Patents Represented by Attorney Robert L. Marben
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Patent number: 4912488Abstract: Camera apparatus including a housing within which an exposure station is provided with a film handling means provided at the exposure station for supporting and disposing a strip of film and a linear array of electric-to-light transducers disposed to direct light from the array to the strip of film as it is moved past the exposure station. Another embodiment employs two linear arrays of electric-to-light transducers which are used to expose separate areas of the film as it is moved past the exposure station.Type: GrantFiled: July 1, 1988Date of Patent: March 27, 1990Assignee: Minnesota Mining and Manufacturing CompanyInventors: Robert S. Berglund, Earl K. Hoyne
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Patent number: 4897555Abstract: A current split circuit that includes a multiplying digital to analog converter (DAC) and a controller. The controller establishes a first and second terminal of the DAC at the same potential so that a digital input to the DAC determines the ratio by which a current at a third terminal of the DAC is split between the first and second terminals of the DAC.Type: GrantFiled: November 23, 1988Date of Patent: January 30, 1990Assignee: Minnesota Mining and Manufacturing CompanyInventor: Eric L. Reed
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Patent number: 4873533Abstract: A marker for positioning near a buried object wherein the marker can be detected to locate the buried object. The marker includes a passive resonant type antenna which becomes inoperative when the initial position for the buried marker is changed. A lead wire and/or a mercury switch that is a part of the antenna serve to make the antenna inoperative due to such change in the initial position of the marker.Type: GrantFiled: October 9, 1987Date of Patent: October 10, 1989Assignee: Minnesota Mining and Manufacturing CompanyInventor: Tomoyasu Oike
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Patent number: 4868507Abstract: A resistance fault locator circuit having a digitally controlled current split circuit, an error amplifier and a programmed microcomputer plus a switching means for establishing several modes of operation of the circuit for determining the distance to a fault between two conductors of a cable.Type: GrantFiled: November 23, 1988Date of Patent: September 19, 1989Assignee: Minnesota Mining and Manufacturing CompanyInventor: Eric L. Reed
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Patent number: 4866388Abstract: A method and system for determining the location of a first insulated conductor and a plurality of similar branch conductors that are branches of the first conductor, but without ohmic contact being made with the first conductors. A passive marker having a resonant circuit that includes an inductor and capacitor is provided for each of the branch conductors and is positioned to be inductively coupled to the first conductor and the associated branch conductor. The first conductor is a part of a closed loop circuit and each branch conductor is a part of separate closed loop circuits. An alternating signal applied to any one of the closed loop circuits is inductively transmitted to each of the other closed loops that is inductively coupled to a passive marker having a resonant frequency equal to the frequency of the alternating signal.Type: GrantFiled: May 11, 1988Date of Patent: September 12, 1989Assignee: Minnesota Mining and Manufacturing CompanyInventors: Armond D. Cosman, Joe T. Minarovic
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Patent number: 4816642Abstract: A hot melt adhesive applicator operable at a number of selected temperatures having a portion of the circuitry for control of the applicator temperature at a point remote from the applicator body. The remotely located circuitry employs a differential amplifier and a zero crossing detector for controlling the operation of a triac which, when turned on, increases the temperature at the applicator. The operational amplifier is protected by a clamping circuit from receiving a signal, when a temperature setting is changed from a high to a low setting, that would otherwise cause the differential amplifier to provide an output required for turning on the triac which would cause a run away condition to exist.Type: GrantFiled: June 26, 1987Date of Patent: March 28, 1989Assignee: Minnesota Mining and Manufacturing CompanyInventor: Richard L. Dennison
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Patent number: 4794632Abstract: Telephone trunk line testing circuitry for connection to a private branch exchange (PBX) and the telephone trunk lines for the PBX including a microcomputer unit (MCU), switching circuitry, a DTMF receiver, and a tone generator for connecting one of the trunk lines as a control trunk for the circuitry. Under the control of the MCU programmed to respond to DTMF various signal commands sent from a telephone at the far end of the control trunk the circuitry operates to selectively disconnect (isolating) one of the other trunks at a time from the PBX and connect it to the circuitry with the circuitry configured under control of the MCU for completing various test involving the trunk under test (TUT), control trunk, switching circuitry and the tone generator, including the supply of tone signals from the tone generator during some of the test configurations.Type: GrantFiled: May 20, 1987Date of Patent: December 27, 1988Assignee: Minnesota Mining and Manufacturing CompanyInventors: Peter G. Burton, James K. Kennedy
