Patents by Inventor Hisao Hurukawa

Hisao Hurukawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • ULTRA-HIGH PRESSURE DISCHARGE LAMP LIGHTING METHOD, ULTRA-HIGH PRESSURE DISCHARGE LAMP TO WHICH THE METHOD IS APPLICABLE AND BALLAST FOR USE THEREIN, AND LIGHTING SYSTEM INCORPORATING THE LAMP AND THE BALLAST
    Patent number: 6713972
    Abstract: There is provided a novel method of lighting an ultra-high pressure discharge lamp (A1) having a discharge bulb (1) made of quartz glass in which a pair of electrodes (2) and (3) are disposed facing each other, the method including: lighting the lamp with alternating current; and providing a time period of at least one second for which the alternating current assumes a lighting frequency of 5 Hz or lower during a period for which the lamp lights, wherein the electrodes (2) and (3) each have a current withstanding capability against a current 1.5 times or more as high as a current value at which the lamp lights stably. This method enables the ultra-high pressure discharge lamp to have a longer life and exhibit a higher luminance.
    Type: Grant
    Filed: July 18, 2001
    Date of Patent: March 30, 2004
    Assignee: Phoenix Electric Co., Ltd.
    Inventors: Atsuji Nakagawa, Toshitaka Hujii, Hisao Hurukawa, Tomihiko Ikeda, Tetsuya Shirai
  • Ultra-high pressure discharge lamp lighting method, ultra-high pressure discharge lamp to which the method is applicable and ballast for use therein, and lighting system incorporating the lamp and the ballast
    Publication number: 20020105288
    Abstract: There is provided a novel method of lighting an ultra-high pressure discharge lamp (A1) having a discharge bulb (1) made of quartz glass in which a pair of electrodes (2) and (3) are disposed facing each other, the method including: lighting the lamp with alternating current; and providing a time period of at least one second for which the alternating current assumes a lighting frequency of 5 Hz or lower during a period for which the lamp lights, wherein the electrodes (2) and (3) each have a current withstanding capability against a current 1.5 times or more as high as a current value at which the lamp lights stably. This method enables the ultra-high pressure discharge lamp to have a longer life and exhibit a higher luminance.
    Type: Application
    Filed: July 18, 2001
    Publication date: August 8, 2002
    Applicant: Phoenix Electric Co., Ltd.
    Inventors: Atsuji Nakagawa, Toshitaka Hujii, Hisao Hurukawa, Tomihiko Ikeda, Tetsuya Shirai