Utilizing Light-sensitive And/or Responsive Means Patents (Class 219/502)
  • Patent number: 5354967
    Abstract: A low cost heater element is disclosed which is formed of a wire wound mica paper substrate and a mica paper cover and a low cost diode acting as a negative temperature coefficient of resistance NTC temperature sensor. A control circuit provides power to the heater element in proportion to the line voltage. As a result, a light weight, low cost heater element is employed for various line voltages available throughout the world. The system employs digital logic to achieve temperature sensing, power sensing and indication that the system is on and operating at the correct temperature.
    Type: Grant
    Filed: November 13, 1992
    Date of Patent: October 11, 1994
    Assignee: Helen of Troy Corporation
    Inventors: Yinon Barzilai, William Levy, Robert Sherwood
  • Patent number: 5350899
    Abstract: A method and apparatus are provided for measuring the temperature of articles such as semiconductor wafers in a sealed chamber of a processing apparatus such as a batch preheating module of a semiconductor wafer processing cluster tool. Wafers of generally known nominal diameter and coefficient of thermal expansion are placed at a known initial temperature into a processing chamber which is then sealed. A pair of beams of parallel light are passed by opposite edges of the wafer and the uninterrupted light from both beams are detected and summed. When the wafer is heated in processing, light from the beams is measured again. Expansion of the wafers changes the amount of uninterrupted light detected, and the changed amount of light is measured. From the measurement, the initial temperature, the nominal diameter and the known coefficient of expansion, processing temperature is calculated and displayed or used to control chamber heaters.
    Type: Grant
    Filed: April 15, 1992
    Date of Patent: September 27, 1994
    Inventors: Hiroichi Ishikawa, Michael S. Kolesa
  • Patent number: 5258602
    Abstract: A method for sensitive and precise determination of the temperature of a thin layer or wafer of bandgap material, without requiring contact to the layer or to the wafer, is based on selection of optical wavelength or wavelengths and the measurements of transmittance through the sample at such wavelength(s). The relationship between the temperature variations of the absorption coefficient, whether determined by band-to-band absorption or a totally different mechanism, and the measured transmittance, provide an indication of the sample temperature, without regard to the ambient temperature. The method prescribes how to select the wavelength(s) based both on the intrinsic properties of the material and on the practical considerations of the measurement situation.
    Type: Grant
    Filed: March 19, 1991
    Date of Patent: November 2, 1993
    Assignee: ITT Corporation
    Inventors: Charles Naselli, Larry E. Reed, Avraham Amith
  • Patent number: 5243171
    Abstract: In a food service system, prepared meals including chilled foods are assembled in individual meal trays (10) and held in the trays for a period prior to regeneration to prepare the food for heating. A control system of a rethermalizing trolley (12), which accommodates a large number of trays, can discern for itself which dishes (30) in the trays need heating and which are to remain cool. Dishes for hot and cold foods have white and black markings respectively, which results in reflected infra-red signals from sensors (42, 44) of the control system to be of discernably different strengths, so identifying the hot food dishes. Dish temperature is continually monitored by the control system by means of thermal contact with thermistors (46), which enables the system to oversee food temperatures both prior to and during regeneration.
    Type: Grant
    Filed: May 23, 1991
    Date of Patent: September 7, 1993
    Assignee: Nasram Investments Limited
    Inventors: Simon J. Wood, Mark M. Gamble
  • Patent number: 5212763
    Abstract: A forced gas electric heater has a serpentine heating element disposed within a cylindrical glass tube. Infrared radiation emanating from the heating element enters the glass tube whereby part of the infrared radiation is directed within the wall of the glass tube to the edge of the glass tube. An infrared sensor is in line of sight with the edge of the glass tube. The infrared sensor senses the hot spot temperature of the heating element and, together with a controller, limits the maximum hot spot temperature of the heating element.
    Type: Grant
    Filed: September 11, 1992
    Date of Patent: May 18, 1993
    Assignee: GTE Products Corporation
    Inventors: Jonathan B. Arold, E. Forrest Decatur, Joan L. Mishou
  • Patent number: 5170041
    Abstract: A method of accurately determining the temperature of a thin layer of bandgap material without requiring contact to the layer involves the use of optical radiation through the layer and the detection of optical absorption by the layer. The relationship between the temperature varying bandgap energy and the resulting optical absorption characteristics provides an indication of temperature independent of ambient temperature. Apparatus for performing high quality temperature detection and control is also provided.
