Patents by Inventor David W. Caldwell
David W. Caldwell has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20040228145Abstract: A panel, such as a component carrier or substrate, is provided with one or more penetrations. A light source associated with a surface of the panel and the corresponding end of each penetration provides light to the interior of the penetration, which guides the light to the other end of the penetration and corresponding surface of the panel. The penetration can be coated with a reflective material to improve its performance as a light guide. Alternatively or additionally, the penetration can be filled with a refractive material. A diffuser can be provided to diffuse light exiting the penetration. The light sources provides light to selected penetrations on demand such that the penetrations function as displays or elements of a display.Type: ApplicationFiled: January 22, 2004Publication date: November 18, 2004Inventors: Bahar N. Wadia, David W. Caldwell
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Publication number: 20040124714Abstract: A touch switch apparatus for detecting the presence of an object such as a human appendage, the apparatus having a touch pad and a local control circuit connected to the touch pad and to a controlled device. The touch pad preferable includes a first electrode and a second electrode spaced from and surrounding the first electrode. The control circuit is preferably in integrated circuit form. A signal is provided to the touch pad to generate an electric field thereabout. Introduction of a stimulus near the touch pad disturbs the electric field. The control circuit detects the electric field disturbance in and generates a control signal in response.Type: ApplicationFiled: December 1, 2003Publication date: July 1, 2004Inventor: David W. Caldwell
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Patent number: 6713897Abstract: A touch switch apparatus for detecting the presence of an object such as a human appendage, the apparatus having a touch pad and a local control circuit connected to the touch pad and to a controlled device. The touch pad preferable includes a first electrode and a second electrode spaced from and surrounding the first electrode. The control circuit is preferably in integrated circuit form. A signal is provided to the touch pad to generate an electric field thereabout. Introduction of a stimulus near the touch pad disturbs the electric field. The control circuit detects the electric field disturbance in and generates a control signal in response.Type: GrantFiled: October 25, 2001Date of Patent: March 30, 2004Assignee: Touchsensor Technologies, LLCInventor: David W. Caldwell
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Publication number: 20030159910Abstract: A touch sensor is physically integrated with a light emitting device to provide a switching device with built-in backlighting. In some embodiments, the touch sensor and the light emitting device share electrical components.Type: ApplicationFiled: October 15, 2002Publication date: August 28, 2003Inventor: David W. Caldwell
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Publication number: 20030121767Abstract: The present invention relates to integration of touch switches with integrated thermoformable, injection molded, and other substrates to yield integrated touch switch/control panel assemblies. The ensuant assemblies can include ridges, depressions, anchors, overlaps, rivets and bezels or other housings. They can have any combination of flat and curved surfaces. Further, such assemblies can be incorporated into components of other assemblies, such as automobiles.Type: ApplicationFiled: October 15, 2002Publication date: July 3, 2003Inventor: David W. Caldwell
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Publication number: 20030122794Abstract: A switch panel includes one or more touch responsive switch devices and an integrated decorative fascia. Both the switch devices and decoration are applied to the same substrate, eliminating the need for a separate user interface panel. Each switch device can include one or more electrodes and a circuit for inducing an electric field about the electrode(s) and responding to disturbances to the electric field.Type: ApplicationFiled: October 15, 2002Publication date: July 3, 2003Inventor: David W. Caldwell
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Publication number: 20030122455Abstract: An intelligent shelving system uses touch sensors to operate power-operated, adjustable shelves. Touch sensors also are used as limit switches to control shelf motion, to monitor the encroachment of shelved items on shelves, to detect spills, and to control other related devices and functions, such as shelf lighting. Display units are provided to provide information relating to objects stored in the shelving system and to the operation of the shelving system.Type: ApplicationFiled: October 15, 2002Publication date: July 3, 2003Inventor: David W. Caldwell
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Publication number: 20030122432Abstract: A touch switch apparatus for detecting the presence of an object such as a human appendage, the apparatus having a touch pad, an electric field generated about the touch pad and also having a preferably integrated and local control circuit connected to the touch pad and to a controlled device. The touch switch apparatus also having at least one of an input circuit portion for providing input signals to a decision circuit, swamping capacitance, active blocking devices, peak detector circuits, and a dual connection output latch circuit portion.Type: ApplicationFiled: October 15, 2002Publication date: July 3, 2003Inventor: David W. Caldwell
