Method of initiating lighting of a discharge lamp, circuit for lighting a discharge lamp, light source device using the circuit, and optical instrument incorporating the light source device

• US 6,756,744 B2
• Filed: 10/31/2001
• Issued: 06/29/2004
• Est. Priority Date: 01/30/2001
• Status: Expired due to Fees

• Current Assignee: Phoenix Electric Co., Ltd.
• Original Assignee: Phoenix Electric Co., Ltd.
• Inventors: Furukawa, Hisao
• Primary Examiner(s): Lee, Wilson
• Application Number:
  US09/984,684
• Publication Number:
  US 20020101201A1
• Time in Patent Office: 972 Days
• Field of Search: 315/224, 315/225, 315/291, 315/247, 315/276, 315/307, 315/244, 315/219, 315/289, 315/261, 315/262, 315/263, 315/264, 315/209.T
• US Class Current: 315/224
• CPC Class Codes: H05B 41/042 using semiconductor devices
• CPC Class Codes: H05B 41/2881 Load circuits; Control thereof
• CPC Class Codes: H05B 41/382 during the transitional start-up phase
• CPC Class Codes: H05B 41/388 for a transition from glow to arc

Abstract

A method of initiating lighting of a discharge lamp is provided including applying to the discharge lamp to be lighted an initiating voltage resulting from superimposition of a step-up pulse voltage of 1,000 to 3,000 V onto a voltage of 500 to 1,500 V which is continuously applied to the discharge lamp. Also provided is a circuit for lighting a discharge lamp, including a ballast for lighting the discharge lamp, and a low-voltage igniter connected to the ballast for initiating lighting of the lamp, the low-voltage igniter comprising: a lighting diode having an input side connected to an output side of the ballast and an output side connected to the discharge lamp; and a step-up device for superimposing step-up pulses onto the output of the lighting diode via a step-up pulse supply branch line connected to the output side of the lighting diode in initiating lighting of the discharge lamp.

Claims

1. A circuit for lighting a discharge lamp, comprising a ballast for lighting the discharge lamp, and a low-voltage igniter connected to the ballast for initiating lighting of the lamp, the low-voltage igniter comprising:

a lighting diode having an input side connected to an output side of the ballast and an output side connected to the discharge lamp;

a step-up output capacitor provided at a step-up pulse supply branch line connected to the output side of the lighting diode;

a trigger element provided at a pulse generation branch line connected to the input side of the lighting diode, and a pulse generation capacitor connected in parallel to the trigger element;

and a step-up transformer having a primary side connected via the trigger element to the input side of the lighting diode and a secondary side with an output terminal connected via the step-up output capacitor to the output side of the lighting diode.

3. The circuit for lighting a discharge lamp according to any one of claims 1 and 2, wherein the ballast is adapted for direct current.

4. The circuit for lighting a discharge lamp according to any one of claims 1 and 2, wherein the ballast is adapted for alternating current.

5. The circuit for lighting a discharge lamp according to claim 1, further comprising short-circuiting means connected in parallel to the lighting diode for short-circuiting the lighting diode after the discharge lamp is lit.

2. A circuit for lighting a discharge lamp, comprising a ballast for lighting the discharge lamp, and a low-voltage igniter connected to the ballast for initiating lighting of the lamp, the ballast having output switching means for outputting non-smoothed current containing a ripple component in initiating lighting of the lamp and for outputting smoothed current in steady lighting, the igniter comprising:

a lighting diode having an input side connected to an output side of the ballast and an output side connected to the discharge lamp; and

a step-up device, having a primary side using the non-smoothed current containing a ripple component outputted from the ballast and a secondary side using step-up induction current induced by the non-smoothed primary current via a step-up pulse supply branch line connected to the output side of the lighting diode as step-up pulse current, for superimposing a step-up pulse voltage of the step-up pulse current onto the output of the lighting diode in initiating lighting of the discharge lamp.