An optical system comprising: a sensor array having a field of view; an emitter array comprising a plurality of emitter units mounted on a surface of a common substrate and arranged in a two-dimensional array, wherein each emitter unit in the plurality of emitter units is spaced apart from its adjacent emitter units by a first pitch and emits pulses of light having a predetermined beam divergence; and a fly's eye element spaced apart from the emitter array and configured to spread light received from each emitter unit in the plurality of emitter units element across the entire field of view of the sensor array, the fly's eye element comprising a first and second arrays of lenslets spaced apart from each other, wherein individual lenslets in the first and second arrays of lenslets are spaced apart from each other in at least one dimension by a second pitch that is different than the first pitch, and wherein each individual lenslets in the first array of lenslets is aligned with a corresponding lenslet in the second arrays of lenslets.
A radio-frequency (RF) data link can be provided between a stationary base component and a rotating component that rotates about an axis defined by a shaft that has a waveguide core (e.g., a hollow core). The rotating component can include a data source such as one or more sensors. An RF transmitter unit can be disposed in the rotating component and can have a first antenna oriented to transmit into one end of the waveguide core of the shaft. The base component can include an RF receiver unit that can have a second antenna located at the other end of the shaft and oriented to receive RF signals through the waveguide core of the shaft. The waveguide core of the shaft can provide a waveguide for RF data transmissions (e.g., in the millimeter-wave band) between the first antenna and the second antenna.
G01S 17/10 - Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
G01L 3/10 - Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft involving electric or magnetic means for indicating
H04B 7/26 - Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
A chaise lounge includes a frame, a first sling anchor, a second sling anchor, a sling and a threaded fastener. The frame includes at least two side members. The first sling anchor connects with a first side member and is movable with respect to the frame. The second sling anchor connects with a second side member. The second side member is disposed on an opposite side of the frame from the first side member. The sling is secured to the first sling anchor and the second sling anchor and spans between the first side member and the second side member. The threaded fastener engages the first sling anchor and the first side member. Rotation of the threaded fastener with respect to at least one of the first sling anchor and the first side member results in movement of the first sling anchor with respect to the first side member, which results in movement of the sling with respect to the first side member.
A chaise chair includes a frame, a main seat attached to the frame, a backrest pivotally attached to the frame, and a mount connected with and selectively movable with respect to the frame. The backrest is pivotal between a lowered position and a raised position. A locking mechanism is associated with the mount and is operable between a locked state in which the mount is precluded from movement with respect to the frame and an unlocked state in which the mount is movable with respect to the frame. A linkage connects with the mount and the backrest and is configured such that movement of the mount with respect to the frame results in pivotal movement of the backrest with respect to the frame. A release mechanism is operatively associated with the locking mechanism so as to change the locking mechanism from the locked state to the unlocked state.
A47C 1/024 - Reclining or easy chairs having independently-adjustable supporting parts the parts, being the back-rest, or the back-rest and seat unit, having adjustable inclination
A61G 13/08 - Adjustable operating tables; Controls therefor the table being divided into different adjustable sections
A47C 1/03 - Reclining or easy chairs having independently-adjustable supporting parts the parts being arm-rests
A47C 1/032 - Reclining or easy chairs having coupled adjustable supporting parts the parts being movably-coupled seat and back-rest
A47C 17/16 - Sofas, couches, settees, or the like, with movable parts; Chair beds changeable to beds by tilting or pivoting the back-rest
A63B 21/055 - Exercising apparatus for developing or strengthening the muscles or joints of the body by working against a counterforce, with or without measuring devices using resilient force-resisters extension element type
A47C 1/028 - Reclining or easy chairs having independently-adjustable supporting parts for changing a straight chair into an easy chair
5.
