Abstract: The disclosure provides a photoelectric sensor that provides useful information to set measurement conditions. The photoelectric sensor includes a light emitting unit having a light emitting element configured to emit detection light toward a detection area, a light receiving unit having a light receiving element configured to receive the detection light from the detection area and to obtain a detection value corresponding to the amount of light received, and a display unit configured to display information about the detection value in the light receiving unit. When the detection value varies across a predetermined threshold, the display unit displays a transit time that is the time from when the detection value crosses the predetermined threshold until when it crosses the predetermined threshold again, and a variation amount of the detection value in the variation.

Abstract: A method for use in a part tracking system including a camera and a motion controller, the method comprising the steps of time synchronizing the motion controller and the camera at a trigger time when it is anticipated that a part is within the field of view of the camera, causing the camera to obtain an image, using the obtained image to determine an actual location of the part at the trigger time, comparing the actual location and the anticipated location of the part to identify a position difference and at the motion controller, using the position difference at the trigger time to adjust at least one operating characteristic of the automated system.

Abstract: The invention relates to a device for measuring the relative position of two objects moving relative to each other along an axis or around a rotating axis (D), with a transmitter (12) which emits unpolarized light, and with a polarizer (20), and with at least one receiver (16) which measures the luminosity of the light passing through the polarizer (20) in order to create a position-dependent signal, such that a polarizing filter is positioned in front of the receiver (16), and the receiver (16) and the polarizer (20) move relative to each other as a function of the relative position of the two objects, and such that the polarizer (20) has at least two different polarizing directions.

Abstract: A patterning device, including alignment targets having alignment features formed from a plurality of diffractive elements, each diffractive element including an absorber stack and a multi-layered reflector stack is provided. The diffractive elements are configured to enhance a pre-determined diffraction order used for pre-alignment and to diffract light in a pre-determined direction of a pre-alignment system when illuminated with light of a wavelength used for the pre-alignment. The diffractive elements may occupy at least half of an area of each alignment feature. The diffractive elements may be configured to enhance first or higher order diffractions, while substantially reducing zeroth diffraction orders and specular reflection when illuminated with a wavelength used for reticle prealignment. The dimensions of each diffractive element may be a function of a diffraction grating period of each alignment feature.

Abstract: The present invention relates to a method and apparatus for measuring precise high speed displacement, and more particularly, to a method and apparatus for measuring precise high speed displacement, which measures displacement of a test specimen by using a uniform intensity laser line and by using differences in a laser transmission amount according to the deformation of the test specimen, and measures a strain rate of the test specimen such as high strength fiber or the like using a high speed tensile test.

Abstract: A system for inspecting a depth relative to a layer using a sensor with a fixed focal plane. A focus sensor senses the surface of the substrate and outputs focus data. In setup mode the controller scans a first portion of the substrate, receives the focus data and XY data, and stores correlated XYZ data for the substrate. In inspection mode the controller scans a second portion of the substrate, receives the focus data and XY data, and subtracts the stored Z data from the focus data to produce virtual data. The controller feeds the virtual data plus an offset to the motor for moving the substrate up and down during the inspection, thereby holding the focal plane at a desired Z distance.

Abstract: The present invention relates to a scanning device for determining at least partial cross-sectional profiles of food products to be sliced in accordance with the light cutting process, having at least one illumination device for generating a light line on the surface of a product and having at least one detection device for taking images of the product surface including the light line, wherein the illumination device includes at least one light source which is configured to generate a light beam propagating in the direction of a scanning region for the product in a scanning plane and widening in so doing and includes an optically effective device which is arranged in the propagation path of the widening light beam and which is configured to counter the divergence of at least some of the incident light.

Abstract: A system for determining a location on a 2D surface or in a 3D volume. The system includes a probe and a tracker. The probe includes a marker, an indicator, and a reflective surface, wherein the probe is configured so the reflective surface forms a virtual image of the marker having an apparent location coincident to a location of the indicator. The tracker configured to measure the apparent location of the virtual image of the marker.

