Abstract: A scanning element includes a circuit board having a first detector unit provided with a first receiver conductor trace arranged circumferentially about an axis in the circumferential direction. The course of the first receiver conductor trace has: a periodic configuration along a first line; a first gap along its extension in the circumferential direction; a first amplitude in the first quadrant or in the second quadrant of a Cartesian coordinate system; and a second amplitude in the third quadrant or in the fourth quadrant of the coordinate system. The origin of the coordinate system is located on the axis, and the ordinate extends centrically through the first gap in relation to the circumferential direction. The second amplitude is smaller than the first amplitude.

Abstract: A system for determining the absolute position of a first object with respect to a second object includes a scalar element attached to the first object and a measuring device attached to the second object. The scalar element comprises a series of coded regions. The coded region represents a number designating a position along an axis of the scalar element. The measuring device includes a two-dimensional optical sensor array configured to capture an image of a portion of the scalar element. The system also includes a processor configured to receive the image and determine an absolute position of the first object with respect to the second object based on at least one coded region of the series of coded regions.

Abstract: An apparatus including a frame, an optical sensor connected to the frame, and an environment separation barrier. The frame is configured to be attached to a housing of a motor assembly proximate an aperture which extends through the housing. The optical sensor comprises a camera. The environment separation barrier is configured to be connected to the housing at the aperture, where the environment separation barrier is at least partially transparent and located relative to the camera to allow the camera to view an image inside the housing through the environment separation barrier and the aperture.

Abstract: An optical rotary encoder includes a code disk, a laser source unit, a focusing unit and a photodetector array. The focusing unit converts the laser beam emitted by the laser source unit into incident laser beams that have a plurality of light points respectively on code tracks of the code disk, such that the code disk modulates the incident laser beams to form optical code signals. The photodetector array receives and converts the optical code signals into electric code signals.

Abstract: A tape rule assembly includes a linear optical encoder for sensing human-readable graduations of length disposed on a surface of a tape, without requiring any other machine-readable indicia to be present on the tape. The optical encoder includes two optical sensors disposed in a sensor holder pivotably disposed in the tape rule housing and configured to be displaced relative to one another in the housing along both the “x” axis and the “z” axis, a set of intersecting “x”, “y” and “z” axes being defined relative to a tape exit in the tape rule housing.

Abstract: A measuring device includes a light-emitting unit that radiates light onto an object, a first lens that changes a divergence degree of the light, a diaphragm having an aperture that reduces a diameter of the light, a second lens that converges and radiates the light onto the object, a light-receiving unit that receives at least part of the light that has been reflected by the object and that has passed through the second lens, a measuring unit that measures the object by using results related to the light-receiving unit, a reflector whose angle with respect to the light is adjustable, and a correction unit that varies a light-receiving position on the light-receiving unit by varying the reflector's angle and corrects a light amount of the light-emitting unit and a sensitivity of the light-receiving unit by using results obtained at each light-receiving position.

Abstract: A resistivity imager uses discrete energy pulsing to determine resistivity of a borehole. The imager has pulse generation circuitry that generates discrete energy pulses. An electrode array exposed to the borehole emits or discharges the discrete energy pulses into the formation. The variations of the formation subject the electrode to impedance levels in response to the discrete energy pulses, and measurement circuitry measures the discharge of the pulsed energy subjected to the impedances. From the measurements, control circuitry determines resistivity parameters of the formation around the borehole. These resistivity parameters can be stored in memory downhole or can be telemetered to the surface. When analyzed, the resistivity measurements can produce an image of the borehole's features, indicate borehole structures, direct geosteering of drilling, or the like.

Abstract: A position measuring apparatus with at least one material measure comprised of an optical structure of an arrangement of 3-D reflectors, at least one light receiver arranged at a distance from the material measure, a light source arranged at a distance from the material measure and at a distance from the light receiver, and at least one transparent substrate present between the material measure and the light receiver, wherein the light receiver is deposited directly on the transparent substrate, on the side of the substrate opposite the material measure in the form of a thin-film structure consisting of several layers arranged one above another. A supporting plate is provided with circuit-board conductors, on which the substrate is arranged, wherein the transparent substrate and the supporting plate are joined solidly together by a Flip-Chip assembly process.