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Publication number: 20030075427Abstract: A control system interface integrates an electronic switching or sensing mechanism with an existing or custom-fabricated, functional or decorative equipment panel. The electronic switching or sensing mechanism is located on the rear surface of the equipment panel and a corresponding touch surface is defined on the front surface of the equipment panel. The electronic switching or sensing mechanism is responsive to a stimulus in the proximity of the touch surface, and it provides a control signal to a control system when it senses such a stimulus.Type: ApplicationFiled: May 6, 2002Publication date: April 24, 2003Inventor: David W. Caldwell
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Publication number: 20020057020Abstract: A touch switch apparatus for detecting the presence of an object such as a human appendage, the apparatus having a touch pad and a local control circuit connected to the touch pad and to a controlled device. The touch pad preferable includes a first electrode and a second electrode spaced from and surrounding the first electrode. The control circuit is preferably in integrated circuit form. A signal is provided to the touch pad to generate an electric field thereabout. Introduction of a stimulus near the touch pad disturbs the electric field. The control circuit detects the electric field disturbance in and generates a control signal in response.Type: ApplicationFiled: October 25, 2001Publication date: May 16, 2002Inventor: David W. Caldwell
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Patent number: 6320282Abstract: A touch switch apparatus for detecting the presence of an object such as a human appendage, the apparatus having a touch pad and a local control circuit connected to the touch pad and to a controlled device. The touch pad preferable includes a first electrode and a second electrode spaced from and surrounding the first electrode. The control circuit is preferably in integrated circuit form. A signal is provided to the touch pad to generate an electric field thereabout. Introduction of a stimulus near the touch pad disturbs the electric field. The control circuit detects the electric field disturbance in and generates a control signal in response.Type: GrantFiled: January 19, 1999Date of Patent: November 20, 2001Assignee: TouchSensor Technologies, LLCInventor: David W. Caldwell
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Patent number: 6310611Abstract: A differential touch sensor apparatus for detecting the presence of an object such as a human appendage, the apparatus having a first electrode, a second electrode positioned proximate to the first electrode, a differential circuit connected to the first and second electrodes, and a pulse or other signal source connected to provide electrical signals that generate an electric field between the first and second electrodes. Introduction of an object near the first electrode affects the electric field between the first and second electrodes, thereby affecting the voltage difference between them. A differential circuit provides an output signal responsive to the difference in voltage between the first and second electrodes. In an alternative embodiment, a strobe electrode is provided proximate to both said first and second electrodes and the pulses or other signals are provided to the strobe electrode to induce an electric field between the strobe electrode and each of the first and second electrodes.Type: GrantFiled: December 8, 1997Date of Patent: October 30, 2001Assignee: TouchSensor Technologies, LLCInventor: David W. Caldwell
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Patent number: 5867111Abstract: A touch control system that is responsive to a user input selection includes an electrically non-conducting substrate, such as glass ceramic, and at least one capacitive-responsive touch pad on the substrate. A source signal having a primary frequency that is greater than 150 kHz, and preferably in the range of between 150 kHz and 500 kHz, is applied to one portion of the touch pad. The touch pad couples the electrical signal to another portion of the touch pad in order to develop a detection signal, which is decoded in order to determine the presence of the capacitance of a user. The decoder preferably includes a peak detector composed of a low gain circuit in order to avoid distortion of the detection signal. Greatly improved performance in the presence of liquids, such as water, on the touch pad is provided. This is especially useful when the touch pad is applied to a horizontal surface, such as a cook top, upon which liquid spills may occur.Type: GrantFiled: November 1, 1996Date of Patent: February 2, 1999Assignee: Donnelly Technology, Inc.Inventors: David W. Caldwell, Nicholas W. Medendorp
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Patent number: 5594222Abstract: A low impedance touch sensor detects manual contact of a dielectric substrate by a human user. The touch sensor includes a first conductive electrode pad having a closed, continuous geometric form and a second conductive electrode which substantially co-planarly surrounds the first electrode and is spaced from the first electrode by a channel. The first and second electrodes are disposed on the same surface of the substrate. An active electrical component, such as a transistor is located on the substrate proximate the first and second electrodes, and is electrically coupled to the first and second electrodes.Type: GrantFiled: October 25, 1994Date of Patent: January 14, 1997Assignee: Integrated ControlsInventor: David W. Caldwell
