Abstract: A device for monitoring a shaft coupling coupling a first shaft to a second shaft includes an optical unit having a receiving element to receive electromagnetic radiation. A modifying unit modifies a radiant energy impinging on the receiving element as the first shaft runs asynchronously with respect to the second shaft. The modifying unit includes a holographic optical component designed for arrangement on and/or within the first shaft, and a diaphragm designed for arrangement on and/or within the second shaft and including radially arranged slots and radially arranged filled regions in an at least substantially regular sequence. The diaphragm includes an at least substantially centrally arranged opening. The holographic optical component is designed for illumination or irradiation with the electromagnetic radiation and generates a pattern having radially arranged areas with a first radiant energy and radially arranged areas with a second radiant energy in an at least substantially regular sequence.

Abstract: Examples described herein relate to a method for synchronizing a wavelength of light in an optical device. In some examples, a heater voltage may be predicted for a heater disposed adjacent to the optical device in a photonic chip. The predicted heater voltage may be applied to the heater to cause a change in the wavelength of the light inside the optical device. In response to applying the heater voltage, an optical power inside the optical device may be measured. Further, a check may be performed to determine whether the measured optical power is a peak optical power. If it is determined that measured optical power is the peak optical power, the application of the predicted heater voltage to the heater may be continued.

Abstract: An encoder abnormality diagnosis device configured to diagnose an abnormality in an encoder that outputs a cosine waveform and a sine waveform according to a rotation angle of an object includes a stop determination processing unit configured to determine whether the object is rotating or stopping, based on a change in a count value of a pulse signal obtained by pulsing of each of the cosine waveform and the sine waveform, a frequency measurement unit configured to measure a frequency of the pulse signal, and a frequency diagnosis unit configured to compare the frequency measured by the frequency measurement unit with a preset upper limit frequency when the stop determination processing unit determines that the object is stopping, and to determine that an abnormality has occurred in the encoder when the measured frequency exceeds the upper limit frequency.

Abstract: A structured light pattern comprising at least two sub-patterns in the direction of motion are projected onto an object during in-line inspection. Images of the object are captured for each sub-pattern. The sub-patterns are used to establish correspondence and to construct a profile using dense per pixel camera-projection correspondence.

Abstract: Measurement method where a code projection which is dependent on a three-dimensional position of a code carrier relative to a sensor arrangement is generated on a sensor arrangement, and at least part of the code projection is captured. An angular position of the code carrier with reference to the defined axis of rotation is ascertained and a current measurement position of the measurement component relative to a base is determined, wherein, a position value for at least one further degree of freedom of the code carrier relative to the sensor arrangement is ascertained on the basis of the code projection and is taken into account to determine the current measurement position, and a relative position of the connecting element with respect to the holder and/or the deformation thereof is determined from the position value in the form of a change in shape or size.

Abstract: A prism spectrometer having higher resolution and wider spectral width through the use of a speckle generating diffuser.

Abstract: Disclosed are an encoder signal sampling method and device. According to the method and device, a data frequency of the encoder is obtained, a clock frequency is determined according to the data frequency, a high-frequency clock signal is generated based on the clock frequency, an input signal of the encoder is sampled based on the high-frequency clock signal to obtain a sampled signal, and finally denoising processing is performed on the sampled signal based on a preset algorithm by a processer.

Abstract: A pulse signal generator suitable for generating a two-phase pulse signal required as information of a rotation angle of a motor from a motor control device is provided. According to an embodiment, the pulse signal generator includes: a compensation unit that outputs a compensation signal for compensating for the deviation between the angle information representing the rotation angle of the rotor provided in the resolver and the fed back angle information; a counter pulse output unit that outputs a counter pulse having a frequency corresponding to the compensation amount of the compensation signal and code information representing the sign of the compensation signal, and a pulse processing unit that outputs a count value by a counter as the angle information, which counts the pulse according to the code information, the pulse processing unit generating two-phase pulse signals PA and PB using the values of the counter.