TABLE OR OUTDOOR ITEM COVER AND COVER-SECURING SYSTEM
A cover for covering an outdoor item includes a weather-resistant main body, at least one flap secured to the main body and a magnetic fastener secured to the at least one flap. The weather-resistant main body includes a main body perimeter and is sized and shaped substantially similar to at least a portion of the outdoor item to be covered. The at least one flap extends from the main body perimeter. The at least one flap is flexible and sized to selectively fold over another portion of the outdoor item to be covered when the main body is covering a covered portion of the outdoor item. The magnetic fastener selectively engages with a fastener provided on the outdoor item, and engagement of the magnetic fastener with the associated fastener holds the main body to the outdoor item.
Circuits, methods, and apparatus that can provide lidar systems having an increased dynamic range. One example can provide a lidar system having emitter elements to emit optical signals and sensor elements to detect incident photons. The emitter elements can emit a first optical signal having a series of pulses at a first power level and a second optical signal having a series of pulses at a second power level. Following first pulses, the sensor elements can determine a number of photons detected during a first number of time bins that begin with an initial time bin and extend to a first time bin. Following the second pulses, the sensor elements can determine a number of photons detected during a second number of time bins beginning with the initial time bin and extending to a second time bin. The second power level can differ from the first power level and the second number can differ from the first number.
G01S 7/4865 - Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak
H01L 31/107 - Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier or surface barrier the potential barrier working in avalanche mode, e.g. avalanche photodiode
G02B 27/18 - Optical systems or apparatus not provided for by any of the groups , for optical projection, e.g. combination of mirror and condenser and objective
G02B 27/09 - Beam shaping, e.g. changing the cross-sectioned area, not otherwise provided for
7.
OPTICAL SYSTEM FOR FULL FRAME FLASH SOLID-STATE LIDAR SYSTEM
A solid-state optical system comprising: a sensor array having a field of view; an emitter array arranged in a two-dimensional array, wherein each emitter unit is spaced apart from its adjacent emitter units by a first distance and emits pulses of light having a predetermined beam divergence; an optical element comprising a plurality of lenses corresponding in number to the emitter units and arranged in a two-dimensional array, wherein the optical element is positioned adjacent to the emitter array such that each lens is spaced apart from and receives the pulses of light emitted from a corresponding emitter unit and is configured to reduce the angle of divergence of the pulses of light emitted by its corresponding emitter unit; and a diffuser disposed adjacent to the optical element and configured to spread light received from the optical element across the entire field of view of the sensor array.
Embodiments describe in-pixel sensor fault detection system that includes plurality of photodetectors to generate signals when a photon is detected, and the number of photons detected for each photosensor is accumulated through a first data path to obtain a first number of total triggered photodetectors of the corresponding photosensor through a first data path and stored in a memory. The memory stores photon counts in time bins based on photon arrival times to form a histogram representation. The number of photons detected for each photosensor is accumulated through a second data path to obtain a second number of total triggered photodetectors of each corresponding photosensor in an integration register. The first number of total triggered photodetectors is compared against the second number of total triggered photodetectors. When the comparison returns an inconsistency, the system flags the corresponding photosensor for further possible actions.
A lidar system may include a programmable configuration memory, configured to receive configuration values for controlling histogramming operations performed by the lidar system. The lidar system may also include an array controller, configured or programmed or set to read the configuration values and send control signals according to the configuration values in the programmable configuration memory. The lidar system may also include a sensor array, where the sensor array includes a plurality of pixels. Each pixel in the plurality of pixels may include a photosensor, summation circuitry, and a memory device. Each of the plurality of pixels may be configured to generate histogram data by collecting photon counts during a plurality of time bins for each of a plurality of laser cycles.
G01S 17/04 - Systems determining the presence of a target
G01S 17/88 - Lidar systems, specially adapted for specific applications
G01S 17/10 - Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
G06T 7/44 - Analysis of texture based on statistical description of texture using image operators, e.g. filters, edge density metrics or local histograms
10.
COAXIAL LIDAR SYSTEM USING A DIFFRACTIVE WAVEGUIDE
A coaxial lidar system includes one or more emitter channels and one or more sensor channels that share an optical module. A diffractive waveguide can be used to redirect received light from the shared optical module to the sensor channels.
