108results about How to "Pulse width adjustable" patented technology

The present invention provides an LCD capable of being driven with various frequencies without deterioration of image quality. According to the present invention, a method of driving an LCD in two-dot inversion for a low vertical frequency and in one-dot inversion for a high vertical frequency is provided. The method determines whether the vertical frequency of the LCD changes, changes the inversion type into one-dot inversion if the vertical frequency is changed from a low frequency to a high frequency, and changes the inversion type into two-dot inversion if the vertical frequency is changed from a high frequency to a low frequency. Moreover, if a flicker is generated when driving in one-dot inversion, the inversion type is changed into two-dot inversion. To avoid the unequal charging generated in the LCD driven in two-dot inversion, the pulse width of the gate signals are adjusted after measuring the load of the data line.

The invention discloses a double-beam multi-functional z scanning optical non-linear measuring device and a double-beam multi-functional z scanning optical non-linear measuring device method. The device uses two light sources and can conveniently switch the light sources; an adjustable attenuation slice is adopted, so laser power is continuously adjustable from 0 and 100 percent; an acoustic optical modulator and a signal generator are adopted, so the pulse width and pulse period of emergent laser are adjustable; and transmission open hole and transmission closed hole data of a sample can be measured and reflecting open hole and transmission open hole data of the sample can also be measured. The device and the method not only can measure nonlinear absorption coefficient and nonlinear refractive index of a transparent sample, but also can measure nonlinear refractive index of a nontransparent sample; and a cold light source serving as an illumination light source is added into the device, a CCD camera is used for observing surface appearance of the sample and an optical filter is used for filtering the effect of the laser, so the measuring accuracy and correctness of the nonlinear absorption coefficient and nonlinear refractive index of the transparent sample and a partially transparent sample are enhanced.

The invention provides a GPS clock synchronization method for a distributed acoustic positioning system, which comprises the steps of: A. when GPS standard time is same as the preset synchronization time, synchronizing by a GPS second pulse triggering system, i.e. establishing time synchronization; B. after the synchronization is begun, according to preset clockc cycle and pulse width, generating a clock signal clkl by common crystal oscillation frequency division, and then generating synchronization pulses with corresponding pulse period and pulse width by clkl frequency division in a synchronizer; and C. when the number of the synchronization pulses reaches the preset number, triggering a GPS second pulse signal to generate a forced zero clearing signal so that all counters count again to eliminate cumulative errors caused by inaccurate common crystal oscillation. The invention is used in the distributed acoustic positioning system and can realize high-precise synchronization among all nodes, less power consumption and low cost.

The invention relates to a z scanning optical nonlinear measurement device and method capable of observing and monitoring in real time. The device mainly comprises a light source modulating and monitoring part, a data collecting part and a luminance observing part. The device adopts two light sources, so that the light sources can be switched conveniently, the pulse width and the pulse period of an emitted laser can be controlled through a signal generator, and the power is adjustable; the data of a transmission open hole and a transmission closed hole of a measured sample can be measured; and the data of a reflection open hole can be measured. According to the invention, the device and the method are suitable for not only the measurement of the nonlinear absorption coefficient and the nonlinear refractive index of a transparent material, but also the nonlinear measurement of an opaque material. A micro-objective, a lighting source and a CCD (Charge Coupled Device) camera are added for a sample moving platform in the device, so that the surface feature of the sample can be observed in real time, and the impact on the measurement data caused by the change of the feather of the sample can be avoided. While an oscilloscope is added to monitor the wave form and the power of the acting laser in real time, and the precision and the accuracy of the nonlinear measurement of material are improved.

Impurity ions are implanted into a semiconductor wafer of which a capacitor insulting film is formed on a principal face. In this impurity ion implantation step, the impurity ions are implanted into the semiconductor wafer in the form of a pulsed beam that repeats ON-OFF operation intermittently.