Abstract: A gas measurement apparatus measures a target gas. The gas measurement apparatus includes a light source, a first light receiving apparatus, a first phase-sensitive detection apparatus, an R calculation unit, and a setting unit. The light source oscillates a laser light that has a central wavelength determined by a main current and is modulated according to a modulation current, with the central wavelength being varied. The first light receiving apparatus outputs a detection signal according to an intensity of the laser light transmitted through a standard sample. The first phase-sensitive detection apparatus obtains a second harmonic component oscillated at a harmonic frequency ?2 twice as large as a modulation frequency ?1. The R calculation unit calculates a peak-bottom ratio R. The setting unit sets a width of wavelength modulation of the laser light so that the peak-bottom ratio R satisfies a predetermined condition.

Abstract: Provided herein is an encoder including a position detecting device provided with a gear mechanism and an optical encoder device. A housing includes a bearing holder provided between a first housing portion and a second housing portion of the housing. The bearing holder serves as a partition wall portion configured to separate the gear mechanism from the optical encoder device. If the gear mechanism is separated from the optical encoder device, abrasion powder or grease can be reliably prevented from scattering from the gear mechanism to adhere to constituent parts of the optical encoder device.

Abstract: An optical encoder and optical encoding system are disclosed. Specifically, an encoder having a light detector elevated relative to a light source is described. The relative height difference between the light source and the light detector enables the optical encoder to minimize noise at the light detector without requiring a separate light baffle between the light source and light detector. Methods of manufacturing and operating such an encoder are also described.

Abstract: A dark field diffraction based overlay metrology device illuminates an overlay target that has at least three pads for an axis, the three pads having different programmed offsets. The overlay target may be illuminated using two obliquely incident beams of light from opposite azimuth angles or using normally incident light. Two dark field images of the overlay target are collected using ±1st diffraction orders to produce at least six independent signals. For example, the +1st diffraction order may be collected from one obliquely incident beam of light and the ?1st diffraction order may be collected from the other obliquely incident beam of light. Alternatively, the ±1st diffraction orders may be separately detected from the normally incident light to produce the two dark field images of the overlay target. The six independent signals from the overlay target are used to determine an overlay error for the sample along the axis.

Abstract: An encoder emits modulated light from a light source section and lets a first light and a second light separated from the modulated light interfere with each other in a moving grating. In the encoder, the light emitted from the light source section is electrically modulated, and the first light and the second light have different light path lengths.

Abstract: A pattern generator includes: a writing tool and a calibration system. The writing tool is configured to generate a pattern on a workpiece arranged on a stage. The calibration system is configured to determine a correlation between a coordinate system of the writing tool and a coordinate system of a calibration plate on one of the stage and the workpiece. The calibration system is also configured to determine the correlation at least partly based on an optical correlation signal, or pattern, in a form of at least one optical beam being reflected from at least one reflective pattern on the surface of the calibration plate.

Abstract: A measuring device for detecting a relative position, the measuring device including a measurement graduation movable in at least one measurement direction and a scanning unit for determining a relative position of the measurement graduation with respect to the scanning unit. The scanning unit includes a light source, a scanning grating disposed on a first side of a transparent carrier element that is positioned in a scanning beam path and a detector arrangement. The scanning unit further includes an attenuation structure that adjusts a light intensity on the detector arrangement in a defined manner, wherein either 1) the attenuation structure is disposed on a second side, opposite the first side, of the transparent carrier element or 2) the attenuation structure has a permeability that varies as a function of location at least along one direction so that a light intensity which is uniform at least in that one direction results on the detector arrangement.

