Phoenix Electric Co., Ltd.

Toshiba Materials Co., Ltd.

Rubycon Corporation

Atsuji Nakagawa

Toshitaka Fujii

Tomihiko Ikeda

Hiroshi Takahashi

Shinichi Ushijima

Yasuhiro Shirakawa

Masahiko Yamakawa

Hiroyasu Kondo

Tetsuya Gouda

Ryoji Tsuda

Tomohiko Inoue

Takashige Yamada

Tetsuya Shirai

Shiyoshi Cho

Tatsuo Yamamoto

Toshitaka Hujii

Hisao Hurukawa

Tomotaka Mori

Shiro Isobe

Hiroki Takahashi

Masahiko Yamakwa

A light emitting device includes: a first white light source which includes N pieces of first white light emitting diodes and emits a first white light; and a second white light source which includes M pieces of second white light emitting diodes and a first resistance element electrically connected in series to the second white light emitting diodes and having a first resistance value, is electrically connected in parallel to the first white light source, and emits a second white light, the light emitting device emitting a mixed white light of the first white light and the second white light. The drive voltage of the first white light source is higher than a drive voltage of the second white light source, and a color temperature of the mixed white light is higher as a total luminous flux of the mixed white light is higher.

Light emitting device and LED light bulb

A method of manufacturing a high-pressure discharge lamp, comprising the steps of: inserting a mount into an interior of a glass tube having an outer diameter smaller than an inner diameter of an end part of a sealed container; radially constricting the glass tube at a first position located away from a metallic foil toward a tip of an electrode; sealing the mount by a region of the glass tube that ranges from the first position to at least the other end of the metallic foil; protruding the electrode out of the glass tube located away from the first position toward the tip of the electrode to form a glass-tube air-tightly sealed mount; inserting the sealed mount into the end part of the sealed container; and radially constricting the end part of the sealed container to sealing the glass tube of the sealed mount by the end part.

Manufacturing method of high-pressure discharge lamp and sealed part structure for high-pressure discharge lamp

The present high-pressure discharge lamp is composed of an arc tube part having an internal space, a pair of tungsten electrodes disposed in opposition to each other within the internal space, and mercury and halogen encapsulated in the internal space. The halogen is excessively encapsulated into the internal space relatively to the capacity of the internal space so as to establish an appropriate halogen cycle when the mercury partially deposits without evaporating.

High pressure discharge lamp and lighting method thereof

An LED lamp comprises: a first LED part, a second LED part that is connected to the first LED part in parallel and is configured to emit a light with a color temperature lower than that of a light to be emitted from the first LED part, and an impedance circuit that is connected to the first LED part in parallel while being connected to the second LED part in series.

LED lamp

A method of lighting a high-pressure discharge lamp is configured to change a power to be supplied to the high-pressure discharge lamp in accordance with a luminance parameter of an image content. The method includes switching between a low temperature operation and a high temperature operation so as to maintain a condition that mercury encapsulated into an arc tube part of the high-pressure discharge lamp constantly partially deposits without evaporating. The low temperature operation is performed where the temperature in the arc tube part is less than or equal to the deposition temperature of the mercury, whereas the high temperature operation is performed where the temperature in the arc tube part is greater than the deposition temperature of the mercury.

Method and circuit for lighting high-pressure discharge lamp

A starting circuit of a starting device for a high-pressure discharge lamp including an auxiliary light source has a diode placed in a forward direction in one of a pair of output lines which connect a main lighting circuit for generating AC voltage to the high-pressure discharge lamp and the auxiliary light source; a capacitor having one end connected to a cathode side of the diode; a boosting transformer including a primary winding, and a secondary winding having one end connected to an anode side of the diode or to the other output line and also having the other end connected to the other end of the capacitor; a high-frequency voltage generation circuit for continuously generating high-frequency voltage in combination with the primary winding; and a short-circuit switch for maintaining a short-circuit condition at both ends of the diode after the high-pressure discharge lamp is started.

Starting circuit of starting device for high-pressure discharge lamp including auxiliary light source, starting device including the starting circuit, and lighting system including the starting device

The high-pressure discharge lamp includes: a pre-seal glass inserted in the internal space of each of seal portions and integrally comprising a metal foil sheathing portion which sheathes a metal foil, an electrode sheathing portion which sheathes a portion of an electrode that extends from a first end of the metal foil toward a base portion and an external lead pin sheathing portion which sheathes a portion of an external lead pin that extends outwardly from the other end of the metal foil; and a conductor for generating discharge between the conductor and the metal foil. The electrode sheathing portion is fused to the base portion. The external lead pin sheathing portion has an outer surface hermetically fused to an inner surface of one of the seal portions. A clearance hermetically sealed between the pre-seal glass and the seal portion encapsulates inert gas therein.