Abstract: A chassis measuring system comprises an illumination device for producing a structured illumination (38, 58, 78, 98), which is developed in such a way that it produces a structured image on a measuring head (32, 52; 72, 92) situated opposite in the transverse vehicle direction, a reference surface (40, 60, 80, 100) facing in the same direction as the illumination device (38, 58, 78, 98), on which a structured image produced by an illumination device (38, 58; 78, 98) of the measuring head (32, 52; 72, 92) situated opposite in the transverse vehicle direction may be projected, and at least one measuring camera (34, 36; 54, 56; 74, 76; 94, 96) facing in the same direction as the illumination device (38, 58, 78, 98), which is developed in such a way that it detects the structured image on the reference surface (40, 60; 80, 100) of the opposite measuring head (32, 52; 72, 92) in order to determine the position parameters of the measuring head (32, 52, 72, 92).

Abstract: An optical position-measuring device includes a light source, a measuring reflector movable in space, a detection unit and a light-beam deflection unit that can align at least one beam of rays, emitted by the light source, in the direction of the measuring reflector. The light-beam deflection unit includes a cardan system having two cardan frames. A first cardan frame is adjustable by motor about a first axis of rotation, and a second cardan frame within the first cardan frame is adjustable by motor about a second axis of rotation oriented in a direction perpendicular to the first axis of rotation. The two axes of rotation intersect in a fixed reference point, at which a reference reflector is disposed. A plurality of mirrors are disposed rigidly on the cardan frames, so that the beam of rays can be pivoted about the fixed reference point via the mirrors during alignment.

Abstract: A proximity sensor with movement detection is provided. The proximity sensor may include an ASIC chip; at least three light sources configured to emit light in a particular sequence; and a photo detector configured to receive light and generate an output signal. The proximity sensor may have a compact size package, wherein the photo detector may be stacked on the ASIC chip and disposed at a substantially equal distance from the at least three light sources. The proximity sensor includes a driver operable to generate a current to a plurality of light sources in a particular timing sequence, a photo detector configured to receive light and generate an output signal, an ASIC configured to report the movement of an object near the proximity sensor if the output signal pattern generated matches one of the output signal patterns from among a set of known output signal patterns. The proximity sensor may be configured to be used as a counter or an on/off switch based on particular movements detected.

Abstract: The general field of the invention is that of optical position/orientation devices for a helmet and more particularly those whose helmet comprises neither emitters, nor receivers but solely passive optical components, detection of which is ensured by fixed opto-electronic means outside the helmet. The optical component for the optical device for detecting position/orientation of a helmet according to the invention comprises a particular “optical cube corner”. It comprises a prism in the form of a trirectangular trihedron, each of the three plane surfaces of the trihedron comprising a blade with plane and mutually parallel faces, the first face being coincident with the plane surface on which it rests, the interface between this first face and said surface comprising a semi-reflecting treatment.

Abstract: An optical tracking system for determining the pose of a moving object in a reference coordinate system includes light emitters, optical detectors, and a pose processor. The processor is coupled with an optical detector and also with a light emitter. The processor determines the object's pose according to detected light. An optical detector and a light emitter are situated at a fixed position in the reference coordinate system. Other ones of the optical detectors and light emitters are attached to the object. One optical detector is a WFOV detector comprising an optical sensor and optical receptors. The receptors are spaced apart and optically coupled with the optical sensor. The sensor senses light received from a light emitter. Each receptor projects a different angular section of a scene on the sensor. The pose processor associates the representation on the sensor, with a respective receptor which projected the light on the sensor.

Abstract: Fringe patterns at first and second spatial frequencies are projected onto a work piece surface and a reference surface, respectively. An image of the projected fringe patterns is obtained and a measurement signal associated with work piece displacements and a reference signal are obtained based on the first and second spatial frequencies. The image of the projected fringe patterns can exhibit substantial or complete overlap of the fringe patterns at the first and second spatial frequencies, and the overlapping patterns can be separated based on the spatial frequencies. Fringe pattern shifts at one or both of the first and second spatial frequencies can be used to adjust a pattern transfer system to permit accurate pattern transfer.

Abstract: A position measuring device including a reflective scale and a scanning unit. The scanning unit includes a retroreflector and a signal unit wherein the signal unit includes a light source and a detector arrangement. The scanning unit and the signal unit are structurally separate from one another and are disposed in planes parallel to one another, and wherein the scanning unit is movable relative to the reflective scale in a measuring direction. The light source emits a beam that propagates freely in a direction to the scanning unit, wherein from the scanning unit along the direction to the signal unit a pair of interfering partial beams propagate freely and wherein between the signal unit and the scanning unit the partial beams propagate freely in a propagation direction that is oriented perpendicular to the planes.

