Matsushita Electric Works, Ltd.

Panasonic Corporation

Nagasaki University

Panasonic Intellectual Property Management Co., Ltd.

Masahito Ohnishi

Takashi Kanda

Masahiro Naruo

Kazuo Yoshida

Shozo Kataoka

Kazuhiro Hori

Fujio Kurokawa

Yoshinobu Murakami

Shigeru Ido

Yoshihiko Matsukawa

Tomoyuki Nakano

Masaaki Ikehara

Hiromitsu Mizukawa

Tomoaki Mannami

Hiroshi Ogasawara

Tadao Uetsuki

Naoki Ohnishi

Kazuhiro Nisimoto

Takashi Yamasaki

Koji Nakagawara

A visible light communication receiver to be attached to a mobile object includes: a light receiving device which receives a light signal for visible light communication, the light signal including predetermined information; and a lens component disposed over the light receiving device. The lens component has a first directional angle on a first plane and a second directional angle on a second plane orthogonal to the first plane. The first directional angle is narrower than the second directional angle.

Visible light communication receiver, mobile object, and visible light communication system

In a control device of a power converter circuit repeating accumulation of energy to an inductor and release of energy from the inductor at each turn on/turn off timing of a switch, a zero cross detecting circuit detects a time when a current flowing through the inductor becomes zero by inputting a voltage between both terminals of the inductor directly without any resistance for detecting the inductor current. There is no electricity loss caused by the resistance for detecting the inductor current and critical mode control of the power converter circuit is precisely carried out.

Control device of a power conversion circuit

In DC/DC converter circuit, the peak value of the reactor current is found based on output voltage and an input voltage, thereby, the operation with the predetermined electric current mode is thereby enabled. The AC/DC converter circuit is run with a predetermined current mode, the power factor improvement is accomplished. The first control partinputs a detected value of output voltage Eo, and a turn-off timing predicted value of switch Tr of the DC/DC converteris calculated. The first control partsends the calculation result to the switch drive signal generate part. The second control partinputs the detected value of the output voltage and the input voltage, and it receives the turn-off timing predicted value from the first control part. Even more particularly, the second control partcalculates the peak value of the reactor current of the DC/DC converterbased on the turn-off timing predicted value, and it calculates the time that the reactor current decreases to a predetermined preset value from the peak value as a turn-on timing predicted value.

Control device for a power converter circuit

An illumination system includes a lighting apparatus having a solid-state light emitting element as a light source; and a dimmer including a bidirectional switching element having a self-sustaining function and connected to a serial circuit of the lighting apparatus and an external power source. The dimmer varies a conduction angle of the bidirectional switching element by controlling a phase of an AC voltage of the external power source, wherein the lighting apparatus performs dimming of the light source based on the conduction angle of the bidirectional switching element, and the dimmer continues to apply driving current to the bidirectional switching element during a first period, which is a part of a second period, the bidirectional switching element being allowed to conduct throughout the second period.

Illumination system

A power source device includes a control circuit which controls switching elements in full-bridge arrangement so as, in decreasing an output to a load, to substantially equalize ON timing of one of two switching elements at diagonal position to the other of them with ON period of the one switching element shortened, that is, with ON duty ratio of the one switching element decreased. Switching operation of the elements in this event is not made to be in the hard switching operation, and a range in which the output to load can be controlled without increasing any stress or noise is thereby broadened, whereby it is enabled to minimize varying width of switching frequency and to attain a wide range control of the output to load without causing any one of the switching elements to be in the hard switching operation.

Power source device

A discharge lamp lighting device includes a rectifier, a first diode connected at the anode in forward direction to a positive polarity output terminal of the rectifier, a smoothing capacitor connected between the cathode of the first diode and a negative polarity output terminal of the rectifier, a second diode connected at the anode in forward direction to the cathod of the first diode, a pair of switching elements connected in series between the cathode of the second diode and the negative polarity output terminal of the rectifier, a first capacitor connected in parallel to one of the first diode and the rectifier, a second capacitor connected in parallel to the second diode, and a control circuit for controlling ON/OFF operation of these switching elements, and a transformer having a primary winding n,connected between a junction point of the pair of switching elements and one of output terminals of the rectifier and a secondary winding connected to a load circuit including a discharge lamp, and their arrangement can reduce peak factor of currents flowing to the load circuit and any loss occurring at the switching elements.

Discharge lamp lighting device

A power converting device includes at least power source section providing a pulsation voltage output of a stepped waveform, and a piezo-electric element for shaping output voltage waveform of the power source section substantially into a sinusoidal waveform and boosting and dropping output voltage value of the power source section. A fundamental wave component of the piezo-electric element is transformed by a boosting and dropping element and a filter element to be applied to a load, whereby it is enabled to apply to the load a required voltage of a substantially continuous waveform, without employing any element of high withstand voltage nor decreasing power conversion efficiency.

