Abstract: A digital pulse circuit receives parallel N digital signals, assuming N is an even integer equal to or greater than 4, the levels of the signals inverted every time a constant quantity of change in an objective quantity to be measured occurs, any phase differences between the successive signals of the signals about 1/N of the constant quantity; has a logic circuit which enables only two signals which can change state in due process corresponding to the next change of the objective quantity to be measured, to enter the next stage; and synchronizes each of the N digital signals by a clock pulse, to make any phase difference among the N digital signals equal to or more than a predetermined phase difference, and the remove the influence of noise superposed on the digital signals (FIG. 10).

Abstract: An apparatus and method are disclosed for indicating the angular position of an object relative to a reference position in which a plurality of different tracks of indicia are positioned on indicia-supporting media that is adapted for movement with the object. High resolution position words are assembled by merging position information resolved from a plurality of different tracks of indica. The position information is resolved by way of sine wave synthesis in which position information from a pair of tracks having different resolutions is used to generate position information of an intermediate resolution. This intermediate position information is merged with position information from the higher resolution track of the two tracks.

Abstract: The optical interrupter system includes a moving member having a sequence of optical flags, interposed between a source of illumination and a detector, such that as the optical flags of the moving member are illuminated and detected, the detector generates a signal having a waveform with a first portion less than a first threshold, a second portion greater than the first threshold and less than a second threshold, and a third portion greater than the second threshold. Signal processing circuitry operates to generate a count signal indicating a transition between the first and third waveform portions.

Abstract: A positional information generating apparatus comprises a code disposed on a main track on which M-sequence codes form a cyclic code of different code words, and sensors disposed for attaining relative movement with reference to a direction of the main track. The code word is detected from the main track by the sensors for generating positional information. A sensor array for the main track in which a greater number of sensors than the number of elements of a code word are disposed over a span corresponding to a length of one code word in such a way that at least one sensor is located on each code element to define a code word to be read. A relative position detector is provided for detecting a relative positional relationship between the sensor array for the main track and the main track.

Abstract: An optical sensor and an optical sensing system and method in which both analog and digital techniques are employed. The sensor comprises an encoder and an illumination source. The encoder includes a plurality of tracks, and the illumination source illuminates each track with an associated optical input signal. Each input signal comprises light in a wavelength range different from the wavelength ranges of the other input signals. Each track includes means responsive to the value of a measurand for modulating the intensity of the associated input signal, in one of N different ways, to produce a corresponding modulated signal, N being greater than 2. The intensities of the modulated signals thereby encode the value of the measurand. The illumination source may also produce a reference signal that is not modulated by the measurand.

Abstract: An absolute encoder providing a multi-bit output binary code indicative of the position of a rotary or linear scale. The encoder employs a code track, which contains a serial code, and a clock track. The encoder may be either rotary or linear, and may be implemented optically, magnetically, inductively, capacitatively or by any other binary sensing technique.

Abstract: An encoder for detecting the state of movement of a scale having a plurality of tracks consisting of arranged predetermined codes comprises first detecting device for reading the codes of the plurality of tracks and detecting data comprising a row of the codes, and second detecting device for detecting the state of movement of the codes of a particular track plurality of tracks to obtain more detailed data. The state of movement of the scale is detected on the basis of the signals from the first and second detecting devices.

Abstract: An optical encoding system for determing the absolute and the incremental positions of a movable member relative to a stationary member. For example, three stationary light sources may be supported by the stationary member for emitting three narrow light beams on respective paths. An encoding band may be supported by the movable member in the paths of the light beams. The band has a timing and incremental encoding track comprising at least one series of alternating light-blocking stripes and light-passing stripes, and a data track comprising a series of distinct absolute position tags. A read head may be supported by the stationary member and has three optical sensors, one for each light beam, two preferably in quadrature with each other for the timing and incremental encoding track, and one for the data track. Each optical sensor includes light sensors for generating an analog signal voltage.

Abstract: An optical type displacement detecting device including a main scale and an index scale, wherein a pitch of a first optical grating formed on the main scale is set at P and a pitch of a second optical grating formed on the index scale is set at P/n, thereby producing divided detection signal having pitch P/n. Furthermore, the pitch of the second optical grating is set at (u+v) P/u or (u+v) P/(2u) (u is a gap between a diffusive light source and the first optical grating and v is a gap between the first and second optical gratings), so that a collimator lens can be dispensed with. Further, higher harmonic components of the first optical grating are utilized, whereby the pitch of the second optical grating is set at substantially (u+v) Q/u or (u+v) Q/(2u) (Q=P/m, and m is a whole number of 2 or more), thereby preventing the pitch of the second optical grating from being divided into small ones.

