Abstract: A method and apparatus for measurement of density of a photosensitive printing plate (130) having a mask (132) embodying image information corresponding to an image to be printed. A density measurement system includes a first radiation source (112) spaced apart from and adjacent the plate and configured to emit radiation having a first wavelength or range of wavelengths toward the plate. A densitometer (110) spaced apart from and adjacent the plate in a fixed relationship relative to the first radiation source receives and measures an amount of the first radiation transmitted through or reflected by the plate and the mask during relative movement between the plate and the density measurement system. The densitometer readings are processed to provide an output correlating to quality of the mask. The density measurement system may be coupled to an exposure system (120,122,124) for curing the plate.

Abstract: A method for determining a location relationship between a camera and a headlight of a vehicle includes positioning the vehicle at a distance in front of a surface exhibiting a calibration pattern, ascertaining the distance between the calibration pattern and the vehicle, projecting a pattern onto the surface using a headlight of the vehicle, and detecting characteristic features in the projected pattern. The method further includes performing the previous steps for at least one additional distance between the vehicle and the surface. In addition, the method includes interpolating positions of detected characteristic features that correspond in each case to one another at the different distances using a linear function, determining an intersection of the ascertained linear functions, and determining the location relationship between the camera and the headlight of the vehicle on the basis of the position of the intersection of the ascertained linear functions relative to the camera.

Abstract: A method including printing a calibration pattern with a wide array printhead having a plurality of printhead dies. The method includes scanning the calibration pattern with a scanbar having a width less than a width of the wide array printhead by indexing the scanbar to a plurality of selected positions across a width of the calibration pattern and providing a scanned calibration image at each selected position, the calibration images together providing a scan of the full width of the calibration pattern, and measuring alignment between successive printhead dies based on the calibration images.

Abstract: An apparatus and method for automatically calibrating a media sensor configured to detect advancing print media in a printing device. In some embodiments, the apparatus selects a first light intensity level and a second light intensity level greater than the first light intensity level. A light source unit, such as a light emitting diode or laser diode is activated to emit light at the second light intensity level. The light passes though print media, for example, a roll of self-adhesive labels, that is advanced along a print path of the printing device. The amount of light transmitted through the print media is measured as the print media advances. If the measured light increases, the light source unit is reactivated to emit light at the first light intensity level. In some embodiments, the apparatus identifies whether print media has changed or an out-of-stock condition exists.

Abstract: A system for measuring properties of a thin film coated glass having a light source, a spectrometer, at least one pair of probes, a first optical fiber switch and a second optical fiber switch. The pair of probes includes a first probe located on one side of a glass sheet and a second probe located on the opposite side of the glass sheet, directly across from the first probe. The first and second optical fiber switches are adapted to couple either probe to the light source and/or the spectrometer. Because the design of the system is optically symmetrical, calibration may be performed without the use of a reference material such as a tile or mirror. Each of the first and second probes has a first leg and a second leg that are separated from each other by a distance n so that angled reflections may be detected.

Abstract: A method for checking the soiling of the windows of a measuring apparatus for checking sheet material, includes having at least two sensor rows oriented transversally to the transport direction of the sheet material. Each of the sensor rows detects the light emanating from the sheet material in a certain spectral channel. For checking the soiling of the window the sensor rows detect the light at several detection times at which no sheet material is present in the capture area of the sensor rows. At least two of the spectral channels are combined with each other and the temporal variation of the intensities of the combined spectral channel is evaluated for the purpose of the soiling check. A small temporal variation of the intensity of the combined spectral channel is employed as an indicator for the presence of a soiling of the window.

Abstract: An off-axis telescope having a primary optical element configured to reflect an energy beam from an optical reference source that emits the energy beam along an optical path. The telescope includes angle sensors arranged on a periphery of the primary optical element to determine angular motion of the energy beam from the optical reference source. The angle sensors are operable to be biased to positional settings associated with a desired pointing direction of the energy beam. A secondary optical element is arranged in the optical path and translated along three orthogonal axes. A plurality of steering mirrors arranged between the optical reference source and the secondary optical element is configured to be tilted in response to a control signal. A controller auto-aligns the telescope by at least translating the secondary optical element and tilting the steering mirrors via the control signal using at least inputs from the plurality of angle sensors.

