44results about How to "Avoid strobe" patented technology

The invention discloses a controlled-silicon adapting LED (light-emitting diode) driving circuit, method and switch power supply. The input voltage signal of the representing sine half-wave voltage signal is compared with a threshold voltage to obtain a first comparison pulse signal, and then the effective width of the first comparison pulse signal is extended for a period of time to obtain a first control signal, wherein the first control signal controls a power switch tube switches off before the input current is reduced to be equal to the maintenance current of a controlled silicon, and the power switch tube switching-off state is made to last for a period of time to the next cycle, so that the load current of the controlled silicon is made to be larger than the maintenance current all the way in the conducting time interval of the controlled silicon, the controlled silicon does not need to be re-conducted irregularly for many times, the input power of the system in each half cycle is same, and LED lamp is prevented from flicking under load and generating noise.

The invention discloses a ripple suppression circuit, a ripple suppression method, and an LED lamp applying the ripple suppression circuit. Ripple reference voltage for representing the ripple is obtained by sampling the ripple from the output voltage of a direct current converter; and controlling the voltage at a load end to change along with the ripple by a transistor based on the ripple reference voltage. Consequently, the voltages at the two ends of the load change along with the ripple so as to enable the voltages of the load to be reduced to constant voltage; and therefore, the ripple acting on the load can be suppressed or eliminated, and the flicker or stroboflash of the LED load is avoided.

The invention discloses an LED drive circuit structure with a separated switching tube. The LED drive circuit structure with the separated switching tube comprises a series connection topological structure, an input voltage detection unit, a load current detection unit and a control unit. The series connection topological structure comprises one or more series connection drive modules. The input voltage detection unit and the load current detection unit are respectively connected with the control unit. The input voltage detection unit is used for detecting the input voltage of the series connection topological structure, and outputting information of the input voltage to the control unit. The load current detection unit is used for detecting a load current of each series connection drive module, and outputting information of the load currents to the control unit. The control unit is connected with the grid electrode of an MOS tube in each series connection drive module, and is used for controlling the voltage of the grid electrode of each MOS tube according to the information of the input voltage and the information of the load currents, so that the load currents are in direct proportion to the input voltage when LED strands are conductive. By means of the LED drive circuit structure, drive efficiency is improved, a power factor of a circuit is improved, and the compatibility between the circuit and a TRIAC light modulator is improved.

The invention relates to a temperature detecting device, a temperaure detecting method and a liquid crystal driving device. The temperature detecting device comprises a state machine, a frame frequency selection unit and a frame frequency output unit. When a current temperature value jumps around a certain critical temperature value, the state machine judges whether the difference value of the current temperature value and the critical temperature value is within the preset range; if the difference value of the current temperature value and the critical temperature value is within the preset range, the state machine determines that the current state is the previous state; if the difference value of the current temperature value and the critical temperature value is out of the preset range, the state machine determines that the current state is the state corresponding to the current temperature value. The frame frequency selection unit connected with the state machine is used for selecting the frame frequency corresponding to the current state according to the current state determined by the state machine. The frame frequency output unit connected with the frame frequency selection unit is used for outputting the frame frequency. When the temperature jumps frequently in a smaller range, the temperature detecting device can avoid the frequent jump of the frame frequency and the flicker of a liquid crystal display screen caused by the frequent jump of the frame frequency, and thus the display quality of liquid crystal display screen is enhanced.

The present invention relates to an intelligent acousto-optic controller, which includes a power module, an infrared remote controller, a keyboard module, and an AC / DC constant current power module. Further, the intelligent acousto-optic controller includes an audio receiving module, an audio encoding and decoding module, a mixed audio control transmitting module, an audio input interface, an infrared receiving module, a mixed audio radio receiving and decoding control module, and a power amplifier loudspeaker module. The mixed audio control transmitting module and the mixed audio wireless receiving and decoding control module are connected wirelessly. Further, the power amplifier loudspeaker module is electrically connected to the mixed audio wireless receiving and decoding control module. The mixed audio wireless receiving and decoding control module is electrically connected to the AC / DC constant current power module. The present invention can realize acousto-optic control in an integrated way.