Abstract: An absolute encoder providing a multi-bit output binary code indicative of the position of a rotary or linear scale. The encoder employs a code track, which contains a serial code, and a clock track. The encoder may be either rotary or linear, and may be implemented optically, magnetically, inductively, capacitatively or by any other binary sensing technique.

Abstract: A position detector is provided with an encoded element having indicia representative of a bit pattern of a pair of bits of a Gray code and a pair of sensors responsive to this indicia. The encoded element is capable of being mechanically coupled to a movable member and the sensors are spaced apart by a distance corresponding to a shift in the bit pattern between two bits of the Gray code such that movement of the encoded element past the sensors is used to produce two bits of the Gray code. Additional encoded elements and sensors are used to produce additional bits of the Gray code.

Abstract: An optical encoding system for determining the absolute position of a movable member relative to a stationary member. For example, a bar-code scanner may be supported by a stationary member for scanning bar-code symbols in its field of view. An encoding band may be supported by the movable member so that a portion of the band is scanned by the bar-code scanner. Affixed to or otherwise marked on the band is a sequential series of bar-code symbols, each symbol encoding the absolute position of its location on the band. A bar-code decoding system, actuated by the signals produced by the bar-code scanner, decodes the bar-code symbol scanned by the scanner, and determines the absolute position of a movable member relative to the stationary member.

Abstract: A first pattern which repeats change in the longitudinal direction with a predetermined pitch and a second pattern which changes in the longitudinal direction with a pitch which is different at least from that of the first pattern; both formed of a predetermined material, are disposed on a surface of a rod section. A detection head section is provided in proximity to the rod section, responds individually to the first pattern and the second pattern, changes its relation of correspondence to the respective patterns in accordance with it linear position with respect to the rod section and produces output signals in accordance with the relation of correspondence to the respective patterns. In accordance with the output signals corresponding to the respective patterns, first and secondd absolute position data of different ranges whose one cycle is constituted of one pitch of the respective patterns can be obtained.

Abstract: Bar codes are shown for measurement of volumes of liquids, e.g., the amount of milk collected in a dairy milking operation, and correlation therewith to identification of the source of the liquid, such as a cow. In the preferred embodiment, infrared or laser scanners are used to scan bar codes to provide an input to a computer for correlating the container or the source of liquid with the volume of liquid, whereby complex volume measuring devices and operator measurements can be substantially eliminated. Similar techniques can be used to provide computer input data representing a wide variety of analog inputs; e.g., by providing a bar code scale for juxtaposition to a thermometer, the segments of the code along the scale being selected in accordance with the mercury level at a given temperature, simple analog-to-digital temperature data conversion and input is obtained. Methods and apparatus for providing machine-readability for a number of differing types of analog instrumentation are described.

Abstract: Computer control apparatus uses sensing apparatus converts a mechanical movement into a direct current electrical signal. An electrical interface circuit is connected to the sensing apparatus for converting the direct current electrical signal into a pulse output used in controlling a computer. The preferred sensor is an inclinometer, which comprises an opaque body having a chamber. A light source is connected to the body to provide light in the chamber. Photocell apparatus is connected to the body to receive light emitted from the light source for providing an electrical resistance in relation to the amount of light received. Supported in the chamber is a liquid filter medium to absorb light emitted from the light source. A sufficient quantity of liquid filter medium is provided in the chamber to prevent light emitted from the light source from impinging upon the photocell apparatus in response to the angular placement of the body with respect to gravity.

Abstract: An analog to digital converter, adapted to convert an optical analog signal to an equivalent optical digital signal being one of x optically presented digital numbers defined by an n-bit digital word, where X=2.sup.n. The optical analog signal is light having an intensity variable over a range from a minimum to a maximum value. The analog to digital converter comprises a linear array of comparator means, a linear array of logic means, and a linear array of decoding means. The linear array of comparator means is responsive to the light at a plurality of input positions, x, and produces binary threshold signals which respresent a one-dimensional spacial reference having a length of corresponding to the magnitude of the sensed intensity. The linear array of logic means is responsive to the binary threshold signals and produces an optical index signal which is a one-point spacial reference having a location, an index postion, corresponding to the length of the one-dimensional spacial reference.

Abstract: An optical sensor comprising an encoder having a plurality of tracks, and illumination means for illuminating each track with an optical input signal that includes a plurality of wavelength components. Each wavelength component comprises light in a wavelength range different from the wavelength ranges of the other components. Each track includes means for modulating the input signal, and for dispersing the input signal to produce a plurality of spatially dispersed output signals. Each output signal comprises one of the wavelength components. Output signals having different wavelength components from different tracks are combined to produce a composite output signal, such that each wavelength component in the composite output signal is modulated by a different track. The output signal may therefore be demultiplexed to produce information indicating the position of the encoder. The encoder preferably comprises a masked diffraction grating.

