Patents Examined by Ephrem Alemu
  • Patent number: 8461772
    Abstract: A high pressure discharge lamp ballast performs driving with a synthesized current waveform comprising a combination of first and second sets of current waveforms. The ballast controls content rates of each of the sets per unit time; detects a rotation synchronization signal for a color wheel; applies a synthesized current waveform in accordance with the synchronization signal and the content rates to a high pressure discharge lamp; and detects a lamp voltage. A period of each of the first and second sets equals to one rotation of the color wheel. The number of inversions of the second set is larger than that of the first set. The content rate of the second set is set to RL% when the lamp voltage exceeds a value V, and the content rate of the second set is set to RH% when lamp voltage falls below a value V?.
    Type: Grant
    Filed: March 18, 2009
    Date of Patent: June 11, 2013
    Assignee: Iwasaki Electric Co., Ltd
    Inventors: Tooru Nagase, Yoshiaki Komatsu, Shinichi Suzuki, Makoto Ohkahara, Hirokazu Harasawa, Yoshiaki Kuroda
  • Patent number: 8432101
    Abstract: A display device includes a display unit in which display elements provided with pixel circuits are arranged so as to have a sequence of three different colors in a row direction and the colors are shifted in a column direction by 1.5 columns. A scanning line is provided in every row of the display unit, a signal line is provided in every column of the display unit, and a column control circuit outputs a display signal for every column. The positions of the pixel circuits are displaced in the row direction with respect to the arrangement of the display elements, and are thus aligned in the column direction and also connected to the signal line only on one side of the signal line. No inversion of the pixel circuit pattern occurs and variations of the circuit characteristics in every row are suppressed.
    Type: Grant
    Filed: August 31, 2011
    Date of Patent: April 30, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Somei Kawasaki, Masami Iseki, Tatsuhito Goden
  • Patent number: 8427068
    Abstract: There are provided a reference signal generator and a PWM control circuit for LCD backlight. The reference signal generator and the PWM control circuit for LCD backlight may be configured to respectively include: a current control unit that controls generation of a variable current sequentially changing; a current generating unit that generates a variable current changing sequentially; and a reference signal generating unit that controls charging until a charged voltage charged by the variable current generated by the current generating unit reaches a first reference voltage level, starts discharging when the charged voltage reaches the first reference voltage level, controls discharging until the charged voltage reaches a second reference voltage level, and generates a triangular wave reference signal that has a frequency buffering interval in which a frequency sequentially changes when the initial driving completion signal or the protection signal is input.
    Type: Grant
    Filed: December 23, 2009
    Date of Patent: April 23, 2013
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Yu Jin Jang, Jeong In Cheon
  • Patent number: 8400074
    Abstract: A discharge lamp ballast is provided for powering a discharge lamp with feedback filament heating control. A startup circuit is coupled between output terminals of a DC-AC power converter together with a discharge lamp. A lamp current detection circuit and a lamp voltage detection circuit detect output signals to the lamp. A control circuit controls the switching elements and generates an operating frequency in accordance with a startup operation to generate a high voltage output from the startup circuit and ignite the discharge lamp, a filament heating operation wherein the operating frequency is controlled so as to set the amplitude of the output current detected by the lamp current detection circuit to a target current amplitude based on the amplitude of the output voltage detected by the lamp voltage detection circuit, and a steady-state operation wherein the operating frequency is decreased to maintain a stable light output from the discharge lamp.
    Type: Grant
    Filed: February 24, 2010
    Date of Patent: March 19, 2013
    Assignee: Panasonic Corporation
    Inventors: Junichi Hasegawa, Nobutoshi Matsuzaki
  • Patent number: 8390200
    Abstract: A coaxial cavity gyrotron with two electron beams includes an electron gun (magnetron injection gun, “MIG,” with two beams), a coaxial beam-wave interaction cavity and an outer magnetic field tube. The coaxial beam-wave interaction cavity consists of two parts: an outer conductor and an inner conductor. The two hollow electron beams produced by the MIG are located between the outer conductor and the inner conductor. The MIG includes inner and outer anodes, with a single cathode located between the anodes. The cathode further includes two emitter rings which produce the two hollow electron beams. The entire gyrotron is immersed in the magnetic field tube such that the magnetic field profile is the same or similar to that for a coaxial gyrotron with one electron beam.
