598 results about "Pulsed mode" patented technology

Imaging apparatus includes an illumination assembly, including a plurality of radiation sources and projection optics, which are configured to project radiation from the radiation sources onto different, respective regions of a scene. An imaging assembly includes an image sensor and objective optics configured to form an optical image of the scene on the image sensor, which includes an array of sensor elements arranged in multiple groups, which are triggered by a rolling shutter to capture the radiation from the scene in successive, respective exposure periods from different, respective areas of the scene so as to form an electronic image of the scene. A controller is coupled to actuate the radiation sources sequentially in a pulsed mode so that the illumination assembly illuminates the different, respective areas of the scene in synchronization with the rolling shutter.

A power tool such as an electric drill typically contains a gear train that couples the output spindle of the motor to the tool bit-receiving chuck. The control circuit for the power tool is operable in a ratcheting or pulse mode that causes the output spindle to rotate in discrete incremental amounts. Corresponding methods for controlling the operation of the electric motor of a power tool are also disclosed.

A method of controlling a current command by comparing voltage with a set value needs to vary the set value depending on voltage fluctuation, which involves taking a complicated control. A vector controller for a permanent-magnet synchronous electric motor, according to the present invention, can realize with a simplified configuration a field-weakening operation in a one-pulse mode in a high speed range by providing a current command compensator that corrects a current command by a corrected current command calculated based on a modulation index.

Epitaxial growth of semiconductor materials is carried out by introducing two or more reaction gases along with their carrier gas into a reaction chamber via one or more concentric pipe inlets and a plurality of separately distributed injection ports with a gas distribution system. The reaction gas can be injected into the reaction chamber either continuously or in pulse mode, wherein reaction gases are mixed together or injected alternately into the reaction chamber. The semiconductor materials are deposited on the substrates which are located on the rotating heated susceptor within the reaction chamber.

A method and apparatus for discriminating the types of radiation interacting with an integrated radiation detector having of a pulse-mode operating photosensor which is optically coupled to a gamma-ray scintillator sensor and a neutron scintillator sensor and uses an analog to digital converter (ADC) and a charge to digital converter (QDC) to determine scintillation decay times and classify radiation interactions by radiation type. The pulse processing provides for, among other things, faithful representation of the true energy spectrum of the gamma radiation field and allows for radioisotope identification by searching for the presence of characteristic energy lines in the gamma energy spectrum. The pulse shape discrimination method ensures that the high sensitivity and resolution of the isotope identification function is not affected during operation in mixed neutron-gamma fields.

A group III nitride nanorod light emitting device and a method of manufacturing thereof. The method includes preparing a substrate, forming an insulating film including one or more openings exposing parts of the substrate on the substrate, growing first conductive group III nitride nanorod seed layers on the substrate exposed through the openings by supplying a group III source gas and a nitrogen (N) source gas thereto, growing first conductive group III nitride nanorods on the first conductive group III nitride nanorod seed layers by supplying the group III source gas and an impurity source gas in a pulse mode and continuously supplying the N source gas, forming an active layer on a surface of each of the first conductive group III nitride nanorods, and forming a second conductive nitride semiconductor layer on the active layer.

A system and method for using terahertz radiation to detect and monitor a substance undergoing a change in phase from a liquid phase to a solid phase or vice-versa is disclosed. By employing terahertz radiation in either the pulsed mode or in the continuous-wave (CW) mode, the system can non-invasively monitor these changes. The system uses the principle that matter in a liquid state will absorb and attenuate terahertz radiation to a larger degree than matter in a semisolid or solid state. Most terahertz radiation absorption occurs due to the rotational motions of molecules, i.e. either whole molecules or groups of atoms rotating about molecular bonds.

A method for effective injection seeding is based on continuous wavelength sweeping for matching the injected seeds with one or more longitudinal mode(s) of the slave oscillator in every pulse. This is achieved through rapidly varying laser drive current, as a result of RF modulation. Depending on the modulation parameters, the seeder may be operated in CW or quasi-CW or pulsed mode, with a narrow or broad bandwidth, for injection seeding of single longitudinal mode or multimode. The wavelength and bandwidth of the laser output can be tuned according to the needs. Injection seeding of high repetition rates is achievable. From pulse to pulse, the master-slave resonance persists though may occur at different longitudinal modes upon cavity length fluctuations. Cavity length control and phase locking schemes are consequently not required. The present invention also encompasses an injection seeding laser system, which is constructed in accordance with the inventive method, and a novel application of RF modulated laser diode to spectrum/wavelength control and to producing high power Gaussian beam with narrow pulse width in a stable, reliable, and cost-effective manner.