Abstract: An electro-optical displacement sensor comprises an optical source including a plurality of optical grating lines for producing from an incident optical signal a transmitted optical signal having a spatially periodic intensity pattern. Optical sensing means receives the transmitted signal as an input across a plurality of optical receptors, each of which receptors provides an output signal corresponding to the amplitude of the transmitted signal as sensed by the receptor. The receptors are spaced one from the other by a distance different from the fundamental spatial wavelength of the transmitted signal. Signal conditioning means derive a signal vector from the receptor output signals, the signal vector than being processed to derive first and second independent component signals. The component signals are then combined to produce an interpolated phase signal corresponding to the interpolated position of the grating lines relative to the optical receptors.

Abstract: A displacement coder of the differential type wherein, in order to reduce the dimensions thereof, a first disk is rotatably connected to a principal shaft coupled to the shaft which controls the displacement of a mobile member being monitored and a second disk which is coaxially mounted on the principal shaft but which is rotated in a ratio of slightly less than 1 to 1 with respect to the first disk through a driving connection which includes a common pinion and two tooth wheels which wheels are also mounted along the principal shaft.

Abstract: Apparatus for sensing locations and magnitudes of forces applied on a surface includes a grid comprised of energy input devices running in one direction and energy output devices running another direction with the input and output devices crossing each other. Transducers that meter energy from the input devices to the output devices as a function of the magnitude of forces applied thereon are positioned at the intersections of the input devices with the output devices. Interrogation apparatus is also included, along with energy output detectors and measuring devices, for sensing and determining locations, as well as magnitudes, of forces applied on the grid. Several embodiments of energy input and energy output devices are shown and described, as well as several embodiments of transducers.

Abstract: An optically powered resolver for detecting an optical property of an encoder at a plurality of encoding sites on the encoder, to permit determination of the position or other state of the encoder. Each encoding site is capable of receiving an optical encoder input signal and of modulating the encoder input signal to produce an optical encoder output signal. The resolver includes a photocell for converting the optical input signals into corresponding electrical input signals, and an energy storage circuit for storing a portion of the energy of the electrical input signals. The resolver also includes an interrogation circuit for interrogating a selected encoding site with an encoder input signal in response to the receipt of an optical input signal by the resolver. Interrogation means provides an optical output signal corresponding to the resulting encoder output signal.

Abstract: The present invention relates to an optical laser analog-to-digital (A/D) converter and the use of such a converter as a transducer. In a first embodiment of the invention, the converter consists of a source which produces a coherent beam of light that is passed through a lens system to produce a line or bar of light. The bar of light passes through a coded optical mask which is made of a thin transparent material with a binary or gray code printed thereon. The mask is mounted to an object whose movement is to be detected. The mask may also be configured in the form of a circle and mounted to a motor shaft to sense motor rotational displacement, RPM or velocity. As the mask moves, the imprinted pattern changes according to the coding on the mask. The portion of the light that passes through the mask strikes the target of a moving recording media.

Abstract: A direction sensitive optical shaft encoder includes an optical shutter disk mounted to a shaft for rotation therewith, the optical shutter disk bearing at least first and second radially concentric tracks having alternating light transmissive and light blocking areas formed thereon. The light transmissive and light blocking areas of one track are angularly offset with respect to the light transmissive and light blocking areas of an adjacent track. A pair of light emitters and light detectors are disposed on opposite sides of the optical shutter disk and aligned with the first and second concentric tracks, respectively. Because the pattern of light transmissive and light blocking areas on the two tracks are angularly offset, the output of the light detectors follows a unique pattern which is dependent upon the direction of rotation of the optical shutter. The frequency of repetition of the pattern of outputs by the light detectors is indicative of the speed of rotation of the optical shutter.

Abstract: An optical position determining apparatus for detecting radiant energy reflected from a target zone includes an emission device for generation and emission of radiant energy, a device for redirecting radiant energy across the target zone, a reflecting device for reflecting the radiant energy back from the target zone, and a detector device for sensing the presence of radiant energy reflected from the target zone. The emission device is stationary and emits a beam of radiant energy toward the redirecting device, which redirects the radiant energy along a primary beam path. The redirecting device also is configured for permitting a return beam of light from the target zone to impinge upon the detector device, which is located therebehind with respect to the direction of travel of the return beam. The detector device includes a CCD (charge coupled device) linear sensor formed of a plurality of sensor elements.

Abstract: An angular position encoder utilizes Moire fringes formed by illuminating regions of coded images arranged circumferentially on wheels rotatable in accordance with angles to be encoded. Movement of the Moire fringes from a reference position is detected and used to determine the angular movement. All non-rotating movements of the coded wheel are compensated by the encoding process and do not effect the output.

