Nichia Corporation

Wataru Ogura

Harumi Sakuragi

Teruo Watanabe

Minoru Kitahara

Wataru Kitahara

Yoshitaka Tanaka

Katsuyuki Onozuka

Yoshinori Momose

Shuji Muguruma

An optical device comprises: at least one first reflecting surface disposed so as to reflect first light that has a light distribution having an optical axis parallel to a first axis, to an arc-shaped first region surrounding the first axis; and a second reflecting surface and a third reflecting surface that are disposed such that the second reflecting surface and the third reflecting surface meet each other on the first axis, and such that the first reflecting surface is disposed between the second reflecting surface and the third reflecting surface.

Optical device and illumination device

An illumination device includes: an optical fiber, the optical fiber allowing light emitted from a light source to be introduced at a first end portion thereof and to be guided through the optical fiber while emitting a portion of the light through a side surface of the optical fiber; a light-transmissive tube, the light-transmissive tube covering the side surface of the optical fiber such that a gap is located between the tube and the side surface of the optical fiber; and a light-shielding cap covering a second end portion of the tube at a side opposite the light source such that a space is located between a bottom portion of the cap and the second end portion of the tube. A second end portion of the optical fiber projects past the second end portion of the tube and is located at an inner side of the cap.

Illumination device

An LED driving apparatus is provided. The apparatus includes an LED Portion, a charging/discharging capacitor, a capacitor charging and discharging paths, and a capacitor charging constant current portion. The LED driving portioncontrols a current in the LED portion. The capacitoris connected in parallel to the LED portion. The charging and discharging paths are connected to the capacitor whereby charging and discharging the capacitor, respectively. The constant current portionis connected on the charging path and controls a charging current so that the capacitor is charged at a constant current. When rectified voltage applied to the LED portion becomes high, the capacitor is charged with the charging current through the charging path. When the voltage becomes low, the capacitor is discharged at a discharging current through the discharging path so that the discharging current is applied to the LED portion.

Light-emitting diode driving device for reducing light off period

A charging diodeis connected to the capacitorand the anode of a first LED, and limits the direction of the charging current. A discharging diodeis connected to the capacitorand the cathode of the first LED, and limits the direction of the discharging current. A charging path CP is provided which includes the capacitor, the charging diode, and the charger. The capacitoris charged through the charging path CP. A discharging path DP is provided which includes the capacitor, the discharging diodeand a discharger. The capacitoris discharged through the discharging path DP. A transient path TP is provided which does not include the capacitorbut includes the first LED, the chargerand the discharger

Light-emitting diode driving apparatus including charging/discharging capacitor

An apparatus includes first and fourth bypasses, a current detector, and a current controller. The first bypass is connected serially to a first LED, and controls the current amount in the first LED. The fourth bypass is connected serially to a second LED, and controls the current amount in the first and second LEDs. The detector detects current detection signal based on the current amount on an output line along which the first and second LEDs are connected serially to each other. The controller provides control signal for controlling the first and fourth bypasses based on the detection signal. The controller includes one output for providing the control signal. The first and fourth bypasses are connected in parallel to the one output.

Light-emitting diode driving apparatus

An LED driving apparatus for suppressing harmonic components is provided. First and fourth portionsandare in parallel to the first and second LEDsand, respectively. The first portioncontrols the current amount in said first LED. The fourth portioncontrols the current amount in said first and second LEDsand. The first and fourth controllersandcontrol the first and fourth portions, respectively. A current detectordetects a signal based on the amount of a current flowing from the first and second LEDsand. A signal providing portionprovides a voltage based on a rectified voltage provided from a rectifying circuit. The first and fourth controllersandcompare the current detection signal with the signal voltage, and control the first and fourth portionsandbased on the comparison.

Light-emitting diode driving apparatus for suppressing harmonic components

A LED driving apparatus includes a rectifying circuit, first, second and third blocks, and first and second switching portions. The rectifying circuit is connected to AC power supply, and rectifies AC voltage of the AC power supply to provide pulsating current voltage. Each block includes a plurality of LEDs. The first, second and third blocks are serially connected to the output side of the rectifying circuit. The first switching portion switches ON/OFF of a first bypass path based on flowing current amount in the first block. The first bypass path bypasses the second block. The second switching portion switches ON/OFF of a second bypass path based on flowing current amount in the first and second blocks. The second bypass path bypasses the third block.

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Okaya, Japan

Wataru Ogura