729 results about "Scan angle" patented technology

A system and method are presented for improving the performance of full range code scanners. A distance detection module determines the distance of the code symbol from the code symbol reader. In response to the detected distance, the sweep angle of the scanning element is changed to ensure that the code symbol is within the code symbol reader's field of view. The sweep angle is larger when the code symbol is in the near range, and smaller when the code symbol is in the far range.

An apparatus and method for aligning a line scan camera with a Light Detection and Ranging (LiDAR) scanner for real-time data fusion in three dimensions is provided. Imaging data is captured at a computer processor simultaneously from the line scan camera and the laser scanner from target object providing scanning targets defined in an imaging plane perpendicular to focal axes of the line scan camera and the LiDAR scanner. X-axis and Y-axis pixel locations of a centroid of each of the targets from captured imaging data is extracted. LiDAR return intensity versus scan angle is determined and scan angle locations of intensity peaks which correspond to individual targets is determined. Two axis parallax correction parameters are determined by applying a least squares. The correction parameters are provided to post processing software to correct for alignment differences between the imaging camera and LiDAR scanner for real-time colorization for acquired LiDAR data.

An illumination light source uses a beam to scan while a relatively small mirror, such as an MEMS mirror, is oscillated at or in the vicinity of the resonance frequency. In this instance, the scan angle is corrected with the use of a correction optical system for uniform illumination to be achieved.

An optical scanner with plural scan beam generation. Scan angle stress is configured in the beam generation.

A 4-dimensional digital tomosynthesis system includes an x-ray source, an x-ray detector and a processor. The x-ray source is suitable for emitting x-ray beams to an object with a periodic motion. The periodic motion is divided into (n+1) time intervals, n being a positive integer. Each of the (n+1) time intervals is associated with a time instance ti, i=0, 1, 2, . . . , n. The x-ray detector is coupled to the x-ray source for acquiring projection radiographs of the object at each time instance ti for each scan angle based on the x-ray beams. The processor is communicatively coupled to the x-ray source and the x-ray detector for controlling the x-ray source and processing data received from the x-ray detector such that all projection radiographs acquired from all scan angles for each time instance ti are reconstructed and (n+1) sets of cross sections of the object are obtained. The cross section is either a coronal cross section or a sagittal cross section. Each of the (n+1) sets of cross sections is for a different time instance ti.

A radar apparatus of an automotive vehicle includes a radar unit which radiates an electromagnetic wave to a target in a forward direction of the vehicle and receives reflection beams from the target to detect the target. A scanning control unit performs a beam scanning of the radar unit to the target so that the reflection beams during the beam scanning are received. A center direction determining unit detects a distribution pattern of the received reflection beams with respect to respective scanning angles of the radar unit, performs a similarity approximation of the distribution pattern by using an antenna directional gain pattern of the radar unit to produce an approximated distribution pattern, and determines a direction of a center of the target based on a peak of the approximated distribution pattern.

Compact scanning techniques that can scan a large degree optical solid angle are disclosed. One particular embodiment is a processor controlled scanner that is capable of a large degree optical solid scan angle. Dual axis scan capability can be provided with a single compact package. A pivoting ball joint on which a mirror assembly is attached is employed. The mirror assembly is operatively coupled to an actuator assembly (e.g., electro-magnets or piezoelectric based actuators). When control voltage is applied to the actuator assembly, the ball joint to moves thereby moving the integrally attached mirror assembly.

Embodiments of methods and / or apparatus for 3-D volume image reconstruction of a subject, executed at least in part on a computer for use with a digital radiographic apparatus can obtain image data for 2-D projection images over a range of scan angles. For each of the plurality of projection images, an enhanced projection image can be generated. In one embodiment, through the application of a resolution increasing interpolator, a prescribed CBCT routine scanning mode with preset binning can increase a spatial resolution, Nyquist frequency or MTF.

A system and method for managing access to a satellite-based transponder by a plurality of aircraft each having a mobile radio frequency (RF) system. The system employs a ground-based, central control system for managing access to the satellite-based transponder so that the aggregate power spectral density (PSD) of the RF signals of all the mobile systems does not exceed, at any time, limits established by regulatory agencies to prevent interference between satellite systems. This is accomplished by a dual control loop arrangement for monitoring the signal-to-noise ratio (Eb / No) of the RF signal transmitted by the satellite-based transponder. A ground-based control loop is used whereby a ground-based central controller monitors the Eb / No and transmits commands to the aircraft (via the satellite transponder) to maintain the Eb / No of the transmitted signal within a predetermined range. A fast scan angle compensation is used by the mobile system of the aircraft to implement another control loop to further adjust the transmit power. This control loop maintains the Eb / No of the signal transmitted to the satellite-based transponder at the commanded level inbetween updates from the ground-based central controller.