G01S 7/481 - Constructional features, e.g. arrangements of optical elements
G01S 7/48 - RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - Details of systems according to groups , , of systems according to group
G01S 17/02 - Systems using the reflection of electromagnetic waves other than radio waves
G01S 17/88 - Lidar systems, specially adapted for specific applications
G01S 17/931 - Lidar systems, specially adapted for specific applications for anti-collision purposes of land vehicles
11.
LIDAR SYSTEM WITH FOG DETECTION AND ADAPTIVE RESPONSE
A LIDAR system can automatically determine, based on analysis of data collected from the sensor channels during operation, whether fog is present. If fog is present, the LIDAR system can operate in a fog mode, and if fog is not present, the LIDAR system can operate in a clear-air mode. The two modes can differ from each other with respect to the emitter signals and/or the signal processing applied to the sensor data.
A stereoscopic imager system, comprising: a sensor array comprising a first plurality of photosensors and a second plurality of photosensors spaced apart from the first plurality of photosensors by a gap, the first plurality of photosensors and the second plurality of photosensors being configured to detect ambient light in a scene; a moving component coupled to the sensor array and operable to move the sensor array between a first position and a second position within a full rotational image capturing cycle; and a system controller coupled to the sensor array and the moving component. The system controller can be configured to: move a field of view of a sensor array by instructing the moving component to capture a first image of an object in the scene with the first plurality of photosensors from a first perspective at the first position, and to capture a second image of the scene of the object in the scene with the second plurality of photosensors from a second perspective at the second position; and calculate, based on the first image and the second image, a distance to the object using an optical baseline defined by the gap.
G01S 17/89 - Lidar systems, specially adapted for specific applications for mapping or imaging
G06T 7/55 - Depth or shape recovery from multiple images
H04N 13/239 - Image signal generators using stereoscopic image cameras using two 2D image sensors having a relative position equal to or related to the interocular distance
G08B 13/194 - Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems using image scanning and comparing systems
13.
PROCESSING TIME-SERIES MEASUREMENTS FOR LIDAR ACCURACY
An optical measurement system may include a light source and corresponding photosensor configured to emit and detect photons reflected from objects in a surrounding environment for optical measurements. An initial peak can be identified as resulting from reflections off a housing of the optical measurement system. This peak can be removed or used to calibrate measurement calculations of the system. Peaks resulting from reflections off surrounding objects can be processed using on-chip filters to identify potential peaks, and the unfiltered data can be passed to an off-chip processor for distance calculations and other measurements. A spatial filtering technique may be used to combine values from histograms for spatially adjacent pixels in a pixel array. This combination can be used to increase the confidence for distance measurements.
An optical measurement system may include a plurality of light sources and a plurality of photosensors, where the photosensors are configured to receive photons from the light sources that are reflected off objects in the surrounding environment. Photons may be stored in memory blocks corresponding to the photosensors to form histograms of the receive photons. A select circuit may be used to share memory blocks between photosensors, such that a plurality of photosensors may write to a single memory block, or a single photosensor may write to a plurality of memory blocks. Sampling clock cycles for the photosensors may be adjusted relative to the clock cycles for the memory blocks based on the select circuit output.
H02K 3/04 - Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
G06F 3/06 - Digital input from, or digital output to, record carriers
G11C 29/02 - Detection or location of defective auxiliary circuits, e.g. defective refresh counters
G06F 13/28 - Handling requests for interconnection or transfer for access to input/output bus using burst mode transfer, e.g. direct memory access, cycle steal
G01S 17/00 - Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
Systems and methods are provided for processing lidar data. The lidar data can be obtained in a particular manner that allows reconstruction of rectilinear images for which image processing can be applied from image to image. For instance, kernel-based image processing techniques can be used. Such processing techniques can use neighboring lidar and/or associated color pixels to adjust various values associated with the lidar signals. Such image processing of lidar and color pixels can be performed by dedicated circuitry, which may be on a same integrated circuit. Further, lidar pixels can be correlated to each other. For instance, classification techniques can identify lidar and/or associated color pixels as corresponding to the same object. The classification can be performed by an artificial intelligence (AI) coprocessor. Image processing techniques and classification techniques can be combined into a single system.
