Abstract: A guided projectile including a precision guidance munition assembly utilizes at least one maneuver envelope to optimally control movement of at least one canard to steer the guided projectile during flight. The maneuver envelopes optimize movements of the at least one canard that effectuate movement in either the range direction or the cross-range direction, or both. The maneuver envelope enables optimal timing such that maneuvering in one direction does not come at the expense of maneuver authority in the other direction.

Abstract: A tandem sub for a perforating gun system includes a tubular housing including a longitudinal first end, a longitudinal second end opposite the first end, a central passage defined by an inner surface, an electrical pass-thru assembly including an electrically conductive signal bar having a longitudinal first end defining a first electrical contact of the tandem sub, and a longitudinal second end opposite the first end and defining a second electrical contact of the tandem sub that is longitudinally opposite and electrically connected to the first electrical contact, wherein the signal bar is rigid along the entire longitudinal length thereof extending from the first end to the second end, and wherein the signal bar is coupled to the housing and a central axis of the central passage of the housing intersects the signal bar.

Abstract: A powder compaction device is disclosed. The device has a drive motor operable connected to a compaction rod that moves through a loading platform to a cartridge holding platform. A powder loading station is positioned below the loading platform and above the cartridge holding platform. The compaction rod moves through the powder loading station, which loads a predetermined volume of propellant powder into one or more reliefs defined in the compaction rod. The cartridge holding platform has a removable cartridge fixture designed to receive an ammunition cartridge to be loaded and compacted with propellant powder. The propellant powder is released into the cartridge fixture from the reliefs as the compaction rod passes a funnel defined at an upper end of the fixture. After releasing the powder, the compaction rod continues into an interior chamber of the fixture to compact the powder contained therein.

Abstract: A arrow system embodying a glue-in configuration or screw-over configuration of broadhead to arrow shaft connection is provided. The glue-in configuration provides an externally threadless broadhead shank for slidably reception into the complementary and cross-sectionally coextensive lumen of the arrow shaft. The screw-over configuration provides a broadhead with female internal threading that operatively associates with male threading of an insert that interconnects the broadhead to the lumen of the arrow shaft.

Abstract: A focusing optical part, including a plastic body, suitable for being delivered on a tape and reel and mounted on a PCB by an automated mounting machine, the plastic body including a concave mirror including a center aperture input surface through which light enters the plastic body, a convex mirror opposite the center aperture, wherein the concave mirror and the convex mirror form a reflective objective that reflects and focuses the light inside the plastic body, and an exit surface surrounding the convex mirror, through which focused light exits the plastic body.

Abstract: Described herein is a method for examining a coating of a probe surface, including the steps of providing sensing data indicative of a depth of the coating at each of a predetermined subset of probe surface points, determining a depth representation of the coating from the sensing data, and deriving a coating property based on the depth representation. The coating property carries objective information about a geometric constitution or structure of the coating, which can be used for assessing the coating with respect to a functionality that is due to its geometric constitution or structure.

Abstract: Disclosed herein is a method for depth-profiling of samples including a target region including a lateral structural feature. The method includes projecting an optical pump pulse on a semiconductor device comprising a target region, such as to produce an acoustic pulse which propagates within the target region of the semiconductor device, wherein a wavelength of the pump pulse is at least two times greater than a lateral extent of a lateral structural feature of the semiconductor device along at least one lateral direction, projecting an optical probe pulse on the semiconductor device, such that the probe pulse undergoes Brillouin scattering off the acoustic pulse within the target region, detecting a scattered component of the probe pulse to obtain a measured signal, and analyzing the measured signal to obtain a depth-dependence of at least one parameter characterizing the lateral structural feature.

Abstract: Some embodiments described herein relate to optical systems and methods for determining the shape and/or size of objects that include projecting a pattern of light onto the object. The pattern of light can be configured such that first-order reflections can be distinguished from second- and/or higher-order reflections, which can be rejected. Thus, even in instances in which the pattern of light is reflected onto the object multiple times, the original, or first-order, reflection can be detected, distinguished, and/or used for laser triangulation. In some embodiments, a pattern of light that does not have reflection and/or rotational symmetry is projected onto the object, such that second-order and/or higher-order reflections can be distinguished from the first-order reflection.