The invention provides a solar direct-current supply station which comprises a solar photovoltaic battery, a storage battery, a solar electricity-generating controller, a complementation charging controller, a mains supply charging module, a storage battery discharging module and a direct-current load. The solar electricity-generating controller is used for adjusting and controlling electric energy converted by the solar photovoltaic battery, sending the adjusted energy to the direct-current load on one hand, and sending the excess energy to the storage battery for storing on the other hand. When electricity generated by the solar photovoltaic battery can not meet the need of the direct-current load, the controller sends the electric energy of the storage battery to the direct-current load through the discharging module. The complementation charging controller is used for controlling the mains supply charging module to charge the storage battery when the electric energy of the storage battery is insufficient, and therefore the storage battery can supply direct currents continuously to the direct-current load. The solar direct-current supply station can provide the stable and continuous direct currents for villages, pasturing areas, mountainous areas and the like where power supply of a public power grid is unstable, and illumination and life of users are facilitated.

The invention discloses a parking stall guiding method and device. The method includes obtaining a plurality of vehicle-free state frame images of a parking stall, and adding to a background queue; when stroboflash of a parking stall indicator light is judged to occur, obtaining a current frame image of the parking stall; calculating Euclidean distance between an HOG feature of the current frame image and an HOG feature of each vehicle-free state frame image in the background queue, and determining a parking stall state of the current frame image; and controlling the turning-on state of the parking stall indicator light through the parking stall state of the current frame image. The method solves the problem of stroboflash of the indicator light.

The invention provides a PWM dimming device, which comprises a dimming signal interface circuit, a drive circuit, a driving power output interface circuit and a control circuit, wherein the dimming signal interface circuit is used for receiving a dimming signal; the drive circuit outputs driving voltage or driving current and the work period is Td; the driving power output interface circuit is connected with a load; the control circuit receives the dimming signal from the dimming signal interface circuit, generates a PWM signal and outputs the PWM signal to the drive circuit; and the control circuit generates the PWM signals with different frequencies during PWM dimming and normal operation of lighting equipment. After the dimming method is adopted, the PWM dimming device can be compatible with dimmer switches at different dimming levels, so that stroboflash can be effectively avoided during normal operation, and meanwhile, a more smooth and softer dimming effect can be obtained

The invention provides a direct drive LED lighting system controlled by an integrated control circuit. The direct drive LED lighting system controlled by the integrated control circuit comprises a constant-voltage unit and direct drive LED lighting devices. At least two direct drive LED lighting devices are connected between the direct current high-voltage output end VH and the reference ground end GND in parallel. Each direct drive LED lighting device comprises multiple LED circuits. Each LED circuit comprises at least two controlled LED particle circuit units and a normally-on LED particle circuit unit connected with the controlled LED particle circuit units in series. Each LED circuit is provided with at least two direct drive LED integrated control circuits. Each direct drive LED integrated control circuit is connected with at least one controlled LED particle circuit unit in the corresponding LED circuit unit. The direct drive LED integrated control circuits at least have the following functions of making a response to input information and controlling LED particles in the controlled LED particle circuit units to be switched on and short-circuited.

An LED driving device and its method are suitable for driving and regulating an illumination brightness of at least one LED. After switching the phase angle of an alternating voltage through a regulation circuit, an integration circuit and a filter circuit are utilized to generate a stable constant voltage. Next, the magnitude of the constant voltage is regulated in stage through a driving circuit based upon a control signal of a control circuit, and the voltage is converted into a constant current for driving the LED. Accordingly, the invention utilizes the constant current with stage variation to achieve the effect of linear dimming to prevent flickering.

The invention discloses a multi-mode control LED dimming constant-current constant-voltage output circuit which comprises an EMI circuit, a full-bridge rectification circuit, a power factor correctioncircuit, a phase detection circuit, a dimming signal detection conversion circuit, a constant-current power supply, a high-voltage oscillation control circuit, a constant-current driving circuit, a detection feedback control circuit and a signal processing circuit. The resonance frequency conversion control is adopted, according to a connected load, an optocoupler with high interference resistance is adopted to return various feedback signals to a resonance control end, and a power factor correction circuit and a phase detection circuit are combined with a control circuit, so that stable implementation of stepless dimming is ensured. After various dimmers are connected, the stable driving of the LED can be realized in the whole dimming process; the starting speed is high, and no flickering phenomenon exists when the brightness is adjusted; no noise exists in any working state; the driving output can be adjusted according to a load LED lamp connection mode used by a client, so that theuniversality of the circuit is ensured; and the full voltage (AC 100-277V) input is achieved, so that the circuit is suitable for various environments.