The invention discloses an intelligent LED (light-emitting diode) video synchronizing impulse stroboscopic supplemental lighting device. The device is composed of an electronic circuit and a shell, wherein the electronic circuit has the following structure: a 220V alternating current is connected with a 24V switching power supply and a synchronization generator, the 24V switching power supply is connected with an LED lamp matrix and a +12V power supply circuit, the +12V power supply circuit is connected with a +5V power supply circuit, a light ray detection circuit is connected with a signal processing circuit, a signal input circuit is connected with the signal processing circuit, the signal processing circuit is connected with a signal output circuit, and the signal output circuit is connected with the LED lamp matrix through an actuator. With the adoption of the device provided by the invention, the phenomena of dazzling, uneven exposure and streaking can be effectively avoided, the synchronous exposure with a frame of a camera and frequency multiplication output of light can be realized, and the problem that the color of the red light in an image shot by a monitoring camera changes from red to yellow during the red light signal of traffic lights is solved.

The invention relates to a laser imaging radar target echo signal simulator in a laser imaging radar guidance semi-physical simulation system, and belongs to the technical field of electro-optical information systems.The target echo signal simulator comprises a reflecting memory card, a target scene generation computer, a synchronizing signal receiver, a signal distributor, an echo signal generator, a light source driving device and a light source array.The target scene generation computer receives target track data transmitted by a simulation computer in real time, generates delay data and pulse width data according to a data generation method and transmits the data to the echo signal generator.Under triggering of a triggering signal, the echo signal generator conducts delaying and widening on the current delay data and the pulse width data, and the light source array is driven by the light source driving device to transmit multiple paths of optical echo signals.The simulator is high in integration level and stability and has the advantage of providing multiple paths of the real-time optical echo signals which are physical, wide in delay range, high in time accuracy and adjustable in pulse width for a tested laser imaging radar sensor.

The invention relates to an explosive detonation property testing system under a pulse high voltage and a tested explosive loading part. The microseond-stage pulse high voltage of the required pulse width is generated by a capacitive energy storage and charging unit and a pulse width control unit, and applied to the tested explosive loading part; then, a tested explosive is ignited by an ignition and explosion propagation unit in time sequence; and finally the high voltage resistance, the time sequence ignition stability, the detonation output property and the like of the tested explosive are measured by utilizing a detonating velocity and detonation voltage testing unit and a high voltage resistant testing unit under the microseond-stage pulse high voltage condition of the required pulse width. The explosive detonation property testing system and the tested explosive loading part are applicable to the explosive detonation property testing under the pulse high voltage, and have the characteristics of low cost, simple structure, adjustable pulse width and the like.

The invention provides a high power factor soft switching three-phase induction coil synthetic heating power supply, three groups of single-phase conversion circuits are adopted, each single-phase conversion circuit adopts a single-phase line for voltage input and adopts a single-phase line voltage diode for rectification respectively, a capacitor is not added for filtering, high-frequency alternating current pulse voltage which can enable output envelope lines to be sine waves and adjust the pulse width is formed by conversion through an inverter circuit, the high-frequency alternating current pulse voltage is inputted into three induction coils which are independent mutually and wound in parallel through resonant load matching of three groups of high-frequency transformers to form synthetic magnetic flux, and eddy current is generated in a workpiece which is heated for heating. Inverter bridges adopt the phase shift power control soft switching technology. Sine wave current outputted by the three single-phase inverter bridges are sampled and converted to alternating current voltage signals, the series connection is adopted for connecting the same frequency and the same phase for addition, square wave signals are formed through a zero-crossing comparison circuit, output pulses can track input square waves through a phase-locked loop circuit, three inverter bridge switching tubes are controlled through a power amplification circuit, a pulse distribution circuit and a driving circuit, and the phase-locked frequency tracking synchronization control is realized.

The present invention provides an LCD capable of being driven with various frequencies without deterioration of image quality. According to the present invention, a method of driving an LCD in two-dot inversion for a low vertical frequency and in one-dot inversion for a high vertical frequency is provided. The method determines whether the vertical frequency of the LCD changes, changes the inversion type into one-dot inversion if the vertical frequency is changed from a low frequency to a high frequency, and changes the inversion type into two-dot inversion if the vertical frequency is changed from a high frequency to a low frequency. Moreover, if a flicker is generated when driving in one-dot inversion, the inversion type is changed into two-dot inversion. To avoid the unequal charging generated in the LCD driven in two-dot inversion, the pulse width of the gate signals are adjusted after measuring the load of the data line.

