.
  • the presence of an agitator produces a wave in the ink of a height which may be of the order of an inch or even more. When the ink is so disturbed, its surface quivers and undulates so as to make it difficult to sense ink level.
  • the space above the ink fountain must be kept relatively clear to allow room for the operator of the printing press to clean the fountain or to enable ink to be fed manually for occasions when special or spot colors are necessary.
  • the sensing of ink level must be done in such manner that the area or space over the ink fountain is not unreasonably obstructed.
  • Ink level sensors may use floating, tactile, capacitance, pneumatic or ultrasonic techniques.
  • U.S. Patent 3,025,793 describes an ink level control for a newspaper press utilizing a float operated ink feed valve. Although such an approach is workable in newspaper presses, which utilize relatively thin or low viscosity inks, the float concept is not feasible in commercial presses requiring thicker inks.
  • a major difficulty encountered with a floating device resides in the accumulation of ink on the float, eventually rendering it inoperable. The float also tends to take up a large amount of space, particularly when such float is directly connected to operate an ink flow control valve.
  • a tactile sensor is employed to monitor the height of the wave of ink generated by an agitator, thereby overcoming the difficulty posed by the waves in measuring the ink level.
  • Gegenheimer et al. also discloses the use of an adjustable timer to limit the duration of ink feed to overcome the difficulty posed by the high ink viscosity which prevents an even ink level from being quickly established when the ink valve is opened.
  • adjustable feed pulses are applied through a relay to actuate the ink valve. The width of the feed pulses and the intervals between the pulses can be selected.
  • a number of prior art systems employ sensors which avoid ink contact by using the capacitance principle.
  • a plate is mounted above the ink fountain to form an electrical capacitor with the ink fountain blade. Since the permitivity of ink differs significantly from air, the capacitance will vary with the ink level and thus provides a non-contacting method for detecting ink level.
  • This sensor design has a disadvantage in that the sensor must be located within approximately an inch of the ink surface, thus obstructing access to the fountain.
  • a pneumatic ink level measuring system is available in the form of a vertical tube which is inserted into the ink fountain.
  • the tube is connected to a source of air and the pressure in the tube is monitored to obtain a measure of ink level. This concept is satisfactory for low viscosity inks but difficult to apply to highly viscous offset printing press inks.
  • Ultrasonic techniques for detecting the level of liquids are well known and have been applied to ink level controls in a limited liquid contacting manner. A general description of ultrasonic techniques can be found in an article entitled "Ultrasonic Instruments for Level and Flow” in the September, 1974 issue of Instrumentation Technology.
  • Ultrasonic systems for determining liquid level utilize one of two basic approaches.
  • a detector provides an on-off signal when the liquid comes into contact with the ultrasonic sensor; see, for example, U.S. Patent 3,520,186 to Adams et al.
  • the liquid level may interrupt ultrasonic waves or cause a change in the dampening characteristics of an ultrasonic transducer when it is contacted by the liquid. Contact by the detector with ink, however, is not desirable.
  • an echo ranging principle is employed, such as described in the U.S. Patent 3,985,030 to Charlton.
  • a pulse of ultrasonic energy is directed by a transducer toward the liquid surface.
  • a receiver listens for an acoustic echo and the time required for the echo to return provides a measure of the distance between the ultrasonic transducer and the liquid surface.
  • a loss of echoes is detected and used to override an automatic level indicator by registering a maximum liquid level depth.
  • U.S. Patent No. 4,000,658 to Snyder discloses an ultrasonic level detector in which ultrasonic pulses are transmitted from the top of a tank by a transducer, are reflected by the surface of the material contained in the tank, and are received by the same transducer. Failure to detect a reflected pulse in a short-range mode automatically switches the detector to a long-range mode utilizing ten millisecond pulses at three hundred millisecond intervals. The echo signals from eight successive long-range pulses are digitized and then integrated according to apparent object distance so that the sum of the true echo signals returned from the surface of the material in the tank is substantially greater than the sum of the random noise signals for each transmitted pulse.