Abstract: A material analysis method is provided. A plurality of wafers processed from a plurality of ingots are measured by a measuring instrument to obtain an average of a bow of each of the wafers processed from the ingots and a plurality of full widths at half maximum (FWHM) of each of the wafers. Key factors respectively corresponding to the ingots are calculated according to the FWHM of the wafers. A regression equation is obtained according to the key factors and the average of the bows.

Abstract: A method for determining a characteristic of a construction material is provided. The method includes imaging the construction material and determining a characteristic of the construction material based off of the imaging.

Abstract: A tool recognition system may comprise a tool recognition assembly and a control system in communication with the tool recognition assembly. The control system may comprise a processor and a memory comprising machine-readable instructions. When executed by the processor, the instructions may cause the control system to receive a first baseline sensor value from the tool recognition assembly and determine a baseline adjustment threshold based on the first baseline sensor value. The instructions may also cause the control system to receive first monitored sensor data from the tool recognition assembly and compare the first monitored sensor data to the baseline adjustment threshold for a predetermined duration. If the comparison satisfies a comparison criterion, a second baseline sensor value may be established using the first monitored sensor data.

Abstract: When extending the leader or tape from a traditional tape measure over a large distance, a user situated away from the body of the tape measure is unable to determine the length that has been extended at the leading edge. Presented herein is a retractable measuring device in which the body of the measuring device is configured to compute and broadcast the amount of tape that has been withdrawn from the body to a receiver. The receiver may be located at the leading edge of the tape or comprise a secondary device such as a smartphone. Alternatively, the broadcast may include tactile, audible, or visual feedback relating to the distance that may be received directly by the user. Additionally, the retractable device may include an interface for setting a desired length and provide either the user or receiver with feedback when the desired length has been reached.

Abstract: A measurement device includes: a probe part including a probe configured to measure a surface of an object to be measured and is attached so as to swing around a swing center according to a shape of the surface of the object to be measured; a scale configured to measure displacement by swinging of the probe part; a scale head configured to read a scale mark of the scale; and an arm part to which the probe part is attached, the arm part is attached so as to swing around the swing center integrally with the probe part, and the scale is attached to the arm part. When thermal expansion coefficients of the probe part, the arm part and the scale are ?, ? and ? respectively, the measurement device satisfies a condition of (?+?)?1/2????(?+?)+1/2?.

Abstract: The present application provides a biasing device for detecting a conductor position and wire processing equipment. The biasing device has a bracket, a first drive mechanism, and a detection mechanism. The first drive mechanism has a first support shaft and a mounting slide block rotatably arranged on the bracket, and a mounting slide block, the mounting block can move relative to the bracket along the extension direction of the first support shaft when the first support shaft rotates; the detection mechanism is fixedly connected to the mounting slide block, and is arranged movably relative to the bracket along the extension direction of the first support shaft to determine whether the measured conductor is located in the detection area of the designated position.

Abstract: In some implementations, an angle sensor may receive a first x-component value and a first y-component value from a first set sensing elements and a second x-component value and a second y-component value from a second set of angle sensing elements. The angle sensor may perform a safety check including determining a first range of angles associated with a target object based on a relationship between a magnitude of the first x-component value and a magnitude of the first y-component value; determining a second range of angles associated with the target object based on a relationship between a magnitude of the second x-component value and a magnitude of the second y-component value; and determining whether the second range of angles is a subset of the first range of angles. The angle sensor may output an indication of a result of the safety check.

Abstract: A method of providing optical coherence tomography (OCT) imaging may comprise using an on-chip frequency comb source interfaced with an OCT system by a circulator as an imaging source and reconstructing OCT images from resulting spectral data from target tissue illuminated by the imaging source.

Abstract: Embodiments described herein provide a processing apparatus comprising compute logic to train a convolutional neural network (CNN) to perform autonomous re-localization for a service robot or mobile device. In one embodiment the apparatus comprises an image processor to process visual data received via a sensor and a general purpose graphics processing engine perform camera pose estimation for image data and generate a transformation matrix to transform positions of camera pose estimations to positions within a human readable map of the location. The images and transformed positions are uses to train the CNN to perform re-localization.

Abstract: In an unmanned system for monitoring lateral deformation of a landslide based on inertial measurement, a deformable coupling pipeline is disposed in a landslide mass. An unmanned trajectory tracer is provided with a battery, a motor wheel, an inertial sensor, and a single chip microcomputer that are electrically connected. The single chip microcomputer controls the motor wheel to drive the unmanned trajectory tracer to move back and forth in the deformable coupling pipeline. The single chip microcomputer controls the inertial sensor to measure a shape of the deformable coupling pipeline. Two monitoring piers are disposed at two ends of the deformable coupling pipeline respectively. The monitoring pier is provided with a GPS device and a communication device, the communication device is in communication connection with the single chip microcomputer, and the single chip microcomputer obtains the shape of the deformable coupling pipeline and sends to the communication device.