Abstract: A method and apparatus for suppressing loss of scale image contrast due to interference effects from optical path length differences, including lens profile aberrations, are provided in a displacement sensing optical encoder that uses a telecentric imaging configuration. According to the invention, the encoder is configured such that the image light that reaches the detector comprises symmetric ray bundles concentrated symmetrically on opposite sides of the optical axis center at the limiting aperture of the telecentric imaging configuration. Central ray bundles, and/or other ray bundles that have an optical path lengths significantly different than the operational symmetric ray bundles are prevented or blocked. As a result destructive interference is prevented and image contrast is improved.

Abstract: Optoelectronic position measurement device comprises a code carrier, a radiation source and a detection unit. The code carrier can be moved relative to said sensor unit by one degree of freedom. A refractive optical element having a focusing segment and at least one neighboring segment are arranged between the code carrier and the first sensor unit. Optical radiation shining in on the focusing segment parallel or at an angle of incidence below a threshold angle ? to the optical axis of the focusing segment can be guided by the focusing segment on the receiving region of the first sensor unit within the optical axis, and radiation that is shining into a deflection angle region above the threshold angle ? to the optical axis of the focusing segment can be deflected by the focusing segment and the neighboring segment to a point outside of the optical axis of the focusing segment.

Abstract: Provided is a rotary encoder, including: a rotary scale, which has a predetermined pattern including continuous patterns and a rotational angle original point formed thereon with reference to a pattern center, has a polygonal outer shape, and has the rotational angle original point defined with reference to at least one side of sides of the polygonal outer shape; a hub, which includes projections for abutting the sides of the polygonal outer shape of the rotary scale and positioning the rotary scale; a rotating shaft, which is press-fitted into the hub and rotates coaxially with the pattern center of the rotary scale; and detecting units for irradiating the rotary scale with light and detecting the light reflected by the rotary scale.

Abstract: An optical encoder is configured as follows. Namely, the optical encoder includes a signal processing circuit which processes encoder signals output from a plurality of encoder heads, a control unit which specifies one of the plurality of encoder heads, sets the signal output of the specified encoder head in an on state, and further sets the outputs of the encoder heads not specified in an off state, thereby causing only the specified encoder head to output an encoder signal to the signal processing circuit, switch signal lines, and a common wiring line which is shared by the plurality of encoder heads and which transmits the encoder signals to the signal processing circuit.

Abstract: Image recognition and distance calculation methods and devices are provided. First, an image corresponding to a level ruler is obtained, wherein the image includes a first predefined scale and a second predefined scale projected on the level ruler. Then, a baseline height of a baseline mark in the level ruler is determined according to the image. The heights of the first predefined scale and the second predefined scale are calculated according to the baseline height of the baseline mark, the position of the baseline mark in the image, and the positions of the first predefined scale and the second predefined scale in the image. Thereafter, a distance to the level ruler is calculated according to a height difference between the heights of the first predefined scale and the second predefined scale.

Abstract: Gas detector tubes may be used to determine a concentration of target gases in air. The gas detector tubes described may be read either by and optical reader or visually by the user. A gas detector tube reader having an optical reader capable of reading a length of stain, a color change and color density of a reagent in a gas detector tube. The gas detector tube may further comprise sensors for measuring the environmental conditions during sampling.

Abstract: A position measuring apparatus with at least one material measure comprised of an optical structure of an arrangement of 3-D reflectors, at least one light receiver arranged at a distance from the material measure, a light source arranged at a distance from the material measure and at a distance from the light receiver, and at least one transparent substrate present between the material measure and the light receiver, wherein the light receiver is deposited directly on the transparent substrate, on the side of the substrate opposite the material measure in the form of a thin-film structure consisting of several layers arranged one above another. A supporting plate is provided with circuit-board conductors, on which the substrate is arranged, wherein the transparent substrate and the supporting plate are joined solidly together by a Flip-Chip assembly process.

