Panasonic Intellectual Property Management Co., Ltd.

Morishita Jintan Co., Ltd.

Meiji Co., Ltd.

Keisuke Seki

Takeshi Kamoi

Daisuke Yamahara

Shigeru Ido

Kazuhiko Hayashi

Hiroshi Kido

Masafumi Yamamoto

Hiroyuki Asano

Akinori Hiramatsu

Masato Himeda

Katsuyuki Doi

Masashi Yamada

Masato Saito

Hideki Sunohara

Hiroshi Tsuchita

Shun Kusuda

Tohru Ohno

Nobuyuki Shibata

Kazuo Shin

Yukihiko Kubota

A lighting device is configured to be connected to a power switch and supply a plurality of light-emitting elements with current and includes: a DC-power supply circuit configured to supply the plurality of light-emitting elements with the current when the power switch is turned on; a switching circuit for switching which light-emitting element or light-emitting elements among the plurality of light-emitting elements is supplied with the current; a detection circuit which detects current or voltage supplied from the DC-power supply circuit; and a control circuit which controls the switching circuit to switch which of the light-emitting element or light-emitting elements from among the plurality of light-emitting elements is supplied with the current, when the power switch is turned from on to off and back to on within a predefined period and the current or the voltage detected by the detection circuit is less than when the power switch is on.

Lighting device and lighting fixture

An illuminating apparatus includes a first light emitter, a second light emitter which emits light including more predefined color components than light emitted by the first light emitter, and a lighting device which supplies current modulated according to a visible light communication signal, to the first light emitter. The lighting device supplies a constant current to the second light emitter, while the first light emitter is supplied with current.

Illuminating apparatus

A lighting device includes: a constant current supply circuit; and a first modulation circuit and a second modulation circuit that are connected in series between output terminals of the constant current supply circuit. The first modulation circuit includes a first capacitor that is connected in parallel to the first modulation circuit. The second modulation circuit includes a second capacitor that is connected in parallel to the second modulation circuit.

Lighting device, luminaire, and signboard

A lighting device is a device that is for supplying current to an LED unit, is connected to a constant current source having output terminals to which a capacitor is connected, and includes: a transistor connected in parallel with the capacitor and connected in series with the LED unit; a modulation circuit (a microcomputer of a modulator, etc.) that causes the transistor to switch ON and OFF based on a signal for visible light communication; and a constant current control circuit that maintains a current flowing through the transistor at a constant current when the current flowing through the transistor is greater than a first predetermined value.

An emission control device includes: a switching circuit for switching which light-emitting element or light-emitting elements from among a plurality of light-emitting elements is supplied with current; a detection circuit which detects current or voltage supplied from a DC-power supply circuit; and a control circuit which controls the switching circuit to switch which of the light-emitting element or light-emitting elements from among the plurality of light-emitting elements is supplied with the current when a power switch is turned from on to off and back to on within a predefined period and the current or the voltage detected by the detection circuit is less than when the power switch is on.

Emission control device, light-emitting module, light-emitting unit, and lighting fixture

A lighting device which supplies a light-emitting element with a current modulated based on a visible light communication signal includes: a DC power supply circuit which supplies the light-emitting element with a first voltage that is a DC voltage; and a current control circuit which (i) includes a current control element connected in series to the light-emitting element, (ii) switches the current control element between a first state and a second state based on the visible light communication signal, the first state and the second state differing in electrical impedance, and (iii) adjusts, to a constant current value corresponding to a constant current instruction signal, a current flowing through the light-emitting element in a period in which the current control element is in the first state, by controlling the current control element.

A lighting device includes: a DC power supply circuit which supplies a light-emitting element with a first voltage; a signal generation circuit which generates a control signal based on a visible light communication signal; a current control element which is connected in series to the light-emitting element and turned on and off based on the control signal; a DC power supply control circuit which causes a second voltage at a first node between the light-emitting element and the current control element to be a constant value, by controlling the DC power supply circuit based on the second voltage; and a first feedback circuit which supplies the DC power supply control circuit with the second voltage. The first feedback circuit supplies the DC power supply control circuit with a predetermined voltage in a period in which the current control element is off.

A light-emitting device includes: a first light-emitting element array including one of a single first light-emitting element or a plurality of first light-emitting elements connected in series, and having a first emission color; a second light-emitting element array including one of a single second light-emitting element or a plurality of second light-emitting elements connected in series, and having a second emission color different from the first emission color, the second light-emitting element array being connected to the first light-emitting element array in parallel; and a third light-emitting element array including one of a single third light-emitting element or a plurality of third light-emitting elements connected in series, and having a third emission color different from the first emission color and the second emission color, the third light-emitting element array being connected to the first light-emitting element array and the second light-emitting element array in series.