Abstract: The invention relates to a method for calibrating a sensor which is configured for checking value documents. The sensor senses measurement signals of a calibration medium which is transported past the sensor. From the sensed measurement signals there are determined reference data of the calibration medium and there is moreover determined a transport property of the calibration medium, e.g. the transport speed or the transport position of the calibration medium. From the transport property there is ascertained at least one correction value which is employed for correcting the sensed reference data of the calibration medium. After the calibration, the corrected reference data are compared with target data of the calibration medium. Optionally there is then effected an adjustment of the sensor using the corrected reference data.

Abstract: A system for measuring properties of a thin film coated glass having a light source, a spectrometer, at least one pair of probes, a first optical fiber switch and a second optical fiber switch. The pair of probes includes a first probe located on one side of a glass sheet and a second probe located on the opposite side of the glass sheet, directly across from the first probe. The first and second optical fiber switches are adapted to couple either probe to the light source and/or the spectrometer. Because the design of the system is optically symmetrical, calibration may be performed without the use of a reference material such as a tile or mirror.

Abstract: A method and apparatus for exposure correction in scanners are disclosed. In the method, exposure is corrected for pixels received in an image sensor array. Exposure time is tracked for the incoming pixel data and a calibration factor is determined for correcting the gain, and the calibration factor is adjusted based on the tracked exposure time. In the apparatus, a scanner includes an illumination source and a sensor for receiving pixel data. Using values stored in a memory, circuitry is provided for determining a calibration factor, for tracking exposure time for the pixel data and for adjusting the pixel data based on the calibration factor and exposure time.

Abstract: A method and systems for calibrating a document scanner are provided. The scanner calibration method includes providing a geometrically operative black absorption device having a structural geometry that is capable of receiving light and limiting propagation of the received light, where the black calibration target has a total light reflectance of less than one percent. The method further includes powering on a light source of a document scanner to provide light toward the black absorption device, where the light source generates a noise signal when providing the light. The method further includes detecting, by a sensor of the document scanner, light reflected from the black absorption device and generating calibration signals based on the reflected light and the noise signal.

Abstract: A method and system for calibrating a multiple-beam curvature/flatness sensor in order to provide an accurate media curvature/flatness measurement. One or more flat media sheets are passed through a multiple-beam media curvature/flatness sensor and the timing data associated with the lead edge/trail edge crossing each beam associated with the multiple beam curvature/flatness sensor is used for the calibration of the curvature/flatness sensor system. The unknown variables in the media curvature/flatness equation which takes into consideration of the manufacture and assembly errors of the sensor as well as the media deflection due to gravity can be determined and eliminated in order to obtain a calibrated media curvature/flatness equation. The calibrated media curvature/flatness equation can further be applied in the curvature/flatness measurement in order to achieve accurate measurement results.

Abstract: Several methods of calibrating a wavelength-modulation spectroscopy apparatus configured to measure a concentration of an analyte in a sample gas are disclosed. Each of the methods allows for calibration and recalibration using a relatively safe gas regardless of whether the sample gas for which the concentration of the analyte can be determined is a hazardous gas. In one embodiment of the invention, calibration that is sample-gas specific is accomplished by determining a first slope coefficient and calibration function for the sample gas, after which a scaling factor can be determined based on the first slope coefficient and a second slope coefficient for the same or a different sample gas and used in a subsequent calibration (or recalibration) to scale the calibration function. In other embodiments of the invention, calibration that is not sample-gas specific is accomplished to allow for the determination of the analyte concentration in variable gas compositions and constant gas compositions.