  • an apparatus for automatically controlling the level of ink in an ink fountain used in a printing press by regulating the feed of ink from a supply through a valve to the fountain comprising: ultrasonic ink level sensing means remotely spaced from the ink fountain for directing ultrasonic pulses of acoustic energy at the ink fountain and for generating an echo signal representative of ultrasonic returns from the surface of the ink; means responsive to the echo signal for generating a measured ink level signal indicative of the operating level of ink in the ink fountain; means for producing a desired ink level reference signal representative of a desired ink level in the fountain; comparing means for comparing the measured ink level signal with the desired ink level reference signal to generate an ink feed signal when the ink level in the fountain drops below the desired level; means responsive to the ink feed signal for generating ink feed pulses spaced by intervals of a predetermined duration selected commensurate with the time period needed to enable ink supplied during a preceding pulse to cause
  • an ink level control apparatus embodying the invention, the ink level is sensed remotely with an ultrasonic pulse-echo technique.
  • An accurate ink level control apparatus is provided capable of detecting ink level even in the presence of a quivering, undulating ink surface and an agitator wave, while providing operational safeguards for reliable and fail-safe operation.
  • an ultrasonic transducer is selected of a type capable of operating within normally encountered space restraints near the ink fountain of a printing press.
  • the transducer can be remotely spaced from an ink fountain to enable access for cleaning, yet can be mounted within the available space and provide a reliable sensor of the ink surface as a result of acoustic pulses directed at the ink.
  • Acoustic reflections from the ink are detected and processed to produce a measured ink level signal representative of the ink level in the fountain.
  • An averaged or smoothed measured ink level signal is compared with a reference representative of a normally desired ink level in the fountain and the comparison used to provide an ink feed signal.
  • the ink feed signal is thereupon converted to ink feed pulses separated by intervals of a predetermined duration.
  • Various ink feed limitations are applied to assure the proper feed of ink in a manner whereby the ink fountain is prevented from overflow.
  • Woith such control apparatus an accurate, non-contacting ultrasonic ink level sensor can be used to maintain the ink level at a desired level while preventing an excessive feed of ink to the fountain.
  • an echo loss detection network is used to detect when echoes are not received. Such loss may arise from the passage of the agitator's ink wave in the path of the ultrasonic beam.
  • a simulated ink feed signal is produced to maintain normal operation of the ink level control apparatus. In the event the echo loss persists longer than a particular time, an alarm is generated.
  • the echo loss detector is particularly useful during field installation of the ink control when the ultrasonic transducer is aligned at the ink surface.
  • the echo loss detector is visually monitored by observing an alarm light energized by an activated echo loss detector.
  • Accurate alignment of the transducer may then be achieved by angularly moving the transducer to determine its angular operating range over which an echo can be obtained.
  • the transducer is then fixed at a midway position of the operating range. This procedure, when carried out for transverse planes which are also normal to the ink surface, provides a convenient technique for using, and field aligning of, a narrow beam ultrasonic transducer.
  • both high and low ink level reference signals are generated to define an acceptable range of ink level within the ink fountain.
  • the measured ink level signal is compared with these reference signals to generate an alarm when the measured ink level falls outside this acceptable range.
  • Enhanced protection is provided by inhibiting the feeding of ink when the ink level drops below its acceptable low level. This feature prevents ink spills when the fountain is opened for cleaning.
  • an ink level control apparatus 10 for a printing press (not shown) is described.
  • An ink fountain 12 as generally described and shown in the Gegenheimer et al. Patent 3,848,529 is illustrated with a fountain blade 14 and an ink fountain roller 16 converging at a nip 18.
  • the ink fountain 12 is provided with an agitator 20 which is moved to and fro as described in the Schwarzheimer et al. patent with a suitable actuator 22.
  • the fountain roller 16 is periodically actuated with a ratchet mechanism (not shown).
  • Ink 23 is supplied to the fountain 12 from a supply 24 through an automatically controlled ink feed valve 26 and conduit 28.
  • Other ink feed supply elements such as a pump have been deleted for clarity.