An optical measurement system may improve the accuracy with which it estimates distances to surrounding objects by upgrading various aspects of its data path. Spatial resolution may be increased by subdividing histogram buckets or integration registers based on spatial location. Saturation at any point in the data path can be detected and used to stop counting photons in individual pixels, which can then be normalized after a measurement is over. Multiple peaks can be detected using recursive or iterative techniques to identify a largest remaining peak at each stage. Instead of iterating through the histogram memory multiple times, a threshold can be pre-calculated based on an estimated ambient noise level, and peaks can be detected in a single pass.
G01S 17/88 - Lidar systems, specially adapted for specific applications
G01S 17/89 - Lidar systems, specially adapted for specific applications for mapping or imaging
G01S 17/10 - Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
G01S 7/483 - RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - Details of systems according to groups , , of systems according to group - Details of pulse systems
H01L 31/107 - Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier or surface barrier the potential barrier working in avalanche mode, e.g. avalanche photodiode
17.
SYNCHRONIZED IMAGE CAPTURING FOR ELECTRONIC SCANNING LIDAR SYSTEMS
Embodiments describe an electronically scanning optical system including an emitter array configured to emit light into a field, a time of flight (TOF) sensor array configured to detect emitted light reflected back from the field, an image sensor array configured to detect ambient light in the field, where a field of view of the emitter array corresponds to a field of view of the TOF sensor array and at least a subset of a field of view of the image sensor array. The optical system further including an emitter controller configured to activate a subset of the plurality of light emitters at a time, a TOF sensor controller configured to synchronize the readout of individual TOF photosensors concurrently with the firing of corresponding light emitters, and an image sensor controller configured to capture an image that is presentative of the field during the emission cycle.
A LIDAR system having light emitters and light detectors can apply per-shot jitter to create variation in the interval between successive emitter pulses. Operation of the detectors can be synchronized with operation of the emitters so that a consistent time of flight measurement corresponds to a consistent distance. Application of per-shot jitter can reduce the effect of crosstalk from other sources of pulsed light and can also reduce range aliasing effects.
Methods are provided for using a light ranging system of a vehicle. A computing system receives, from light ranging devices, ranging data including distance vectors to environmental surfaces. A distance vector can correspond to a pixel of a three-dimensional image stream. The system can identify a pose of a virtual camera relative to the light ranging devices. The light ranging devices are separated from the pose by first vectors that are used to translate some of the distance vectors using the first vectors. The system may determine colors associated with the translated distance vectors and display pixels of the three-dimensional image stream using the colors at pixel positions specified by the translated distance vectors. The system may use one or more vehicle models with the ranging data to provide semantic labels that describe a region that has been, or is likely to be, in a collision.
A multispectral sensor array can include a combination of ranging sensor channels (e.g., LIDAR sensor channels) and ambient light sensor channels tuned to detect ambient light having a channel specific property (e.g., color). The sensor channels can be arranged and spaced to provide multispectral images of a field of view in which the multispectral images from different sensors are inherently aligned with each other to define an array of multispectral image pixels. Various optical elements can be provided to facilitate imaging operations. Light ranging/imaging systems incorporating multispectral sensor arrays can operate in rotating and/or static modes.
The present disclosure provides for a protective covering, which includes a cover portion, an elongated piece of fabric, a first coupling mechanism, and a second coupling mechanism. The cover portion is for a seat cushion. The elongated piece of fabric extends from the cover portion. The first coupling mechanism couples the cover portion to a first end of the elongated piece of fabric. The second coupling mechanism is configured to couple the cover portion to a second end of the elongated piece of fabric.