Abstract: In a state where a sheet exists, an current I is gradually increased. When an voltage V reaches a light receiving level Vx, the current I at the time is stored as I1. The voltage V immediately before the voltage V reaches the light receiving level Vx is stored as V1. In a state where no sheet exists, the current I is gradually decreased from the above I1. When the voltage V reaches a non-light receiving level Vy, the current I at the time is stored as I2. The voltage V immediately before the voltage V reaches the non-light receiving level Vy is stored as V2. Then, the current I at the time of normal operation is set within a range between I1 and I2. A reference voltage Vs is set within a range between V1 and V2.

Abstract: A light output control device for laser light sources for respective RGB colors includes, for each of RGB, three sets, each including: a semiconductor laser for one of the colors; light output detection unit for detecting a light output from the semiconductor laser; light output adjustment unit for updating a light output target value; light output control unit for controlling the semiconductor laser based on the updated light output target value; and division unit for dividing the light output by an output from the light output adjustment unit to obtain a ratio of the rising of the light output, and includes rising determination unit for determining, based on results obtained by the respective division unit, a semiconductor laser with a slowest rising and outputs light output adjustment values for the respective colors. The light output adjustment unit update their respective light output target values based on the light output adjustment values.

Abstract: A real-time in-situ sensor system is provided for measurement of bioluminescence and determination of bioluminescence surface signature. The system measures bioluminescence in the wake of a submerged moving object as well as ambient light levels outside of the wake. Along with measurements of depth and water-quality parameters including turbidity, temperature and salinity, the surface signature of the induced underwater bioluminescence can be calculated by considering light transmission and attenuation through water. With this real-time information, the operator of the submerged moving object can employ tactical maneuvers to affect the resultant surface signature.

Abstract: Several methods of calibrating a wavelength-modulation spectroscopy apparatus configured to measure a concentration of an analyte in a sample gas are disclosed. Each of the methods allows for calibration and recalibration using a relatively safe gas regardless of whether the sample gas for which the concentration of the analyte can be determined is a hazardous gas. In one embodiment of the invention, calibration that is sample-gas specific is accomplished by determining a first slope coefficient and calibration function for the sample gas, after which a scaling factor can be determined based on the first slope coefficient and a second slope coefficient for the same or a different sample gas and used in a subsequent calibration (or recalibration) to scale the calibration function. In other embodiments of the invention, calibration that is not sample-gas specific is accomplished to allow for the determination of the analyte concentration in variable gas compositions and constant gas compositions.

Abstract: A calibrating apparatus for lens carrier, includes a carrier, a driving unit, a first-dimension detector, and a control unit. The driving unit is capable of moving the carrier in a first-dimension direction. The first-dimension detector is capable of generating a corresponding first-dimension positional signal for the carrier according to a condition of whether detecting the carrier. The control unit is capable of receiving the first-dimension positional signal. The control unit determines whether the driving unit performing a first-predetermined driving operation based on the first-dimension positional signal for the carrier received when starting to calibrate. Finally, a position of the carrier in the first-dimension direction is adjusted based on the first-dimension positional signal for the carrier received after performing the first-predetermined driving operation.

Abstract: Several methods of calibrating a wavelength-modulation spectroscopy apparatus configured to measure a concentration of an analyte in a sample gas are disclosed. Each of the methods allows for calibration and recalibration using a relatively safe gas regardless of whether the sample gas for which the concentration of the analyte can be determined is a hazardous gas. In one embodiment of the invention, calibration that is sample-gas specific is accomplished by determining a first slope coefficient and calibration function for the sample gas, after which a scaling factor can be determined based on the first slope coefficient and a second slope coefficient for the same or a different sample gas and used in a subsequent calibration (or recalibration) to scale the calibration function. In other embodiments of the invention, calibration that is not sample-gas specific is accomplished to allow for the determination of the analyte concentration in variable gas compositions and constant gas compositions.