Abstract: A movable body system includes a movable body to which an image pickup apparatus is attached; an image analyzer that performs image matching between the image captured by the image pickup apparatus and an image, which is previously captured on the travel path of the movable body; a wall-surface detector that detects directions of the movable body with respect to wall surfaces, which are arranged along the travel path, and distances between the wall surfaces and the movable body; and a traveling-direction calculator that detects a shift of the movable body with respect to the travel path from an output of the image analyzer or the wall-surface detector, and calculates a traveling direction to cause the movable body to travel on the travel path.

Abstract: A detecting device includes an actuating unit for driving a transparent grating structure, a light source for emitting light to the transparent grating structure driven by the actuating unit, a light sensor for sensing the light emitted from the light source as the transparent grating structure is moved to different positions relative to the light source so as to generate a corresponding optical intensity signal, a transforming circuit coupled to the light sensor for transforming the optical intensity signal into a transforming signal, and a processing unit coupled to the transforming circuit for determining a position of the transparent grating structure according to the transforming signal transmitted from the transforming circuit.

Abstract: A device sends a first light beam to a target which returns a portion of the first beam as a second beam. First and second motors direct the first light beam to a first direction determined by first and second angles of rotation about first and second axes. First and second angle measuring devices measure first and second angles of rotation. A distance meter measures a first distance between device and target. A second portion of the second beam passes through a diffuser and onto a position detector which produces a first signal in response. A control system sends a second signal to the first motor and a third signal to the second motor, the second and third signals based on the first signal. The control system adjusts the first direction of the first beam to the target position. A processor provides a 3D coordinate of the target.

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

Abstract: The present invention relates to an arrangement for measuring relative movement. The measuring arrangement comprises a light source (110, 210) for emitting a light beam, a moving element (120, 220) having a reflective surface (121, 221) adapted to reflect a first wavefront portion of the light beam, and a reference element (130, 230) having a reflective surface (131, 231) adapted to reflect a second wavefront portion of the light beam. The arrangement further comprises detecting means (140, 240) for detecting changes in a spatial interference pattern produced by the light reflected from the moving element and the reference element, and processing means (150, 160, 250, 260) for calculating the relative movement between the moving element and the reference element from the phase change in the detected spatial interference pattern. The invention also relates to a method for measuring relative movement.

Abstract: High-resolution optical position sensing is disclosed using sparse, low-resolution detectors. Precise location of two-dimensional position or angular orientation of an optical beam at the focal plane of a sensor system is made possible using sparse low-resolution detectors. The beam may be emitted directly from a source, or scattered from a remote target. The high precision in determining the beam or focal spot location is the result of a novel data processing and analysis method for the signals from the low-resolution detectors.

Abstract: A relocating device for locating and relocating a first object relative to a second object is for use in association with a means for defining a location point on the second object. The relocating device includes at least one light source, a power source. The at least one light source is producing at least two beams of light wherein each beam of light is capable of defining a beam location point on the second object. The at least one light source is operably connected to the first object. The power is source operably connected to the at least one light source. The means for defining a location point on the second object defines each beam location point on the second object.

Abstract: An optical detection device includes: an irradiation unit that emits irradiation light onto an area formed along a planar area; first and second light receiving units that receive reflection light of the irradiation light reflected by a target object; and a calculation unit that calculates positional information of the target object based on a light reception result of at least one of the first and second light receiving units. A distance between the second light receiving unit and the planar area is shorter than a distance between the first light receiving unit and the planar area, and the first and second light receiving units receive the reflection light that is incident in a direction along the planar area.

Abstract: A system measures the position of a light source in space using an imager and transparent surface with a pattern on top. The pattern consists of a repetitive pattern and a distinctive element. The system achieves sub-micron precision. It also handles the measurement of several light sources simultaneously, and the measurement of the position of a retroreflector instead of the light.