A 2-D beam scan method using a galvanometer mirror and a polygon scanner has a problem that the polygon scanner is large and noises are increased. Also, a method of oscillating a compact mirror has a problem that a brightness distribution is produced depending on a scan angle. Hence, a beam is scanned while a relatively small mirror, such as an MEMS mirror, is oscillated at or in the vicinity of the resonance frequency. In this instance, the scan angle is corrected with the use of a correction optical system for uniform illumination to be achieved.

The present invention is a wide band GaAs microwave monolithic integrated circuit (MMIC) transmit chip that is capable of transmitting linearly or circularly polarized signals when connected to a pair of orthogonal cross-polarized antennas. In an active phased-array antenna environment, this transmit chip is capable of transmitting signals with different scan angles. This invention also contains a digital serial to parallel converter that uses TTL signal to control the phase shifter and attenuator circuits that are required for controlling the polarization and scan angle of the transmitted signal.

The invention discloses a method for automatically extracting road information in a vehicle-mounted laser scanning point cloud. The method for automatically extracting the road information in the vehicle-mounted laser scanning point cloud comprises the steps that all scanning lines are extracted from the discrete point cloud according to the information, such as the traveling track, the laser point scanning angle and the scanning time, which is recorded by a vehicle-mounted system, and a half scanning line index suitable for data processing is established; the spatial relation between two adjacent points is analyzed, laser point generation clustering is conducted, and dynamic window point sets which can describe the type characteristics of certain types of ground objects are generated; the main geometrical characteristic factors, comprising elevation difference factors and horizontal projection distance factors, of the different ground object window point sets are analyzed; window starting point types are judged according to the main geometrical characteristic factors of the window point sets, movement type dynamic window classification is conducted from a central angle point to the two sides according to the half scanning line index until a non-road-surface point is found; clustering and denoising are conducted on roadside points according to the distribution relation of bottom points of roadside stones and by the adoption of the principle of consistency between the scanning angle and the distance.

A display apparatus includes a scanning assembly that scans about two or more axes, typically in a raster pattern. A plurality of light sources emit light from spaced apart locations toward the scanning assembly such that the scanning assembly simultaneously scans more than one of the beams. The scanning assembly includes a plurality of mirrors that sweep their respective beams through respective regions of an image field. The regions are immediately adjacent so that an overall image is produced by “tiling” of the regions. Because sweeps of the scanning assembly scan a plurality of tiles simultaneously the resolution and / or field of view of a display for a given scan angle and mirror size is increased relative to a single mirror sweeping a single beam. In alternative embodiments, tiling is used for imaging. Also, various approaches to controlling the frequency responses of the various scanners are described, including active control of MEMs scanners and passive frequency tuning.

In the on-vehicle radar apparatus of the present invention, the vertical scanning width of the radar beam is narrowed, before the horizontal scanning, thereby avoiding unnecessary data processing and improving the data processing efficiently. Further, the SIN ratio of the target detection signal is increased, thereby stabilizing the distance detection and its accuracy. The vertical scanning antenna is a single travelling wave excitation antenna (TWEA) constructed by a plurality of antenna elements. At the same time, the horizontal scanning antenna is a multi-channel antenna wherein a plurality of TWEAs is assigned to a plurality of horizontal directions. The horizontal scanning angle is arbitrarily widened by increasing the number of TWEAs.

An apparatus for introducing a light beam into a pupil of an eye of a viewer, to thereby project an image onto a retina of the eye is disclosed, in which a light beam generator generates and outputs a light beam corresponding to the image, a scanning device scans the light beam output by the light beam generator, a guiding device guides the light beam scanned by the scanning device toward the pupil, and an angle modifying device modifies a pupil incident angle at which a center line of a scanning angle of the scanning device enters the pupil.