Light-emitting device and luminaire

A light-emitting apparatus includes: a light source unit to which constant current corresponding to a dimming level is supplied from a constant current supply (dimming LED driver), and which includes a first light-emitting element column and a second light-emitting element column connected in parallel with the first light-emitting element column; a first detector circuit (resistor) which is connected in series to the first light-emitting element column, and detects a magnitude of a current flowing through the first light-emitting element column; a current adjuster circuit which adjusts a relationship of the magnitude of the current flowing through the first light-emitting element column to the constant current, based on the magnitude of the detected current; and a relationship adjuster circuit (variable resistor) which adjusts the dimming level at a changing point where a relationship of the magnitude of the current flowing through the first light-emitting element column to the dimming level changes.

Light-emitting apparatus, luminaire, and method of adjusting light-emitting apparatus

Lighting apparatus which supplies a current to solid-state light-emitting device (LED) includes: DC power supply circuit (AC/DC converter); and DC/DC converter that converts an output voltage of DC power supply circuit and applies, to solid-state light-emitting device, the output voltage converted. DC/DC converter includes: switching element; and DC/DC control circuit that performs a control of repeatedly turning ON and OFF switching element in a boundary conduction mode, and DC power supply circuit adjusts the output voltage to make a switching frequency of switching element higher than a first frequency, based on a forward voltage to be applied to solid-state light-emitting device.

Lighting apparatus and luminaire that adjust switching frequency based on output voltage

A lighting device includes a rectifier circuit, a conversion circuit, a constant current circuit and a control circuit. The conversion circuit includes a first series circuit, a second series circuit and a third series circuit. The conversion circuit is configured to output a DC current by on/off of a switching element being controlled by the control circuit. A high potential-side terminal of the third capacitor is electrically connected to an output terminal. The low potential-side terminal of the third capacitor is electrically connected to an output terminal, via the constant current circuit.

Lighting device and lighting fixture using same

Lighting apparatus includes: AC/DC converter which converts AC voltage Vac to DC voltage Vdc; DC/DC converter which converts DC voltage Vdc to a DC voltage to be applied to LED; and detection circuit which detects AC voltage Vac. DC/DC converter includes switching element, and control circuit that performs a control of repeatedly turning on and off switching element in a boundary conduction mode. Control circuit performs the control under which ON time Ton is kept from exceeding an upper limit that is previously determined, and raises the upper limit when AC voltage Vac detected by detection circuit falls below a predetermined value. ON time Ton is a period of time during which switching element is kept ON.

Reduced flickering lighting apparatus and luminaire

A lighting device which outputs a current to a solid-state light emitting element includes: a direct current-to-direct current (DC-to-DC) converter; and an output detector which detects an output from the DC-to-DC converter, wherein the DC-to-DC converter includes: a switching element; a control device which controls the switching element in order to generate the output; and a current detector which detects a current which flows through the switching element, and if a current value of the current detected by the current detector is less than a predetermined threshold, the control device controls the switching element according to a duty cycle determined based on an output value of the output detected by the output detector, and if the current value is greater than the predetermined threshold, the control device controls the switching element according to a duty cycle lower than the duty cycle determined based on the output value.

Lighting device and illumination apparatus

An illumination system includes: a first light-emitting element column including one of a single first light-emitting element or a plurality of first light-emitting elements connected in series; a second light-emitting element column connected in parallel with the first light-emitting element column, and including one of a single second light-emitting element or a plurality of second light-emitting elements connected in series; a constant current supply that supplies a constant current to the first light-emitting element column and the second light-emitting element column which are connected in parallel; a resistor that is connected in series with the first light-emitting element column, and detects a magnitude of current flowing through the first light-emitting element column; and a current adjuster circuit that adjusts the magnitude of the current flowing through the first light-emitting element column, according to the magnitude of the current detected by the resistor.

Illumination system and luminaire

An illumination system includes: a first light-emitting element column in which one or more first light-emitting elements are serially connected; a second light-emitting element column connected in parallel with the first light-emitting element column, and in which one or more second light-emitting elements are serially connected; a constant current supply that supplies constant current to a light source unit including the first and second light-emitting element columns; a resistor that is connected in series with the first light-emitting element column, and detects magnitude of current flowing through at least the first light-emitting element column; a bypass circuit that passes, to the resistor, at least part of current flowing through the second light-emitting element column, when a predetermined condition is satisfied; and a current adjuster circuit that adjusts the magnitude of the current flowing through the first light-emitting element column, according to the magnitude of the current detected by the resistor.

Growing community of inventors

Osaka, Japan

Keisuke Seki