The invention discloses an all-fiber structural laser system capable of generating high-energy wave-free split rectangular pulse, which aims to solve the technical problems that the current erbium-doped fiber laser has low pulse energy and poor stability and is difficult to realize rectangular pulse output. The all-fiber structural laser system comprises two wavelength division multiplexers, an erbium-doped fiber, a first polarization controller, a polarization dependent isolator, a second polarization controller and an output coupler connected in turn through an intra-cavity single mode fiber, wherein the input ends of the two wavelength division multiplexers are provided with pumping light sources. The length of the erbium-doped fiber is 10 to 20 meters, the total length of the single mode fiber is 5 to 10 meters, and the whole intra-cavity net dispersion is kept in a large positive value. The all-fiber structural laser system has the advantages of simple structure, low price, good stability and the like on application; and compared with a solid laser for generating high-energy rectangular pulse, the all-fiber structural laser system has the advantages of high pumping efficiency, adjustment convenience, good pulse quality and the like, and is easy for fiber coupling.

The invention discloses a square wave generating circuit comprising a high-voltage direct current source, a tank circuit, a semiconductor switch, a charge resistor and a pulse output end used for loading tested equipment under test. Resistance value of the charge resistor can be reasonably selected by connecting the charge resistor in parallel on the pulse output end, so that charging time of semiconductor switch junction capacity can be greatly shortened, and a steep square-wave pulse of a falling edge can be realized; and meanwhile, a high-energy square-wave pulse with adjustable pulse width and level amplitude can be outputted by controlling closing time of the semiconductor switch, wide-range pulse adjustment from nanosecond level to millisecond level can be realized, and square wave generating circuit has the advantages of wide pulse adjustable range, level amplitude, convenience in control, reliable circuit and the like.

The invention discloses a laser dazzler with an adjustable laser beam divergence angle. The laser dazzler comprises a laser emitting device, a concave lens, a convex lens, a transmission motor and a control circuit; the laser emitting device, the concave lens and the convex lens are placed in sequence from left to right and are positioned on the same axis; the distance position between the laser emitting device and the concave lens is fixed, and the distance between the concave lens and the convex lens is changed through the movement of the convex lens; a control circuit comprises a laser emitting module and a motor control module; the laser emitting module is connected with the laser emitting device; the motor control module is connected with the transmission motor. The control circuit ofthe laser dazzler with the adjustable laser beam divergence angle can realize the functions of adjusting pulse frequency, pulse width and emitting power by changing the duty cycle of a driving signalof the laser emitting device.

The invention relates to a semiconductor-laser narrow pulse driving circuit and a working method thereof. The semiconductor-laser narrow pulse driving circuit comprises an external power supply interface circuit, a narrow pulse generating circuit and a MOSFET pulse driving circuit. The external power supply interface circuit provides power for the narrow pulse generating circuit and the MOSFET pulse driving circuit respectively. Through controlling a pulse width and a repetition frequency of a narrow pulse generating circuit trigger signal, a semiconductor laser can acquire a light pulse signal with the continuous adjustable pulse width and the repetition frequency. The trigger signal generated by the narrow pulse generating circuit directly drives a drain electrode switch of a MOSFET driving chip field effect transistor and a grid electrode of the field effect transistor is connected to a stable voltage so that a problem that signal rise time and fall time are too long when a pulse signal is directly used to drive the grid electrode of the field effect transistor can be avoided.

The invention provides a shifting register unit, a driving method, a Gate On Array and a display device. The shifting register unit comprises an input resetting module, a first storing node potentialmaintaining module, a second storing node potential control module, a pull-up node control module, a pull-up node potential maintaining module, a pull-down node control module and a grid driving output module, wherein the pull-up node control module is used for controlling the potential of a pull-up node to be an active level under the control of a second storing node, a second clock signal inputend and a fourth clock signal input end, and controlling the pull-up node and a second voltage input end to be connected or disconnected under the control of a second clock signal input end and a third clock signal input end. Through the adoption of the shifting register unit disclosed by the invention, pulse modulation for a grid driving signal can be controlled by controlling a first clock signal and a second clock signal, so that the pulse width of the grid driving signal is adjustable.