    Type: Grant
    Filed: September 20, 1990
    Date of Patent: December 8, 1992
    Assignee: ITT Corporation
    Inventors: Avraham Amith, Charles Naselli, C. Scott Nevin
  • Patent number: 5164571
    Abstract: A heating apparatus for use in the process of coating workpieces with an aqueous colored material such as a water-base paint. Radiant heaters are used in a flash-off operation to remove moisture from the coating material on the workpieces while the workpieces are transported between the heaters. The coating color is specified in advance, and an optimal moisture removal operation is performed by automatically regulating the radiant heat intensity suitable for the specified color.
    Type: Grant
    Filed: September 25, 1990
    Date of Patent: November 17, 1992
    Assignee: Trinity Industrial Corporation
    Inventors: Yukio Asaoka, Hitoshi Yano, Touichi Watanabe
  • Patent number: 5126536
    Abstract: A control arrangement for an electric food heating device having heating elements for heating foodstuff and providing a source of light impinging on the foodstuff, the control arrangement comprising: a peaking circuit (42, 30) to determine maximum reflected light from the foodstuff and provide a first signal (VI), and measuring subsequently reflected light from the foodstuff and providing a second signal (V2), said peacking circuit including amplifier means (30) for determining the difference between the first and the second signals, and providing a third signal (V3); and a comparator means (26) for comparing the third signal (V3) and a preset signal (VB), the preset signal being proportionate to a desired heating level, the comparator means providing a terminating signal (DONE) to deactivate heating when the preset and the third signals are substantially equal.
    Type: Grant
    Filed: December 28, 1989
    Date of Patent: June 30, 1992
    Assignee: Black & Decker Inc.
    Inventor: John C. Devlin
  • Patent number: 5044263
    Abstract: An electrically heatable toaster includes at least one bread holder which is held in toasting position by an electromagnet. The electromagnet has a tripping device which is actuated manually as well as electrically by a timing control. The timing control includes a clock pulse actuated counting circuit connected to a frequency-determining charging capacitor and a voltage divider. The voltage divider includes a temperature-dependent resistor for compensating the influence of the toasting degree temperature and for triggering the electromagnet tripping device after a preset degree of toasting is reached. An oscillator with two complementary transistors combined in a programmable unijunction transistor circuit operates the counting circuit. The transistors are connected on the input side to a charging current circuit of the frequency determining capacitor and on the output side through a dividing point of the voltage divider with the temperature-dependent resistance to a clock input of the counting circuit.
    Type: Grant
    Filed: November 3, 1989
    Date of Patent: September 3, 1991
    Assignee: Rowenta-Werke GmbH
    Inventors: Karl Birkert, Heinz Marburger, Gunter R. Kullik
  • Patent number: 5018437
    Abstract: Toaster comprising a housing (1), a heating resistance controlled by a switch (2) associated with a timer, a breed carriage (3) guided within the housing and adapted to occupy at least two positions, namely a toasting position in which the carriage (3) closes the switch (2) actuating the timer, and in which the carriage (3) is moved by the user and maintained during the toasting cycle by a catch (5) operated by an electromagnet (6) which comes into engagement with an abutment (7) of the carriage (3), or a rest position into which the carriage (3) is moved by a return spring (8), at the end of the toasting cycle, when the catch (5) frees the abutment (7).
    Type: Grant
    Filed: April 9, 1990
    Date of Patent: May 28, 1991
    Inventor: Antonio B. San Juan
  • Patent number: 5017761
    Abstract: A heater probe assembly used to heat treat a portion of a metallic tube that is surrounded by a heat sink is disclosed. The heater probe assembly heats the tube to a selected temperature range to relieve stress in and prevent degradation of the tube portion. The heater probe assembly includes an elongated probe body that is insertable and slidably movable within the tube portion. A radiant heat source is removably mounted on the probe body and heats the tube portion to incandescence within the selected temperature range. A temperature monitoring device monitors the temperature of the tube portion. The temperature monitoring device includes first and second optical measuring devices which determine the color of the tube portion at its longitudinally middle and end portions of the tube portion. An optical pyrometer translates the optical color measurement into a temperature measurement.
    Type: Grant
    Filed: January 18, 1989
    Date of Patent: May 21, 1991
    Assignee: Westinghouse Electric Corp.
    Inventor: Michael G. Brunner
  • Patent number: 5008516
    Abstract: A relay control for a cooking appliance having a heating element includes a sensor for detecting the occurrence of an arc upon a change of state of a relay coupled between the heating element and a power supply. Upon detecting an arc, the sensor provides a timing signal which is coupled to a microprocessor that controls the energization and deenergization of the relay. The microprocessor is responsive to the timing signal from the sensor to determine the time delay between the last energization/deenergization of the relay and the changing of the relay's state. From the time delay, the microprocessor determines a delay constant. Subsequently, the microprocessor energizes the relay at a time after the detection of a zero crossover point of the power supply signal, wherein the time is equal to the determined delay constant to cause the relay to change state at or slightly before a zero crossover point of the power supply signal.