Abstract: A laser level including a control mechanism housing which houses a control mechanism, the control mechanism including at least a top surface and a bottom surface. A protective structure extends from the control mechanism housing configured to protect the control mechanism from impact and including an upper structure which extends from a top surface of the control mechanism housing and a lower structure which extends from a bottom surface of the control mechanism housing.

Abstract: A target reflector search device. This device comprises an emitting unit for emitting an emission fan, a motorized device for moving the emission fan over a spatial region, and a receiving unit for reflected portions of the emission fan within a fan-shaped acquisition region, and a locating unit for determining a location of the reflection. An optoelectronic detector of the receiving unit is formed as a position-resolving optoelectronic detector having a linear arrangement of a plurality of pixels, each formed as an SPAD array, and the receiving unit comprises an optical system having an imaging fixed-focus optical unit, wherein the optical system and the optoelectronic detector are arranged and configured in such a way that portions of the optical radiation reflected from a point in the acquisition region are expanded on the sensitivity surface of the optoelectronic detector in such a way that blurry imaging takes place.

Abstract: A technique that enables easily determining an attitude of a laser scanning apparatus is provided. A surveying device includes a sunlight incident direction measurement unit, a Sun direction acquisition unit, and an attitude calculator. The sunlight incident direction measurement unit measures an incident direction of sunlight that enters a laser scanning apparatus, based on a detected waveform of incident light entering the laser scanning apparatus. The Sun direction acquisition unit acquires a direction of the Sun as seen from the laser scanning apparatus, from astronomical data, based on a position of the laser scanning apparatus. The attitude calculator calculates an attitude of the laser scanning apparatus in an absolute coordinate system, based on the incident direction of sunlight and the direction of the Sun as seen from the laser scanning apparatus, which is acquired from the astronomical data.

Abstract: A system and method for estimating a velocity of a vehicle, including obtaining readings of at least one inertial sensor that is attached to the vehicle, calculating a time difference between a time when an irregularity is sensed in a first location of the vehicle and a time when the irregularity is sensed in a second location of the vehicle, and calculating the velocity of the vehicle based on the time difference.

Abstract: Systems and methods for the external aiding of inertial navigation systems are described herein. In certain embodiments, a device includes an inertial navigation system. In some embodiments, the inertial navigation system includes one or more inertial sensors and an input interface for receiving measurements. In further embodiments, the measurements include at least one of delta attitude and/or delta position measurements from an external system, and position and attitude information in an arbitrary map frame. In certain embodiments, the inertial navigation system includes a computation device that is configured to calibrate the errors from the one or more inertial sensors using the received measurements.

Abstract: A method of movement tracking includes: performing, when it is determined that a strength of an external signal is greater than a threshold, positioning based on the signal to generate a first record; performing, when it is determined that the strength is not greater than the threshold, measurement of a movement variation to generate a second record; performing, when it is determined that the strength increases from being not greater than the threshold to being greater than the threshold, positioning based on the signal to obtain coordinates of an exact position; and computing corrected data based on the second record and the coordinates, and generating a movement path record based on the first record and the corrected data.

Abstract: A method, system and computer program tie physical events to virtual events by analyzing motion information from a computing device of a vehicle or analyzing contextual information from a computing device of a vehicle. Initiation of a virtual event with a display device is timed in response to detecting an impending change in center of mass motion of the user from analyzing the motion information or contextual information. A motion in the virtual event is dynamically associated with subsequent motion information.

Abstract: An apparatus, method, and computer readable medium related to determining the position of a device, for example determining the pose of a camera. Varying embodiments discuss the use of sensors and captured images to construct an environment property map, which provides reference information in the form of environment properties that are associated with positions, such as camera poses. Embodiments of the disclosure discuss using the environment property map online (e.g. in real time) in order to determine the position of a device. In some embodiments, the environment property map provides a coarse position that is used to refine or limit the necessary work for determining a more precise position.