Optical pump modules using VCSEL arrays are provided to pump optical gain media for achieving high power laser output in CW, QCW and pulse operation modes for operation. Low divergence and symmetric far-field emission from VCSELs are particularly suitable for compact arrays. VCSEL arrays configured as laser pump modules are operable at high temperatures with practically no degradation over a long period of time. VCSEL pump modules are adaptable for side- or end-pumping configurations to pump high power lasers in CW, QCW and pulse mode. Power output from VCSEL pump modules is scalable. Incorporating microlens arrays with the VCSEL arrays improve brightness of the pump modules. High power and high temperature operation of VCSEL modules make it suitable for making compact high power solid state lasers that are operable in small spaces such as, ignition of internal combustion engines, stationary power generation engines and pulsed detonation engines.

An efficient and low-noise solid-state laser is optically pumped by one or more laser diode(s) driven by RF modulated current. The solid-state laser operation is stabilized by the pump source stable in both spectrum and intensity, in conjunction with automatic power control wherein the feedback loop accurately reflects the true drift in the output power. Moreover, the pump efficiency is optimized and the optical noise is minimized by adjusting the diode operation temperature such that the pump wavelength coincides with the absorption peak of the gain medium. By internally or externally modulating the amplitude of the drive current, the pump diode(s) operate in pulsed mode with controllable shape, width, repetition rate, and pulse-to-pulse intervals, which enables essentially constant optical energy produced from each pulse of the solid-state laser in high repetition rates with variable pulse-to-pulse intervals.

Methods of fabricating flexible, free-standing LED structures are provided. An LED structure can be formed on a sapphire substrate, and the surface of the LED structure can then be coated with epoxy and attached to a rigid supporting substrate. A laser lift-off process can be performed using an ultraviolent beam from a high-power pulsed-mode laser and a shadow mask, causing at least a portion of the LED structure to separate from the sapphire substrate. The structure can then be immersed in an acetone bath to dissolve the epoxy and separate the structure from the supporting substrate.

A solid state igniter device for hot restrike of discharge lamps with an associated supply circuit. The ignitor device comprises a primary circuit with at least one solid state switch element controlled to switch to induce in the primary circuit a controlled oscillation phenomenon at a frequency greater than a megahertz and a secondary circuit including a resonant circuit with a high quality factor Q (at least 100), capable of resonating and producing a pulse signal for striking the discharge of the lamp, controlled through the controlled oscillation phenomenon produced in the primary circuit. A control unit acting on the switch element controls the oscillation phenomenon in a pulse mode as a function of the characteristics of the lamp and the power supply, wherein the control unit induces the controlled oscillation phenomenon for a predetermined time duration a programmable number of times in a predetermined time interval.

An apparatus and method for NMR analysis of a plurality of core samples includes a core holder (11) that holds a core sample under pressurized conditions. A radio frequency coil (51) disposed about the core holder (11) generates a pulsed-mode magnetic field component over a sample volume occupied by the core sample. A support structure is removably secured to the respective core holder. A permanent magnet (65A, 65B) has an open configuration such that it is removably disposed into a position within the support structure about the radio frequency coil and the core holder. The open configuration allows the same permanent magnet to be used for NMR analysis of a plurality of core samples without the need for depressurizing the respective core holder and disassembling the core holder and corresponding load frame for each core sample. It also allows multiple core samples to be prepared for NMR analysis while separated from the NMR measurement apparatus.

The invention discloses an on-line actual error compensation system of a sine and cosine encoder, which compensates for an error in the subdivision process of improving the resolution ratio of a sine and cosine output encoder on the basis of the subdivision technology of the sine and cosine output encoder so as to improve the accuracy of a feedback value of the encoder. The system has simple implementation, good using effect and excellent adaptability by combining an on-line actual error compensation method of the sine and cosine encoder with an accuracy compensation device of the sine and cosine encode, wherein the accuracy compensation device comprises a difference compensation period generation module, a sine and cosine data sampling and calculating module, an entire period calculating module, a table look-up module, an output mode selection module, a pulse mode output module, a modulus output module, an error table storage module and a summation module; and the system is suitable for the wide popularization in the fields of position measurement, angle measurement and motion control such as numerical control machine tools, high-accuracy measurement instruments and the like which are outputted by using a sine and cosine signal.

A laboratory NMR methodology (and corresponding laboratory apparatus) defines a sample volume. The method stores downhole tool data corresponding to a hydrocarbon-bearing sample collected from a given subsurface formation. The downhole tool data includes parameters pertaining to magnetic fields used by a downhole tool during a suite of NMR measurements of the given subsurface formation. The sample is positioned in the sample volume of the laboratory apparatus, which applies a static magnetic field in the sample volume. Furthermore, the laboratory apparatus applies a suite of NMR measurements to the sample volume to thereby determine a property of the sample. The NMR measurements of the suite each include a pulse sequence of oscillating magnetic field in conjunction with a pulsed-mode gradient field. The pulsed-mode gradient field is based on the stored downhole tool data corresponding to the sample. A laboratory NMR methodology for optimizing downhole NMR measurements is also described.