    Type: Grant
    Filed: February 5, 2010
    Date of Patent: March 5, 2013
    Inventors: Shenggang Liu, Chaoyu Liu
  • Patent number: 8384291
    Abstract: A backlight protection circuit includes a driving circuit, two lamps, a pulse modulator, and a feedback circuit. The pulse modulator controlling the operating state of the driving circuit includes an over-voltage sampling end. Each of the two lamps includes a high voltage end connected to the driving circuit, and a low voltage end connected to the over-voltage sampling end through the feedback circuit. The pulse modulator stops the operation of the driving circuit when the voltage of the low voltage end exceeds a reference voltage.
    Type: Grant
    Filed: July 6, 2009
    Date of Patent: February 26, 2013
    Assignee: Chimei InnoLux Corporation
    Inventor: Ching-Chung Lin
  • Patent number: 8384305
    Abstract: The present invention discloses an LED driver with direct AC-DC conversion and control function, and a method and integrated circuit therefor. The LED driver comprises: a primary side circuit receiving rectified AC power, the primary side circuit including at least one power switch; a transformer coupled to the primary side circuit and controlled by the at least one power switch to convert a primary voltage to a secondary voltage which is supplied to an LED circuit; and a secondary side circuit coupled to the transformer, the secondary side circuit directly controlling current flowing through the LED circuit and sending a feedback signal to the primary side circuit to control the at least one power switch thereby.
    Type: Grant
    Filed: February 24, 2010
    Date of Patent: February 26, 2013
    Assignee: Richtek Technology Corporation
    Inventors: Chia-Wei Liao, Jing-Meng Liu, Roland Van Roy
  • Patent number: 8368307
    Abstract: The invention regards a system and method for using a handheld programming device to configure a lighting control system wirelessly. In one embodiment, at least one device configured with a processing section is installed in the lighting control system. A communications receiver that is operable to receive a signal from the handheld programming device is also installed in the lighting control system, wherein the signal includes an instruction for configuring the lighting control system. Further, the signal is wirelessly sent from the handheld programming device to the communications receiver, and the instruction is transmitted from the communications receiver to a device in the system. The instruction functions to configure the lighting control system.
    Type: Grant
    Filed: October 29, 2010
    Date of Patent: February 5, 2013
    Assignee: Lutron Electronics Co., Inc.
    Inventors: Audwin W. Cash, Christopher J. Rigatti, Dragan Veskovic
  • Patent number: 8354794
    Abstract: The light emitting device has a limiter transistor which is connected to a monitoring element, and an inverter an output terminal of which is connected to a gate electrode of the limiter transistor and an input terminal of which is connected to one electrode of the limiter transistor and the monitoring element. In the case where the monitoring element is short-circuited, the limiter transistor can be turned off by the inverter to correct a defect of the monitoring element.
    Type: Grant
    Filed: April 7, 2011
    Date of Patent: January 15, 2013
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Mitsuaki Osame, Aya Anzai
  • Patent number: 8350480
    Abstract: A plasma lamp for an electrodeless plasma lamp having a shaped dielectric waveguide body. The shaped body may have a relatively thin region containing a bulb, and a second region thicker than the first region. Microwave probes may be positioned in the second region to provide power to the waveguide body. The body may be shaped to intensify the electric field in the first region adjacent to the bulb to allow operation at a lower frequency than a solid cylindrical or rectangular waveguide body having the same volume and dielectric constant.