Power converting device supplying AC voltage of a continuous wave form

An electronic ballast for discharge lamps comprises a main resonance circuit for applying a voltage necessary for operating of a discharge lamp having filaments to both ends of the discharge lamp and a filament resonance circuit for supplying a filament current to the filaments, wherein the main resonance circuit and filament resonance circuit have resonance circuits having different resonance characteristics in an output path leading to the discharge lamp and also change their outputs depending on an operating frequency of switching elements. Thereby a filament current and a voltage across the discharge lamp can be set at suitable one of respective operational modes of the discharge lamp according to an operational state of the discharge lamp.

Electronic ballast for discharge lamps

A discharge lamp lighting device includes first voltage source of a high voltage capable of increasing lamp current, the voltage value of which being sequentially variable, and second voltage source of a low voltage capable of decreasing the lamp current, the voltage value of which being sequentially variable, lighting connection of the first and second voltages sources to a discharge lamp being alternately changed over for its stable lighting, whereby the stable lighting of the lamp can be made with any current limiting element minimized and a response to variation in outputs over a wide range as well as any radiant noise can be effectively improved.

Discharge lamp with two voltage levels

A power converter apparatus in which a switched capacitor circuit includes one or more sets of cells connected in series each having a capacitor as a voltage supply source and a bridge circuit for inverting the polarities of the capacitor, the switched capacitor circuit is connected to a load, there is provided a means for parallelly charging the capacitors of the cells with a D.C. voltage source, any number of the cell capacitors are connected in series with any polarity to control supply of an A.C. output to the load. Whereby the power converter apparatus using the switched capacitor circuit can supply A.C. power with less distortion to the load without increasing the withstand voltage of the switching elements and without any need for provision of large inductors or capacitors.

Power converter apparatus for a discharge lamp

A power converting system rendering an applied voltage to a load to be a continuous voltage waveform, wherein a plurality of capacitors are charged so that their terminal voltages will reach predertermined voltages mutually different, the respective capacitors are sequentially connected respectively through a switching element to a series circuit of an inductor and a load-use capacitor, the load-use capacitor is charged with a resonance current of the capacitor and inductor, and the applied voltage to the load-use capacitor is made to be a pulsating waveform by properly adjusting the terminal voltages upon charging of the respective capacitors as well as change-over timing of the respective switching elements.

Power converting system with a plurality of charging capacitors

A power converter has two switched capacitor circuits each including at least a plurality of sets of capacitors and switching elements, first of which circuits is provided for supplying a DC power to a load while second of which accumulates a power in a period receiving a higher input voltage, and the first switched capacitor circuit being made to receive, in a period receiving a lower input voltage, a power supplied from a DC power source and also the power supplied from the second switched capacitor circuit for supplying to the load the DC power of a constant voltage, in which an input current collectively taken up by the two switched capacitor circuits is made similar in the waveform to the input voltage to eliminate any harmonics distortion of the current drawn from the source, for attaining the supply of the DC power of the constant voltage to the load, whereby the power converter is rendered not to require any large inductor to be capable of being minimized in size and restraining any noise radiation from occurring.

Power converter

An apparatus for operating discharge lamps with a stable electric current supply and minimal dimensional area requirements. The apparatus includes an input power source coupled across a capacitor, establishing a first loop circuit. A discharge lamp may also be connected across the capacitor, thereby forming a second loop circuit. A first switch repeatedly turns ON and OFF, making and breaking the first loop circuit at a first frequency, and thereby charges the capacitor. A second switch repeatedly turns ON and OFF, making and breaking the second loop circuit at a second frequency, and thereby discharges the capacitor through the discharge lamp. A control mechanism controls the first and second switches for supplying a predetermined current to the discharge lamp for flickerless operation.

Apparatus for operating discharge lamps

A discharge lamp lighting device employs first and second series circuits, each series circuit including two switching elements and a connecting point located therebetween. The first and second series circuits are both connected in parallel across a DC voltage source. A load circuit, including a discharge lamp, is connected between the two connecting points in the first and second series circuits. ON/OFF timing of the switching elements in the first series circuit varies between in-phase and 180 degrees out-of-phase from ON/OFF timing of the switching elements in the second series circuit. The ON period ratio of the switching elements is different in at least one of the first and second series circuits. The device allows dimming of the discharge lamp over a wide range, and lighting of the discharge lamp with a small supplied power.

Full-bridge inverter for discharge lamp lighting device with varied

An apparatus for operating discharge lamps includes first closed circuit for connecting a discharge lamp through first switching means to a pulsating power source, second closed circuit for connecting the lamp to the power source through a series circuit of second switching means which operates during OFF period of the first switching means and an energy-storing means, and an arrangement for controlling the both switching means. A pulsating source voltage is thereby applied to the discharge lamp. The apparatus is made thus capable at least of minimizing current-limiting impedance and realizing a continuously stabilized discharge of the lamp.

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Kadoma, Japan

Masahito Ohnishi