Abstract: Disclosed is a method and device for target sequence identification, wherein an optical binary sequence and an all-zero sequence are subjected to an XNOR operation and a first candidate sequence set is generated by splitting the result sequence; a second candidate sequence set is generated by splitting the optical binary sequence; multiple binary sequences are selected from the first candidate sequence set and the second candidate sequence set according to the target sequence to generate a to-be-delayed sequence set; various delay duration are configured for each binary sequence of the to-be-delayed sequence set; a to-be-matched sequence set is generated after delaying; an AND operation is performed on the sequences of the to-be-matched sequence set to generate a final sequence; and the number and position of the target sequence in the binary sequence can be determined according to the number and position of a pulse in the final sequence.

Abstract: An instant correction method for an encoder includes the following steps. The motion of a device under test is sensed to obtain a first wave signal and a second wave signal. The first and second wave signals are sampled to generate N first digital signal values and N second digital signal values. N positioning positions are generated according to the N first and second digital signal values, and the N positioning positions are added to a calculation group. A regression analysis is performed for the calculation group to generate a regression curve. The (N+1)-th prediction position is predicted using the regression curve. The ideal position of the device under test is determined at a time point of the (N+1)-th prediction position according to an ideal position curve. An error value between the (N+1)-th prediction position and the ideal position is applied to correct the device under test.

Abstract: A method for producing round stock (10) which is provided with at least one inscription and/or marking (16), at least the surface (12) of the round stock (10) consisting of a metallic material, in particular of chromium or steel, for example of hardened steel, chromium-plated steel or stainless steel.

Abstract: Embodiments of the present invention provide a signal transmission method. The method includes: sequentially rotating phases of to-be-sent signals on a line set 1 by different angles and in relative to phases of to-be-sent signals on a line set 2, and sequentially sending, to a user side, the to-be-sent signals whose phases are rotated. The method also includes receiving a rotation factor that is of a high-quality received signal on the line set 1 and that is fed back by the user side, where the high-quality received signal includes a received signal with a high signal-to-noise ratio or high power. The method also includes using the rotation factor fed back by the user side as a fixed rotation factor, and rotating, according to the fixed rotation factor, a phase of a signal to be subsequently sent on the line set 1.

Abstract: A sensor system is disclosed. The sensor system includes a first sensor path comprising a first sensing element and a second sensing element being connected in series between a first supply terminal and a second supply terminal and an intermediate node connected in between the first supply terminal and the second supply terminal, a second sensor path comprising a third sensing element and a fourth sensing element connected in series between the first supply terminal and the second supply terminal, a first reference node connected in between the first supply terminal and the second supply terminal, and a second reference node connected in between the first supply terminal and the second supply terminal, and a processing unit to receive an input signal from the intermediate node, a first reference signal from the first reference node, and a second reference signal from the second reference node.

Abstract: A user interface device for a saw is mounted to an exterior of a housing in the saw. The user interface device includes a light emitting diode (LED) mounted on a printed circuit board (PCB), an antenna formed on the PCB, an optically opaque member with a first opening and a second opening, the first opening aligned with the LED, an optically translucent member engaging the second opening of the optically opaque member, and a base member connected to the PCB, optically opaque member, and optically translucent member, the base member being configured to be mounted to an exterior of a housing of the saw.

Abstract: Apparatus for increasing resolution of cryogenically cooled vacuum-sealed infrared imaging detector. A two-dimensional detector array of photosensitive pixels is successively exposed to an image scene, acquiring multiple imaging samples. A masking filter, disposed between the detector array and image scene focal plane, is maintained at a fixed position with respect to the detector array, and reduces the region of pixels collecting incident radiation for each imaging sample such that only a portion of each pixel area of the image scene is imaged onto the corresponding detector array pixel. Shifting means successively shifts the optical path of the image scene relative to the masking filter, by a shifting increment or fill-factor reduction amount equal to a fraction of the array pixel width, to image different sub-pixel regions in each imaging sample. A processor reconstructs an image frame having a resolution greater than the intrinsic detector resolution by the fill-factor reduction amount.