Abstract: Disclosed is an apparatus including a mechanical reference frame and a rigid object mechanically coupled to the reference frame by two or more constraints. The stiffnesses of at least two of the constraints are different from one another, and the relative locations and stiffnesses of the constraints cause a designated point on the rigid object to remain stationary with respect to the reference frame during thermal expansion of the rigid object over a range of temperatures.

Abstract: An optical encoder device is provided, in which the number of light transmissive slits of a stationary slit plate can be increased as much as possible according to the length of a light receiving surface of a light receiving element to produce an output signal with little distortion. A movable slit plate 3 includes a slit row R1 in which a plurality of light transmissive slits (light transmissive portions) S1 each having a slit width of 180° in terms of electrical angle and a plurality of light non-transmissive slits (light non-transmissive portions) S2 each having a slit width of 180° in terms of electrical angle are alternately formed. A stationary slit plate 4 includes a slit row R2 in which a plurality of light transmissive slits S3 each having a slit width of 180° in terms of electrical angle and a plurality of light non-transmissive slits S4 each having a slit width of (360Xk-180)° in terms of electrical angle are alternately formed.

Abstract: An encoder configuration comprises a dual-modulation scale track pattern that provides a first intensity modulation component for producing periodic signals, and a second intensity modulation component for producing a long-range absolute signal. The dual-modulation scale track pattern increases the range-to-resolution ratio of the encoder without the use of additional scale tracks that would increase the width of the encoder components. The long-range signal may be encoded in the dual-modulation scale track pattern either by varying certain dimensions of pattern elements included in the scale track or by superimposing a layer including an optical density variation along on the track on pattern elements of similar areas. In either case, the net offset and/or amplitude levels of the associated signals are modified along the scale track. These modified offset and/or amplitude levels provide the basis for the long-range absolute signal.

Abstract: An optical encoder includes a linear power transmission member which moves longitudinally, a reflector which is provided on an outer peripheral surface of the linear power transmission member and which is longitudinally movable integrally with the linear power transmission member, the reflector including two kinds of reflecting portions different in reflectance are longitudinally arranged, and a light source which radiates light. Further, the optical encoder includes a linear light transmitter which guides the light from the light source to the reflector and to which reflection light reflected from the reflector is guided, and a calculation mechanism configured to calculate a longitudinal displacement of the reflector on the basis of an intensity of the reflection light from the reflector which is guided via the linear light transmitter.

Abstract: The invention relates to a method for optically scanning the three-dimensional geometry of an object by means of triangulation, in which a pattern (9, 9?) is projected onto the object (7) to be scanned in order to obtain a 3D data set, and the projected pattern (9, 9?) is recorded in an image (40, 41). In a first step for the production of at least one first image (40), a first pattern (9) is projected and in a second step for the creation of at least one further image (40), a further pattern (9?) deviating from the first as regards position or shape is projected onto the object (7) to be scanned and the image (41) is created. The first image (40) and the further image (41) comprise at least one common point (44). The 3D data acquired from the images (40, 41) are merged in a subsequent step on the basis of the 3D data of the at least one common point (44) such that the 3D data acquired from said images (40, 41) agree at least with reference to the 3D data of the common point (44) in the 3D data set.

Abstract: An optical encoder includes a rotation disc, an annular slit, a light source, an absolute-value-related detecting unit, and a signal processing device. The annular slit includes a first annular slit and a second annular slit which are decentered in a mutually different direction. The light source is configured to irradiate light on the annular slit. The absolute-value-related detecting unit is configured to detect transmitted light or reflected light irradiated from the light source and transmitted or reflected at the annular slit to output a detected signal. The absolute-value-related detecting unit includes a first detecting unit corresponding to the first annular slit and a second detecting unit corresponding to the second annular slit. The signal processing device is configured to detect an absolute rotational angle of the rotation disc based on the detected signal output from the absolute-value-related detecting unit.

Abstract: A sensor may simultaneously sense the angular position of a first rotatable member relative to a frame of reference and the angular position of a second rotatable member relative to the first rotatable member. The sensor may include a first and second disk, each having an annular pattern which alternates between two different levels of optical transparency. One disk may be coupled to the first rotatable member, the other disk may be coupled to the second rotatable member. A signal processing system may determine both angular positions based on sampling a consolidation of the first and the second annular patterns at locations that are not at a transition in the consolidated pattern.