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Patent number: 4767237Abstract: A marking tape that is positioned underground above utility lines wherein the marking tape carries a pair of closely spaced, parallel, insulated conductors that extend the length of the tape and at least one other insulated conductor extending the length of the tape which is separated from the pair of conductors at a distance that is greater than the distance between the conductors of the pair of conductors. Passive markers having a resonant circuit can be selectively placed along the tape wherein the resonant circuit is electromagnetically coupled to the pair of conductors and the other conductor. The other insulated conductor can be one of a pair of conductors similar to the other pair of conductors. A method is disclosed whereby the making tape can be electromagnetically traced with the position of the passive markers established. A method is also disclosed for determining the distance to a break in the tape which causes the pair of conductors to be severed.Type: GrantFiled: February 8, 1988Date of Patent: August 30, 1988Assignee: Minnesota Mining and Manufacturing CompanyInventors: Armond D. Cosman, Joe T. Minarovic
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Patent number: 4761656Abstract: A passive marker device including a tuned circuit enclosed in a housing which includes a base member with an upstanding rim with a cover member bonded to the rim and to a central portion of the base member. An opening is provided that extends through the housing at the central portion of the housing. A boss extends from the central portion of the base member to the cover member. The boss is recessed on the side of the base member that is away from the cover.Type: GrantFiled: May 23, 1986Date of Patent: August 2, 1988Assignee: Minnesota Mining and Manufacturing CompanyInventors: Armond D. Cosman, Larry R. Cox
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Patent number: 4761660Abstract: A laser scanner apparatus using a laser reference beam that is directed to and scans a grating plate which is used for producing a data clock for the apparatus. The grating plate has a line grating formed by a plurality of lines that are equally spaced along the scan of the grating plate by the laser reference beam. The plurality of lines, if extended, intersect at a single point. The grating plate can have more than one such line grating.Type: GrantFiled: December 15, 1986Date of Patent: August 2, 1988Assignee: Minnesota Mining and Manufacturing CompanyInventor: Charles C. Lee
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Patent number: 4734881Abstract: Circuitry for the validation of repetitive signals including input/output circuitry providing information regarding signals received that is connected to a progammable microprocessor, a read only memory and random access memory. The microprocessor is programmed so the circuitry determines the receipt of an input signal at any one of several signal inputs. When a first signal is received at one of the signal inputs a "lock-out" time interval is provided during which another signal cannot be received at any signal input. This is followed by a "window" time interval during which another input signal can be received at the signal input receiving the first signal. A "lock-out" and a "window" time interval are provided for each signal received at the signal input during a "window" time period at which the first input signal was received. Such signals are counted until a predetermined count is reached thereby establishing the received signals as valid signals.Type: GrantFiled: February 18, 1986Date of Patent: March 29, 1988Assignee: Minnesota Mining and Manufacturing CompanyInventors: Theodore D. Klein, Michael R. Oran
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Patent number: 4730603Abstract: An improvement to an implantable amplitude modulated frequency receiver wherein a resistor in the demodulator portion of a prior art receiver, which provides a discharge path for a capacitor, is replaced with an active circuit portion that includes a semiconductor device that provides the discharge path wherein the conductivity level of the semiconductor device is inversely related to the level of conduction of a rectifier to which the received amplitude modulated signal is applied. The active circuit portion improves the efficiency of the receiver in that less power is lost than in the case of the resistor the active circuit portion replaces.Type: GrantFiled: January 28, 1987Date of Patent: March 15, 1988Assignee: Minnesota Mining and Manufacturing CompanyInventor: Robert J. Fretz
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Patent number: 4711566Abstract: Apparatus using a single document transport means for microfilming the document and scanning the document for obtaining digital signals for storage that are indicative of the image carried on the document. One embodiment provides for sequential presentment of the document for filming and scanning. Another embodiment provides for simultaneous filming and scanning. Circuitry is disclosed by which the digital signals are processed for use in controlling the light source used for filming of the document. Circuitry is disclosed for supplying information for later retrieval of the digital signals and/or the microfilm for a particular document.Type: GrantFiled: October 31, 1985Date of Patent: December 8, 1987Assignee: Minnesota Mining and Manufacturing CompanyInventor: Bruce M. Evans
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Patent number: 4712094Abstract: A passive marker including a tuned circuit having an inductance and a capacitance carried by a carrier enclosed within a hollow sphere that is partially filled with a liquid to freely float the carrier. The inductance includes a coil which, when the carrier is floating, positions the axis of the coil so it is closer to the vertical than the horizontal. The passive marker is of a type that is buried relative to portions of utilities such as gas, telephone, water and power lines, for use in locating such portions when necessary.Type: GrantFiled: May 29, 1986Date of Patent: December 8, 1987Assignee: Minnesota Mining and Manufacturing CompanyInventor: John H. Bolson, Sr.