The invention discloses a camera fill light control circuit. The camera fill light control circuit includes a power module, a fill light module and a photosensitive module. The circuit further comprises a main control module. The power module is connected with the main control module, the photosensitive module and the fill light module. The photosensitive module and the fill light module are all connected to the main control module. The invention also discloses a camera fill light control method. The method includes: reading an external brightness parameter G2 again by delaying three seconds after a fill light is turned on; adding an external illumination reference value into the brightness parameter G2 to obtain a T1; re-reading an external brightness parameter G3 at this time; comparingthe current external brightness parameter G3 with the T1, turning off the light if the G3 is greater than the T1, and keeping turn-on of the fill light if the G3 is less than T1. The main control module is added to the circuit provided by the invention, and the set control program is burned into the main control module, thereby controlling the fill light module to be turned on or off at the righttime; the strobe of the fill light can be avoided, and the power consumption of the whole circuit is reduced; and the camera can achieve the best surveillance image quality.

The invention provides a lighting system, which comprises an integrating circuit, a driving circuit and a light source. A pulse width modulation signal is connected into the input end of the integrating circuit, and the integrating circuit is used to convert the pulse width modulation signal into an analog signal. The control end of the driving circuit is connected into the output end of the integrating circuit. The output end of the driving circuit is connected with the light source. The duty cycle corresponding to the pulse width modulation signal is directly proportional to the voltage corresponding to the analog signal. The lighting system of the invention avoids the stroboflash problem of the light source caused by direct PWM dimming. At the same time, because the voltage value of theanalog signal output by the integrating circuit is directly proportional to the duty cycle of the input pulse width modulation signal, the process of adjusting the brightness of the light source through the analog signal is synchronized with the PWM dimming signal. Therefore, flicker-free dimming is realized on the premise of ensuring the dimming accuracy, and the damage to the human body causedby the stroboflash of the light source is avoided.

The invention relates to a shutter type vacuum furnace inspection window. The shutter type vacuum furnace inspection window comprises an inspection window cylinder which can be arranged on a vacuum furnace inspection opening, an imaging pore plate arranged at the foremost end of the inspection window cylinder, a glass optical lens, a lens pressing plate and a sealing ring which is arranged betweenthe lens and the cylinder and used for forming a vacuum sealing loop, wherein the glass optical lens and the lens pressing plate are arranged at the rear end of the inspection window cylinder. An argon inflating channel is formed between the glass optical lens and the imaging pore plate. An imaging lens cone is arranged on the outer side of the glass optical lens, and the lens cone is internallyprovided with a focusing lens and an imaging lens. Due to the fact that blade slits are driven to form a shutter through the rotation of the motor, the stroboflash phenomenon cannot be avoided. When an operator directly observes, visual fatigue can be caused by stroboflash, which is very harmful to the operator which works for a long time. When a camera is used for carrying out remote monitoring,due to the fact that the speed of the slit shutter is different from the scanning frequency of the camera, alternate dark space frequently appears on a remote monitoring screen. The problems are all caused by slit stroboflash and cannot be avoided.

A high performance linear driving circuit converting an AC voltage of an external power supply into a DC output current and then outputs the DC current to at least one LED includes a detection unit, a control unit and a current unit. In a 180-degree phase sine wave period of the AC voltage, the total current of the output current is formed by a first working section, an energy saving section and a second working section, and the detection unit detects at least a voltage value of the AC voltage or a current value of the output current to generate a detection signal, and drives the control unit to modulate the duty cycle and current value of the first working section, energy saving section and second working section, and the amounts of current of the first and second working sections are greater than that of the energy saving section.

The invention discloses a local dimming driving circuit, method and system and electronic equipment. The local dimming driving circuit comprises a dimming control circuit and a constant-current driving circuit; the input end of the dimming control circuit is connected with the mainboard, the output end of the dimming control circuit is connected with the input end of the constant-current driving circuit, and the output end of the constant-current driving circuit is connected with the backlight lamp panel; the main board is used for providing first backlight brightness data and a first vertical synchronizing signal; the dimming control circuit is used for obtaining second backlight brightness data according to the first backlight brightness data and outputting the second backlight brightness data at the refresh frequency of the first vertical synchronizing signal, and is also used for outputting a second vertical synchronization signal, wherein the refresh frequency of the second vertical synchronization signal is a preset value greater than the refresh frequency of the first vertical synchronization signal; and the constant-current driving circuit is used for driving the backlight lamp panel to display according to the second backlight brightness data when receiving the second vertical synchronizing signal. The stroboscopic problem of the display panel is improved, and picture switching is smoother.