  • the ink surface 36 tends to distort from its normal level as shown at 37 depending upon the frequency of operation of the agitator 20, fountain roller 16 and the viscosity of the ink. A more or less permanent quivering and undulated bulge such as 39 extending over the length of the fountain 12 is often encountered.
  • the transducer 30 is selected of a type capable of generating acoustic pulses and providing an echo signal representative of acoustic returns or echoes from the ink surface 36 within the available space of a printing press.
  • the transducer 30 must be capable of operating within the available space above the fountain 12.
  • the transducer Since the transducer must operate in air, it tends to produce an undamped acoustic pulse followed by undesirable ringing effects and a greater spacing from the ink is needed to allow such trailing acoustic transients to die down. With the printing press' space limitation, however, the increased spacing frequently is difficult to accommodate and a high frequency transducer, capable of operating in the range of about 200 KHz is preferred. Such higher frequency transducer 30 enables one to employ remote acoustic ink surface sensing on printing presses with acceptable accuracies. The high frequency transducer, however, has a narrow beam, of the order of about six degrees. Hence, the transducer 30 is also carefully aligned and positioned to sense the various ink surfaces encountered on printing presses.
  • a control network 38 is provided to actuate transducer 30 and respond to the echo signal for control over the ink-level in fountain 12.
  • Ultrasonic transducers capable of generating and detecting acoustic pulses are well known and need not be further described.
  • Transducer 30 is controlled with a transceiver 40 formed of a digital circuit as may be commonly purchased.
  • the transceiver 40 responds to pulses, Tx, on line 41 from a timer 42 which may generate these at a high rate of the order of 100 pulses per second.
  • Each transmitter pulse causes the transceiver to deliver a large driving pulse on line 44 to transducer 30 which generates an acoustic pulse towards the ink surface 36.
  • Acoustic returns from ink surface 36 are detected by transducer 30, amplified by transceiver 40 and made available as an echo signal for processing on an output line 46.
  • the echo signal is applied to a gate 48 which is normally enabled by the level on line 50 from an inverter 52 coupled to the timing pulses Tx from timer 42. While pulses Tx are active, gate 48 is disabled. This prevents erroneous responses when transducer 30 generates an acoustic pulse. If desired, a longer lasting inhibition of gate 48 may be obtained by replacing inverter 52 with a pulse network whose output pulse would last while an acoustic return from ink surface 36 could not occur; for example, an inhibiting pulse lasting for slightly less than the round trip transit time of the acoustic energy could be used.
  • the disabling level on line 50 is also applied to reset a flip-flop 54.
  • flip-flop 54 When gate 48 is enabled and receives an echo signal from transceiver 40, flip-flop 54 is set to provide an echo signal on line 56 to an ink level signal generator 58. The latter is responsive to transmitter pulses Tx on line 41 and the echo signal from flip-flop 54 to measure the time therebetween and produce, an output line 60, an ink level signal representative of the actual ink level in fountain 12.
  • the measurement of the distance between transducer 30 and ink surface 36 can be carried out with a variety of different ink level signal generators 58.
  • the latter may be an analog or digital circuit capable of providing a signal representative of the ink level.
  • transducer 30 Since transducer 30 provides an echo signal at a time which is a function of the spacing of transducer 30 from ink surface 36, the ink level signal is similarly related. However, by placing transducer 30 a fixed known distance from ink fountain 12, the ink level signal on line 60 represents actual Ink level in the fountain reference relative to, for example, the deepest level 59.1 at nip 18.
  • the ink level signal on line 60 is applied to a comparator 62 together with a reference signal representative of an operating ink level 59.3 desired to be maintained in fountain 12.
  • This reference signal is obtained on line 64 from a suitable network 66 and a resulting comparison is produced as an ink feed signal on output 68 of comparator 62 when the ink level, as measured, drops below the operating reference.
  • the comparator 62 is of a type which does not present an output as long as the measured ink level is above the operating level.
  • the ink feed signal occurs on output 68 of comparator 62 it enables a clock 70 which generates ink feed pulses 72 separated by ink leveling inter- . vals 74 on line 75.
  • the ink pulses 72 are applied to an ink feed relay 76 coupled to operate valve 26 and enable ink to flow into fountain 12.