Abstract: Disclosed is a lane information generating method that can generate lane information of an increasing or decreasing lane which increases or decreases from a traveling lane with high accuracy is provided. By determining characteristic points based not only on traveling trajectory information of a vehicle but also on the shape of the increasing line of the increasing lane increasing from two traveling lanes, a control unit can complementarily using information of a shape of the increasing line at a position at which variation is easily generated in the traveling trajectory, and thus generate the characteristic points as the lane information of an increasing line with high accuracy.

Abstract: Systems and methods are disclosed for improved mapping data validation using randomness measures. Methods may include receiving a map dataset that includes a plurality of map features. A knowledge graph may be generated based on the map dataset that may include nodes representing or corresponding to the map features. Nodes corresponding to map features of a particular feature type may be identified and edges connected to the identified nodes may be processed to identify a plurality of paths. A randomness measure for the particular feature type may be determined based on the plurality of paths. The randomness measure may indicate a predictability of occurrences of map features of the particular feature type in the map dataset. The randomness measure may then be compared to a second randomness measure determined based on another map dataset.

Abstract: Particular embodiments described herein provide for a system and method for facilitating autonomous delivery using a delivery assembly transported by an autonomous vehicle, the system and method can include determining a location of the delivery assembly and in response to determining the location of the delivery assembly, configuring a user interface to facilitate the autonomous delivery. The user interface has at least a point of origination configuration and a user configuration. In addition, the user interface can authenticate a user, allow the user to access one or more cubbies of the delivery assembly, and inform the user through one or more indicators on the user interface that the user can access a specific cubby.

Abstract: Disclosed embodiments include systems, vehicles, and methods for receiving inputs indicative of a destination and a potential intermediate destination and determining a time potentially available at the intermediate destination. In an illustrative embodiment, a system includes a computing device having computer-readable media storing computer-executable instructions configured to cause the computing device to receive a first input indicative of a destination. A second input is received that is indicative of a desired arrival time at the destination. A third input is received that is indicative of an intermediate destination to be visited before traveling to the destination. A first travel time to the intermediate destination, a second travel time to the destination, and a time available at the intermediate destination are determined. The time available at the intermediate destination is communicated to a user.

Abstract: The present disclosure relates to systems and methods for managing a fleet of ridesharing vehicles. In one implementation, the system may include a communications interface configured to receive requests for shared rides from a plurality of users; a memory configured to store indications of passenger-capacity for specific ridesharing vehicles in the fleet; and at least one processor configured to receive information from the communications interface and access the memory The at least one processor may be further configured to assign, to ridesharing vehicles already transporting users, additional users for simultaneous transportation in the ridesharing vehicles; track a current utilized capacity of each specific ridesharing vehicle; and implement a threshold block that prevents assignment of additional users to a ridesharing vehicle when the ridesharing vehicle's current utilized capacity is above a threshold being less than the ridesharing vehicle's passenger-capacity.

Abstract: The technology involves pullover maneuvers for vehicles operating in an autonomous driving mode. A vehicle operating in an autonomous driving mode is able to identify parking locations that may be occluded or otherwise not readily visible. A best case estimation for any potential parking locations, including partially or fully occluded areas, is compared against predictions for identified visible parking locations. This can include calculating a cost for each potential parking location and comparing that cost to a baseline cost. Upon determining that an occluded location would provide a more viable option than any visible parking locations, the vehicle is able to initiate a driving adjustment (e.g., slow down) prior to arriving at the occluded location. This enables the vehicle to minimize passenger discomfort while also providing notice to other road users of an intent to pull over.

Abstract: Various examples are directed to systems and methods for routing an autonomous vehicle. For example, a system may access temporal data comprising a first temporal data item. The first temporal data item may describe a first roadway condition, a first time, and a first location. The system may also access a routing graph that comprises a plurality of route components and determine that a first route component of the routing graph corresponds to the first location. The system may generate a constrained routing graph at least in part by modifying the first route component based at least in part on the first roadway condition. The system may additionally generate a route for an autonomous vehicle using the constrained routing graph; and cause the autonomous vehicle to begin traversing the route.

Abstract: An apparatus and a method for identifying one or more sources of an airborne pollutant in a geographical area and for mitigating release of the airborne pollutant, comprising: receiving emission data and vehicle location data associated with a plurality of corresponding vehicles in the geographical area; receiving ambient air quality data for respective locations in the geographical area; apply a vehicle emission plume air dispersion model to process the received emission data, the received vehicle location data, and the received ambient air quality data; identify one or more principal sources of the airborne pollutant based on the processed emission data, vehicle location data, and ambient air quality data; and transmit an instruction related to one or more vehicles associated with the one or more identified principal sources of the airborne pollutant.

