Light source device

• US 20030098659A1
• Filed: 11/26/2002
• Published: 05/29/2003
• Est. Priority Date: 11/26/2001
• Status: Active Grant

• Current Assignee: Ushio Denki Kabushiki Kaisha
• Original Assignee: Ushio Denki Kabushiki Kaisha
• Inventors: Yokota, Toshio, Okamoto, Masashi
• Granted Patent: US 6,894,437 B2
• Time in Patent Office: Days
• US Class Current: 315/291
• CPC Class Codes: H05B 41/2928 for protecting the lamp against abnormal operating conditions
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A HID lamp light source device in which the disadvantage of acoustic resonance is avoided is achieved in a light source device in which a discharge lamp has a pair of opposed electrodes connected to a feed device which is used for starting the discharge lamp and for supplying a discharge current to the electrodes by the feed device using a switching device for controlling the amount of feed for the discharge lamp and in which phase modulation is added to the essentially periodic switching operation of the switching device.

Claims

1. Light source device, comprising:

a discharge lamp having a pair of opposed electrodes; and

a feed device connected to the electrodes for starting the discharge lamp and for supplying a discharge current to the electrodes,

wherein the feed device has a switching device with an essentially periodic switching operation for controlling the amount of feed for the discharge lamp, and wherein the switching device is provided with a phase modulation arrangement for providing phase modulation to the essentially periodic switching operation.

2. Light source device, comprising:

a discharge lamp having a pair of opposed electrodes; and

a feed device connected to the electrodes for starting the discharge lamp and for supplying a discharge current to the electrodes,

wherein the feed device is an alternating current feed device for providing an essentially periodic alternating current to the discharge lamp, and wherein the feed device is provided with a phase modulation arrangement for providing phase modulation to the essentially periodic alternating current.

3. Feed device for starting a discharge lamp and for supplying a discharge current, comprising a switching device with an essentially periodic switching operation for controlling the amount of feed for the discharge lamp, and wherein the switching device is provided with a phase modulation arrangement for providing phase modulation to the essentially periodic switching operation.

4. Feed device for starting a discharge lamp and for supplying a discharge current, comprising an alternating current feed device for providing an essentially periodic alternating current to the discharge lamp, and wherein the feed device is provided with a phase modulation arrangement for providing phase modulation to the essentially periodic alternating current.