Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Masaru Ikeda

Masahiro Yamamoto

Syunsuke Ono

Minoru Ozasa

Tomoyuki Seki

Kazuhisa Tanaka

Takeshi Saitoh

Tatsuo Mifune

Go Yamada

After discharge has begun in a high pressure discharge lamp, constant current control is performed so a lamp current becomes 4 [A]. Then, the current supplied to a pair of electrodes in the lamp is controlled so an electrode tip temperature t [degrees C.] at this time and an electrode tip temperature T [degrees C.] during stable lighting satisfy the relationship t [degrees C.]&#x3c;=1.1 T [degrees C.]. When a power of the lamp reaches a rated power value, power control is changed to constant power control. This method enables suppressing an excessive rise in the temperature of the electrode tips in an initial lighting interval from lighting commencement until stable lighting, thereby preventing an increase in arc length due to melting of the electrode tips. Accordingly, illuminance does not readily decrease, particularly in a lamp unit including a high pressure discharge lamp mounted to a reflecting mirror.

Lighting method and lighting apparatus for a high pressure discharge lamp, a high pressure discharge lamp apparatus, and a projection-type image display apparatus

The high-pressure discharge lamp lighting device of the invention includes a lighting circuit for supplying an alternating current to a high-pressure discharge lamp to cause lighting, the high-pressure discharge lamp having an arc tube in which a halogen material is enclosed and a pair of electrodes is disposed, and each electrode having a protuberance at a tip thereof. A frequency of the alternating current varies without dependency on operating data that varies as a lighting time of the high-pressure discharge lamp elapses.

Device for lighting a high-pressure discharge lamp by supplying alternating current

The present invention provides a high-pressure discharge lamp having a long life. A high-pressure discharge lamp () comprises a light emitting part (); first and second sealing parts (); first and second electrodes (); a first conductive lead () wound around the first sealing part; a first lead wire () electrically connecting the first conductive lead to the first electrode; a second conductive lead () wound around the second sealing part; and a second lead wire () connecting the second conductive lead to the first electrode. The second lead wire detours the light emitting part to avoid being affected by heat. After the lamp is turned off, the temperature of base parts of the electrodes immediately falls, and much mercury can be collected in the vicinities of the base parts.

High-pressure discharge lamp, lamp unit and image display device

Provided is a method for lighting a high pressure discharge lamp capable of increasing the life thereof. The lighting method is as follows. When the time elapse after lighting up the discharge lamp is within a predetermined condition (e.g. 5 minutes or less), constant current control is performed if the lamp voltage is lower than switching voltage (here, a first voltage value V) and constant power control is performed to maintain the lamp power at a power value Wif the lamp voltage is equal to or above the switching voltage. After the predetermined condition (5 minutes) is exceeded, the constant power control is performed by lowering the value of the switching voltage from the first voltage value Vto the second voltage value V. If the lamp voltage is equal to or above the switching voltage lowered, the lamp power is maintained at power value W

High pressure discharge lamp operation method, operation device, light source device, and projection type image display device

A lamp comprises a glass substrate and a shading film. The shading film is formed by applying a greensheet comprising an inorganic pigment and an inorganic matrix compound to a surface of the glass substrate and then, firing the greensheet. The formed shading film has a portion whose thickness is 90% or more of the maximum thickness of the shading film within the range of 0.5 mm from an edge of the shading film.

Lamp with shading film

A greensheet comprising an inorganic pigment and an inorganic matrix component is applied to a surface of a glass substrate and fired for fixing. The formed shading film has a portion whose thickness is 90% or more of the maximum thickness of the shading film within the range of 0.5 mm from an edge of the shading film. Thus, a shading film that has distinct end faces and has an excellent thickness uniformity can be formed with a good positional accuracy. Therefore, a lamp having a highly precise light distribution property can be obtained. In addition, a lamp having such a property can be obtained with a few steps and at a low cost.

Growing community of inventors

Osaka, Japan

Masaru Ikeda