VastView Technology Inc. Patent applications |
Patent application number | Title | Published |
20150359051 | LOW FLICKER LED DRIVING CIRCUIT WITH HIGH POWER FACTOR - An LED-based lighting apparatus comprises a rectified AC voltage source having a rectified output connected to a storage capacitor through a switching device, a plurality of LED segments controlled by a linear driving circuit and at least one charging path connected between the LED segments and the storage capacitor. One or more controllable linear LED driving units may be connected in parallel with the storage capacitor to provide balance between reducing flicker and increasing power factor of the lighting apparatus. | 12-10-2015 |
20150230298 | APPARATUS FOR DRIVING LEDS USING HIGH VOLTAGE - An apparatus for driving LEDs using high voltage includes a plurality of LEDs divided into a plurality of LED segments connected in series with a switching voltage detector and a current limiting device. Each of the plurality of LED segments is connected in parallel with a switching device. A high input voltage supplies power to the apparatus. The switching voltage detector generates a first mode change signal when the input voltage increases and a second mode change signal when the input voltage decreases. A switch controller receives the two mode change signals and generates a plurality of switching control signals to respectively control the switching devices of the plurality of LED segments. | 08-13-2015 |
20150084516 | LED-BASED LIGHTING APPARATUS WITH LOW FLICKER - An LED-based lighting apparatus is powered by multi-phase AC voltages to reduce flicker. A multi-phase AC-to-AC power generator is used to generate a plurality of AC voltages from an AC power source. The plurality of AC voltages each having a different phase are rectified by a plurality of rectifiers to provide a plurality of rectified AC voltages for a plurality of LED lighting units. Each LED lighting unit has voltage dependent brightness and reaches maximum brightness at different time due to the phase difference in the rectified AC voltage. The peak-to-peak variation in the total brightness is reduced and therefore the LED-based lighting apparatus has low flicker. | 03-26-2015 |
20140312793 | APPARATUS FOR DRIVING LEDS USING HIGH VOLTAGE - An apparatus for driving LEDs using high voltage includes a plurality of LEDs divided into a plurality of LED segments connected in series and a plurality of three-terminal voltage controlled current limiting devices. Each of the current limiting devices is associated with one of the LED segments and has a first terminal connected to a negative end of the associated LED segment, a second terminal applied with a bias voltage and a third terminal connected to a common node. A current source is connected between the common node and ground. A power-loss reduction circuit having a plurality of LEDs controlled by an LED controlling circuit may further be inserted between the common node and the current source to reduce the power loss in the current source because of the high voltage at the common node. | 10-23-2014 |
20140217909 | APPARATUS FOR DRIVING MULTI-COLOR LED STRINGS - An apparatus comprises red, green and blue LED strings each having a corresponding switching circuit. Each LED string is divided into a plurality of LED segments. The three LED strings are connected in parallel or in series. Each LED string may be connected in series with a respective current source or share a common current source. A controller controls each switching circuit so that the number of LED segments connected in series in the red, green or blue LED string can be respectively controlled according to a color setting signal and the voltage level of an input voltage. A first control method is provided for controlling the apparatus having a constant input voltage and a second control method is provided for controlling the apparatus having a periodically time-varying input voltage. | 08-07-2014 |
20140160415 | LIQUID CRYSTAL DISPLAY DEVICE HAVING ELECTRODES WITH ELONGATED APERTURES - A liquid crystal display (LCD) device comprises a first substrate formed with a first electrode, a second substrate formed with a second electrode and a liquid crystal layer disposed between the two substrates. The LCD device includes at least one pixel area having at least one display unit. In the display unit, the first or second electrode is formed with a plurality of elongated apertures arranged in parallel and positioned outwardly one by one from the center of the display unit along at least four different directions. The plurality of elongated apertures forms solid or dotted edges around the circumference of the first or second electrode. The solid or dotted edges of the first electrode may be aligned with or extend outwardly more or less than the solid or dotted edges of the second electrode from the center of the display unit. | 06-12-2014 |
20140160412 | LATERAL ELECTRIC FIELD TYPE LIQUID CRYSTAL DISPLAY DEVICE HAVING NON-UNIFORM SPACINGS BETWEEN TWO ELECTRODES - A lateral electric field type liquid crystal display (LCD) device comprises a first substrate formed with a plurality of first electrodes and at least one second electrode, a second substrate and a liquid crystal layer disposed between the two substrates. Each first electrode comprises an array of electrode segments and every adjacent first and second electrodes have a minimum spacing smaller than a maximum spacing in between. Each second electrode is a strip electrode or also comprises an array of electrode segments. Each electrode segment is a V-shape electrode rotated with an angle or an electrode segment having at least an extruded portion and at least an intruded portion. The array of electrode segments may be a sinusoidal electrode. The first and second electrodes are oriented in parallel with or at a specific angle with respect to the data line of the lateral electric field type LCD device. | 06-12-2014 |
20140159593 | APPARATUS HAVING UNIVERSAL STRUCTURE FOR DRIVING A PLURALITY OF LED STRINGS - An apparatus comprises a plurality of controllable LED strings interposed with a plurality of switching units with each switching unit being connected between a leading controllable LED string and a trailing controllable LED string. A controller controls the switching units so that controllable LED strings are connected in a combination of series and parallel connections by connecting two adjacent leading and trailing controllable LED strings in series or parallel or by-passing the leading controllable LED string based on an automatically detected input voltage range. Each controllable LED string includes a plurality of LEDs connected in series between positive and negative ends of the controllable LED string and a plurality of controlling switches each corresponding to an LED. The number of LEDs connected in series in each controllable LED string is further adjusted by the controller as the input voltage varies with time. | 06-12-2014 |
20080266236 | Driving method of liquid crystal display device having dynamic backlight control unit - A dynamic control method for controlling backlight module of liquid crystal display (LCD) comprises steps of: receiving a frame data which is transferred to the LCD and consists a plurality of raw grayscale level; processing a statistical analysis for distribution of the plurality of raw grayscale level; and transferring a plurality of corrected grayscale level which is resulted from the statistical analysis corresponding to the raw grayscale level to the backlight control unit and a data modification simultaneously, wherein the backlight control unit uses the plurality of corrected grayscale level to modify brightness of backlight module and the data modification uses the plurality of corrected grayscale level to compare with the plurality of raw grayscale level for accurate display performance, so that the electrical power consumption is reduced and image quality is enhanced. | 10-30-2008 |
20080198516 | Electrostatic discharge (ESD) protection device and method therefor - A method and device for providing electrostatic discharge (ESD) protection are disclosed. The method uses the gate-controlled conductivity of field n-channel metal-oxide-semiconductor field effect transistor (field NMOSFET), wherein considerable ESD current can be conducted away when any ESD event beyond range of operation voltage, unlike PMOS ESD protection which is to be turned on at negative voltage. Instead of the traditional two-stage ESD protection (using one ESD protection between open drain output and V | 08-21-2008 |