Abstract: Provided are an absolute position measurement method, an absolute position measurement apparatus, and a scale. The scale includes a scale pattern formed by replacing repeatedly arranged pseudo-random-codes with a sequence of a linear feedback shift register of N stages using a first symbol with first width representing a first state and a second symbol with second width representing a second state. The first is divided into two or more first symbol areas of different structures, and the second symbol is divided into two or more second symbol areas of different structures. There is at least one overlap area in which the first symbol and the second symbol overlap each other to have the same structure.

Abstract: A new framework for video compressed sensing models the evolution of the image frames of a video sequence as a linear dynamical system (LDS). This reduces the video recovery problem to first estimating the model parameters of the LDS from compressive measurements, from which the image frames are then reconstructed. We exploit the low-dimensional dynamic parameters (state sequence) and high-dimensional static parameters (observation matrix) of the LDS to devise a novel compressive measurement strategy that measures only the dynamic part of the scene at each instant and accumulates measurements over time to estimate the static parameters. This enables us to lower the compressive measurement rate considerably yet obtain video recovery at a high frame rate that is in fact inversely proportional to the length of the video sequence. This property makes our framework well-suited for high-speed video capture and other applications.

Abstract: Provided is a position detection device including a detection unit configured to have a photo-reflector including a light emitter and a light receiver, the light receiver receiving light emitted from the light emitter and reflected by a reflective surface moved in a predetermined direction, the detection unit detecting a movement amount of the reflective surface based on a change in intensity of the received light, and a transparent member configured to be disposed between the reflective surface and the detection unit and to move together with the reflective surface, the transparent member being provided with a light blocking surface configured to block light and a light transmitting surface configured to transmit light, the light blocking surface and the light transmitting surface being arranged in a moving direction of the reflective surface.

Abstract: The disclosure discloses an information processing method for an electronic device with a touch screen. The method includes: touch with a touch screen is detected; an information pickup area is set on the touch screen according to the touch; and information in the information pickup area is picked up according to an information pickup command and the picked-up information is stored. In the disclosure, existing information, such as an image or a signature, is picked up via an information processing device, such as a stylus, on a touch screen of an electronic device; and a user can autonomously control its image, signature and other information to display on the touch screen of the electronic device when needed. Therefore, great convenience is brought to users using a portable electronic device such as a tablet PC and a smart phone, and their personalized application can also be met to a great extent.

Abstract: An encoder includes a scale that includes a pattern row, a detector array, and a signal processor. The pattern row has a plurality of different modulation periods in the moving direction, an amplitude of the energy distribution in the pattern having at least one modulation period being configured to change with a position of the scale in the moving direction. The signal processor acquirers an amplitude of an energy distribution of a corresponding modulation period based on an output signal from the detector array, and an amplitude signal obtained by normalizing a plurality of amplitudes obtained by the plurality of amplitude acquirers, the amplitude signal serving as a position signal representative of the position of the scale.

Abstract: A linear position measuring system (10) and a method for determining a position of a carriage in relation to a slide rail (12), with an incremental scale (14) placed along the slide rail (12) and a scanner secured to the slide scale. The scanner is designed to scan a plurality of incremental markings along the incremental scale (14), wherein the incremental markings can be scanned as an essentially analog signal progression. The scanner is designed to scan the incremental markings with a variable scanning frequency. The scanning frequency can be adaptively varied in relation to a currently acquired frequency of the analog signal progression, wherein the variable scanning frequency measures at least twice the currently acquired frequency of the analog signal progression.

Abstract: A position detection encoder includes a scale and a detection head and has position detection circuits which are capable of outputting respective pieces of position information on Xf, Xs two tracks. The displacement detection encoder includes: a speed detection circuit which is provided in the detection head and detects a relative speed Xf, Xs relative to the scale; and a delay generation circuit which provides a time difference between two output request signals, the time difference being provided on the basis of a fine adjustment time tadj based on the relative speed Xf, Xs and the respective pieces of position information Xf, Xs on the two tracks, the output request signals St1, St2 urging the first and second position detection circuits to output the pieces of position information on Xf, Xs the two tracks.