The invention relates to an LED (light-emitting diode) desk lamp, which comprises a transparent plate, a lamp panel, a lampshade, a screw, an adjusting handle, a universal movable head, a lamp pole, an L-shaped handle, a counterweight handle, a full-tooth tube, a base, a level switch, a power switch, a base rubber pad, a lead and a power adapter, wherein the transparent plate and the lampshade are fixed through the screw, the lamp panel is sealed inside, the lampshade is connected with the lamp pole through the universal movable head, the adjusting handle is arranged on the universal movable head, the lamp pole and the counterweight handle are fixed through the L-shaped handle, the full-tooth tube is arranged between the counterweight handle and the base, the lead penetrates through the base, the full-tooth tube and the like and is connected with the lamp panel, the level switch, the power switch and the base rubber pad are arranged on the base, and the base is externally connected with the power adapter. By introducing the LED lamp panel to avoid flashing, the eyesight of users is effectively protected, the service life is long, the luminous efficiency is high and the LED desk lamp is an energy-saving eye-protection LED desk lamp.

The invention provides a driving circuit for an OLED (organic light emitting diode) lighting device. The driving circuit for the OLED lighting device comprises a current source (31), a voltage source (32), a waveform generator (33), two switches (34 and 35), one resistor (36) and one capacitor (37). The driving circuit has the following beneficial effect of realizing the driving mode of adding the reversed pulse voltage in each forward pulse period or every a plurality of forward pulse periods while the forward pulse current driving is adopted. Therefore, the reliability of the OLED lighting device is obviously improved and the problem of a failed dynamic short circuit is prevented.

The electron ballast is used for driving fluorescent lamp and HID lamp to emit light and comprises: a rectifying power supply circuit connected to the AC power supply and used for providing DC power for the half-bridge type electronic ballast; a central control circuit connected to the inverse frequency control end of the electronic ballast; a voltage sampling circuit connected to the input of voltage detecting signals in the central control circuit; a transform rectify and voltage stable circuit connected to the AC power supply and used for providing power for the central control circuit and the voltage sampling circuit. The voltage sampling circuit is used for detecting the voltage fluctuation of AC power supply through the transform rectify and voltage stable circuit; the central control circuit is used for controlling the inverse frequency according to said voltage fluctuation.

The invention discloses a display brightness adjusting method and a device thereof and a display device. The display brightness adjusting method comprises the following steps: an initial dimming conversion brightness level of the display device is set; the mura degree of a display image of the display device between the dimming conversion brightness level and the highest display brightness level is determined; wherein the display brightness is adjusted in a PWM dimming mode in an interval formed by the lowest display brightness level and the dimming conversion brightness level, and the displaybrightness is adjusted in a DC dimming mode in an interval formed by the dimming conversion brightness level and the highest display brightness level; and the dimming conversion brightness level is adjusted according to the mura degree of the display image to obtain an optimal dimming conversion brightness level, wherein the mura degree of the display image of the display device between the optimal dimming conversion brightness level and the highest display brightness level meets a preset mura degree. According to the technical scheme, the probability of uneven display brightness of the display device is reduced, and the display effect of the display device is optimized.

The invention provides an adjustable illuminating lamp capable of imitating natural lights, comprising a light-emitting light source, a driving power supply, a control device and a time signal generator, wherein the driving power supply is electrically connected with the light-emitting light source; the control device is used for controlling the driving power supply; the time signal generator is connected with the control device in a signal manner; the light-emitting light source at least comprises a first secondary light source and a second secondary light source; a C / P (Citopic) value of emitted lights of the first secondary light source is more than 3.0 and the C / P value of the emitted lights of the second secondary light source is less than 2.5; the C / P values which are changed along with time and light strength information are stored in the control device; time information is sent to the control device by the time signal generator and a control signal is output to the driving power supply by the control device according to the input time information; the driving power supply is used for respectively controlling the strength of all the secondary light sources, so that a light source with the corresponding C / P value and light strength is formed by the light-emitting light source. The adjustable illuminating lamp capable of imitating the natural lights, provided by the invention, has the substantial characteristics of being beneficial to human health and being particularly applicable to habitation environments including indoor offices, homes and the like, and closed environments including airplanes, submarines for illumination and the like.