Abstract: An optical encoder comprises an encoder head and a scale having a second grating that has an optical pattern. The encoder head has a light emission unit to emit specific light to the scale, a light transmission member to transmit the light emitted from the light emission unit and a light detection unit having light detection elements arranged at a predetermined pitch. The light transmission member has a first grating having an optical pattern of a predetermined pitch and an aperture to narrow the light emitted from the light emission unit and impinging on the second grating of the scale. A motion of an image on the light detection elements of the light detection unit is detected. The image is formed by the light reflected or diffracted by the second grating of the scale after the light impinges on the scale through the light transmission member.

Abstract: An optical encoder assembly has an encoder sensor, a code strip, and a base having a first portion and a second portion, wherein the encoder sensor is mounted on one of either the first portion or the second portion and the code strip is mounted on the other portion. An optical encoder assembly has a base having an upper base and a lower base, the upper base joined to the lower base with at least one flexible beam, an encoder sensor mounted to one of the upper base or the lower base, and a code strip mounted to the other of the upper base or the lower base. A method includes mounting an encoder sensor to a first mating surface on the first side of a base, mounting a code strip to a second mating surface on the second side of the base with the first and second sides of the base connected by at least one flexible beam, and attaching the base to an object to be measured such that deflections between the first and second mating surfaces can be measured using the encoder sensor.

Abstract: An optical encoder for measuring the rotary angle of a rotating shaft comprising an electronic board with light emitter and light sensor means disposed between a pair of overlying light guides having a common symmetry axis that coincides with the shaft rotation axis, the light guides receiving light from a light emitter means on the electronic board and returning light to a light sensor means the electronic board; an optical pattern of two concentric annular sections attached to the rotating shaft and an optical pattern of two concentric annular sections on a stationary device. A method for measuring the rotary angle of the rotating shaft by emitting light from the electronic board into the light guides and processing the signals received on the electronic board from light rays returning through the light guides after interacting with the said optical patterns.

Abstract: A method of providing a set of alignment marks on a substrate including the following steps. Exposing a first pattern on at least one exposure area of a layer of a substrate, the first pattern comprising a repetitive set of elements having a first element size. Exposing a second pattern on the at least one exposure area on top of the first pattern, the second pattern comprising a repetitive set elements of a second element size, the second element size being larger or smaller than the first element size. The elements of the first and second patterns partly overlap and combined form a set of repetitive large-sized alignment marks, such that the edges of the alignment marks in the direction of repetition are formed by small-sized elements.

Abstract: An angle sensor for detecting an out-of-round condition includes a disc supporting angle coder rigidly attached to a rotating shaft and at least one fixed optical system including a coherent light source emitting a beam interfering with the angle coder of the support disc in order to code its angular position, a collimator of the said beam before interference and a photo detector of the modulated beam after interference. In one embodiment, two optical systems arranged 90° from each other are employed. An alternative embodiment includes one optical system and the disc includes a circular track radially centred in at least one of its angular positions relative to the incident collimated light beam, and a radially orientated photo detector.

Abstract: Optoelectronic position measurement device comprises a code carrier, a radiation source and a detection unit. The code carrier can be moved relative to said sensor unit by one degree of freedom. A refractive optical element having a focusing segment and at least one neighboring segment are arranged between the code carrier and the first sensor unit. Optical radiation shining in on the focusing segment parallel or at an angle of incidence below a threshold angle ? to the optical axis of the focusing segment can be guided by the focusing segment on the receiving region of the first sensor unit within the optical axis, and radiation that is shining into a deflection angle region above the threshold angle ? to the optical axis of the focusing segment can be deflected by the focusing segment and the neighboring segment to a point outside of the optical axis of the focusing segment.