Abstract: An exemplary aspect of the present disclosure, there is provided a light detection device including a first detecting portion to detect fluorescence from a first detection position on a conveyor path along which a sheet is conveyed, a second detecting portion to detect afterglow from a second detection position on the conveyor path along which the sheet is conveyed, a lighting portion to apply excitation light over a range including the first detection position and not including the second detection position, a first reference member which includes fluorescent material that emits fluorescence by being excited by the lighting portion and which emits reference light toward the first detecting portion, a second reference member to emit reference light toward the second detecting portion when the sheet is present at the second detection position, the reference light not influencing a result of detection by the second detecting portion, and a correction controller to correct a result of detection by the first dete

Abstract: A sheet conveying device includes a conveying unit that conveys a sheet in a sheet conveying direction; a measuring unit that measures a position of a side edge of the sheet in a measurement area; a shielding unit having an end portion that is projected into the measurement area for shielding the sheet; a first determining unit that determines whether the shielding unit is detectable in the measurement area; and a second determining unit that determines whether the measuring unit has been mounted in the sheet conveying device based on a result obtained in the first determining unit.

Abstract: A method for correcting the measuring errors caused by the lens distortion of an objective in a coordinate measuring machine is disclosed. For a plurality of different types of structures, the lens distortion caused by an objective is determined in an image field of the objective. The position of a type of structure is determined in the image field of the objective by a measuring window. The correction of the lens distortion required for the type of structure to be measured is retrieved from the database as a function of the type of structure to be measured.

Abstract: The present invention relates to projection systems. According to one embodiment the system comprises one or more projectors oriented to project an image on a projection screen and one or more image sensors oriented to acquire an image projected on the projection screen. The projector is operated to project a calibration image comprising one or more image fiducials on the image projection screen. The image sensor acquires the projected calibration image including the image fiducials. The respective positions of the image fiducials are identified and the identified fiducial positions are validated by applying a parametric model to compare respective ones of the identified fiducial positions with corresponding approximations of the identified fiducial positions. Corrected fiducial positions are generated when a result of one of the comparisons exceeds an error threshold. Additional embodiments are disclosed and claimed.

Abstract: A non-destructive test structure for printed circuit board characterization and method of testing the same are disclosed. In one form, a method for testing a printed circuit board can include applying a test signal to a first test location of a first test structure associated with a first inner bus layer of a printed circuit board. The method can also include measuring a crosstalk voltage at a second test location operably associated with the first test structure. The method can further include comparing the crosstalk voltage to a crosstalk specification of the printed circuit, board.

Abstract: A device includes a housing, illumination means, a reflective plate, and a detector. The housing defines an aperture. The illumination means is for providing illumination (natural or artificial) along an optical axis that passes through the aperture. The reflective plate is movable, relative to the housing, between a retracted and a deployed position. The positions are defined so that during such movement, the optical axis traces a line across the reflective plate. The detector is aligned to detect illumination from the illumination means after light through the aperture is reflected from the reflective plate. A method is also described. The device is particularly suitable for moving the reflective plate temporarily in front of a pushbroom or whisk broom type sensor for calibration because the line traces across a first portion of the diffusing surface that is subject to sunlight degradation and a second portion that is always shielded from sunlight.

Abstract: Disclosed is a machine direction measurement system having an increased cross direction sampling area (significantly larger than the natural sensor measurement window) to generate a more representative and stable machine direction reading of the process. In effect, the sensor should have as wide a coverage area as possible without having to resort to the expense of measuring the entire width of the sheet.

Abstract: A vision alignment system and method is provided. The vision alignment system includes one or more grouped alignment plates with guiding inserts configured to receive multiple devices, and groups of three actuators, configured to actuate the alignment plates to correct the position offsets of multiple devices as a group. The position offsets between the device and contactor are determined by a device-view camera during runtime and a contactor-view camera during calibration time. The vision alignment system also includes a pick-and-place handler, configured to transport devices.

Abstract: A method for finding holes, and other related defects and measuring characteristics of sheets of industrial material. Optical detections systems are constantly plagued by intense ambient light and challenged in accuracy. The invention exhibits a defect detection method and apparatus that is resistant to intense ambient light and is capable of inspecting sheets of material (410, 510, 610, 710) continuously, without integration of long periods. In the invention, synchronous detection between the optical transmitters and receivers is utilized. The invention is applicable for inspecting and measuring materials like paper, metal, rubber, plastic, aluminum foil, copper foil, film, coated metal sheet or any other sheet-like material that could run on a production line. The invention is also applicable for finding special defects like holes, pinholes, scratches, spots, cracks, edge faults, streaks, surface faults or any other conceivable defects.