    Type: Grant
    Filed: January 25, 2010
    Date of Patent: January 8, 2013
    Assignee: Luxim Corporation
    Inventors: Marc DeVincentis, Yian Chang, Frederick M. Espiau, legal representative
  • Patent number: 8339046
    Abstract: A lighting control device of a lighting device for a vehicle includes a switching regulator for supplying a driving current to a semiconductor light source. The lighting control device also includes control means having a current detecting portion for detecting the driving current and serving to control dimming of the semiconductor light source in order to reduce a mean current of the driving current by repeating driving and stopping operations of the switching regulator at a high speed upon receipt of a dimming control signal. The current detecting portion has a current holding portion for holding the driving current, detected for a driving period of the switching regulator, for a stopping period after a passage of the driving period.
    Type: Grant
    Filed: December 23, 2009
    Date of Patent: December 25, 2012
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Yusuke Kasaba, Masayasu Ito
  • Patent number: 8330389
    Abstract: A switching power supply for supplying a load requiring a controlled current includes a PFC pre-regulator for receiving an input voltage and providing an output voltage, and a DC-DC switching converter for receiving at input the voltage output by the pre-regulator and for providing at output a supply voltage of said load. The switching DC-DC converter operates at a fixed and constant operating frequency, is a resonant converter and includes an LLC resonant circuit.
    Type: Grant
    Filed: December 21, 2009
    Date of Patent: December 11, 2012
    Assignee: STMicroelectronics s.r.l.
    Inventor: Claudio Adragna
  • Patent number: 8294368
    Abstract: An electrodeless plasma lamp includes a bulb containing a gas-fill and light emitter(s) excited to produce light using radio-frequency (RF) energy. Input and output coupling elements separated from each other by a gap couple RF energy from an RF source to the bulb. One end of the input coupling element is electrically connected to an RF source while the other end is connected to ground. One end of the output coupling element is connected to ground while the other end is connected to the bulb.
    Type: Grant
    Filed: June 18, 2010
    Date of Patent: October 23, 2012
    Assignee: Topanga Technologies, Inc.
    Inventors: Frederick M. Espiau, Mehran Matloubian, Timothy J. Brockett, David Schmelzer
  • Patent number: 8283866
    Abstract: An electrode-less plasma lamps comprises generally of a bulb containing a gas-fill that is excited to produce light using radio-frequency (RF) energy. In specific embodiments, the use of grounded coupling-elements with integrated bulb assemblies simplifies manufacturability, improves resonant frequency control, and enables the use of solid, partially filled, and hollow lamp bodies. In some embodiments, a method of operating an electrodeless plasma lamp device includes transferring RF energy from the RF source to an input coupling-element and illuminating electromagnetic energy substantially from the length of a gas-filled vessel from discharge of the gas-filled vessel.
    Type: Grant
    Filed: October 13, 2010
    Date of Patent: October 9, 2012
    Assignee: Topanga Technologies, Inc.
    Inventors: Frederick M. Espiau, Timothy J. Brockett, Mehran Matloubian
  • Patent number: 8278826
    Abstract: A multimode controller for LED light sources, especially sources in warning lights, such as light bars, provides for a temporary increase in brightness from the LEDs by providing a burst mode, in addition to a flashing mode and a continuous mode. The modes are carried out by programming a microprocessor which receives signals from control switches, which may be pressed and released. The programming precludes the burst mode to continue for longer than a predetermined time thereby ensuring that the power does not exceed the LEDs damage threshold characteristic. The controller thereby provides for temporary bursting to make visible the region in front of or around an emergency vehicle for a short period of time without the need for light sources dedicated solely to the high intensity brightness mode of operation of a warning light system.
    Type: Grant
    Filed: December 12, 2008
    Date of Patent: October 2, 2012
    Assignee: Star Headlight & Lantern Co., Inc.
    Inventor: James J. Cronmiller
  • Patent number: 8264164
    Abstract: A method for driving a discharge lamp having a first electrode and a second electrode includes the steps of, in a situation where a tip portion of the first electrode becomes higher than a tip portion of the second electrode in temperature when power of the same amount is fed to the first and second electrodes during a steady operation, changing a difference between the absolute values of average current values for two polarities during one cycle of the AC current in accordance with a predetermined pattern, and setting an operation time ratio of the first electrode as an anode during one cycle so as to be smaller than an operation time ratio of the second electrode as an anode during one cycle.
