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...When G.G. Hubbard learned of his future son-in-law's invention, he called it "only a toy." His daughter was engaged to a young man named Alexander Graham Bell.
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| Number | Title | Issue Date |
| 8004434 | RD converter and angle detecting apparatus An RD converter is disclosed that has a first multiplier multiplying a resolver signal S1 by an output of a SIN ROM; a second multiplier multiplying a resolver signal S2 by an output of a COS ROM; a subtractor subtracting an output of the first multipl... | 08/23/2011 |
| 7538700 | Angular position detector and rotary electric device drive unit including the same The invention provides an angular position detector that can be configured at low cost and that accurately detects the angular position of a rotor in a rotary electric device and permits reliable control thereof even when the rotary electric device runs at a high sp... | 05/26/2009 |
| 7411530 | Method for the evaluation of a first analog signal and a second analog signal, and evaluation circuit corresponding therewith Two analog signals are substantially sinusoidal and out-of-phase by about 9020 relative to each other when an element moves in a temporally uniform manner in relation to a stationary element. The two analog signals make it possible to determine the actual pos... | 08/12/2008 |
| 7401001 | Position determining A position determining system for determining a position of a rotor of a rotating motor has sensors that are coupled to the rotor. The sensors generate, in response to a rotation of the rotor, a quadrature signal that has sine and cosine components. The position det... | 07/15/2008 |
| 7388527 | Method of detecting abnormality of R/D converter To achieve miniaturization of a resolver apparatus as a system, to obtain the resolver apparatus at a low cost, and to improve failsafe by installing an abnormality detection unit and a self-diagnosis circuit within the R/D converter. According to the present invent... | 06/17/2008 |
| 7382295 | Control unit for electric power steering apparatus Since an abnormality is judged by executing a square calculating process with respect to sin θ and cos θ for detecting an abnormality in an angular resolver, a processing time is elongated, and a burden to a CPU is great. Since the invention prepares a map which c... | 06/03/2008 |
| 7321113 | Precision material-handling robot employing high-resolution, compact absolute encoder An absolute encoder employs multiple sub-encoders of different resolutions and a linking algorithm for combining the sub-encoder outputs to form an accurate, high-resolution position estimate. The sub-encoders can utilize edge modulation of a main grating track, slo... | 01/22/2008 |
| 7263452 | Resolver-to-digital converting apparatus, method and program A resolver-to-digital converting apparatus calculates a resolver rotational angle from two-phase sampling values that are the result of sampling two-phase output signals, which are obtained from a single-phase-excited, two-phase output resolver, at peak timings of a... | 08/28/2007 |
| 7253395 | Absolute encoder employing concatenated, multi-bit, interpolated sub-encoders An absolute encoder employs multiple sub-encoders of different resolutions and a linking algorithm for combining the sub-encoder outputs to form an accurate, high-resolution position estimate. The sub-encoders can utilize edge modulation of a main grating track, slo... | 08/07/2007 |
| 7250881 | Encoder output signal correction apparatus and method An offset error, an amplitude error, a phase error and a third harmonic component contained in two-phase sinusoidal signals are removed using relatively simple digital computations. An offset error contained in two-phase sinusoidal signals with a phase difference ou... | 07/31/2007 |
| 7247839 | Encoder for detecting position or displacement of moving body An encoder that can detect the presence of noise occurring within the encoder. The encoder is constructed by incorporating within the same apparatus: a movement detecting unit for detecting the movement of a moving body; a signal processing circuit for processing a ... | 07/24/2007 |
| 7183952 | Resolver A resolver can make accurate angle detection in an entire detection range. The resolver includes a resolver stator having an excitation winding of one phase adapted to be excited by a power supply and a first and a second output winding of two phases for outputting ... | 02/27/2007 |
| 7138795 | Rotation angle detector and its temperature correcting method A first sin phase voltage representing the rotational angle of a resolver is derived from the sum of a rotational angle voltage involving a temperature component and a bias voltage. The rotational angle voltage and the bias voltage are calculated by calculating the ... | 11/21/2006 |
| 7126305 | Apparatus for correcting current value of three-phase electric motor and correcting method An apparatus corrects a current value of a three-phase electric motor including a current detector that detects current of each of three phases including a first phase, a second phase, and a third phase. The apparatus includes a current-value correcting unit. When c... | 10/24/2006 |
| 7109900 | Encoder output signal correction apparatus and method A third harmonic distortion corrector is equipped for correcting a third harmonic distortion contained in a two-phase sinusoidal signals with different phases output from an encoder. A third harmonic calculator/detector calculates the amplitude a3 and the... | 09/19/2006 |
| 7084791 | Analog-to-digital converter with correction of offset errors An analog-to-digital converter (200) includes at least one stage (105) for converting an analog input signal into a digital output signal using a parallel quantizer (115) comparing the analog input signal with a plurality of threshold values in ... | 08/01/2006 |
| 7079066 | D/A converter A D/A converter. The D/A converter comprises a R-2R ladder network and a correction circuit. The R-2R ladder network receives first and second reference voltage terminals and generates an analog voltage at an output terminal in response to a digital input code. The ... | 07/18/2006 |
| 7061411 | Device and method for enhancing resolution of digital encoder The present invention provides a device and a method for enhancing the resolution of the digital signal of a digital encoder. The device comprises a digital encoder which outputs a fundamental position signal. Beside, the device comprises a selected integral circuit... | 06/13/2006 |
| 7049776 | Rotor-position sensor assembly and method for detecting a rotor position An electric motor has a stator and an external rotor (40). Its external rotor (40) has a sensor magnet (54) having a plurality SP of sensor poles (55). The motor also has: at least one rotor position sensor (42, 44) for generating ... | 05/23/2006 |
| 7046176 | Rotary encoder A rotary type encoder is provided with a signal generating portion 2 for generating a sine wave signal of N periods for each revolution in accordance with the rotation of the shaft 4 of a motor; a calculation means for obtaining the rotation angle of t... | 05/16/2006 |