Abstract: A device for calibrating a sensor using solar radiation includes a sensor configured to measure electromagnetic radiation received through a field of view (FOV) having a normal line of sight and at least two baffles removably insertable across the FOV of the sensor and inclined to the line of sight. Each baffle has first and second opposing surfaces, with the first surface disposed to face the solar radiation and the second surface disposed to face the sensor. One of the first or second surface is configured as a diffused surface, and the other of the first or second surface is configured as a specular surface.

Abstract: Disclosed is a method and system for calibrating an image capturing sensor. The method and system include generating a test pattern on an image receiving device and measuring one or more colorimetric properties of the test pattern with an image sensor. The disclosed method and system measure the test pattern with the image sensor located in two or more different cross-process positions to determine an independent uniformity profile for the image sensor and the image rendering process.

Abstract: A method for calibrating an illumination system is disclosed herein. The illumination system comprises at least one light emitter and at least one color sensor. The method comprises emitting a first wavelength of light from the a light emitter and measuring the color of light emitted by the light emitter using the color sensors. A second wavelength of light is emitted from the a light emitter and the color of light emitted by the light emitter is measured using the color sensors. The shift in color space based on the measurements is calculated. At least one calibration matrix based on the shift in colors space is calculated.

Abstract: Disclosed is a method and system for calibrating an image capturing sensor. The method and system include generating a test pattern on an image receiving device and measuring one or more colorimetric properties of the test pattern with an image sensor. The disclosed method and system measure the test pattern with the image sensor located in two or more different cross-process positions to determine an independent uniformity profile for the image sensor and the image rendering process.

Abstract: A first grating is placed on the upper surface of wafer stage WST, and on the +Y side of the first grating, a calibration area is arranged where an auxiliary grating is formed. By performing a predetermined calibration process using the calibration area, such as calibration process related to position measurement of the wafer stage using a head and the like of an encoder, it becomes possible to perform position control of the wafer stage in the predetermined direction with good precision using the encoder after the calibration process.

Abstract: An enhanced toner area coverage (ETAC) sensor may be calibrated to adjust for changes in LED intensity by determining a functional relationship between specular developed mass per unit area (DMA) values and diffuse readings obtained from the sensor. Specular and diffuse readings are obtained from an ETAC sensor that senses reflected light from toner patches generated with incrementally increasing densities on the photoreceptor belt. The specular readings in a particular range and their corresponding diffuse readings are selected for the calibration computations. Reflected ratios are computed from the specular readings and used to determine specular DMAs. The specular DMAs and selected diffuse readings define a set of points for which a functional relationship is determined.

Abstract: The present disclosure relates to phase-sensitive calibration of an SLM system. In particular, it relates to selecting among local calibrations when there is more than one calibration that satisfies a calibration intensity criteria. It utilizes information available before Fourier filtering, from non-zeroth order diffraction components to counter drift among alternative local calibrations.

Abstract: A measuring optical system for emitting and receiving light is fixedly installed in a ceiling portion of a measuring device, and a wafer holding part for supporting a semiconductor wafer is provided in a bottom portion of the measuring device. A support table is horizontally laid between support pins of the wafer holding part, and a calibration standard member for calibration is placed on an upper surface of the support table. When a semiconductor wafer is supported by the support pins, light emerging from the measuring optical system impinges upon the semiconductor wafer, and the reflection intensity of the light is measured. When no semiconductor wafer is supported by the support pins, light emerging from the measuring optical system impinges upon the calibration standard member, whereby the calibration can be done at any time.