  • Clock 70 has an interval control network 78 to control the duration of intervals 74 and a pulse width selection network 80 to regulate the widths of pulses 72.
  • the pulse widths are selected to be long enough to keep up with the printing press' utilization of ink, but not so long that the fountain would overflow.
  • the intervals 74 must be long enough to allow the ink to level out in between feeds to prevent an overflow, but short enough to keep up with the ink utilization of the printing press.
  • the interval control network 78 sets the time between successive pulses 72. This interval is made sufficiently long to enable a change in the ink level to be registered in response to a previous ink supply pulse.
  • the duration is a function of viscosity with more viscous inks requiring longer intervals.
  • the pulse widths may be of the order of 1 to 15 seconds separated by intervals of 15 seconds for an ink having a viscosity of the order of 200 poise.
  • the ink level control apparatus 10 maintains ink in the fountain below maximum level 59.5 by applying a high ink level reference signal on line 82 from a reference source 84 to a comparator 86.
  • the high ink level reference signal represents the maximum acceptable ink level 59.5 in the fountain 12 and is compared with the measured ink level signal on line 60 to produce an alarm on comparator output 88 when the ink level exceeds the maximum level 59.5.
  • an ink wave such as caused by the action of the agitator 20, generates an acoustic return which causes the measured ink level signal on line 60 to temporarily represent an ink level above the maximum level 59.5.
  • comparator 86 may produce an alarm signal on output 88.
  • a timer 90 is employed to screen out momentary high ink level detections. Timer 90 is of a type whereby the high ink level alarm on line 88 must persist for a minimum time period to cause a high ink level alarm on output 92 to activate a high level relay 93. The relay may be used to sound an audible alarm 94.
  • the ink level in fountain 12 is normally kept at or above operating level 59.3. If, notwithstanding such control, the ink level drops below the operating level 59.3 and also below minimum level 59.2, the condition is identified as a malfunction with a minimum level control 95.
  • the measured ink level signal on line 60 and a low ink level reference signal on line 96, representative of minimum level 59.2 and generated by a source 98, are compared by a comparator 100. If the measured ink level drops below minimum 59.2, a low ink level alarm signal is produced on comparator output 102.
  • a low ink level alarm is construed as a malfunction of the system, such as may occur if the ink fountain is in an open unused condition
  • the comparator output 102 is applied to an inhibit input of comparator 62 to inhibit it from generating an ink feed signal on line 68.
  • Comparator output 102 is also applied to a relay 104 to operate such devices as appear necessary to repond to such low ink level condition since the low level may also be due to valve 26 being stuck or the ink supply being depleted.
  • Relay 104 may, for example, sound an audible alarm 106.
  • ultrasonic transducer 30 provides the advantage of remote sensing of the ink level. However, from time to time the ink surface 36 is not level so that acoustic returns are reflected in the direction of arrow 35 instead of back onto transducer 30. As a result, an echo may be lost and no echo signal produced on line 56. In order to avoid a misinterpretation of such echo loss as an excessively low ink level, the loss of echo signal is detected with a network 110 and an appropriate ink level signal is simulated and provided on line 60.
  • Echo loss detector 110 includes a pulse network 112 which sets a flip-flop 114 in the event an echo signal fails to occur on line 56 within a certain time period following a transmitter pulse Tx. If an echo signal does occur, the setting pulse from pulse network 112 is inefective since the echo signal on line 56 from flip-flop 54 is applied to maintain flip-flop 114 in its reset state.
  • an echo simulator circuit 120 is activated to provide a simulated ink level signal on line 122 representative of an ink level 59.4 between the operating level 59.3 and maximum level 59.5.
  • the ink level signals is applied to network 58 and appears on line 60 as long as echoes are lost.
  • flip-flop 114 is reset and the simulated ink level signal on line 118 deactivated.
  • a malfunction signal is produced with a timer 124 actuated by the echo loss signal on line 118.
  • Timer 124 generates an alarm signal on line 126 for actuation of an appropriate alarm 128.
  • Fig. 2 illustrates an analog form of echo simulator 120 for generating a simulated ink level signal.