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Patent number: 4706293Abstract: Circuitry usable in a tamper protected recording system for characterizing audio signals at the time of recording including a filter for selecting a portion of the audio signal, a zero crossing detector to detect zero crossings, a threshold detector to determine when the threshold of the detector is satisfied, a first microprocessor for counting the zero crossing detections for successive time intervals and determining for each of the time intervals whether the threshold was satisfied and a second microprocessor for converting the counts and threshold information into data signals that can be recorded with the audio signal.Type: GrantFiled: August 10, 1984Date of Patent: November 10, 1987Assignee: Minnesota Mining and Manufacturing CompanyInventor: Michael J. Knowd
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Patent number: 4706282Abstract: An improved decoder for a recorder-decoder system wherein a threshold level detector is included in the decoder. The recorder provides for the recording of an audio signal plus a data signal. The data signal includes zero crossing information for sequential increments of time plus an indication of whether the threshold level was met for an increment of the recorded audio. Upon playback the decoder also provides a data signal based on the recorded audio. The threshold level detector of the decoder is higher than that of the recorder. If the recorded data signal indicates the threshold was not met and the same threshold indication is not provided by the threshold level detector of the decorder for the corresponding increment of the recorded audio signal, tampering of such audio increment of the recorded audio is considered to have occurred.Type: GrantFiled: December 23, 1985Date of Patent: November 10, 1987Assignee: Minnesota Mining and Manufacturing CompanyInventor: Michael J. Knowd
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Patent number: 4683551Abstract: Random access memory (RAM) clock switching circuitry for a laser printer having a RAM for storage of microprocessor information plus storage of font information with separate clock generators is provided for use in accessing the two types of information. The switching circuitry has a switch portion for alternately connecting the clock generators to a lockout circuit portion. A lockout request signal from the laser printer microprocessor determines when clock pulses presented to the lockout circuit can be applied to the RAM.Type: GrantFiled: March 28, 1984Date of Patent: July 28, 1987Assignee: Minnesota Mining and Manufacturing CompanyInventor: David J. Schoon
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Patent number: 4668851Abstract: A circuit arrangement for control of the temperature of a heating element adapted for contact by a material to be heated includes a transformer wherein the secondary winding is a metal ring which is the heating element with a temperature detection winding provided on the core of the transformer. An electronic switch and current sensing means are connected to the primary. A comparator, which receives input signals from the current sensing means and temperature detection winding, is operatively connected to the electronic switch to control its operation.Type: GrantFiled: September 6, 1985Date of Patent: May 26, 1987Assignee: Minnesota Mining and Manufacturing CompanyInventor: Anton K/u/ pper
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Patent number: 4660968Abstract: An exposure control for an imaging apparatus, the apparatus producing a light image based on an image member presented to the apparatus which is directed to a light responsive member via a partially silvered mirror of the apparatus. The exposure control includes a photocell which receives light transmitted through the mirror via a condensing lens, the photocell being connected to a circuit means which produces a signal having a duration, which varies according to the resistance of the photocell. The signal is used by a portion of the circuit means for controlling the exposure of the light responsive member to the light image.Type: GrantFiled: April 9, 1985Date of Patent: April 28, 1987Assignee: Minnesota Mining and Manufacturing CompanyInventor: Arnold J. Alderman
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Patent number: 4649402Abstract: An electrographic stylus recording apparatus producing a toner powder image on a receptor belt wherein non-imaging toner powder is collected at a cylindrical sleeve located downstream from the stylus array and is subsequently returned from the cylindrical sleeve to the upstream side of the stylus array by depositing toner powder from the cylindrical sleeve onto the receptor belt by adjustment of the toner powder on the cylindrical sleeve relative to the space between the cylindrical sleeve plus the application of a d.c. voltage to the cylindrical sleeve.Type: GrantFiled: March 7, 1986Date of Patent: March 10, 1987Assignee: Minnesota Mining and Manufacturing CompanyInventors: George G. Lunde, Earl K. Hoyne, Charles K. Nordeen