Abstract: An optical tracking system can include at least one scanning detector having a scanning mirror and one or more fixed photo-detectors located near the scanning mirror. The scanning mirror can be configured to deflect a light beam from a source towards a retroreflective target and the photodetectors are configured to collect a portion of the light beam that is retroreflected from the target. A scanning optical detector apparatus may optionally comprise a substrate, a scanning mirror having at least one portion monolithically integrated into the substrate, and one or more photodetectors monolithically incorporated into the substrate. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the claims' scope or meaning.

Abstract: A projection display device having a projection device projecting an image on a surface, and a position detection function of detecting an object's position between the surface and the projection device, includes: a light source emitting light beams toward the object; a light detector detecting the light beams reflected by the object; and a position detector detecting the object's position in an imaginary plane based on the light detector's result, wherein the light source emits, as the light beams, first through third light beams having first through third intensity distributions, the second intensity distribution having a highest intensity at a position failing to overlap a highest intensity of the first intensity distribution, and the third intensity distribution having a highest intensity portion at a position failing to overlap a straight line connecting the highest intensity portions of the first and second intensity distributions.

Abstract: A positioning method and a positioning system based on light intensity are provided. The positioning system comprises a lighting system, a sense feedback device and a positioning module. The lighting system comprises at least three point light sources and sequentially adjusts luminance of these point light sources to light up a target. The sense feedback device is disposed on the target and used to collect light intensity information of the light projected on the target by the lighting system. The positioning module calculates a distance between the target and each of the point light sources based on the light intensity information and calculates a positioning location of the target based on the locations of the point light sources and the distances between the target and the point light sources.

Abstract: The present disclosure relates to a device for measuring a static tilt angle of a voice coil motor. The voice coil motor includes a movable part for coupling to a lens barrel. The device includes a laser transmitter and receiver, a fixture opposite to a surface of the laser transmitter and receiver, a reflective component on the movable part, and a processor electrically connected to the laser transmitter and receiver.

Abstract: A metrology apparatus is arranged to illuminate a plurality of targets with an off-axis illumination mode. Images of the targets are obtained using only one first order diffracted beam. Where the target is a composite grating, overlay measurements can be obtained from the intensities of the images of the different gratings. Overlay measurements can be corrected for errors caused by variations in the position of the gratings in an image field.

Abstract: The disclosure relates to a system and a method for light beam interrogation of an optical biosensor and for monitoring a biological event on the biosensor for use, for example, in microplate image analysis. The system and method correct pointing-errors that can be encountered, for example, in scanning label-independent-detection biosensor applications.

Abstract: A lithography apparatus includes a projection system configured to project a radiation beam onto a substrate, a detector configured to inspect the substrate, and a substrate table configured to support the substrate and move the substrate relative to the projection system and the detector. The detector is arranged to inspect a portion of the substrate while the substrate is moved and before the portion is exposed to the radiation beam.

Abstract: In an optical tracking system for determining the pose of a moving object in a reference coordinate system, the system including at least one light emitter, at least one optical detector for detecting the light emitted by the at least one light emitter and a pose processor, coupled with the at least one optical detector, and with the at least one light emitter, for determining the pose of the moving object according to the light detected by the at least one optical detector.

Abstract: A system for generating position information includes a reflector, an image collection system, and a processor. The image collection system is configured to collect at least two sets of image data, where one set of image data includes a stronger indication of the reflector than the other set of image data. The two sets of image data can be collected in many different ways and may include using a retroreflector as the reflector. The two sets of image data are used to generate position information related to the reflector. In particular, position information related to the reflector is generated by taking the difference between the two set of image data. Because one set of image data includes a stronger indication of the reflector than the other set of image data, the difference between the two sets of image data gives a definitive indication of the reflector's position.

Abstract: Object detection and selection for use in a device having digital camera functionality is described. The mechanism detects the occurrence of a gesture by a pointing member in an image frame captured by an IR image sensor. The gesture is then recognized and an object pointed to is detected. The object detected is then selected as a result of the gesture recognition.

Abstract: The invention provides a robot including a connection member relatively displaceably connected, and configured to control the displacement of the connection member based on a reference posture that can be adjusted, the robot including: a light emitting unit to emit a laser beam in a predetermined direction; a light receiving unit to receive the laser beam when the connection member is located in a detection posture that is away, by a preset displacement amount, from a predetermined zero posture; and a zeroing unit to relatively displace the connection member so as to make the light receiving unit receive the laser beam, and then to adjust the reference posture to the zero posture based on the posture of the connection member when the laser beam is received as well as on a relationship between the zero posture and the detection posture.