Abstract: A scanning device for a position encoder is provided that comprises a plurality of sensor elements for generating a plurality of sensor signals. A summation unit is also provided for generating at least a first summation signal and a second summation signal that provide information on the relative alignment of the scanning device and an associated scale. The first summation signal is generated from a first subset of the plurality of sensor signals and the second summation signal is generated from a second subset of the plurality of sensor signals. The plurality of sensor elements are substantially evenly spaced apart from one another N and sensor elements are provided per period of an associated scale, wherein N is an integer value and a multiple of three and four. In this manner, the third harmonic contribution to the summation signals is suppressed.

Abstract: The encoder includes a scale including first and second periodic patterns, and a detector relatively movable with respect to the scale and whose detection state is switchable between a first detection state to read the first periodic pattern and output a first signal and a second detection state to read the second periodic pattern and output a second signal. A processor performs a first process to detect a first absolute position by using the first and second signals and then performs a second process to calculate a relative movement amount by using a specific signal that is one of the first and second signals and detect a second absolute position by using the relative movement amount and the first absolute position. The specific signal is obtained from the detector set in a same detection state as that set last in the first process.

Abstract: A signal output unit generates an A phase output signal of a rectangular wave and a B phase output signal of a rectangular wave from the A phase sinusoidal wave signal and the B phase sinusoidal wave signal, respectively and outputs the generated signals. An internal signal generating unit (comparator) generates an A phase internal signal of a rectangular wave and a B phase internal signal of a rectangular wave from the A phase sinusoidal wave signal and the B phase sinusoidal wave signal, respectively, which are further processed by counters, and an abnormality detector. Each counter resets in response to a pulse edge of a signal for detection. The abnormality detector detects an abnormality when the count value of at least one of counters reaches a prescribed value.

Abstract: An aspect of one embodiment, there is provided a signal processor includes an AD-convertor outputting a conversion result and a conversion end flag, a second comparator configured to compare signal levels, a channel selection signal generation unit to select an input channel to input the AD-convertor, an direction identification flag generation unit to generate an direction identification flag, an edge signal generation unit to generate rising edges and lowering edges, an up-down counter to subject to be up or down on a count value in an output of each of edge signals, and an arithmetic processing unit to interlink the count value of the up-down counter and the conversion result of the AD-convertor to generate output data, wherein the arithmetic processing unit interpolates the count value of the up-down counter in the interlinking by using a correction value corresponding to a value of the direction identification flag in a period between an output of the edge signal and an output of the conversion end flag.

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: Method for working out the angular position of a rotating element, using at least one light source emitting a light beam in the direction of a fixed sensor and computing elements for processing an output signal of the sensor, includes: arranging the light source with respect to the rotating element and the sensor so as to induce an interaction between the light beam and the sensor which depends on the angular position of the rotating shaft, arranging on the path of the light beam, in a fixed position with respect to the sensor, a perforated mask which presents a repetitive pattern of perforations, detecting shadows generated by the mask on the sensor, processing the output signal of the sensor for determining the position of the shadows on the sensor, and computing the angular position of the rotating element using the position of the shadows.

Abstract: An optical encoder includes: an optical scale having periodical optical patterns and can be relatively and angularly displaced; a projector for irradiating the optical scale with light; a light receiver for receiving light from the optical scale; and a calculator for calculating an absolute rotation angle ? of the optical scale in accordance with a signal from the light receiver. The optical patterns include a plurality of light shielding portions and a plurality of light transmitting portions, each of the portions being located alternately.

Abstract: An absolute rotary encoder comprises a scale having marks arranged at a first pitch; a first detector and a second detector including plural photoelectric conversion elements arranged at a second pitch smaller than the first pitch, and configured to detect a predetermined number of marks, the second detector disposed opposite to the first detector; and a computing device. The computing device is configured to generate a data string by quantizing a periodic signal output from the first detector, and obtains first angle data from the data string, to normalize amplitudes of the periodic signals output from the first and second detectors, to average the normalized periodic signal to obtain second angle data from a phase of the averaged periodic signal, and to combine the first and second angle data to generate data representing an absolute rotation angle.