A neutron generator includes a sealed envelope providing a low pressure environment for a gas. One end of the envelope defines an ion source chamber. A target electrode is disposed at the other end of the envelope. An extracting electrode is spaced apart from the target electrode by an accelerating gap. The extracting electrode bounds the ion source chamber. A dispenser cathode electrode and grid electrode are disposed in the ion source chamber for inducing ionization in the ion source chamber. The dispenser cathode electrode, the grid electrode and the extracting electrode operate at a positive high voltage potential and the target electrode operates at or near ground potential. This configuration provides an electric field gradient that accelerates ions towards the target electrode to induce collisions of ions with target material, thereby causing fusion reactions that generate neutrons. High voltage power supply circuit means supplies a positive high voltage signal to the electrodes of the ion source. The positive high voltage signal has a low voltage signal component floating on a positive high voltage signal component. For the dispensing cathode electrode, the low voltage signal component can be a DC or AC signal suitable for emitting electrons from the dispensing cathode electrode. For the grid electrode, the low voltage signal component can be a positive pulsed-mode signal (preferably with magnitude in the range between 100 to 300 volts). High voltage insulation surrounds and electrically insulates the high voltage power supply circuit means. Other ion source electrode configurations, such as cold cathode (Penning) ion source and RF-driven ion source, can also be used.

Methods are provided for treating prostate glands or other targeted soft tissue using a solid-state laser. The laser can be operated to generate a pulsed output beam having pulse durations of between 0.1 and 500 milliseconds. The output beam is delivered to the targeted tissue through an optical fiber, preferably terminating in a side-firing probe or diffusing tip. By operating the laser in a long-duration pulse mode, charring of the targeted tissue is initiated quickly, thereby increasing ablation rates and reducing overall procedure time.

A hybrid-technology metal detector, using pulse-induction and sine-wave excitation of the transmitter coil alternately, in rapid succession. The energy stored in the transmitter coil, in the pulsed mode, is used to shock-excite a high-Q circuit formed by the coil and a parallel capacitor into oscillations in the sine-wave mode. The multiplicative action of the circuit Q causes high currents to flow in the transmitter coil, causing high fluxes to be impressed on the searched area, with increased sensitivity as a result. Using a linear coil-current ramp to assess and minimize the coupling between the transmitter and receiver coils permits effective separation of the reactive and resistive components of the target signals, making accurate identification of targets possible.

A control system is provided and includes a catalyst module that generates a multi-mode enable signal based on a catalyst light off enable signal. A transition control module controls transitions between a single pulse mode and multi-pulse mode based on the multi-mode enable signal. The transition control module receives a first torque signal and generates a second torque signal based on the first torque signal. The engine torque control module generates an air per cylinder signal, a throttle area signal, and a spark timing signal based on the second torque signal. The single pulse mode is associated with a single fuel injection pulse per combustion cycle. The multi-pulse mode is associated with multiple fuel injection pulses per combustion cycle.

A coordinated torque control system includes a catalyst module that generates a multi-mode enable signal based on a catalyst light off enable signal. A torque reserve module generates a torque reserve signal based on the multi-mode enable signal, an engine speed signal and an air per cylinder signal. The torque reserve module operates in a multi-pulse mode that is associated with injecting N pulses of fuel into a combustion chamber during a combustion cycle of the engine based on the multi-mode enable signal. N is an integer greater than or equal to 2.

An integrated radiation detector having a pulse-mode operating photosensor optically coupled to a gamma sensing element and a neutron sensing element is disclosed. The detector includes pulse shape and processing electronics package that uses an analog to digital converter (ADC) and a charge to digital converter (QDC) to determine scintillation decay times and classify radiation interactions by radiation type. The pulse shape and processing electronics package determines a maximum gamma energy from the spectrum associated with gamma rays detected by the gamma sensing element to adaptively select a gamma threshold for the neutron sensing element. A light pulse attributed to the neutron sensing element is a valid neutron event when the amplitude of the light pulse is above the gamma threshold.

An imaging device for biochemical or medical samples, the pulse mode light source of which incorporates flash lamps and a rotating mirror in an inclined position, the said mirror reflecting the light emitted by each flash lamp in turn along the same optical path to the sample. The flash lamps are switched on alternately in phases and synchronised with the rotating mirror and the emission light chopper, which comprises two rotating discs. The turning mirror directs the light at the sample from above and/or below, in which case a double-acting transparent scattering plate can be used.