Abstract: A method of effecting a purchasing transaction includes providing a printed form having printed thereon coded data distributed over an area; capturing an image of the form using a sensing device, the captured image showing a portion of the coded data; decoding at least some of the coded data within the captured image; determining from the coded data an identity of the form, a position of the coded data on the form, and a parameter of the purchasing transaction; determining a position of the sensing device relative to the form from a distortion of the captured image and the determined position of the coded data; compiling the identify of the form, the position of the sensing device, and the parameter of the purchasing transaction as indicating data; receiving in a computer system the indicating data; and identifying, in the computer system and from the indicating data, at least one parameter relating to a purchasing transaction.

Abstract: A method for determining the position of one of two components in relative motion with respect to each other, using optical means, comprises: directing at least one light beam emitted by a light source attached to one component towards a diffractive support attached to the second component, calculated and manufactured for generating an optical signal indicative of the positioning of said support, the optical signal being produced by the diffractive support in transmission and/or in reflection, and the optical signal including information indicative of its quality; detecting and reading at least one optical code formed by said signal, which corresponds to a unique position of the diffractive support relatively to the beam; and assigning a position to each detected optical code.

Abstract: A method for absolute position measuring that includes scanning a code having code elements arranged one behind the other in a measuring direction, wherein the code elements include sequential first and second code elements which define a code word containing absolute position information. The method including generating scanning signals within the first code elements and the second code elements. The method further including forming information regarding the sequential first and second code elements from the scanning signals via a reference value and determining the reference value as a function of at least one of the scanning signals within the first code elements and the scanning signals within the second code elements.

Abstract: An encoder position signal processing system comprises an analog encoder reader and a codewheel. The codewheel possesses an optical track that modulates the quadrature encoder signal amplitude in order to generate an amplitude change (home pulse) once per revolution of the codewheel. The analog encoder reader outputs a quadrature signal comprised of sine and cosine signals. The quadrature signal is converted to a magnitude signal that is sampled in order to generate a rate of change (ROC) signal, which increases the signal-to-noise ratio. An algorithm using the characteristic shape of the ROC home pulse signal can then be applied to the ROC signal to increases robustness of detecting the home pulse.

Abstract: A position transducer system is disclosed for a limited rotation motor that includes an illumination source that directs illumination toward an illumination reflector that rotates with a rotor of the limited rotation motor, and a plurality of detector areas adjacent the illumination source for receiving modulated reflected illumination from the illumination reflector.

Abstract: According to one embodiment, there is provided an optical encoder having a photodetector array comprising motion detection photodetectors and at least one reference photodetector vertically offset from the motion detection photodetectors. The output signal generated by the at least one reference photodetectors is employed to correct undesired variations in the amplitudes of the output signals generated by the motion detection photodetectors. Such variations typically arise from various mechanical and optical misalignments in the optical encoder, and are compensated for by using the reference output signal to add to or subtract from, as required, the amplitudes of motion detection output signals.

Abstract: The invention refers to a device for determining the angular position of a compressor stator blade, which is rotatable around its longitudinal axis and arranged in a compressor, with which is associated a measuring surface which rotates synchronously with it. For a reliable, simple and approximately error-free recording of the angular positions, the angular position of the compressor stator blade can be determined via the device in an automated manner. For this purpose, it has at least one mounting unit provided for aligned fastening of the device on the compressor, and at least one measuring and evaluating unit which comprises at least two distance sensors which each record a distance to the measuring surface which is rotatable from the reference position, as a result the angular position of the measuring surface, relative to the reference position depends upon the two recorded distances, is determined by the measuring and evaluating unit.

Abstract: A scanning unit is for scanning a measuring standard having a coded track formed by a graduated scale, such as an incremental track, and a reference mark system, including a detector system for scanning the coded track and an additional detector system for scanning the reference mark system. The detector system, when scanning the associated coded track or reference mark system, receives scanning signals on a signal-sensitive surface, and the additional detector system includes at least two sensors, of which only one is used for scanning the reference mark system during operation of the scanning unit. Each of the two sensors is connected to one of the two inputs of a differential amplifier, and the sensor not used for scanning is deactivated in that its signal-sensitive surface is covered.