    Type: Grant
    Filed: August 4, 1988
    Date of Patent: April 16, 1991
    Assignee: Whirlpool Corporation
    Inventor: Ronald W. Holling
  • Patent number: 4957012
    Abstract: A method of predicting aging of polymers operates by heating a polymer in the outdoors to an elevated temperature until a change of property is induced. The test is conducted at a plurality of temperatures to establish a linear Arrhenius plot which is extrapolated to predict the induction period for failure of the polymer at ambient temperature. An Outdoor Photo Thermal Aging Reactor (OPTAR) is also described including a heatable platen for receiving a sheet of polymer, means to heat the platen and switching means such as a photoelectric switch for turning off the heater during dark periods.
    Type: Grant
    Filed: June 16, 1989
    Date of Patent: September 18, 1990
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Edward F. Cuddihy, Paul B. Willis
  • Patent number: 4891499
    Abstract: A silicon semiconductor wafer (26) is placed in a vacuum chamber (12) device side (28) facedown. Laser beams of equal power are directed at an edge point (72) and a center point (74) of the wafer (26). The laser beams are reflected from the edge point (72) and the center point (74) into first and second infrared photo-detectors (40-42). A differential amplifier (44) evaluates the reflected laser beams for a power difference and signals a current source (82). Current source (82) heats a quartz ring (46) which surrounds the wafer (26). The quartz ring (46) passes the heat to the wafer (26) until the amplifier (44) no longer senses a power difference, which is indicative of an equal wafer surface temperature.
    Type: Grant
    Filed: September 9, 1988
    Date of Patent: January 2, 1990
    Assignee: Texas Instruments Incorporated
    Inventor: Mehrdad M. Moslehi
  • Patent number: 4876435
    Abstract: A device which, after washing hands, permits hands to be dried rapidly using hot air directed over, under, and around the hands. The hot air is activated when a hand is placed in position for drying and remains activated until the hand is removed. A touchless switch eliminates the spread of germs by eliminating the need to touch a switch or other object touched by and perhaps contaminated by others who previously used the hand drying device. Furthermore, since the hot air remains activated until the hand is removed, there is no need to retrigger the device since hot air is available as long as it is needed to dry the hands.
    Type: Grant
    Filed: January 13, 1988
    Date of Patent: October 24, 1989
    Inventor: Junior F. Hawkins
  • Patent number: 4849625
    Abstract: The device makes use of at least one photoemitter and at least one photodetector, operating in conjunction with the inspection glass of the oven against which the coffee beans tumble continually throughout the roast; the photodetector is located remotely, and receives its light input through an optic fiber link the transmitting end of which is supported, together with the photoemitters, by a block fitted to the discharge hatch of the oven directly over the inspection glass and invested with a coolant in order to maintain the temperature at the monitoring location within the preferred operating limits specified for the photoemitters and the optic fiber material.
    Type: Grant
    Filed: November 29, 1988
    Date of Patent: July 18, 1989
    Assignee: Officine Vittoria S.p.A.
    Inventor: Pier Cesare Camerini Porzi
  • Patent number: 4795883
    Abstract: An aroma generating apparatus includes a driver circuit which functions as a real time lapse counter and includes a signal indicator to designate the replacement period of useful lifetime of the aroma producing cartridge. The driver circuit continuously operates between a low frequency during the off state of the resistance heating element and a high frequency during energizing of the resistance heating element. The dual frequency permits monitoring ofthe real time operation of the apparatus without the need of providing memory devices to accommodate inoperative periods of the apparatus.
    Type: Grant
    Filed: October 13, 1987
    Date of Patent: January 3, 1989
    Assignee: Environmental Fragrance Technologies, Ltd.
    Inventors: Dov Z. Glucksman, Constantine D. Pezaris
  • Patent number: 4749280
    Abstract: An apparatus for measuring the temperature in a heating system comprising a cooking pot with cooking material positioned on a hot plate where a radiation receiver is arranged at a distance from the wall of the cooking pot and aligned with it, which receiver produces a temperature measurement signal corresponding to the temperature of the cooking material in the cooking pot. The temperature measurement signal is derived from a detected radiation area on the wall of the cooking pot which corresponds to the radiation measuring field of the radiation receiver. The effect of different distances of the cooking pot from the radiation receiver is automatically compensated for by aligning the center axis of the radiation measurement field at an acute angle to the support surface of the hot plate, so that the distance of the center of the detected radiation area from the bottom of the cooking pot increases with an increasing distance of the wall of the cooking pot from the radiation receiver.