Abstract: Disclosed are various embodiments of circuitry and methods for generating interpolated signals in an optical encoder. The optical encoder configurations and circuitry disclosed herein permit very high resolution reflective optical encoders in small packages to be provided. Methods of making and using such optical encoders are also disclosed. According to one embodiment, the interpolated signals are generated through the use of signal generation circuitry, peak voltage generation circuitry, reference voltage generation circuitry, slope detection circuitry, and a clocked comparator that is configured to output interpolated output pulses.

Abstract: A position encoder kit, including: a scale comprising a series of position features; and a readhead. The readhead includes a detector for receiving configuration information from a configuration item. The readhead is configured to operate in accordance with the configuration information. The readhead also includes a receiver interface via which the readhead can supply position information to a receiver.

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: This invention provides a phase detector with more than two detector units on a printed circuit layer. A detector set includes a pair of detector units or one detector unit, and a detector row includes a plurality of detector sets in one line. The phase detector includes a plurality of detector rows and each row has a detector set in one period, wherein all detector units are interleaved to have the same interval between any two adjacent detector units, which is defined as a pitch and the pitch is equal to one period dividing the detector pair number, which is the half sum of the number of one detector set for all rows.

Abstract: Methods and apparatus are provided for a control device and control device operation. In one embodiment a control device includes a slider configured to support a control knob, a rack coupled to the slider and configured to linearly displace the slider. The rack including slots. The control device may further include a drive element configured to displace the rack and position the control knob, and an optical detection module configured to detect position of the control knob based on one or more optical signals detected relative to slots of the rack. According to another embodiment, a control console is provided including control devices.

Abstract: Provided is a rotation detection device that detects a rotational direction and amount of a rotatable operation member. The detection device manages to reduce the rotation detection pitch while maintaining sufficient clearance for a rotation detection switch to operate. In other words, sufficient distance is given between rotation detection members such that the switch can accurately detect the movement from one member to the next. The rotatable operation member generally includes a plurality of switch driving sections that rotate in unison. A rotation detection switch generally includes a portion that moves in a first and second direction opposite to each other when coming into contact with the rotatable operation members, and is configured to output a detection signal at each movement. The switch and rotatable operation members are configured so that the movement direction of the detector is in a direction orthogonal to the circumferential direction of rotation.

Abstract: An optical encoder comprising a set of light sources configured to emit light rays in a serial manner, an encoded scale configured to reflect at least a portion of the emitted light rays, and a photodetector, where the photodetector is configured to detect at least a portion of the reflected light rays and to generate signals based on the detected light rays for each of the light sources.

Abstract: Disclosed herein is a position detection apparatus including: a signal line along which a bit array including a plurality of bits used for expressing information on one of absolute positions in a direction determined in advance is created repeatedly in the direction determined in advance; and an information reading-out section which is capable of making a movement relative to the signal line in the direction determined in advance in accordance with a driving operation carried out by driving means determined in advance and is used for reading out the information expressed by the bits from the signal line.

Abstract: An encoder detects a relative displacement between an encoder scale and an encoder head. The encoder head incorporates a light source, a light-receiving element to receive light from the light source via the encoder scale, and a signal-processing circuit to process an electrical signal from the light-receiving element. The encoder has a signal detection unit, a signal discrimination unit, and a switching unit. The signal detection unit is activated selectively in accordance with setting. When activated, the signal detection unit detects one or more signals having an almost sinusoidal waveform from the encoder head. The signal discrimination unit is activated selectively in accordance with setting. When activated, the signal discrimination unit determines the waveform of one or more signals having an almost sinusoidal waveform from the signal detection unit. The switching unit switches the current to be supplied to the light source to one of various magnitudes.

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: An encoder signal processing circuit is connected to encoder heads outputting an encoder signal in accordance with a relative displacement with respect to a corresponding scale in such a way that signals can be transmitted to and received from the encoder heads, and processes encoder signals from the encoder heads. The circuit includes a processing unit and a processing decision unit. The processing unit generates displacement information from the encoder signal. The processing decision unit decides at least one of content of processing for the encoder heads and content of processing on encoder signals read from the encoder heads after starting to read an encoder signal from one of the encoder heads.