Abstract: The present disclosure relates to an apparatus and methods of estimating a traffic volume of moving objects. In particular, the present disclosure estimates the traffic volume based on amounts of traffic volume of the moving objects observed at observation points based on a routing matrix and a visitor matrix. The routing matrix indicates whether moving objects that pass through specific waypoints are to be observed at an observation point. The visitor matrix indicates whether a moving object departing or arriving at the observation point. The present disclosure enables estimating a traffic volume of moving objects on various routes based on observed data with errors in data and varying lengths in observation periods.

Abstract: Based on position information indicating a position of a vehicle on a map, whether the vehicle has arrived at an entrance of an area in a vicinity of a destination of the vehicle where road links do not exist is determined, a history of the vehicle having parked in the area is stored as parking information, the parking information is referenced when it is determined that the vehicle has arrived at the area, and guidance information is output as information which guides the vehicle based on recommendation information and which includes at least a parking position in the area.

Abstract: Systems and methods for landmark-based localization of an autonomous vehicle (“AV”) are described herein. Implementations can generate a first predicted location of a landmark based on a pose instance of a pose of the AV and a stored location of the landmark, generate a second predicted location of the landmark relative to the AV based on an instance of LIDAR data, generate a correction instance based on the comparing, and use the correction instance in generating additional pose instance(s). Systems and methods for validating localization of a vehicle are also described herein. Implementations can obtain driving data from a past episode of locomotion of the vehicle, generate a pose-based predicted location of a landmark in an environment of the vehicle, and compare the pose-based predicted location to a stored location of the landmark in the environment of the vehicle to validate a pose instance of a pose of the vehicle.

Abstract: A designated location preview method includes obtaining an image of a portion of an environment of a vehicle dispatched to a designated location in response to a service request from a user, wherein the obtaining is performed using at least one onboard sensor of the vehicle; and displaying the image of the environment portion on a user interface (UI) of a user device substantially in real-time.

Abstract: An apparatus for suggesting stopping by facilities includes a processor to suggest, as a stop, facilities, which are suitable for a user tendency or a user situation, of facilities positioned on a driving path of an autonomous vehicle, and a storage to store data and an algorithm executed by the processor. The processor provides, to a user, a list of the facilities suitable for the user tendency or the user situation, and adds facilities, which are selected by the user, to the stop on the driving path to guide to the driving path.

Abstract: Provided are an electronic device for generating map data and an operating method of the electronic device. The operating method of the electronic device includes: obtaining image data of a first resolution and image data of a second resolution for each of a plurality of nodes generated while the electronic device moves; obtaining location information with respect to each of the generated nodes, by using the image data of the second resolution; generating and storing map data by matching the obtained location information with the image data of the first resolution for each node; and estimating a current location of the electronic device by using the generated map data and the image data of the first resolution.

Abstract: The present application discloses a map data updating method, an apparatus, a device and a readable storage medium. The specific implementation solution is: after receiving road information reported by an electronic device, a server obtains multiple sequences according to the road information, and each road information belonging to the same sequence has the same type and location. After that, the server inputs each road information contained in the sequences to a pre-trained neural network model, so that the neural network model outputs a recognition result according to the sequences. The server updates map data according to the recognition result. With such solution, valid road information is recognized by combining context of each road information in the sequences and the neural network technology, and the map data is updated, which achieves the purpose of accurately updating the map data.

Abstract: A device for calibrating a laser level includes a base platform, a target, and an image recognition device. The base platform is configured to support the laser level that is to be mounted on the base platform at a first position. The target is arranged at a second position of the base platform and configured to receive a laser. The image recognition device is configured to obtain images of lasers projected on the target before and after the laser level rotates a first angle, determine, based on an image recognition result of the images, positions of the lasers emitted by the laser level to determine a deviation distance, and determine whether the laser level needs to be calibrated based on the deviation distance. The deviation distance is determined by position data of the first position and the second position, and the first angle.