The invention provides a shift register unit, a signal generation unit circuit, a driving method and a display device. The shift register unit comprises a first node control circuit, a second node control circuit and an output circuit. The first node control circuit is used for controlling the potential of a first node. A second node control circuit controls the potential of the second node; and the output circuit is used for controlling and maintaining the potential of the first node and the potential of the second node, controlling the output end to be communicated with the second clock signal end under the control of the potential of the first node, and controlling the output end to be communicated with the second voltage end under the control of the potential of the second node. According to the invention, multi-pulse signals can be output, and the pulse number and the pulse width can be adjusted so as to correspond to threshold voltage compensation time required by different internal compensation circuits.

The invention relates to the field of laser micro-area machining and preparation of electron microscopy in-situ samples, in particular to a device and method for fine machining and forming an electronmicroscopy sample by utilizing a converged laser. The device comprises a femtosecond laser device and converging scanning system, a sample table mechanical numerical control moving system, a coaxialmicroscopic observation and positioning system, a computer centralized data monitoring and visualization system, a damping system and a protective system. The device can be utilized to quickly and conveniently use femtosecond laser to conduct fine machining such as numerical control cutting and punching on various electron microscopy samples such as a metal sheet, an alumina ceramic block and transparent quartz glass, thereby the in-situ electron microscopy sample with the specific shape and notch can be prepared through the device; combining with an in-situ observation technology through an electron microscope, in-situ observation research such as mechanics, electrics and corrosion behaviors can be conducted on some special tissues and structures; and the device has the advantages of being wide in machining area, and high in precision, having no heat-affected zone and no pollution and the like.

An object of the invention is to suppress the amount of heat generated by a light emitting diode and prevent the light emitting diode from being overheated without reducing the amount of emitted light even when the light emitting diode is a high-power light emitting diode. A light emitting device is configured so that one or more light emitting diodes 11 are lighted by a lighting circuit 12. A DC power is converted into a pulse power by a switching regulator 13 of this lighting circuit 12 and the voltage of a pulse power converted by this switching regulator is lowered by an output control portion 14. The pulse width of a pulse power lowered in voltage by this output control portion is adjusted by a pulse width adjusting oscillation means 16, and the current of a pulse power adjusted in pulse width by this pulse width adjusting oscillation means is limited by a limiting resistor 17. The light emitting device is configured so that a pulse power limited in current by this limiting resistor is outputted to a light emitting diode.

The invention discloses a device and method for detecting the thickness of a thermal barrier coating through employing a laser transmission method to excite an IR thermal wave, and the device comprises a signal generator, a power amplifier, a pulse laser, an IR thermal imager and an industrial control computer. The method comprises the steps: employing low-power and high-power pulse laser to carry out the thermal excitation of a thermal barrier coating base body side; collecting the temperature information of the coating side through the IR thermal imager; carrying out the linear fitting of the temperature difference-frame number curve data points under the two types of power; solving the slope and intercept of the fitting line; substituting the thermal diffusivity of the thermal barrier coating and the collection frame frequency of the IR thermal wave, and calculating and obtaining the thickness of the thermal barrier coating. The method overcomes the limitation of a conventional method for detecting the thickness of a thermal barrier coating through employing a coating side flash lamp for the thermal excitation of an IR thermal wave, and the surface of the coating does not need to be painted, so there is no paint layer thickness error and paint pollution risks. The method is wide in application range, and can test the thickness of an alloy base body thermal barrier coating with the poor thermal conductivity and big thickness. Meanwhile, the method employs a non-contact mode, is large in observation area, and is high in accuracy.

The invention discloses an online coding synchronization control system used for coding imaging and a method. The synchronization control system is formed by an upper computer, a microcontroller and a field programmable gate array. In the synchronization control system, through serial port communication, the upper computer sends a sequential control parameter to the microcontroller. The microcontroller decodes and transcodes the acquired sequential parameter. Then the microcontroller controls the field programmable gate array FPGA to realize multipath coded TTL signal output according to the sequential parameter acquired through decoding. Finally, the multipath coded TTL signal is used to trigger a corresponding synchronization work device so as to complete synchronization control respectively. A pulse width of the multipath coded TTL signal and a relative time delay between different signals can carry out on-line coding. Characteristics of on-line real-time configuration, good expansibility and the like are possessed. The system and the method can be applied to the synchronization control fields of gated imaging, fluorescence lifetime imaging and the like.