Abstract: A trackball in one embodiment includes a PCB including an aperture, a socket including upper and lower chambers communicated with each other, rollers disposed around bottom of the upper chamber, a ball rotatably supported by the rollers, a ring cover secured to the socket, a light guide plate mounted between the socket and the PCB and including an inclined light guide tube and an optical element; and an optical assembly mounted under the aperture and including a light source (e.g., LED) for emitting light through the light guide tube prior to impinging on the ball, and a photosensor. Rolling the ball will reflect the light from the ball through the optical element to be received by the photosensor such that the rotational movement of the ball can convert into a digital signal useable to move a cursor a corresponding distance and direction on a display.

Abstract: A method for calibrating a laser three-dimensional digitizing sensor. First, a three-dimensional coordinator X-Y-Z is defined and a calibrating surface is provided. Second, a first mapping table of a two-dimensional digital image to the Z axis is established by translating the calibrating surface along the Z axis. Subsequently, the calibrating surface rotates along the Y axis by a predetermined angle and translates along the Z axis to establish the second mapping table of the two-dimensional digital image and the X axis according to the first mapping table.

Abstract: Techniques for determining wafer stage grid and yaw in a projection imaging tool are described. The techniques include exposing an overlay reticle onto a substrate having a recording media, thereby creating a plurality of printed fields on the substrate. The overlay reticle is then positioned such that when the reticle is exposed again completed alignment attributes are created in at least two sites in a first and a second printed field. The substrate is then rotated relative to the reticle by a desired amount. The overlay reticle is then positioned such that when the reticle is again exposed, completed alignment attributes are created in at least two sites in the first and a third printed field. Measurements of the complementary alignment attribute and a dynamic intra-field lens distortion are then used to reconstruct wafer stage grid and yaw error of the projection imaging system.

Abstract: Systems and methods provide calibration for a linear array sensor. A test pattern having a plurality of lines is used. Comparison between expected and measured spacing between a pair of neighboring lines is used to determine sensor position displacement.

Abstract: Aspects of the present disclosure include systems and methods for indicating an amount of use of a pulse oximetry sensor. According to one embodiment, the system includes an oximeter that monitors the amount of use for a given sensor. The oximeter and/or the sensor may advantageously include a visual alarm, an audio alarm, a vibrational alarm, a power down function, or the like, which can be activated when a predetermined amount of use has expired. According to another embodiment, the system includes a sensor having a memory device storing a unique identifier.

Abstract: Systems and methods provide calibration for a linear array sensor. A test pattern having a plurality of lines is used. Comparison between expected and measured spacing between a pair of neighboring lines is used to determine sensor position displacement.

Abstract: A system for measuring radiation at a peak wavelength that is radiated from a probe tip of a near-field scanning optical microscope (NSOM) probe used for laser machining, including: a laser source; the NSOM probe; a coupling substrate that is substantially transmissive to the peak wavelength; an NSOM mount to controllably hold the probe and the coupling substrate; an NSOM probe monitor coupled to the mount; an NSOM controller; and a photodetector optically coupled to the substrate. Light is coupled into the probe. The mount includes a Z motion stage. The probe monitor determines the distance between the probe tip and the coupling substrate. The controller is coupled to the probe monitor and the motion stage. It controls the distance between the probe tip and the coupling substrate such that radiation is coupled from the probe tip into the coupling substrate. The photodetector measures the power of this radiation.

Abstract: A calibration pattern unit which obtains correction information of an imaging system by imaging at the imaging system is formed by combining a plurality of three-dimensionally arranged planes. The calibration pattern unit comprises supporting members each of which has a predetermined surface corresponding to one of the planes, and a calibration pattern in which a predetermined pattern is formed on the predetermined surface of the supporting member. The supporting member can selectively set the calibration pattern unit to a first form for photographing when the correction information is obtained, and a second form for other purposes.

Abstract: A focal plane detector adapted to be calibrated using an image of part of the human body. Further, a method of calibrating a focal plane detector having a plurality of detector elements, comprising the steps of presenting a first and a second image to the focal plane detector array, measuring the output from each detector during each first and second image, analysing the outputs and compensating for errors in the output of each detector element such that the outputs from the detector elements are substantially equal when illuminated with electromagnetic radiation of a given intensity. The first and second images have substantially no discernible features therein, and one of the first and second images comprises an image of part of the human body. The apparatus and method are particularly applicable to focal plane detectors sensitive to infrared radiation.