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Patent number: 5572205Abstract: A touch control system that is responsive to a user input selection includes an electrically non-conducting substrate, such as glass ceramic, and at least one capacitive-responsive touch pad on the substrate. A source signal having a primary frequency that is greater than 150 kHz, and preferably in the range of between 150 kHz and 500 kHz, is applied to one portion of the touch pad. The touch pad couples the electrical signal to another portion of the touch pad in order to develop a detection signal, which is decoded in order to determine the presence of the capacitance of a user. The decoder preferably includes a peak detector composed of a low gain circuit in order to avoid distortion of the detection signal. Greatly improved performance in the presence of liquids, such as water, on the touch pad is provided. This is especially useful when the touch pad is applied to a horizontal surface, such as a cook top, upon which liquid spills may occur.Type: GrantFiled: March 29, 1993Date of Patent: November 5, 1996Assignee: Donnelly Technology, Inc.Inventors: David W. Caldwell, Nicholas W. Medendorp
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Patent number: 5289365Abstract: A module electrical control system for controlling office equipment includes a plurality of control modules interconnected with an input module via a system bus assembly. The input module includes an input-generating device, such as a keypad or the like, for generating an input signal, an output port to which the system bus assembly is connected and a circuit that is responsive to the input signal for supplying a command signal to the output port. The circuit includes a switch control unit that is responsive to a particular state of the input signal by producing a switched low voltage output signal and an address and command control until that is responsive to a particular state of the input signal by producing a particular value of a data signal. The system bus assembly includes at least two signal channels; one selectively supplied with the switched low voltage signal and the other selectively supplied with the data signal. Each control module is one of at least two types.Type: GrantFiled: December 23, 1991Date of Patent: February 22, 1994Assignee: Donnelly CorporationInventors: David W. Caldwell, Nicholas W. Medendorp
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Patent number: 5239152Abstract: A capacitive touch sensor panel includes a generally planar substrate, a graphic layer behind the substrate defining user readable graphic symbols and a light source behind the graphic layer including individual selectively actuatable light elements behind particular ones of the graphic symbols. A flexible substrate supporting a plurality of electrically capacitive sensing pads are juxtaposed with the graphic symbols in a manner that functions associated with the graphic symbols are invoked by actuation of the sensing pads overlaying the corresponding symbol. The substrate has optical transmission characteristics at selected light frequencies in order to project images of the graphic symbols juxtaposed with actuated light elements and to impart a homogeneous appearance to portions of the substrate overlying nonactuated light elements, the later defining a "sleep mode" in which the touch panel blends in with surrounding surfaces.Type: GrantFiled: October 30, 1990Date of Patent: August 24, 1993Assignee: Donnelly CorporationInventors: David W. Caldwell, Nicholas W. Medendorp
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Patent number: 5189417Abstract: A circuit for detecting user contact of one of a plurality of touch pads includes a plurality of drive lines and a plurality of sense lines coupled with the touch pads. A sense circuit responsive to the signals on the sense lines produces a pulse having a width that is proportional to the amplitude of each of the sense signals. A control circuit measures the width of the pulses produced by the sense circuit and compares each measured pulse width to a reference pulse width to distinguish between a touch and no-touch condition for each touch pad. The sense circuit is illustrated in the form of a comparator having a threshold input that is always exceeded by the sense signal to produce the variable width pulse. Separate amplifiers may be provided for each sense line.Type: GrantFiled: October 16, 1990Date of Patent: February 23, 1993Assignee: Donnelly CorporationInventors: David W. Caldwell, Nicholas W. Medendorp
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Patent number: 5164609Abstract: A user operable power distribution system that is suitable for supplying switched power to an individual workstation, or to an entire office, is expandable to accommodate additional loads. The system includes a user command device, such as a touch panel, for supplying low voltage command signals and a connection device, which responds to the low voltage command signal to interconnect a load with a supply voltage, such as an AC power outlet. The connection device further responds to the low voltage input command signal by producing a low voltage output command signal which may be applied to another connection device to cause that particular connection device to connect another load with a source of supply voltage. In this manner, the connection devices may be ganged in an indefinite number.Type: GrantFiled: June 8, 1990Date of Patent: November 17, 1992Assignees: Donnelly Corporation, Steelcase, Inc.Inventors: Robert P. Poppe, Nicholas W. Medendorp, David W. Caldwell
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Patent number: 5157273Abstract: A user operable power distribution system that is suitable for supplying switched power to an individual workstation, or to an entire office, includes a user command module, such as a touch panel, for supplying low voltage command signals and a plug strip, which responds to the low voltage command signal to interconnect a load with a supply voltage, such as an AC power outlet. An unregulated power supply is provided in the plug strip and supplies the low voltage requirements for the switching circuit in the plug strip. In addition, the unregulated low voltage is supplied to the user command module to provide its low voltage power requirements.Type: GrantFiled: June 8, 1990Date of Patent: October 20, 1992Assignee: Donnelly CorporationInventors: Nicholas W. Medendorp, David W. Caldwell