The present disclosure is directed to an outdoor cushion. The disclosed outdoor cushion includes a body portion and a cover for the body portion. The cover includes a water resistant fabric housing and a vent. The vent corresponds to a first side of the body portion. In some examples, the outdoor cushion further includes a water resistant exterior cover. In some examples, the body portion is a foam cushion, for example, made of memory foam. The disclosed outdoor cushion therefore allows air exhaust when pressure is applied to the cushion (for example, when a user sits down), but does not allow for water retention or absorption.
Methods, systems, and devices are provided for calibrating a light ranging system and using the system to track environmental objects. In embodiments, the approach involves installing light ranging devices, such as lidar devices, on the vehicle exterior. The light ranging system may be calibrated using a calibration device to scan the vehicle exterior and construct a three-dimensional model of the vehicle exterior comprising the positions of the installed light ranging devices on the vehicle exterior. The calibrated light ranging system may use the model in conjunction with ranging data collected by the installed light ranging devices to track objects in the environment. In this way, the light ranging system may detect a proximity of environmental objects and help a driver of the vehicle avoid potential collisions. The light ranging system may further measure the vehicle exterior and thereby detect changes to the vehicle exterior.
A light ranging system including a shaft; a first circuit board assembly that includes a stator assembly comprising a plurality of stator elements arranged about the shaft on a surface of the first circuit board assembly; a second circuit board assembly rotationally coupled to the shaft, wherein the second circuit board assembly includes a rotor assembly comprising a plurality of rotor elements arranged about the shaft on a surface of the second circuit board assembly such that the plurality of rotor elements are aligned with and spaced apart from the plurality of stator elements; a stator driver circuit disposed on either the second or the first circuit board assemblies and configured to provide a drive signal to the plurality of stator elements, thereby imparting an electromagnetic force on the plurality of rotor elements to drive a rotation of the second circuit board assembly about the shaft; and a light ranging device mechanically coupled to the second circuit board assembly such that the light ranging device rotates with the second circuit board assembly.
G01S 17/89 - Lidar systems, specially adapted for specific applications for mapping or imaging
G01S 7/00 - RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - Details of systems according to groups , ,
G01S 17/88 - Lidar systems, specially adapted for specific applications
G02B 26/08 - Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
26.
LIGHT RANGING DEVICE WITH ELECTRONICALLY SCANNED EMITTER ARRAY AND SYNCHRONIZED SENSOR ARRAY
Embodiments describe a solid state electronic scanning LIDAR system that includes a scanning focal plane transmitting element and a scanning focal plane receiving element whose operations are synchronized so that the firing sequence of an emitter array in the transmitting element corresponds to a capturing sequence of a photosensor array in the receiving element. During operation, the emitter array can sequentially fire one or more light emitters into a scene and the reflected light can be received by a corresponding set of one or more photosensors through an aperture layer positioned in front of the photosensors. Each light emitter can correspond with an aperture in the aperture layer, and each aperture can correspond to a photosensor in the receiving element such that each light emitter corresponds with a specific photosensor in the receiving element.
Methods and systems can augment 360 degree panoramic LIDAR results (e.g., from a spinning LIDAR system) with color obtained from color cameras. A color-pixel-lookup table can specify the correspondence between LIDAR pixels (depth/ranging pixels) and color pixels, which may be done at different viewing object distances. The operation of the color cameras can be triggered by the angular positions of the LIDAR system. For example, a color image of a particular camera can be captured when the LIDAR system is at a particular angular position, which can be predetermined based on properties of the cameras (e.g., shutter speed). Alternatively or in addition, a common internal clock can be used to assign timestamps to LIDAR and color pixels as they are captured. The corresponding color pixel(s), e.g., as determined using a color-pixel-lookup table, with the closest timestamp can be used for colorization.
