Vehicular lamp

• US 7,208,880 B2
• Filed: 05/06/2005
• Issued: 04/24/2007
• Est. Priority Date: 05/10/2004
• Status: Expired due to Fees

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Ito, Masayasu, Takeda, Hitoshi
• Primary Examiner(s): Tran; Thuy V.
• Assistant Examiner(s): LE, TUNG X
• Application Number:
  US11/124,479
• Publication Number:
  US 20050248294A1
• Time in Patent Office: 718 Days
• Field of Search: 315/291, 315/209.R, 315/77, 315/82, 307/10.1, 307/10.8, 362/487, 362/507
• US Class Current: 315/82
• CPC Class Codes: H05B 41/282 with semiconductor devices H05B41/2806, H05B41/288, H05B41/295 take precedence
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

There is provided a vehicular lamp that can reduce a high-frequency noise occurring between a primary side and a secondary side of an anode voltage applying coil at low cost. The vehicular lamp includes a cold cathode fluorescent lamp having a cathode, a gate, and an anode, and an anode voltage applying coil operable to apply an acceleration voltage between the cathode and the anode of the cold cathode fluorescent lamp, in which one end of a secondary side of the anode voltage applying coil is connected to a reference potential of a primary side. Moreover, the vehicular lamp further includes an anode current detecting unit operable to detect an electric current flowing between a connecting point to the reference potential in the secondary side of the anode voltage applying coil and the cold cathode fluorescent lamp.

Claims

1. A vehicular lamp comprising:

a cold cathode fluorescent lamp having a cathode, a gate, and an anode;

an anode voltage applying coil operable to apply an acceleration voltage between the cathode and the anode of said cold cathode fluorescent lamp; and

a gate voltage applying coil operable to apply a gate voltage between the cathode and the gate, wherein

one end of a secondary side of said anode voltage applying coil is connected to a reference potential of a primary side, and

one end of a secondary side of said gate voltage applying coil is connected to a reference potential of a primary side via a capacitor.

2. The vehicular lamp as claimed in claim 1, further comprising an anode current detecting unit operable to detect an electric current flowing between a connecting point to the reference potential in the secondary side of said anode voltage applying coil and said cold cathode fluorescent lamp.

3. The vehicular lamp as claimed in claim 1, further comprising a gate current detecting unit operable to detect an electric current between a connecting point to the capacitor in the secondary side of said gate voltage applying coil and said cold cathode fluorescent lamp.