Abstract: An linear encoder includes: a scale; a light-emitting element that emits light onto the scale; a detecting head that has a light-receiving element that receives the light emitted by the light-emitting element to be reflected or transmitted by the scale; and a connector connected to the detecting head via a cable. The connector comprises a display that displays a status of the light received by the light-receiving element and a connector controller that controls the display. The connector controller includes a display controller that controls the display in accordance with the intensity of the light received by the light-receiving element.

Abstract: A rotary encoder includes two first detection units disposed at positions that are symmetrical about a rotation axis, each of the first detection units outputting an incremental signal, and second detection unit that outputs an absolute signal ?A. The rotary encoder includes a storage unit that stores a plurality of formulas for correcting errors of the incremental signals, the formulas being different from each other in accordance with the signal ?A, and the errors being generated due to eccentricity; a calculation unit that calculates a corrected phase ?I by performing operation on the incremental signals by using one of the formulas corresponding to the signal ?A; and a generation unit that generates a rotation angle of the scale on the basis of the phase ?I and the signal ?A.

Abstract: A scale of a photoelectric encoder includes a base member which is conductive and has a light reflection surface, and light absorptive black gratings which are arranged at a prescribed pitch on the base member.

Abstract: An optical sensing device includes a shell, at least one light emitting member, a rotator type shading member and at least one optical sensing member. The shell is formed with a black-body condition space having a light emitting chamber, a shading chamber and at least one optical sensing chamber. The light emitting member projects a light beam. The rotator type shading member is rotatably restrained within the shading chamber, and has a geometric center and a weight center offset from the geometric center. When the optical sensing device is lifted in a lifting azimuth or lowered in a lowering azimuth, the rotator type shading member is rotated by the geometric center to make the weight center located in the lowering azimuth with respect to the geometric center. The optical sensing member is arranged in the optical sensing chamber, and senses the light beam to accordingly send out a sensing signal.

Abstract: A photoelectric encoder has a scale in which a main track for detecting an amount of movement is formed in a measuring direction. The photoelectric encoder includes an origin signal generating portion provided at a part of the main track in a direction orthogonal to the measuring direction. Thereby, change in a light receiving signal due to passage of the origin signal generating portion is detected to generate an origin signal. Thus, the origin signal which is in agreement with a main signal in phase is obtained and improve the reproducibility of an origin position.

Abstract: Disclosed are various embodiments of a single track reflective optical encoder featuring current amplifiers disposed in the signal generating circuit thereof. Voltage amplifiers and their associated feedback resistors are eliminated in the various embodiments disclosed herein, resulting in decreased die size and improved encoder signal accuracy and performance, especially at high speeds The single track optical encoder configurations disclosed herein permit very high resolution reflective optical encoders in small packages to be provided. Methods of making and using such optical encoders are also disclosed.

Abstract: A photoelectric encoder includes: a scale having a grating formed with a predetermined period Ps; and a detector head being movable relative to the scale and including a light source and a light receiving unit. In a configuration where light receiving elements in the light receiving unit output N-points light and dark signals (N is an integer of 3 or more), and where phases of the N-points light and dark signals are detected by a least-squares method to fit a sinusoidal function with fixed period to N-points digital signals digitized from the N-points light and dark signals, an N-points light and dark signal period P is set at an integral multiple of a data-point interval w of the N-points digital signals, and an overall length M of the light receiving elements is set at an integral multiple of the N-points light and dark signal period P. Thereby, position detecting errors occurring due to a stain of the scale and/or a defect in the grating can be reduced by simple computing.

Abstract: A mobile device having an internal printer is disclosed. A media path is provided for receiving a print medium and a media drive mechanism transport the print medium along the media path past a printhead of the printer. An optical sensor and two separate optical pathways are also provided. The first optical pathway allows the optical sensor to image a surface of the print medium in the media path. The second optical pathway allows the optical sensor to image an area external to the mobile device.