The invention provides a tag communication device, a tag moving direction detecting system and a tag moving direction detecting method able to detect the moving direction of a moving body attaching a RFID tag thereto by simple processing, and able to easily detect the moving direction even when its moving speed is increased. A scan antenna scans a beam of a transmitted radio wave toward a belt conveyer for conveying baggage with a RFID tag. ID is read from the RFID tag, and reading NO. and a scan angle are related and recorded to a measuring data table, and plot data are generated. These plot data are plotted in an XY coordinate system, and a plot graph is generated. Further, a linear approximate straight line is calculated from this plot graph, and a moving direction of the baggage is detected from an inclination value of the linear approximate straight line.

Embodiments of methods and / or apparatus for 3-D volume image reconstruction of a subject, executed at least in part on a computer for use with a digital radiographic apparatus, can obtain image data for 2-D projection images over a range of scan angles. For each of the plurality of projection images, an enhanced projection image can be generated. In one embodiment, a first scatter intensity distribution through the plurality of projection images can be modulated based on a first scaling function and a SPR to generate a second scatter intensity distribution through the plurality of projection images, which can be combined with the original plurality of projection images.

The invention discloses a large turn angle piezoelectric scanning micromirror integrated by single chips, comprising a micro reflector surface, a piezoelectric micro driver, an angle sensor and a support frame, wherein the reflector surface, the piezoelectric micro driver and the support frame are all manufactured on a same silicon substrate, and the reflector surface and the piezoelectric micro driver are arranged in the structure of the support frame. In the invention, the micromirror is driven by adopting a mode of piezoelectric drive, and the piezoelectric micro driver comprises a plurality of piezoelectric folded beams, therefore, large angle scanning of the micromirror can be realized under lower work voltage. The middle part of the micromirror is supported by a pair of torsion beams to enable the micromirror to rotate around the torsion beams, thereby inhibiting translation outside the micromirror surface and increasing the stability of a system. The invention also integrates the piezoelectric angle sensor and realizes accurate measurement of scanning angles, therefore, an angle detection device is not additionally needed, and the system volume is reduced. The invention can be widely applied to the fields of micro spectrometers, optical imaging and the like.

A direct retinal display (50) for displaying an image on the retina of an eye (62) with a wide field of view. The direct retinal display (50) comprises a scan source (52) that is arranged to generate a scanned optical beam (58), modulated with an image, in two dimensions over a scan angle. The direct retinal display (50) further comprises a diverging reflector (54) in the path of the scanned optical beam (58) that is arranged to reflect the scanned optical beam (58) incident on the diverging reflector (54) outwardly with a magnified scan angle toward a converging reflector (56) that is arranged to reflect the scanned optical beam substantially toward a convergence spot at the pupil (60) of the eye (62) for reconstruction and display of the image on the retina with a wide field of view.

A three-dimensional video laser radar system based on acousto-optic scanning comprises a laser, a laser emission module, a laser receiving module, a signal processing module, a master control circuit module and an upper computer processing program module. The three-dimensional video laser radar system based on acousto-optic scanning overcomes the defects that in a three-dimensional imaging laser radar application based on a traditional scanning method, the imaging speed is low and the size and mass are large, two-dimensional acousto-optic scanning devices are utilized to quickly and flexibly change scanning angles, the scanning angle range and angular resolution, three-dimensional video imaging is achieved, and demands of special occasions with a high imaging speed requirement can be met; meanwhile, the advantages of the small size, light weight, low power consumption and the like of the two-dimensional acousto-optic scanning device are made use of, so the size and weight of the system are greatly reduced.

An optical beam scanning device comprises optical beam scanning means for rotational polygonal mirror to deflect entering luminous flux and scan an object to be scanned with the luminous flux; pre-deflection optical system which shapes a luminous flux emitted from light source means to image the resultant luminous flux onto the optical beam scanning means; and imaging optical system which images the luminous flux from the optical beam scanning means onto the object to be scanned. In the optical beam scanning device, the imaging optical system comprises an imaging optical element that in the entire main scanning area for luminous flux from the optical beam scanning means, the central scanning position has a main scanning direction curvature different from that of the scanning position of the scanning end, and a scanning angle α0 [rad] at which the optical beam scanning means scans the object to be scanned with the luminous flux is defined by the following expression,α0≦π{(2 / N)−(Vr / 3)×10−7}wherein N indicates the number of surfaces of the rotational polygonal mirror and Vr [r.p.m.] indicates the revolution of the rotational polygonal mirror.