    Type: Grant
    Filed: October 17, 1986
    Date of Patent: June 7, 1988
    Assignee: Kurt Wolf & Co. KG
    Inventors: Kurt Wolf, Wolfram K. Andre
  • Patent number: 4698767
    Abstract: An infrared dryer is provided for a printing press which uses a series of carriers, each comprising one or more gripper bars, on a conveyor to respectively carry printed sheets past the dryer. The sensor produces different binary signals in response to the presence or absence of material, viz, a gripper bar structure or carried sheets in the path, each carrier producing a predetermined number of transitions between the presence and absence signals, the only change between an empty carrier and one carrying a sheet being the duration of the presence and absence signals. A microprocessor is programmed to cyclically count from zero to the predetermined number of transitions, with each count cycle representing the passage of a carrier. The microprocessor also measures and compares the total durations of the presence and absence signals during each count cycle. If the presence signal duration exceeds the absence signal duration, then the heater is actuated to a preselected operating intensity.
    Type: Grant
    Filed: August 14, 1985
    Date of Patent: October 6, 1987
    Assignee: Electro Sprayer Systems, Inc.
    Inventors: Neil D. Wensel, Gary E. Norris, Craig G. Beierwaltes
  • Patent number: 4693179
    Abstract: A rotary screen printing apparatus for delivering coating fluid from the inside of a print cylinder through patterned openings onto an adjacent advancing substrate, having a print cylinder support frame, a drive mechanism for rotatably driving the print cylinder, a resilient suspension device for supporting the print cylinder at high rotational speeds, an adjacent radiant heater for generating heat energy for absorption by the print cylinder, an enclosure substantially surrounding the print cylinder and confining the radiated heat therein, at least one infrared sensor for sensing heat emitted from the print cylinder, and a control circuit for controlling the radiant heat energy from the heater in response to the sensed emitted radiant energy, about a manually controlled set point.
    Type: Grant
    Filed: October 31, 1985
    Date of Patent: September 15, 1987
    Assignee: Lockwood Technical, Inc.
    Inventor: John D. Watts
  • Patent number: 4687909
    Abstract: An apparatus for heating an air current, includes a heating coil being heated until it glows providing radiation in a given region, a device for conducting an air current past the heating coil, an electronic heating power control device connected to the heating coil, and a control sensor connected to the control device in the form of a light radiation sensitive circuit element disposed in the given region.
    Type: Grant
    Filed: May 23, 1985
    Date of Patent: August 18, 1987
    Assignee: Bosch-Siemens Hausgeraete GmbH
    Inventors: Walter Eichler, Karlheinz Farber, Elisabeth Fischer
  • Patent number: 4679948
    Abstract: Radiation measuring probe for contactless measurement of the surface temperature of an object, independent of the emissivity of the object. The probe includes a radiation receiver and a housing having interior surfaces defining an interior space. The radiation receiver is disposed in the interior space, thermally insulated with respect to the housing. The housing includes a shield which has a shield surface facing outwardly so as to be towards a surface of an object whose surface temperature is to be measured. The shield has an aperture opening into the shield surface, communicating with the interior space and through which thermal radiation emanating from the object impinges on the radiation receiver. The shield surface is blackened and configured to correspond to the contour of the surface of the object, and the interior surfaces of the housing are of low emissivity.
    Type: Grant
    Filed: November 7, 1985
    Date of Patent: July 14, 1987
    Assignee: Uranit GmbH
    Inventors: Gunter Hempowitz, Gustav Meyer-Kretschmer
  • Patent number: 4617441
    Abstract: An induction heating cooking apparatus contains a cooker main unit (1), comprising a connector (17) attached to an operation part (7) of the cooker main unit (1) in a freely attachable/detachable manner. A probe (13) containing a thermistor therein is coupled to the connector (17). The probe (13) is inserted into the foodstuff to be cooked in a cooking pan (5), and the thermistor detects the temperature thereof. A light emitting device (23) installed in the connector (17) outputs a light signal in response to the output from the thermistor. This light signal is introduced into the cooker main unit (1) through a light transmitting part (25) formed at a bottom part (19) of the connector (17) and another light transmitting part (27) formed in the operation part (7), being received by a light receiving device (29). In response to the output from the light receiving device (29), a driving circuit drives an inverter.
    Type: Grant
    Filed: June 22, 1984
    Date of Patent: October 14, 1986
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Satoshi Koide, Kiyoshi Hiejima
  • Patent number: 4614441
    Abstract: This invention provides an apparatus for measuring the temperature of the contents of a saucepan in a heating system comprising a saucepan and its contents placed on and heated by a heating element. The invention provides saucepans having radiating surfaces encircling the pan in a transition area between the bottom and side wall of the pan, a radiation sensor with a focusing device aligned with the radiating surface of the saucepan placed on the heating element, and provides for the radiation sensor to be spaced from the radiating surface at a distance corresponding to the focal point of the radiation focusing device.