Abstract: A positioning structure of plane image input apparatus comprises a hollow body, carrying scanned documents and setting a correct picture on outer and inner opposite sides, and an optical module inside the body moving back and forth. The optical module has a correct light source to emit light, a correct hole for reflect light passing through and propagating to the optical module, a guiding mirror set to guide light, and a charge couple device to receive light. The correct light source and the correct hole are respect to the correct picture side of the body. After reflected by the correct picture, light passes the correct hole, to the optical module and is guided by the guiding mirror set to the charge couple device for the optical module to correct color rank and to position. Thus, the positioning structure improves accuracy of correcting color rank and positioning of the correct picture.

Abstract: A processing apparatus calculates and applies calibrations to sensors that produce quasi-sinusoidal, quadrature signals, using fixed or programmable electronic circuits, a circuit to calculate the phase and magnitude corresponding to the two input (quadrature) signals, and a circuit for accumulating the number of cycles of the input signals. The apparatus also includes a circuit to generate Gain, Offset, and Phase calibration coefficients by comparing a phase space position of a measured phasor with the position of an idealized phasor whose locus in phase space is a circle of predetermined radius with no offset. The calculation of the coefficients occurs without user intervention, according to a pre-programmed rule or rules. The apparatus also includes a circuit to apply the Gain, Offset, and Phase calibration coefficients to the measured quadrature signals xi and yi according to predetermined formulae using scaling coefficients, offset coefficients and a phase coefficient.

Abstract: A scanner and calibration method use therein. Setting first exposure duration and a second exposure duration for a transparency, wherein the first exposure duration is proportional to the second exposure duration. Scanning the transparency and a calibration area to produce a scan signal and a calibration signal, respectively, wherein the exposure duration for scanning the transparency is referred to as the first exposure duration, and the exposure duration for scanning the calibration area is referred to as the second exposure duration. Calculating a first gain coefficient according to the calibration signal. Calculating a second gain coefficient according to the first gain coefficient and a specific ratio of the first exposure duration to the second exposure duration, and finally, amplifying the scan signal by the second gain coefficient.

Abstract: The present invention is a method of optical tracking sensing using block matching to determine relative motion. The method includes three distinct means of compensating for non-uniform illumination: (1) a one-time calibration technique, (2) a real-time adaptive calibration technique, and (3) several alternative filtering methods. The system also includes a means of generating a prediction of the displacement of the sampled frame as compared to the reference frame. Finally, the method includes three cumulative checks to ensure that the correlation of the measured displacement vectors is good: (1) ensuring that “runner-up” matches are near the best match, (2) confirming that the predicted displacement is close to the measured displacement, and (3) block matching with a second reference frame.

Abstract: Method for shading an optical sensing element of an optical sensor. Reference values are sequentially obtained of the output signal of the sensing element while relatively moving the optical sensor including the sensing element over a shading reference target. An edge detection filter is applied to each of the reference values obtained in step a) in determining if each of the reference values is or is not from an optical defect on the shading calibration strip. An average is calculated of the reference values obtained while excluding each of the reference values determined to be from any optical defect in calculating the average. The output signal of the sensing element is calibrated to the shading reference target using at least the calculated average.

Abstract: A print head for use in a wire dot printer has a plurality of wires, an armature connected to each of the wires, a core of a magnetic circuit which is disposed in opposing relation to the armature, a resilient member for biasing the armature in a direction in which it is separated from the core, and a rear case disposed so as to cover the upper side of the armature. Each of the wires is driven by the action of the armature which is attracted toward the core when a coil wound on the core is energized. The print head is provided with an armature guide having a resilient stopper disposed between each armature and the rear case to support the armature against the biasing force from the resilient member. Thus, it is possible to support each armature inserted into the armature guide by means of the stopper even more stably during an assembling step carried out before the rear case is mounted. Accordingly, the assembling operation is simplified and facilitated.