High-pressure discharge lamp and light sources device using the same

An object of the invention is to provide method of operating a projection-type system, which method is capable of suppressing flicker and minimizing gradation disorder at the same time by superimposing a pulse current on a d.c. lamp current to stabilize arc while synchronizing the superimposition of the pulse current on the d.c. lamp current with a predetermined segment. The method of operating a projection-type system configured to pass light emitted from a high-pressure discharge lamp lit by d.c. lighting through divided plural color segments sequentially to project an image onto a screen, includes superimposing a pulse current on a d.c. lamp current in the high-pressure discharge lamp in synchronism with at least one specific color segment.

Projection-type system and method of operating the same

A power supply unit capable of varying power supplied to a light source at timings determined by synchronization signals is provided. The power supply unit comprises an interface that receives a plurality of types of synchronization signals with different pulse widths and a control unit that changes a setting of output power supplied by the power supply unit in accordance with the pulse widths of the plurality of types of synchronization signals. The control unit includes obtaining a standard time interval from a cycle of a standard type of synchronization signal that has a longest pulse width, parsing for determining type of each synchronization signal, redefining supply power values corresponding to respective types of synchronization signals, and changing the setting of output power of the power supply unit to a supply power value corresponding to a type of the synchronization signal.

Power supply unit for light source and method of controlling the same

To prevent scattering of broken pieces of a reflecting mirror even if a high pressure discharge lamp with a reflector bursts. A light source device according to the present invention is a light source devicethat has an arc tubeand a reflectorand a cover glassis externally fitted and fixed to the rear of the reflectorat opposite ends thereof with a gap S therebetween. With such a configuration, even if the arc tube bursts to cause a crack in the reflector, the cover glass prevents scattering of the broken pieces of the reflector.

Light source device

To provide a lighting circuit of a projector that can be driven by both the commercial alternating-current power supply and a battery and is convenient for portable use. A lighting circuit for a high-pressure discharge lampincludes: a DC/DC converterthat boosts a direct-current voltage and outputs the boosted direct-current voltage; an AC/DC converterthat rectifies an alternating-current voltage to output a direct-current voltage; an input switch circuitand a power switch circuitthat switch between the DC/DC converterand the AC/DC converter; a ballast circuitthat stabilizes the lighting of the high-pressure discharge lamp; a power control sectionthat controls the power supply from the ballast circuitto the high-pressure discharge lamp; a lighting initiation circuitthat starts lighting of the high-pressure discharge lamp; and the high-pressure discharge lamp, and the power switch circuitperforms power switching in such a manner that a relatively low power is supplied to the high-pressure discharge lampwhen a direct-current power supply is connected only to the DC/DC converter, and a relatively high power is supplied to the high-pressure discharge lampwhen the commercial alternating-current power supply is connected to the AC/DC converter

Lighting circuit for high-pressure discharge lamp

This invention provides a method of operating a projection system wherein light emitted from a high-pressure discharge lamp being lit with d.c. lamp current is passed through color segments of a color filter sequentially and then reflected by an optical element to project an image on a screen, the color segments of the color filter including red, green and blue color segments and a color segment comprising a green ND filter having a relatively low lightness. The method includes making lower a crest value of the d.c. lamp current fed to the high-pressure discharge lamp for a first illumination period during which the color segment comprising the green ND filter is illuminated than a crest value of the d.c. lamp current fed to the high-pressure discharge lamp for a second illumination period during which any one of the other color segments is illuminated, in synchronism with the first illumination period.

Projection system using a high-pressure discharge lamp adapted to d.c. lighting, and method of operating the same

Improved method and device for lighting a high pressure discharge lamp are provided which prevent arc jump and inhibit deterioration of lamp voltage and luminance. The method includes the step of: alternately repeating a superposition operation for superposing a pulse current on a lamp current applied to the high pressure discharge lamp for a predetermined time period and a superposition stopping operation for stopping the superposition of the pulse current for a predetermined time period.

Growing community of inventors

Himeji, Japan

Atsuji Nakagawa