    Type: Grant
    Filed: November 15, 1984
    Date of Patent: September 30, 1986
    Assignee: Kurt Wolf & Co. KG
    Inventor: Kurt Wolf
  • Patent number: 4605852
    Abstract: Apparatus for preventing the formation of condensation within a cabinet. A light reflective surface is mounted within the cabinet and thermally linked to the exterior of the cabinet so that the reflective surface temperature responds more rapidly to changes in the external ambient temperature than the cabinet itself. The formation of condensation on the reflective surface is detected by monitoring a light beam reflected from the reflective surface. When the formation of condensation on the reflective surface is detected a heater inside the cabinet is turned on to cause the condensation to evaporate.
    Type: Grant
    Filed: September 21, 1983
    Date of Patent: August 12, 1986
    Assignee: Unicell Limited
    Inventor: Allen D. Muirhead
  • Patent number: 4556779
    Abstract: A temperature control arrangement for a heat roller, which includes an infrared sensor unit disposed in the vicinity of the heat roller and including a pyroelectric infrared sensor, a chopper mechanism and a reference temperature measuring heat sensitive element, a set temperature signal generation circuit for the heat roller, a comparison circuit for comparing a temperature detection value of the heat roller as detected by the sensor unit with the set temperature signal from the set temperature signal generation circuit, and a control circuit for subjecting a heater element of the heat roller to on/off control based on a comparison signal of the comparison circuit.
    Type: Grant
    Filed: March 3, 1983
    Date of Patent: December 3, 1985
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Kaoru Hashimoto, Kenzo Nagata
  • Patent number: 4494314
    Abstract: A coffee roaster which roasts coffee beans in an oven chamber employing both radiant and convection heating techniques while the beans are continually intermixed in a fluidized bed. Roaster control means are provided to terminate the roasting process by quenching the beans and oven chamber while maintaining the beans in a fluidized bed to avoid scorching or further roasting by the residual heat of the coffee bean mass.
    Type: Grant
    Filed: November 28, 1983
    Date of Patent: January 22, 1985
    Inventor: Harold A. Gell, Jr.
  • Patent number: 4493983
    Abstract: A device for incorporation into the power supply circuit of an electrical apparatus comprising (a) a switch which is movable from one condition to another on application of power to the switch and which is held in the moved condition, as long as power is applied to the switch; (b) a signal emitter adapted to emit a power signal of short duration and being connected to the switch so that on emission of the power signal the switch will be moved to the other condition for the duration of the power signal; and (c) a current detector capable of detecting when a current flows in a line and being connected to the switch to supply power thereto when current flows in the line. The current detector may be a light emitting diode (L.E.D.) and a light detector arranged to transmit current to a relay switch coil which is electrically connected to the line by a current transformer.
    Type: Grant
    Filed: April 20, 1983
    Date of Patent: January 15, 1985
    Inventor: Russell H. Taggert
  • Patent number: 4492840
    Abstract: An induction heating process and apparatus for flameless heating of metallic dental laboratory tools, medical instruments, and the like. The induction heating coil is energized by placement of instruments within the annular zone formed by the windings of the coil, and differential light sensors are utilized to compensate for variations in ambient light levels.
    Type: Grant
    Filed: June 25, 1982
    Date of Patent: January 8, 1985
    Inventor: August Lex
  • Patent number: 4455472
    Abstract: A bed heater with two spaced, perforated, non-metallic plates between which there is arranged spaced loops of an insulated cover-type resistance heating fuse wire. At least some side area between the plates is open allowing lateral movement of air to prevent overheating. Power is supplied through a parallel SCR and diode circuit controlled by an R-C circuit including a temperature responsive resistor and a light responsive resistor.
    Type: Grant
    Filed: January 12, 1981
    Date of Patent: June 19, 1984
    Inventor: Arlon R. Moss
  • Patent number: 4435637
    Abstract: An apparatus for heating a sheet- or web-like material during its transport through a processing machine, comprises at least one infrared heating panel facing the path of transport of the material. The apparatus is provided with a controlling circuit for controlling the heat emission of the heating panel in response to a control signal generated by a control means. The heating panel is switched off if the transport speed of the material becomes smaller than a minimum speed by means of a monitoring circuit which can switch off the controlling circuit, said monitoring circuit being coupled to a detector means reacting to the transport speed. The monitoring circuit may further comprise at least one zone detector means reacting to the presence of the material within a given zone extending transversely to the transport direction of the material on either side of the desired path of transport, wherein the monitoring circuit switches off the controlling circuit if the material leaves the zone.