Embodiments describe optical imagers that include one or more micro-optic components. Some imagers can be passive imagers that include a light detection system for receiving ambient light from a field. Some imagers can be active imagers that include a light emission system in addition to the light detection system. The light emission system can be configured to emit light into the field such that emitted light is reflected off surfaces of an object in the field and received by the light detection system. In some embodiments, the light detection system and/or the light emission system includes micro-optic components for improving operational performance.
A light ranging system can include a laser device and an imaging device having photosensors. The laser device illuminates a scene with laser pulse radiation that reflects off of objects in the scene. The reflections can vary greatly depending on the reflecting surface shape and reflectivity. The signal measured by photosensors can be filtered with a number of matched filter designed according to profiles of different reflected signals. A best matched filter can be identified, and hence information about the reflecting surface and accurate ranging information can be obtained. The laser pulse radiation can be emitted in coded pulses by allowing weights to different detection intervals. Other enhancements include staggering laser pulses and changing an operational status of photodetectors of a pixel sensor, as well as efficient signal processing using a sensor chip that includes processing circuits and photosensors.
G02B 6/00 - Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
G01J 1/00 - Photometry, e.g. photographic exposure meter
G01J 1/02 - Photometry, e.g. photographic exposure meter - Details
G01J 1/08 - Arrangements of light sources specially adapted for photometry
G01J 1/24 - Photometry, e.g. photographic exposure meter by comparison with reference light or electric value intensity of the measured or reference value being varied to equalise their effects at the detector, e.g. by varying incidence angle using a variable element in the light-path, e.g. filter, polarising means using electric radiation detectors
30.
OPTICAL SYSTEM FOR COLLECTING DISTANCE INFORMATION WITHIN A FIELD
An optical system for collecting distance information within a field is provided. The optical system may include lenses for collecting photons from a field and may include lenses for distributing photons to a field. The optical system may include lenses that collimate photons passed by an aperture, optical filters that reject normally incident light outside of the operating wavelength, and pixels that detect incident photons. The optical system may further include illumination sources that output photons at an operating wavelength.
Optical systems and methods for collecting distance information are disclosed. An example optical system includes a first transmitting optic, a plurality of illumination sources, a pixel array comprising at least a first column of pixels and a second column of pixels, each pixel in the first column of pixels being offset from an adjacent pixel in the first column of pixels by a first pixel pitch, the second column of pixels being horizontally offset from the first column of pixels by the first pixel pitch, the second column of pixels being vertically offset from the first column of pixels by a first vertical pitch; and a set of input channels interposed between the first transmitting optic and the pixel array.
B23P 17/00 - Metal-working operations, not covered by a single other subclass or another group in this subclass
G02B 6/04 - Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres
G02B 6/06 - Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres the relative position of the fibres being the same at both ends, e.g. for transporting images
H01L 21/00 - Processes or apparatus specially adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
H01L 21/302 - Treatment of semiconductor bodies using processes or apparatus not provided for in groups to change the physical characteristics of their surfaces, or to change their shape, e.g. etching, polishing, cutting
32.
SYSTEMS AND METHODS FOR CALIBRATING AN OPTICAL DISTANCE SENSOR
A calibration system is provided including an aperture layer, a lens layer, an optical filter, a pixel layer and a regulator. The aperture layer defines a calibration aperture. The lens layer includes a calibration lens substantially axially aligned with the calibration aperture. The optical filter is adjacent the lens layer opposite the aperture layer. The pixel layer is adjacent the optical filter opposite the lens layer and includes a calibration pixel substantially axially aligned with the calibration lens. The calibration pixel detects light power of an illumination source that outputs a band of wavelengths of light as a function of a parameter. The regulator modifies the parameter of the illumination source based on a light power detected by the calibration pixel.
G01N 21/01 - Arrangements or apparatus for facilitating the optical investigation
G01N 21/17 - Systems in which incident light is modified in accordance with the properties of the material investigated
G11B 7/125 - Optical beam sources therefor, e.g. laser control circuitry specially adapted for optical storage devices; Modulators, e.g. means for controlling the size or intensity of optical spots or optical traces
patents