An improved counter-top bar code scanner is equipped with a bump protection mechanism and a scan angle adjustment mechanism. The bump protection mechanism is provided in the form of a protective sheath fabricated of a shock-absorbing material. The scan angle adjustment mechanism is provided in the form of a movable bracket adjustably mounted to the scanner housing. If the bracket is mounted to a fixed surface, the bracket remains fixed but permits adjustments of the housing to any of the plurality of positions relative to the fixed surface.

A display apparatus includes an image source that scans about two axes. To offset motion about a first of the axes during sweeps about the second axis, the apparatus includes a structure to produce offsetting motion about the first axis at a scanning rate equal to the twice-scanning rate about the second axis. The offsetting scan can be a ramp or other motion. In one embodiment, the offsetting motion is a resonant sinusoid. The offsetting motion may be produced by an auxiliary scanner such as a mechanical scanner, a piezoelectric scanner, a MEMs scanner or other scanner. Because the offsetting motion is very small, the auxiliary scanner can function with a very small scan angle.

The invention discloses a metamaterial cladding dual-frequency phased array antenna, comprising a cladding structure and an antenna array, the cladding structure is composed of M×N rectangular mushroom-shaped claddings arranged periodically, and the antenna array is coupled by periodically arranged slots The antenna is composed of the same number of slot-coupling antennas as the number of rectangular mushroom-shaped claddings, and each slot-coupling antenna is located vertically below each rectangular mushroom-shaped cladding. The invention solves the problem that the traditional phased array antenna cannot achieve high gain and large-angle scanning in two frequency bands at the same time, and the antenna can realize multi-frequency band operation and low-frequency to high-frequency scanning compensation, so that the scanning angle is greatly improved. There is almost no scanning blind area in the array direction, which is suitable for multi-functional antenna systems.

The invention discloses a grouped wave beam based multi-user precoding method and a device. The method includes the following steps of: a grouped wave beam matrix is constructed based on non-overlapped wave beams, and one or more wave beam groups which at least contain two wave beams are divided up; elements in each column of the grouped wave beam matrix represent the weight vector of a first i wave beam formed by an antenna array; by the utilization of at least one wave beam group, coverage area of a base station community is scanned to acquire non-interfering multiple users, and a precoding matrix of the users is obtained according to the weight vector of the wave beam in the wave beam group and scanning angle of the wave beam group during acquisition of the multiple users; and signals of the users undergo precoding treatment by the utilization of the precoding matrix of the users. According to the method, discrete wave beam scanning is carried out by the adoption of grouped wave beams, multi-user paring users are quickly searched while the multi-user precoding matrix is also provided, and each user will not interfere with other paring users. Therefore, performance of the whole system is raised.

The invention provides a method for forming circular array antenna digital wave beams. Part of adjacent arrays in a circular array consisting of a plurality of arrays form a small circular array, a main wave beam extending outward along the centre of a circle is formed in the normal direction of the arrays in the center of the circular array, so that a circular array can be constructed by taking every array as a center so as to form a wave beam extending outward along the center of the circle, and the whole circular array can form a plurality of wave beams at equal intervals, which cover the 360-degree space; thus the circular array antenna digital wave beams are formed. The method solves the problems of the prior art, and the problems that a planar array antenna cannot simultaneously cover the 360-degree space, and the antenna beamwidth is increased along with the increment of a scanning angle and the antenna gain and angle measurement accuracy are reduced along with the increment of the scanning angle.

The invention discloses a method and a device for the real-time compensation of the roll angle deviation of an airborne laser radar. A roll angle compensation control device and a roll angle driving device are designed mainly. The devices comprise a roll angle compensation controller, a laser Q switch control circuit, a pumping lamp high-frequency pulse power supply and an electro-optic Q switch.The roll angle compensation controller receives the roll angle deviation measured by a GPS / INS combined measuring system, combines a real-time angle measured by a rotary prism optical electric axial angle encoder for making a judgment and outputs a high-level conduction control signal; the signal and a high-frequency pulse signal of the pumping lamp power supply commonly act on the laser Q switchcontrol circuit so that the laser Q switch control circuit outputs the high-voltage pulse signal to the electro-optic Q switch in a control signal connection period so as to control a laser emitter to emit laser pulses in a proper scanning angle area to realize real-time high-precision compensation of the roll angle deviation.