    Type: Grant
    Filed: September 30, 1982
    Date of Patent: March 6, 1984
    Inventor: Jacob de Vries
  • Patent number: 4433232
    Abstract: Disclosed is a heating apparatus which is capable of heating an object to be heated placed in its heating chamber until the color of the surface of the object changes to a given extent, and in which the wavelength of light of visible spectrum range which is emitted from a light source to illuminate the surface of the object placed in the heating chamber and reflected therefrom is sensed by a color sensor to judge the degree of change in the hue of the surface of the object on the basis of the wavelength sensed by the color sensor to thereby control the heating operation on the basis of the result of judgement.
    Type: Grant
    Filed: May 29, 1981
    Date of Patent: February 21, 1984
    Assignee: Hitachi Heating Appliances Co., Ltd.
    Inventors: Hajime Tachikawa, Shuji Ohkawa
  • Patent number: 4426572
    Abstract: A heating apparatus in which an object to be heated placed in its heating chamber can be heated until the surface of the object is charred as desired by the user. A first photo sensor senses the intensity of light of visible spectrum range directed toward and reflected from the surface of the object being heated, and a second photo sensor senses the light intensity related to the light reflected from the surface of the object, that is, at least one of the intensity of illuminating light emitted from a light source and the intensity of illuminating light coming from the exterior of the heating chamber. The degree of charring of the surface of the object is judged on the basis of the output signals from the first and second photo sensors, and the heating operation is controlled on the basis of the result of judgement.
    Type: Grant
    Filed: May 29, 1981
    Date of Patent: January 17, 1984
    Assignee: Hitachi Heating Appliances Co., Ltd.
    Inventors: Hajime Tachikawa, Masahiro Ishihara
  • Patent number: 4404462
    Abstract: Various electronic circuits are disclosed for controlling the temperature of an object by means of a resistive heating element. Some of the circuits include a digital display for displaying the actual temperature A plurality of different temperature sensors may be used, such, for example, as a resistive sensor, a thermocouple or a thermistor. The sensor may either have a positive or a negative temperature coefficient. Since most of the sensors are not strictly linear, different means are disclosed for compensating for their nonlinearity. Some of the control circuits feature a proportional control to which may be added an anticipatory control. Less sophisticated and more inexpensive circuits simply provide an on-off control.
    Type: Grant
    Filed: March 30, 1981
    Date of Patent: September 13, 1983
    Assignee: Edsyn, Inc.
    Inventor: Wayne A. Murray
  • Patent number: 4369354
    Abstract: A heating arrangement in a fixing station of a printing device has its operation monitored by an arrangement in which a measuring element is disposed in series with the heating element and a switch element. The measuring element is traversed by the heating current and emits a corresponding voltage which is supplied to an amplifier circuit which produces pulse-shaped clock signals as long as the heating current flows through the measuring element and the heating element. The clock signals are supplied to a reset input of a flip-flop whose dynamic input is connected to an oscillator operating at a frequency lower than that of the alternating current so that as long as clock pulses occur, the flip-flop is constantly reset. Therefore, the flip-flop can only be set over a longer interval when no heating current is flowing.
    Type: Grant
    Filed: October 14, 1980
    Date of Patent: January 18, 1983
    Assignee: Siemens Aktiengesellschaft
    Inventors: Ludger Goedecke, Hans von Hayek
  • Patent number: 4367116
    Abstract: A binding apparatus, for attaching loose sheets to a folder or file provided with a binding agent, comprises a hotplate (2) against which the folder is inserted through an opening (4) defined between supporting means (5, 6). The hotplate is kept constantly heated, while a time circuit controlled by means of a push button unit (10) activates an alarm means (12) when a set time is at an end. The regulatable time circuit is always zeroed when the folder is taken out of the opening, since the folder affects a light beam across this opening to a photocell which is connected to the time circuit (FIG. 1).
    Type: Grant
    Filed: April 6, 1981
    Date of Patent: January 4, 1983
    Assignee: Semotex AB
    Inventor: Sture H. Wiholm
  • Patent number: 4363957
    Abstract: A heating apparatus capable of heating an article to be heated accommodated within a heating chamber to a degree that the article becomes charred. Illumination intensity of reflected light from the surface of the article illuminated with visible light rays from a light source is detected by an optical sensor, to thereby identify the degree of charring produced in the article, wherein heating operation is controlled on the basis of the identified degree of charring.
    Type: Grant
    Filed: December 3, 1979
    Date of Patent: December 14, 1982
    Assignee: Hitachi Heating Appliances Co., Ltd.