An LED driving system with power transmission path coincided with data transmission path, having a plurality of LED driving chips, each having a main input end, a main output end, a logic control module, an RGB gray adjustment module, a power supply module, a voltage clamping module, a digital signal extraction module and a signal processing module. The input end of the voltage clamping module is connected with the main output end of the previous LED driving chip, the output end is connected with the main input end of the next LED driving chip The main input end of the LED driving chip is connected with the digital signal extraction module, which then connects with the signal processing module whose output end is connected with the logic control module which has an output end connected with the RGB gray adjustment module.

The invention provides a multi-module pulsed power supply based on energy storage of high-temperature super-conduction pulsing transformers, and belongs to the technical field of pulse power. The multi-module pulsed power supply comprises two or more than two single-module pulsed power supplies, wherein each single-module pulsed power supply consists of primary charging power supplies, discharging switches, a high-temperature super-conduction pulsing transformer, a power diode, a pulsed capacitor and a load; the primary charging power supplies of each single-module pulsed power supply are connected to two ends of a primary winding of the corresponding high-temperature super-conduction pulsed transformer through the corresponding switches in parallel; and each power diode and the corresponding load are serially connected with a secondary winding of the corresponding high-temperature super-conduction pulsed transformer to form a loop. The multi-module pulsed power supply is characterized in that the single-module pulsed power supplies are connected to one another in parallel, and each single-module pulsed power supply is connected with the corresponding pulsed capacitor through a switching circuit switch and is connected with a one-way conduction unit in parallel. The multi-module pulsed power supply based on energy storage of the high-temperature super-conduction pulsing transformers has the advantages that the transmission efficiency is high, pulse amplitudes and pulse widths of outputting current are adjustable, and the voltage of a discharging end of the primary winding is low.

An impulse generation circuit is provided for generating an impulse using a transmission line. Impulse characteristics of the impulse generation circuit are varied with the length of a transmission line rather than the characteristic variation of various devices used therein. The length of the transmission line is adjusted, such that a width of a generated pulse is adjusted. Because an end of the transmission line is short-circuited, the transmission line length can be easily adjusted on a substrate, and a ringing phenomenon due to re-reflection can be removed using termination impedance.

The invention relates to a 1.6-micron wave band pulse type single-frequency linear polarization laser which is characterized by comprising a seed resource laser, a seed isolator, a beam splitter, a raman optical fiber amplifier, an amplification stage isolator, a collimator, a coupling system and a solid laser amplifier which are connected in sequence. The laser has no complex control system and has the advantages of being compact in structure, high in stability and repetition frequency, adjustable in pulse width and the like.

A management circuit for a self-powered microprocessor protection device microprocessor comprises a watchdog circuit, a power monitoring and resetting circuit and a logic enabling circuit, wherein the logic enabling circuit is connected with the output end of the watchdog circuit and the output end of the power monitoring and resetting circuit. When the power monitoring and resetting circuit outputs effective power signals and the watchdog circuit outputs resetting signals, resetting signals of the microprocessor are output. Resetting false operation generated in the power-on and power-off processes of an external power source are avoided. Resetting false operation caused by delayed resetting when a general watchdog circuit is used after the power is connected can be avoided. The power monitoring and resetting circuit is connected with the microprocessor and provides effective signals, synchronous with the watchdog circuit, of the external power source, real-time monitoring of the state of the external power source and synchronizing of the watchdog circuit can be achieved by the microprocessor, and false operation due to the fact that the microprocessor can not forecast the state of the watchdog circuit can be avoided. Based on the synchronous signals, active peripheral circuit management is achieved, and the power consumption is reduced.