Abstract: Disclosed herein is a display apparatus including an input/output section for displaying an image as well as detecting a light beam representing an input received from an external source and is capable of handling inputs received from the external source as inputs destined for a plurality of points on a display screen. The apparatus further includes a target generation section configured to generate information on a target located on the display screen to represent a series of inputs received from the external source on the basis of a timewise or spatial relation between input portions located on the display screen as portions receiving inputs from the external source. The apparatus still further includes an event generation section configured to recognize an event representing a change of a state of the target on the basis of the information on the target and generate information on the event.

Abstract: A machine tool with a main positioning device for positioning a main support element in a translational linear direction within a main region of displacement is provided. A main machining device and an accessory machining device are arranged on the main support element. The machining devices have pivoting devices for pivoting the machining heads in a rotatory basic pivoting direction. Every accessory pivoting device is connected to the main support element via a respective supplementary accessory positioning device for positioning the respective accessory machining head in the translational linear direction relative to the main support element within a respective supplementary accessory region of displacement.

Abstract: Measurement of the deviation of a laser beam from a straight line, where the laser beam is of a type which causes thermal blooming, is used to determine the integrated effect which wind will have on an article traveling through airspace, for example, to enable an adjustment in the aim point of the article. The invention includes correcting the aim point of a gun firing a projectile, correcting the flight path of an aircraft, and correcting the path of a watercraft. The invention includes a method and means for measuring the flow of fluid in a conduit or as a free mass, for purposes other than adjusting the path of a projectile or the like.

Abstract: A beam irradiation device includes a photodetector which receives servo light and outputs a detection signal depending on a light receiving position of the servo light, and a signal processing section which obtains the light receiving position based on the detection signal. In the above arrangement, the signal processing section has an A/D conversion circuit which converts the detection signal into a digital signal, and an error signal adjusting circuit which converts an error component signal to be outputted from the photodetector when the photodetector is not irradiated by the servo light, into a signal within a processable range of the A/D conversion circuit, and supplies the converted signal to the A/D conversion circuit. A first digital signal derived from the detection signal is corrected with a second digital signal derived from the error component signal.

Abstract: A method for making a sample for evaluation of laser irradiation position and evaluating the sample, and an apparatus which is switchable between a first mode of modification of semiconductor and a second mode of making and evaluating the sample. Specifically, a sample is made by irradiating a semiconductor substrate for evaluation with a pulse laser beam while the semiconductor substrate is moved for evaluation at an evaluation speed higher than a modifying treatment speed, each relative positional information between pulse-irradiated regions in the sample is extracted, and stability of the each relative positional information between pulse-irradiated regions is evaluated. The evaluation speed is such a speed that separates the pulse-irradiated regions on the sample from each other in a moving direction.

Abstract: According to one embodiment, a method is disclosed for determining position of an auxiliary pattern on a photomask. The method can include generating a first set for each of three or more imaging positions of an exposure optical system. The method can include generating a second set for each of the three or more imaging positions by inverse Fourier transforming each of the first set. The method can include calculating a second order differential with respect to the imaging position of an index indicating amplitude of light belonging to the second set. In addition, the method can include extracting a position where the second order differential assumes an extremal value on an imaging plane of the exposure optical system. At least part of positions on the photomask each corresponding to the position assuming the extremal value on the imaging plane is used as a formation position of the auxiliary pattern.

Abstract: An optical angle of arrival measurement system uses an optical element to form at least one narrow width line on a focal plane array (FPA) which is oblique with respect to the FPA's row and column axes and which traverses at least two rows or columns along its length; forming two perpendicular narrow width lines in a cross-pattern is preferred. Interpolating the position of the lines on the FPA provides coordinates that can be used to calculate the optical angle of arrival in accordance with ?x=A(x)·tan?1(x/f), and ?y=B(y)·tan?1(y/f), where f is the focal length of the optical element, and A(x) and B(y) are parameters that account for optical distortion and other imperfections of the system. The resolution ?? of the angle of arrival measurement can be improved to at least ??˜(d/n)/f, where d is the FPA pixel width and n is the length in pixels of the imaged line.