    Inventors: Hajime Tachikawa, Mitsuru Watanabe, Kenjiro Yokoyama
  • Patent number: 4278870
    Abstract: A dental mirror warmer to prevent fogging when the mirror is placed in a patient's mouth includes a housing with a cover having an opening. Below the opening is a heating well to receive the reflective end of the mirror. The well has a stainless steel wall connected to a transformer which supplies high current at low voltage to heat the wall. The supply to the transformer is controlled by a photoresponsive device responsive to insertion of the mirror and a timing circuit which permits current supply for a short heating interval. A temperature sensor shortens the interval when heating cycles are initiated frequently. The photoresponsive device is mounted in the housing in juxtaposition with a light transmissive opening in a wall of the heating well. The photoresponsive device includes a source of light arranged to direct light into the heating well through the opening and a photoresponsive element arranged to receive light reflected from the reflective surface of a mirror inserted into the heating well.
    Type: Grant
    Filed: July 6, 1979
    Date of Patent: July 14, 1981
    Inventors: John S. Carleton, Karl A. Senghaas
  • Patent number: 4245148
    Abstract: A control circuit is disclosed suitable for use with a toaster or other food browning device which utilizes a radiant energy source to brown food. A light sensitive variable resistor, or photocell, is optically coupled to light reflected from the food being browned in the device. A voltage generated by a voltage divider including the light sensitive resistor therein is compared with a preselectable voltage generated by a second voltage divider to determine whether the heat source should be turned on or off. Suitable solid state control circuitry is provided to ensure that a start-up delay is provided at the beginning of each browning cycle and to reset the circuit for future operation when the desired browning of the food is achieved.
    Type: Grant
    Filed: September 14, 1979
    Date of Patent: January 13, 1981
    Assignee: Wisco Industries, Inc.
    Inventors: Edward T. Gisske, Robert J. Sandberg
  • Patent number: 4238672
    Abstract: A temperature control circuit particularly for use with a graphite tube atomizer of an atomic absorption spectrometer provides rapid temperature rise and a leveling at a constant predetermined temperature. A.C. power applied through a transformer to electrodes on the ends of the graphite tube rapidly heats the tube and the visible radiation thus produced is measured by a photocell, the output of which is amplified to control a relay in the graphite tube power circuit. When the desired tube temperature is approached, the photocell output actuates the relay so that the tube power circuit will switch from the high voltage rapid heating mode to a controlled lower voltage that will automatically maintain the constant predetermined tube temperature.
    Type: Grant
    Filed: January 16, 1978
    Date of Patent: December 9, 1980
    Assignee: Boderseewerk Perkin-Elmer & Co. GmbH
    Inventor: Hans Siess
  • Patent number: 4191512
    Abstract: A predetermined pressure ratio is maintained between a foreline and a load port of a vacuum diffusion pump including a bath of oil that is vaporized by a heater. A property of the pump is sensed to derive a signal indicative of the pressure ratio. The signal is compared with a set point value to derive an error signal that controls the amount of power continuously supplied by the heater to the oil bath. The sensed property can be the RMS power supplied by the heater, the heat supplied to the bath, or the density of vaporized fluid in the pump.
    Type: Grant
    Filed: August 29, 1977
    Date of Patent: March 4, 1980
    Assignee: Varian Associates, Inc.
    Inventors: Charles D. O'Neal, III, Leo J. Blumle, Marsbed Hablanian
  • Patent number: 4180722
    Abstract: A liquid heating device particularly adapted to the heating of sealed bottles containing liquids which are maintained in sterile condition until used, such as dialysates and the like. The device employs sealed bottles having a temperature sensitive element in intimate contact with the liquid being heated, which changes to a predetermined color and hue as the desired temperature is obtained. This color is compared with a color standard using a single source of light which is reflected against the indicator and the standard. The light reflected from these elements is photoelectrically compared, and the operation of the heating element is interrupted when a match is made. An independent timer interrupts said operation in the event of a failure of the photoelectric comparison.
    Type: Grant
    Filed: July 7, 1977
    Date of Patent: December 25, 1979
    Inventor: Bonnie Clewans
  • Patent number: 4170932
    Abstract: An electronic control for controlling the degree of toasting of a bread slice in a toaster. The control includes a thermocouple located within the passage of the toaster for the bread slice and responsive to the temperature of the toaster casing, the slice of bread and the air temperature within the passage to produce a voltage proportional to the resultant temperature. This voltage is integrated and actuates an electronic pulse generator with an adjustable pulse width which produces a triggering pulse. This pulse is used to actuate a solenoid which unlatches the support for the bread slice. The operational amplifier has a predetermined output voltage of reference defining the threshold of operation of the pulse generator. The electronic control is very stable and, therefore, produces uniform toasting, since it integrates the time required to obtain the desired degree of toasting as a function of the temperature variation to which the bread slice is subjected.