    Type: Grant
    Filed: February 23, 2009
    Date of Patent: September 11, 2012
    Assignee: Seiko Epson Corporation
    Inventors: Kentaro Yamauchi, Takeshi Takezawa
  • Patent number: 8232729
    Abstract: For production of plasma from a medium gas mass in an elongated shape, electric field forming elements 3, 4 that form an electric field in the medium gas mass are provided. The electric field forming elements form an electric field so that partial discharge occurs from the electric field forming elements toward both sides in the longitudinal direction of the medium gas mass. Accordingly, plasma 5 is produced from the medium gas mass. The medium gas mass is formed by, for example, gas supply members 1,2 that guide medium gas, through an internal hollow, to the electric field forming elements. An electric field forming area includes, for example, at least one high-potential electrode 3 and a voltage applying unit 4 that applies a voltage to the high-potential electrode. Plasma limited in medium gas can be produced with high energy efficiency stably over a wide range of parameters through a simple configuration.
    Type: Grant
    Filed: June 12, 2007
    Date of Patent: July 31, 2012
    Assignee: Osaka University
    Inventors: Katsuhisa Kitano, Satoshi Hamaguchi, Hironori Aoki
  • Patent number: 8203280
    Abstract: To prevent biased consumption of electrodes in a discharge lamp and to prevent biased precipitation of the electrode material, a light source is provided. The light source device has a discharge lamp that emits light by discharge between a first electrode and a second electrode; and a driver that supplies alternating current to the first and the second electrodes so as to maintain the discharge, and changes duty ratio of the alternating current in accordance with predetermined pattern. The predetermined pattern includes a plurality of section periods for which the duty ratio maintains mutually different values for a predetermined period.
    Type: Grant
    Filed: December 5, 2008
    Date of Patent: June 19, 2012
    Assignee: Seiko Epson Corporation
    Inventors: Kentaro Yamauchi, Tetsuo Terashima, Takeshi Takezawa, Kazuo Okawa, Shigeyasu Soma
  • Patent number: 8188668
    Abstract: An image display apparatus includes a rear plate provided with a plurality of electron-emitting devices, each electron-emitting device emitting electron; a face plate disposed opposite the plurality of electron-emitting devices and provided with a plurality of pixels of phosphor, each pixel of phosphor being irradiated with electrons emitted from corresponding ones of the electron-emitting devices to generate light; and a driver for scanning the plurality of electron-emitting devices for emitting electron from the plurality of electron-emitting devices. The phosphor has luminescence center of allowed transition type material, and the driver scans the plurality of electron-emitting devices so that maximum of charge density dosed in one pixel phosphor, during one scanning period, is equal to or larger than 3×10?8 C/cm2.
    Type: Grant
    Filed: April 20, 2007
    Date of Patent: May 29, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Daisuke Sasaguri, Yuji Kasanuki
  • Patent number: 8174206
    Abstract: A controlled lighting system includes an encoding device and a lamp. The encoding device includes a rectifier for rectifying an AC voltage input to result in a rectified signal, and an encoder for generating an encoded signal from the rectified signal and display data. The encoded signal has consecutive signal regions with a waveform of a positive half-cycle of an AC sinusoidal wave or a low potential. The lamp includes a LED unit and a decoding device. The decoding device includes a direct current converter for extracting a direct current voltage from the encoded signal, a detecting circuit for extracting a wave signal from the encoded signal, a processor for generating decoded data related to a light-emitting operation according to the wave signal, and a driver for driving the LED unit according to the direct current voltage from the direct current converter and the decoded data from the processor.
    Type: Grant
    Filed: July 8, 2008
    Date of Patent: May 8, 2012
    Assignees: Silitek Electronic (Guangzhou) Co., Ltd., Lite-On Technology Corp.
    Inventors: Hsiang-Chun Hsueh, Horng-Ming Tai