Abstract: An optical coordinate system input device including multiple opposed pairs of light emitting elements and light receptor elements which are sequentially selectively activated via a switching circuit, a variable impedance circuit connected in series with the light receptor elements to form a voltage divider, and an impedance detection circuit for detecting a low impedance of the light receptor elements caused by ambient light, wherein a detection signal from the impedance detection circuit lowers the impedance of the variable impedance circuit to increase the sensitivity of the input device to small changes in impedance of said light receptor elements upon detection of a light signal, emitted by said light emitting elements, by said light receptor elements in presence of strong ambient light.

Abstract: A circuit for correcting a variation in phase of a train of clock pulses detected from a pattern of a coding disc of a rotary encoder which detects the rotation angle of a rotating shaft, comprises an ROM in which data for correction of a phase variation corresponding to the rotation angles of the coding disc are preliminarily stored. The correction data are read from the ROM by designating addresses of the ROM by means of the counter which counts up a train of clock pulses from the rotary encoder before the clock pulse train is subjected to correction. The clock pulses are phase-modulated by the correction data from the ROM to provide a corrected train of clock pulses which correctly represent the rotation angles of the rotating shaft.

Abstract: An apparatus for measuring differences by incrementally counting graduations has additional equidistant graduations as well as a corresponding sensor and evaluation device. The intervals between the marks of each additional graduation are multiples of one interval of an incremental graduation. The intervals of one additional graduation differ from those of others by an integral number of incremental intervals. A simple determination of the absolute position of marks from a zero position is done by using an incremental counter for counting the steps between successive marks of two of the additional graduations. This method requires only small motions of the carrier and sensing of the zero position itself is not required.

Abstract: A rotary encoder having first and second slit disks are disposed between a light emitting diode and a light sensor coaxially in proximity to each other, the two slit disks each having a large number of slits formed radially at equal intervals in a peripheral edge portion of the disks, the first slit disk being connected to and rotated by a rotational shaft, and the second slit disk being rotated by interlocking gears in a direction opposite to that of the first disk.

Abstract: The single channel encoder comprises a transparent scale in which the scale divisions are defined by transverse opaque lines having a width greater than the width between the opaque lines. An emitter holder and a detector holder snap together, clamping an aperture plate there between. The aperture plate has a slit therein which is disposed in the optical path between the emitter and the detector. Projections functioning as scale supports on the opposite sides of the emitter holder and the detector holder are disposed in longitudinally spaced positions and define a gap therebetween for engaging the outside edges of the encoder scale outside of the opaque transverse lines to precisely position the scale in the optical path for maintaining a constant gap between the encoder scale and the aperture plate.

Abstract: An encoder device of the absolute position type for outputting a shift position or angle of rotation relative to the absolute position. The device comprises a code plate having first and second grid patterns wherein information is stored as 1 or 0 in a periodic manner at pitches slightly different from each other; first and second sensory arrays for detecting the first and second grid patterns; driving means for driving the sensors relative to the grid patterns and for obtaining an alternating signal from each array; and computation means for measuring the phase angle of the alternating signal from each array, and the phase angle difference therebetween and for calculating the position using such phase angles. Advantageously, the invention is suitable for miniaturization due to its simplicity, relaibility, and efficiency.

Abstract: A rotary encoder apparatus of an incremental-type construction, including: a rotary unit mechanically joined to a movable machine; a unit for outputting at least two signals having a phase shift and a periodic waveform in response to rotation of the rotary unit; a battery-type power supply; and an electric circuit including a circuit for generating a timing pulse having predetermined frequency and pulse width, a circuit for detecting a change of the signals from the signal outputting circuit and for outputting a pulse signal in response to the change of signals, and a circuit for counting the pulse signal from the signal-change detecting circuit. The apparatus may be optical or magnetic in construction.

Abstract: An incremental position encoder comprising a first member arranged for movement with a second member the movement of which is to be monitored, a plurality of light transmissive or reflective elements of three distinct colors, said elements being arranged in a row on said first member, and the elements being arranged in the row in a repeating sequence of said three colors, a light source directing light to said elements and a color sensitive light detector for receiving light transmitted by, or reflected from said elements, said color sensitive detector being arranged to produce, at any given instant, one of three distinct outputs dependant upon the color of the three available, of the element which is at that instant transmitting or reflecting light from the source to the detector.

Abstract: An incremental optical code reader of the wholly integrated type including a reading assembly, a pair of photodiodes, a differential amplifier receiving the outputs of the photodiodes and a trigger connected to the output of the amplifier. An electronic assembly with "exclusive OR" logic gates, AND logic gates and OR logic gates, receiving the outputs of the triggers for the channels and feeding into the outputs.