| 7012397 | Encoder and control apparatus for motor In a control apparatus, a “characteristic value calculation” block calculates a characteristic value (such as amplitude value, offset value, or waveform distortion for each phase of two-phase sinusoidal signals optically input from an encoder, or phase differenc... | 03/14/2006 |
| 6972403 | Position encoder An optical encoder that includes an optical grating and a quadrature optical encoder sensor that move relative to each other. The optical grating includes a first encoder bar and a plurality of second encoder bars, wherein the first encoder bar is optically configur... | 12/06/2005 |
| 6970108 | Encoder interface An encoder interface device that permits automatic discovery of an unknown encoder that is physically connected to the interface device, so as to enable correct operation. The device permits discovery of characteristics of an unknown encoder including the primary qu... | 11/29/2005 |
| 6963820 | Analog encoder method for determining distance moved A method for determining the distance moved by a component (such as a printer paper-feed roller) operatively coupled to an analog encoder having analog first and second output signals. At least one of a first inverse signal which is the inverse of the first output s... | 11/08/2005 |
| 6925401 | Method and apparatus for correcting resolver output A resolver output correction device receives sine output signal and cosine output signal from a resolver. Each of the sine output signal and the cosine output signal has an offset error and a gain differential error due to a secular variation. The correction device ... | 08/02/2005 |
| 6803863 | Method and circuitry device for non-linear output displacement conversion with reference to signal speeds coming from displacement detector A conversion device converts linear displacement signals from a displacement detector into non-linearly adjusted displacement signals for supply to a target such as a computer cursor controller. The displacement signals from the displacement detector are incremented... | 10/12/2004 |
| 6765563 | Monolithic integrated circuit implemented in a digital display unit for generating digital data elements from an analog display signal received at high frequencies A monolithic integrated circuit for use in a digital display unit. The circuit may include an analog-to-digital converter (ADC), a scaler and a clock recovery circuit. The present invention enables the integration of at least these components into a single monolithi... | 07/20/2004 |
| 6639529 | System and method for delay calibration in position encoders Systems and methods are provided for calibrating a sample delay time between a position request time from a host computer and a position encoder sample time. The position encoder includes a readhead with a transducer and transducer electronics, and encode... | 10/28/2003 |
| 6563443 | Method and device for absolute position determination A method for the absolute determination of the position of two objects, which are movable in relation to each other over a defined measuring distance. The method includes scanning a first measuring graduation with a first graduation period so as to genera... | 05/13/2003 |
| 6556153 | System and method for improving encoder resolution A system and method are disclosed for improving resolution of an encoder or other position sensing device that provides one or more signals indicative of relative movement between two bodies. The signals are employed to determine an operating mode, which ... | 04/29/2003 |
| 6515600 | Circuit arrangement for regenerating the black level of video signals In a circuit arrangement for regenerating the black level of video signals during A/D conversion, in which a deviation of the black level of the digital video signals from a predetermined value influences the black level of the analog video signals, the s... | 02/04/2003 |
| 6445316 | Universal impedance control for wide range loaded signals In one embodiment of the present invention, a compensation driving circuit includes a code generator, an enable circuit, and a driver. The code generator generates a driver code from a compensation code according to a selector signal. The driver code corr... | 09/03/2002 |
| 6424276 | Successive approximation algorithm-based architectures and systems A digital calibration system for an analog-to-digital converter system includes a computational system receiving digital bits from an analog-to-digital converter representing selection of elements of the digital-to-analog converter in response to an analo... | 07/23/2002 |
| 6407686 | Waveform measuring apparatus A reference signal generation portion generates a reference signal independently of a repetition cycle of a signal under test. A frequency measuring portion measures a repetition frequency of the signal under test by using a reference signal from the refe... | 06/18/2002 |
| 6404372 | Asynchronous A/D converter with moving window An A/D converter has been described that compares the bounds of a voltage window with an analog input signal Vin. When Vin is not within the boundaries of the voltage window, the position of the voltage window is moved either upwards... | 06/11/2002 |
| 6339388 | Mixed analog and digital integrated circuit and testing method thereof The constitution of mixed analog/digital integrated circuits and their testing methods are disclosed. These testing methods are aimed at verification and the linearity of D/A and A/D converters. The mixed analog/digital integrated circuit is given a const... | 01/15/2002 |
| 6329936 | Statistical adjustment of A/D non-linearities to correct intensity ARI Spurious artifacts in intensity emulation caused by measurement non-linearities within a statistically created raster display are reduced or eliminated by first characterizing the non-linearities. Armed with this information the collection of code values ... | 12/11/2001 |
| 6317071 | Method and apparatus for analog-to-digital conversion by combining digital sample values An analog-to-digital (A/D) converter system converts an analog input signal into a digital output value by combining a plurality of digital sample values. For example, an A/D converter converts an RF analog signal into digital sample values. The A/D syste... | 11/13/2001 |
| 6292117 | Integrated adjustable current to voltage converter and digital quadrature generator in a printer paper positioning system In a printer, a paper positioning system is used to control feeding a printing medium, such as paper, through the printer. An optical encoder is used to generate analog current waveforms as the paper is fed through the printer. An integrated adjustable cu... | 09/18/2001 |
| 6215426 | Offset correcting circuit for encoder An offset correcting circuit for an encoder capable of detecting a correct offset value even when a sampling period is long as in the case of a low-speed A/D converter and restraining the influence of noise. The offset correcting circuit for an encoder ad... | 04/10/2001 |