A LED lighting system performs no flicking. A rectifier receives an AC input voltage to generate a rectified input voltage at an input power line and a ground voltage at a ground line. A LED string comprises LEDs connected in series to have a main anode and a main cathode. The main anode is coupled to the input power line. A power bank is connected to the input power line and the main cathode. The circuit conducts a first driving current from the main cathode to the ground line, and a second driving current from the power bank to the ground line. The second driving current increases electric energy stored in the power bank. Both the first and second driving currents flow through the LED string. The power bank releases the electric energy to make at least one of the LEDs illuminate when the AC input voltage is about 0V.

The present invention pertains to a tunnel lighting technology, which is object to reduce the stroboscopic the driver generates to the traditional lighting means and lights in the moveing vehicles in an one-way tunnel. The present invention designs two new lamps, one lamp installed along the location of the traditional lights collocation, the second lamp installed on the roof surface of the tunnel. The lights irradiated by both lamps have a rear cut-off angle designed based on the installation angle of the car windshieldsed, thereby reducing the stroboscopic; and at the same time the lamps all have a shining surface with a certain brightness which sends the light backwards, which alows the driver in the moving vehicles to understand the direction of the front road, playing a guiding role.

The invention relates to an electronic ballast and its working method. It has a half-bridge electronic ballast for driving fluorescent lamps or HID lamps to emit light; It also has: a central control circuit connected to the inverter frequency control terminal of the half-bridge electronic ballast; a voltage sampling circuit connected to the voltage detection signal input terminal of the central control circuit; transformer rectification and stabilization The voltage circuit is connected with the city AC and is used to provide power to the central control circuit and the voltage sampling circuit; the voltage sampling circuit is used to detect the voltage fluctuation of the city AC through the transformer rectification and voltage stabilization circuit; Fluctuation controls the inverter frequency of the half-bridge electronic ballast to keep the luminance of fluorescent lamps or HID lamps constant. The electronic ballast of the invention can improve the light efficiency of the fluorescent lamp or the HID lamp, prevent flickering and keep the brightness constant.

Embodiments of the invention provided a driving circuit for powering a light-emitting diode (LED) light source. The driving circuit includes a rectifier, a filter capacitor, and a control circuit. The rectifier converts an AC voltage from an AC power source to a rectified AC voltage. The filter capacitor coupled to the rectifier filters the rectified AC voltage to provide a DC voltage. The control circuit controls power supplied to the LED light source. The control circuit enables a discharging current periodically to discharge the filter capacitor if a switch coupled between an AC power source and a rectifier is turned off and disables the discharging current if the control circuit determines that the switch is turned on.

The invention discloses a high-power factor and non-strobe LED drive circuit which comprises a voltage reduction type converter structure and a boosting type converter structure at the same time. By the adoption of the structure, the high-power factor and non-strobe LED drive circuit can continuously work within one power frequency cycle, energy is transmitted from input voltage to output voltage all the time, and output current does not have power frequency ripple waves. According to the high-power factor and non-strobe LED drive circuit, the purposes of improving the power factor and avoiding strobe can be achieved at the same time without a large output capacitor or a special power factor correction constant output control chip.

The invention belongs to the technical field of camera stroboflash prevention, and discloses a camera stroboflash prevention device which is arranged in front of a lens of a camera module and comprises a light reducing piece module, a movement mechanism is connected to the light reducing piece module, and multiple groups of light reducing piece assemblies are arranged in the light reducing piece module in a sliding mode. Coaxial light holes are formed in the light reducing piece module and the movement mechanism, the light reducing piece module comprises a guide rail plate and a light reducing piece assembly, a guide groove is formed in the guide rail plate, the light reducing piece assembly is arranged in the guide groove, and the movement mechanism drives the light reducing piece assembly to slide in the guide groove. According to the device provided by the invention, camera stroboflash can be avoided, the picture brightness is relatively natural, the camera stroboflash can be avoided, the picture effect can be considered in different scenes, and overexposure cannot be generated. Meanwhile, the device is compact in structure, small in size, simple in structure and suitable for being widely applied to camera modules in the fields of mobile phones, computers, intelligent television equipment, digital conference equipment and the like.