Lighting device for electric discharge lamp

• US 5,083,065 A
• Filed: 10/19/1990
• Issued: 01/21/1992
• Est. Priority Date: 10/23/1989
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Futami, Tohru, Iijima, Yoichi, Segoshi, Toru, Sakata, Masao
• Primary Examiner(s): MIS, DAVID C
• Application Number:
  US07/599,929
• Time in Patent Office: 459 Days
• Field of Search: 315/82, 315/224, 315/307, 315/308, 315/DIG. 2, 315/DIG. 5, 315/ DIG. 7, 315/209
• US Class Current: 315/307
• CPC Class Codes: H05B 41/2883 the controlled element being a DC/AC converter in the final stage, e.g. by harmonic mode starting
• CPC Class Codes: H05B 41/2887 characterised by a controllable bridge in the final stage
• CPC Class Codes: H05B 41/386 for speeding-up the lighting-up
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
• CPC Class Codes: Y10S 315/07 Starting and control circuits for gas discharge lamp using transistors

Abstract

A lighting device for an electric discharge lamp comprises an LC series resonant circuit, and control means for controlling an inverter circuit. Immediately after the occurrence of a dielectric breakdown in the electric discharge lamp. AC voltage with a relatively low frequency is applied to the lamp so as to pass a heavy current therethrough. Subsequently, the frequency is increased stepwise by a relatively small variation until a terminal voltage of the electric discharge lamp reaches a predetermined value. Thereafter, the frequency is increased stepwise by a relatiely large variation until the electric discharge lamp assumes a discharge stable state.

Claims

1. A method of starting an electric discharge lamp bulb until the electric discharge lamp bulb assumes a predetermined discharge stable state, comprising the steps of:

supplying electric power to the electric discharge lamp bulb;

detecting a terminal voltage across the electric discharge lamp bulb;

determining whether said terminal voltage is greater than a predetermined value;

increasing a frequency of said electric power by a first frequency value when it is determined that said terminal voltage is greater than said predetermined value; and

increasing said frequency of said electric power by a second frequency value when it is determined that said terminal voltage fails to be greater than said predetermined value.

2. A method as claimed in claim 1, wherein said second frequency value is smaller than said first frequency value.

3. A system for starting an electric discharge lamp bulb until the electric discharge lamp bulb assumes a predetermined discharge stable state, comprising:

a source of electric power, said electric power being supplied to the electric discharge lamp bulb;

means for detecting a terminal voltage across the electric discharge lamp bulb; and

a control unit including;

means for determining whether said terminal voltage is greater than a predetermined value;

means for increasing a frequency of said electric power by a first frequency value when it is determined that said terminal voltage is greater than said predetermined value; and

means for increasing said frequency of said electric power by a second frequency value when it is determined that said terminal voltage fails to be greater than said predetermined value.

4. A system as claimed in claim 3, wherein said second frequency value is smaller than said first frequency value.