The invention discloses an EAST central timing system based on PXI (extension for instrumentation), comprising a master control computer, a database server, PXI master nodes, PXI partial nodes and a separated driver which accesses to the PXI master nodes and the PXI partial nodes, wherein the master control computer, the database server, the PXI master nodes and the PXI partial nodes access to anEAST local area network respectively. In the system, a LabVIEWFPGA technology is adopted, thus system functions are upgraded more flexibly and conveniently. The system can be used to provide nanosecond-level clock signals and trigger signals with adjustable pulse width, selectable polarity and controllable enabling property, and is provided with an event trigger function, a signal acquisition function and a system self-checking function. The system can realize clock synchronization and trigger synchronization among partial nodes accurately and is convenient to expand. In the system, PXI industrial products are selected, and a virtual instrument technology is utilized to realize information interaction between hardware equipment and application programs seamlessly.

The invention relates to a three-terminal modulator for a lower-frequency modulating type radiometer receiver, which is based on a Dicke type modulating receiving system. The three-terminal modulator for the lower-frequency modulating type radiometer receiver is characterized in that the input end of the Dicke type modulating receiving system is provided with the three-terminal modulator, three ports are respectively connected with an antenna, a terminal load and an electronic receiving front end input port, wherein the electronic receiving front end input port is continuously switched between the antenna and the terminal load with a certain frequency. The three-terminal modulator adopts a fast response electromagnetic switch consisting of a reed pipe, a magnet coil and a tubular magneticshielding outer cover as a basic switching unit, a relay inductive load drive integrated circuit comprising a biasing resistor and a negative peak restrain diode as a basic breakover control unit anda CMOS (Complementary Metal Oxide Semiconductor) circuit which is controlled by modulating square signals output by a low-frequency system of the Dicke type modulating electric radiation receiver as a double-phase control voltage generating unit.

The present invention discloses a timing synchronizer for a medical circular accelerator. The timing synchronizer comprises a master control computer, a database server, a local area network host, a plurality of PXIe partial nodes and a plurality of optoelectronic isolation devices. The master control computer, the database server and all the PXIe partial nodes all access the local area network, the PXIe partial nodes are respectively connected with the optoelectronic isolation devices, and the parameters of the clock channels and the triggering channels on the PXIe partial nodes are arranged through the master control computer. The timing synchronizer for the medical circular accelerator selects a reconfiguration I / O module, and establishes the I / O device of user customization; the customization device is large in the number of the channels, fast in the event response speed and simple in system function upgrading and extension; and moreover, the power supplies of each channel unit of an optoelectronic device and an electro-optic device are independent to ensure the independence and communication of the timing synchronizer and peripheral devices.

The invention discloses an adjustable pulse generator which comprises a waveform generation circuit, a waveform delay circuit and a waveform processing circuit. After the waveform generation circuit is powered on, rectangular waves with the adjustable duty ratio and period are periodically generated. The waveform delay circuit delays the rectangular wave for a first time and outputs the delayed rectangular wave as a first output signal, and delays the rectangular wave for a second time and outputs the delayed rectangular wave as a second output signal, wherein the second time is greater than the first time, and the time difference between the two times is adjustable; and the waveform processing circuit performs waveform processing based on the first output signal and the second output signal to obtain a pulse signal with adjustable pulse width, pulse value and pulse period. Visibly, the pulse width, the pulse value and the pulse period of the pulse signal provided by the adjustable pulse generator are adjustable, so that the pulse signal can well simulate the noise signal to be input into the line to test the filtering capability of the line, and the reference value of the line filtering capability test is improved.

The invention discloses a single-photon avalanche photodiode calibration system, relates to the field of quantum communication, and solves the problem of how to accurately and automatically test SPADkey parameters. The system comprises an upper computer, an SPAD calibration system control panel, a picosecond pulse laser, a variable optical attenuator, an SPAD mounting plate and a temperature box;the SPAD calibration system control panel is connected with the picosecond pulse laser; the picosecond pulse laser is connected with the variable optical attenuator; the variable optical attenuator is connected to an SPAD to be tested through an optical fiber, and the mounting plate is provided with a gating signal interface, a bias signal interface and an avalanche signal interface. The SPAD tobe tested is mounted on the mounting plate; the mounting plate is mounted in the temperature box; the calibration system control panel is connected with the upper computer; the invention further provides a single-photon avalanche photodiode calibration method. The system has the advantages that multiple performance parameters of the SPAD to be tested can be tested in a short time, and the system is efficient, convenient, easy to operate and easy to learn.