  • the simulator operates with an ink level signal generator 58 of an analog type whereby the average voltage from flip-flop 54 (proportional to ink level) is stored in a capacitor 132.
  • an echo loss signal When an echo loss signal occurs on line 118, it closes a transistor switch 134 having a simulated reference level signal from a source 136 coupled to a power electrode 138 such as the collector.
  • the other power electrode 140, the emitter, is coupled to capacitor 132 to clamp its voltage to the simulated reference level from source 136.
  • a simulated ink level signal is provided on line 60.
  • capacitor 132 involves its smoothing effect upon the ink level signal. Such smoothing is desirable in view of the occasional loss or changes in the arrival time of an echo signal due to the vibratory and disturbed nature of the ink surface 36. This smoothing is done over a time period sufficient to average a desired number of echo signals.
  • a time constant associated with the charging of capacitor 132 may be of the order of about a third of a second.
  • the ink level control apparatus embodying the invention can be obtained with a digital network.
  • a microprocessor may be programmed to respond to the transceiver output 46 and transmitter pulses, Tx, to provide a digital echo signal.
  • One method in which this can be done is to enable an internal microprocessor clock to enter pulses into a register and terminate this when the transceiver generates an echo signal.
  • the accumulated count in the register represents the two-way travel time of an ultrasonic pulse from transducer 30 to ink surface 36. The actual distance is directly proportional to the travel time and can be derived using a value of the speed of sound in air.
  • the distance value effectively represents the measured ink level by virtue of the known distance between the transducer and the bottom level 59.2 of the ink fountain.
  • the distance value is thus converted to a measured ink signal within the microprocessor and stored in a suitable memory location.
  • a suitable averaging technique may be employed to smooth out the effect of ink level surface variations.
  • the number of travel time or distance measurements to be averaged depends upon the travel speed of the agitator 20 and the size and frequency of the vibrations of the ink surface 36. In a pulse echo ink level control apparatus which generates of the order of about 100 echo pulses per second, the averaging of about 50 measured travel times can be used.
  • the stored ink level signal is then compared with various previously stored digital values for the high, low an doperating levels to provide an ink feed signal to the ink feed valve 26.
  • An echo loss can be detected by comparison with a particularly low ink level reference value such as 59.1.
  • the digital form of ink level control apparatus 10 may thus take the form of a programmed microprocessor or with discrete digital circuits as may appear desirable.
  • a digital form of the measured ink level signal such as developed either by generator 58, or its digital counterpart, is stored in a memory such as a represented by storage network 57. This storage may be a location in a microprocessor memory or a particular output register for subsequent comparison with the reference signals.
  • the stored ink level signal is retained until replaced as a result of a new measurement with an echo signal.
  • the output on line 118 is applied to network 57 to prevent replacement of the previously stored digital measured ink level signal.
  • Such effect may, for example, be obtained by blocking the input to register 57 with suitable logic gates.
  • the detection of an echo loss on line 118 is used to replace the digital signal in storage network 57 with one representative of a predetermined ink level to avoid ink fountain overflows as may occur when the previous ink level measurement sensed a low ink level.
  • Such digital simulated predetermined ink level signal may be generated as soon as an echo loss is detected or may, for example, be obtained from a digital form of the simulated reference source 136 as shown in Fig. 2 such as can be stored in a memory location of a microprocessor.
  • the echo loss detector 110 may be conveniently employed to align the ultrasonic transducer 30 onto ink surface 36. This is done by mounting transducer 30 for pivoting in transverse planes which are also normal to ink surface 36. The transducer 30 is then pivoted until the echo is lost as observed by detecting a visual alarm 128 energized by detector 110. The middle of the pivot range for each plane is then selected as the aligned position of transducer 30.
  • the described alignment procedure may also be carried out by observing a light source 53, such as an LED, driven by the reset output 55 of flip-flop 54.
  • a light source 53 such as an LED
  • the output 55 will be off most of the time and hence a very dim LED output is obtained as a sensing of the proper operation of the ink level control apparatus.
  • the reset output 55 will be continuously on and as a result the LED output significantly brighter.