Abstract: A scale has a first incremental track with first incremental patterns including first light and dark patterns formed at equal intervals in first periods, an absolute track with absolute patterns representing absolute positions, and a second incremental track with second incremental patterns including second light and dark patterns formed at equal intervals in second periods longer than the first periods. A light source emits a measurement light to the scale. A photodetector receives the measurement light reflected at or transmitted through the scale. A signal processing circuit processes the received light signal of the photodetector to detect an absolute position of the scale.

Abstract: A code disk for a high-resolution encoder that can detect an absolute position and a method for manufacturing a mold to produce the code disk are provided. The code disk is formed by using transparent substrate. The code disk includes a plurality of tracks provided on the transparent substrate and an area provided between the plurality of tracks. Each surface of the plurality of tracks has a different pattern. A level of the area is different from that of the each surface of the plurality of tracks. The method for manufacturing the mold includes steps of processing a plurality of tracks with a flat surface on material; processing an area with a level different from that of each surface, between the plurality of tracks; forming different patterns on the each surface; plating the first material; and peeling plating from the first material to obtain a mold.

Abstract: An optical encoder (100) is provided with: a light-emitting element (30) including a main-signal light-emitting element (31) having a red LED (31A) that emits red light and an origin light-emitting element (32) having an infrared LED (32A) that emits infrared light; and a receiver unit (40) including a main-signal photo detector (41) that receives the red light to generate a predetermined signal and an origin photo detector (42) that receives the infrared light to generate a predetermined signal. Accordingly, even when the infrared light enters the main-signal photo detector (41) or the red light enters the origin photo detector (42), no signal is generated by the light, thereby effectively preventing crosstalk. Thus, the measurement accuracy of the optical encoder (100) can be improved.

Abstract: Methods and systems are disclosed which relate to online purchasing via interface surfaces printed with information and coded data. The coded data, encoded visibly or invisibly, may be queried by an appropriate sensing device. The sensing device communicates with a computer system. Together, the interface surfaces, sensing device and computer system are capable of effecting purchasing transactions over a network.

Abstract: A detection apparatus detecting predetermined positions of a member includes: n (n?2) sensors one-dimensionally disposed at a sensor pitch equal to or greater than a distance D; and a member to be detected having m (2?m?n) parts to be detected, the m parts to be detected being formed in k respective positions (k?nCm) in respective patterns of disposition which are unique with respect to each other.

Abstract: A rotary encoder includes a shaft which serves as a rotation axis, a disc supporting plate fixed to the shaft, an encoder disc having a center hole, a first side face, and a second side face opposing the first side face, an elastic member contacting and pressing the second side face of the encoder disc, and a retaining member retaining the second side face of the encoder disc via the elastic member. The first side face is contacted with a surface of the disc supporting plate. The shaft is inserted into the hole. A belt conveyance apparatus includes an endless belt, a roller configured to rotate the endless belt, including a shaft and the rotary encoder. The rotary encoder is provided on the shaft of the roller. An electrophotographic image forming apparatus includes an image forming unit and the belt conveyance apparatus.

Abstract: An encoder with signal conditioning of an emitter drive signal is described. In one embodiment, the encoder includes a peak comparator, a pulse generator, a threshold comparator, and digital circuitry. The peak comparator outputs a peak comparator signal based on a comparison of an input sinusoidal signal stored at a first time with the input sinusoidal signal stored at a second time. The pulse generator determines a peak of the input sinusoidal signal based on the peak comparator signal. The threshold comparator compares a differential signal amplitude with a differential signal amplitude window at approximately the peak of the input sinusoidal signal. The differential signal amplitude is associated with the input sinusoidal signal. The digital circuitry generates an emitter modification signal in response to a determination that the differential signal amplitude is outside of the differential signal amplitude window.