    Type: Grant
    Filed: June 21, 1977
    Date of Patent: October 16, 1979
    Inventor: Lionel Lalancette
  • Patent number: 4167663
    Abstract: An apparatus for warming blood and other parental fluids as they are infused through a disposable flow system includes a pair of heating elements which heat the blood as it passes through a warming bag provided in the flow system. The heating elements are recurringly switched on and off with a duty cycle dependent on both the temperature of the blood at the output of the warming bag, and the temperature differential between the output and input of the bag to maintain the blood at a predetermined temperature independent of flow rate. A duty cycle alarm circuit senses current supplied to the heating elements and trips the main circuit breaker of the apparatus to terminate operation in the event current is continuously applied over a predetermined interval of time, and temperature range and door alarm circuits sound an alarm if the output temperature of the blood falls outside of a predetermined range or if the operator attempts to remove the warming bag from the apparatus while the apparatus is in operation.
    Type: Grant
    Filed: January 24, 1977
    Date of Patent: September 11, 1979
    Assignee: Baxter Travenol Laboratories, Inc.
    Inventors: Daniel B. Granzow, Jr., Robert J. Froehlich
  • Patent number: 4130955
    Abstract: A pressing iron contains a safety turn-off switch to prevent scorching if the iron is held stationary for too long.An acceleration sensor produces a signal in response to a predetermined acceleration of the iron and an actuating circuit turns off the iron if the iron is not sufficiently accelerated.
    Type: Grant
    Filed: June 16, 1977
    Date of Patent: December 26, 1978
    Inventors: Erich R. Baumgartner, Peter Doehler
  • Patent number: 4109134
    Abstract: A circuit for controlling the power transmitted from an a.c. voltage source by a switching element, particularly a triac, connected in series with a power element, e.g. with the heating element of an image fixing device in an electro(photo)graphic copier, is safeguarded against errant operation by the provision of a checking circuit which comprises means for blocking periodically the transmission of power by the switching element under its normal control and means effective in intervals of the interruption of said transmission by the blocking means for detecting whether power is then being transmitted to the power element and, if it then is, producing a corrective control signal.
    Type: Grant
    Filed: August 2, 1976
    Date of Patent: August 22, 1978
    Assignee: Oce-van der Grinten N.V.
    Inventor: Jozef Marie Van Herten
  • Patent number: 4085310
    Abstract: Control of a heating system by means of modulating electronic thermostats. Two thermostats are coupled by an opto-electronic device in order to meet the requirements with respect to the "bi-junction" heating system. A double power-limiting device moreover allows the ratio of the maxiumum power dissipated by the two resistors with which the heating convector is equipped to be varied.
    Type: Grant
    Filed: March 25, 1976
    Date of Patent: April 18, 1978
    Assignee: U.S. Philips Corporation
    Inventors: Jean-Pierre Rene Coulmance, Jean-Claude Gerard Six
  • Patent number: 4039770
    Abstract: An interface for controlling the energy to a flash lamp based on document information. An area converage sensing device senses the density of document information advanced along a predetermined path and produces electrical signals thereof. A circuit conditions the signals and transmits them to an energy storage for driving the flash lamp.
    Type: Grant
    Filed: June 11, 1975
    Date of Patent: August 2, 1977
    Assignee: Xerox Corporation
    Inventors: Richard C. Johnson, Ihor Kulbida
  • Patent number: 4031355
    Abstract: A solid state multi-channel temperature responsive control system having thermocouples positioned to monitor the temperature at various process control locations. Each thermocouple generates an electrical sensor signal representing the monitored temperature at the corresponding control location. The sensor signal from each thermocouple is supplied to an associated channel of control circuitry which automatically compares the sensor signal with a manually adjustable set-point signal representing the desired temperature at the monitored control location. The sensor signal for any particular channel may be selectively displayed on a voltmeter calibrated in degrees of temperature, and the set-point signal for the selected channel may be displayed on the same meter to facilitate adjustment thereof. The comparison circuitry in each channel generates a difference signal reflecting variation of the monitored temperature from its set-point value.
    Type: Grant
    Filed: March 31, 1975
    Date of Patent: June 21, 1977
    Inventor: Stephen A. Leonik, Jr.
  • Patent number: 4001541
    Abstract: A flash fusing system for fusing toner images onto support material in which the support material is transported in a path past one or more flash fusing lamps. The flash fusing lamps are coupled to a circuit including a power supply voltage which is adjusted by an input from a sensing circuit including, a photodiode which measures the density of the unfused toner images on support material and converts the information into electrical signals. The electrical signals are supplied to an integrator which in turn is coupled to the power supply voltage of the circuit for energizing the flash lamps.
    Type: Grant
    Filed: June 11, 1975
    Date of Patent: January 4, 1977
    Assignee: Xerox Corporation
    Inventors: Gilbert J. Hatch, Richard C. Johnson, Ihor Kulbida