  • the level of ink can be precisely controlled without direct contact with the ink and while the ink surface is disturbed by an agitator. Variations from the described embodiment may occur to one skilled in the art.
  • the echo loss simulator network may be in digital form to accommodate a digital ink level signal generator. Also, a plurality of ink controls may be used.

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  • Inking, Control Or Cleaning Of Printing Machines (AREA)
  • Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
EP79900421A 1978-04-21 1979-01-18 Ink level control apparatus Expired EP0015954B1 (en)

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Application Number Priority Date Filing Date Title
US89892578A 1978-04-21 1978-04-21
US898925 1978-04-21

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EP0015954A1 EP0015954A1 (en) 1980-10-01
EP0015954B1 true EP0015954B1 (en) 1984-06-13

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EP (1) EP0015954B1 (US07714131-20100511-C00038.png)
JP (1) JPH042431B2 (US07714131-20100511-C00038.png)
DE (1) DE2967046D1 (US07714131-20100511-C00038.png)
IT (1) IT1118516B (US07714131-20100511-C00038.png)
WO (1) WO1979000955A1 (US07714131-20100511-C00038.png)

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US11292261B2 (en) 2018-12-03 2022-04-05 Hewlett-Packard Development Company, L.P. Logic circuitry package
US11312145B2 (en) 2018-12-03 2022-04-26 Hewlett-Packard Development Company, L.P. Logic circuitry package
US11407229B2 (en) 2019-10-25 2022-08-09 Hewlett-Packard Development Company, L.P. Logic circuitry package
US11738562B2 (en) 2018-12-03 2023-08-29 Hewlett-Packard Development Company, L.P. Logic circuitry

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US11338586B2 (en) 2018-12-03 2022-05-24 Hewlett-Packard Development Company, L.P. Logic circuitry
ES2955564T3 (es) 2018-12-03 2023-12-04 Hewlett Packard Development Co Sistema de circuitos lógicos
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US11292261B2 (en) 2018-12-03 2022-04-05 Hewlett-Packard Development Company, L.P. Logic circuitry package
US11312146B2 (en) 2018-12-03 2022-04-26 Hewlett-Packard Development Company, L.P. Logic circuitry package
US11331924B2 (en) 2018-12-03 2022-05-17 Hewlett-Packard Development Company, L.P. Logic circuitry package
US11345159B2 (en) 2018-12-03 2022-05-31 Hewlett-Packard Development Company, L.P. Replaceable print apparatus component
US11345156B2 (en) 2018-12-03 2022-05-31 Hewlett-Packard Development Company, L.P. Logic circuitry package
US11312145B2 (en) 2018-12-03 2022-04-26 Hewlett-Packard Development Company, L.P. Logic circuitry package
US11345157B2 (en) 2018-12-03 2022-05-31 Hewlett-Packard Development Company, L.P. Logic circuitry package
US11738562B2 (en) 2018-12-03 2023-08-29 Hewlett-Packard Development Company, L.P. Logic circuitry
US11364724B2 (en) 2018-12-03 2022-06-21 Hewlett-Packard Development Company, L.P. Logic circuitry package
US11351791B2 (en) 2018-12-03 2022-06-07 Hewlett-Packard Development Company, L.P. Logic circuitry package
US11407228B2 (en) 2018-12-03 2022-08-09 Hewlett-Packard Development Company, L.P. Logic circuitry package
US11511546B2 (en) 2018-12-03 2022-11-29 Hewlett-Packard Development Company, L.P. Logic circuitry package
US11407229B2 (en) 2019-10-25 2022-08-09 Hewlett-Packard Development Company, L.P. Logic circuitry package

Also Published As

Publication number Publication date
EP0015954A1 (en) 1980-10-01
IT1118516B (it) 1986-03-03
WO1979000955A1 (en) 1979-11-15
JPH042431B2 (US07714131-20100511-C00038.png) 1992-01-17
IT7967619A0 (it) 1979-03-26
DE2967046D1 (en) 1984-07-19
JPS55500276A (US07714131-20100511-C00038.png) 1980-05-08

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