Abstract: A level gauge includes a housing, a vertical member, and a perpendicular member. The housing includes a bottom wall and a side wall. A surface of the side wall includes a first scale. The bottom wall and the side wall enclose a receiving cavity. The vertical member is arranged in the receiving cavity and includes an axis maintained in a vertical orientation in a natural state. A center of gravity of the perpendicular member is arranged on top of the vertical member. A plane of the perpendicular member is maintained perpendicular to the axis of the vertical member. When the bottom wall is placed on a gauging surface, an inclination angle and inclination direction of the gauging surface are obtained simultaneously.

Abstract: The present disclosure relates to a sensor housing for a multi-parameter sensor, the sensor housing including: at least two connection points, wherein a first connection point is configured to receive a first sensor, and a second connection point is configured to receive a second sensor different from the first sensor, wherein the first connection point includes a first mistake-proofing feature for the first sensor, and the second connection point includes a second mistake-proofing feature for the second sensor, wherein the first and second mistake-proofing feature are configured such that only the first sensor can be inserted into the first connection point and only the second sensor can be inserted into the second connection point, respectively.

Abstract: A method of position estimation including: a signal detection step in which N (where N is an integer of 3 or more) sensors each detect a magnetic field which is in accordance with a position of a mover and output a detection signal as an electrical signal, the detection signals being displaced in phase by an angle obtained by dividing 360 degrees by N; a crossing detection step in which a crossing detection section sequentially detects a crossing at which each detection signal having been output through the signal detection step crosses another; a subdivision detection step in which a subdivision detection section detects a portion of the detection signal that connects from a crossing to another crossing which is adjacent to that crossing, as one or more subdivision signals; and a line segment joining step in which a line segment joining section sequentially joins the subdivision signals and estimates the position of the mover based on the plural subdivision signals having been joined, to generate an estimate

Abstract: A method of position estimation including: a signal detection step in which N (where N is an integer of 3 or more) sensors each detect a magnetic field which is in accordance with a position of a mover and output a detection signal as an electrical signal, the detection signals being displaced in phase by an angle obtained by dividing 360 degrees by N; a crossing detection step in which a crossing detection section sequentially detects a crossing at which each detection signal having been output through the signal detection step crosses another; a subdivision detection step in which a subdivision detection section detects a portion of the detection signal that connects from a crossing to another crossing which is adjacent to that crossing, as one or more subdivision signals; and a line segment joining step in which a line segment joining section sequentially joins the subdivision signals and estimates the position of the mover based on the plural subdivision signals having been joined, to generate an estimate

Abstract: A multi-layer electrode for a capacitive pressure sensor is manufactured according to a method including co-extruding a conductive polymer layer and a dielectric foam layer and forming coextruded layers of the capacitive pressure sensor and pressure rolling an XY layer and the coextruded layers together and forming the multi-layer electrode.

Abstract: The position detector of an object includes a body defining an input receiving an optical fibre delivering a light signal, and an output delivering a signal representative of the position of the object. A mirror is mounted to move between first and second positions in the body with respect to the input. The first position or the second position ensures transmission of the light signal from the input to the output. The other of the first position and the second position prevents transmission of the light signal to the output. A spring is mounted in the body in order to place the mirror in the first position. A tip is movable relative to the body between a first position and a second position along a direction of movement and is intended to cooperate with the object to be monitored.

Abstract: An optical detection system includes a marker product and an optical encoding device. The marker product includes a substrate and at least one structural portion. The structural portion has a first surface, a second surface and a dividing axis. The first surface and the second surface are arranged on opposite sides of the dividing axis. A sidelong direction aligning the first surface with the second surface is parallel to a moving direction between the optical encoding device and the marker product. The optical encoding device is disposed adjacent by the marker product. The optical encoding device includes an optical projector and an optical encoder. The optical projector is configured to project the optical detecting signal onto the marker product. The optical encoder is configured to receive an optical reflecting signal from the marker product and encode intensity variation of the optical reflecting signal into digital data.

Abstract: An encoder includes a scale and a sensor. The scale has first and second absolute patterns. The sensor includes a light source, and first and second absolute light receivers. The first and second absolute light receivers receive light from the first and second absolute patterns, respectively. The first absolute light receiver receives light from the first pattern and includes first and second light receiving elements. Each first light receiving elements outputs a first signal with a first phase. Each second light receiving elements outputs a first signal with a second phase. The first and second light receiving elements are arranged alternately. The second absolute light receiver includes third and fourth light receiving elements. Each third light receiving element outputs a second signal with the first phase. The third and fourth light receiving elements are arranged alternately. Each fourth light receiving element outputs a second signal with the second phase.