Abstract: Aerosol and hydrosol particle detection systems without knowledge of a location and velocity of a particle passing through a volume of space, are less efficient than if knowledge of the particle location is known. An embodiment of a particle position detection system capable of determining an exact location of a particle in a fluid stream is discussed. The detection system may employ a patterned illuminating beam, such that once a particle passes through the patterned illuminating beam, a light scattering is produced. The light scattering defines a temporal profile that contains measurement information indicative of an exact particle location. However, knowledge of the exact particle location has several advantages. These advantages include correction of systematic particle measurement errors due to variability of the particle position within the sample volume, targeting of particles based on position, capture of particles based on position, reduced system energy consumption and reduced system complexity.

Abstract: A tilt sensor includes a body, a light emitting diode (LED), a first photosensitive element, a second photosensitive element, and a moving element. The body can tilt in a plurality of tilt directions. The LED is disposed at the body for providing a light beam. The first photosensitive element is disposed at the body and at the opposite side of the LED. The second photosensitive element is disposed at the body and at another side of the LED. The moving element is disposed at the body. When the body tilts toward different tilt directions, the moving element moves toward different directions so that different light receiving situations are produced.

Abstract: A pixel shifting unit moves the relative position between the luminous flux entering an image pickup device and the device to a plurality of predetermined positions in a predetermined order. A control unit controls the device, and allows the image of a subject image formed by the luminous flux on the photoreception surface of the device when the relative position is in any of the plurality of predetermined positions. A combination unit combines the plurality of obtained images to generate a high-resolution image. A prediction unit predicts a shooting environment when the device hereafter shoots an image of the subject image on the basis of a change of at least two images. A setting control unit controls a setting of a shooting condition when the image of the subject image is shot on the basis of a result of the prediction of the shooting environment.

Abstract: A measuring head system for a coordinate measuring machine, having a scanning element for contacting a measured object as a contacting part, which can be moved such that an object to be measured can be mechanically scanned using the scanning element. An optical sensor is fixed on the measuring head base. Means are provided to generate a projection on the sensor line using at least one radiation source. The means have at least one first mask element to generate a first partial projection on the sensor line such that said partial projection is optimized to determine an x displacement and a y displacement of the contacting part in relation to the measuring head base in the x direction or y direction. An analysis unit is configured to determine the x displacement and the y displacement from signals only generated by the one sensor line.

Abstract: Described herein is a projective optical metrology system including: a light target formed by a first number of light sources having a pre-set spatial arrangement; and an optical unit including an optoelectronic image sensor, which receives a light signal coming from the light target and defines two different optical paths for the light signal towards the optoelectronic image sensor. The two optical paths are such that the light signal forms on the optoelectronic image sensor at most an image of the light target that can be processed for determining at least one quantity indicating the mutual arrangement between the light target and the optical unit.

Abstract: A device sends a first light beam to a target which returns a portion of the first beam as a second beam. First and second motors direct the first light beam to a first direction determined by first and second angles of rotation about first and second axes. First and second angle measuring devices measure first and second angles of rotation. A distance meter measures a first distance between device and target. A second portion of the second beam passes through a diffuser and onto a position detector which produces a first signal in response. A control system sends a second signal to the first motor and a third signal to the second motor, the second and third signals based on the first signal. The control system adjusts the first direction of the first beam to the target position. A processor provides a 3D coordinate of the target.

Abstract: A position-determining apparatus, such as measuring or surveying instruments, is disclosed. In at least one embodiment, the present invention relates to a tilt sensor for a measuring instrument including a movable housing that is controllably rotatable around a rotational axis, wherein the rotational axis may be positioned so that it deviates from a true vertical axis being parallel with a gravitational axis. In at least one embodiment, the tilt sensor includes a gravity sensitive gradient indicating element arranged such that a surface of the element is positioned orthogonally to the true vertical axis during movements of the measuring instrument, wherein the gravity sensitive gradient indicating element is arranged in connection to the non-rotating base; and a detecting device adapted to produce at least one detecting signal and to receive at least one response signal, wherein a deviation between the rotational axis and the true vertical axis is detectable using the at least one response signal.

Abstract: A hazard area protection system wherein it includes a projection device designed to project a light beam on at least part of the surface area on the ground of the hazard area.