§
Luxuse
Patent Intelligence
Sign In
← Back to Patent Explorer
EP0371439A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Discharge lamp lighting apparatus for controlling voltage of switching transistor by raising starting voltage

Assignee: Toshiba Lighting and Technology Corp
•
Filing: 1989-11-28
•
Granted: —
•
Expires: 2009-11-28
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A discharge lamp lighting apparatus of this inven­tion includes an inverter circuit (20) and a control circuit (30) connected to a power source rectifier (14) for supplying a D.C. voltage. The inverter circuit (20) includes a parallel voltage resonance circuit of an output transformer (T1) and a resonance capacitor (C2) and the output side of the output transformer (T1) is connected to a discharge lamp (16) and a timer circuit (50). The inverter circuit (20) further includes a switching transistor (Q1) for switching the D.C. power source and a voltage detection circuit (40) for detect­ing a voltage V CE between the collector and emitter of the switching transistor (Q1). In the start-up opera­tion of the discharge lamp (16), the control circuit (30) raises the control level of V CE of the switching transistor (Q1) so as to set the output voltage of the inverter circuit (20) high until it receives a signal which is output after a preset time determined by the timer circuit (50) has elapsed, and under this condi­tion, the discharge lamp (16) is started.

Inventors

  • 👤 Kazutoshi Mita
  • 👤 Keiichi Shimizu

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-01 19:47
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/282; H05B41/2825; H05B41/2827; H05B41/24; Y; Y10; Y10S; Y10S315/00; Y10S315/07

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 192 words
A discharge lamp lighting apparatus comprising means for supplying a D.C. voltage; switching means for switching a voltage from said D.C. voltage supplying means; parallel voltage resonance circuit means includ­ing an inductor and a resonance capacitor and connected at a connection point in series with said switching means across said D.C. voltage supplying means; voltage detection means connected to said connection point, for detecting a voltage of said switching means at said con­nection point; and control means for controlling the voltage of said switching means detected by said voltage detection means to a constant level when said discharge lamp is started; characterized in that said control means (30) effects the control opera­tion to raise the voltage of said switching means (Q1), detected by said voltage detection means (40), to a relatively high constant preset level for a predeter­mined period of time from the time at which said D.C. voltage supplying means (12, 14) is turned on until said discharge lamp (16) is lit and set the voltage of said switching means (Q1) detected by said voltage detection means (40) to a relatively low constant level after said discharge lamp (16) is lit.
Claim 2
Dependent Claim 192 words
A discharge lamp lighting apparatus comprising means for supplying a D.C. voltage; switching means for switching a voltage from said D.C. voltage supplying means; parallel voltage resonance circuit means includ­ing an inductor and a resonance capacitor and connected at a connection point in series with said switching means across said D.C. voltage supplying means; voltage detection means connected to said connection point, for detecting a voltage of said switching means at said con­nection point; and control means for controlling the voltage of said switching means detected by said voltage detection means to a constant level when said discharge lamp is started; characterized in that said control means (30) effects the control opera­tion to raise the voltage of said switching means (Q1), detected by said voltage detection means (40), to a relatively high constant preset level for a predeter­mined period of time from the time at which said D.C. voltage supplying means (12, 14) is turned on until said discharge lamp (16) is lit and set the voltage of said switching means (Q1) detected by said voltage detection means (40) to a relatively low constant level after said discharge lamp (16) is lit.
Claim 3
Dependent Claim 51 words
An apparatus according to claim 1, character­ized in that said control means (30), independently from the lighting condition of the discharge lamp (16), raises the voltage of said switching means (Q1), detect­ed by said voltage detection means (40), to a relatively high preset constant level, for a predetermined period of time.
Claim 4
Dependent Claim 120 words
An apparatus according to claim 1, character­ized by further comprising timer means (50) for counting time which has elapsed after said D.C. voltage supplying means (12, 14) is turned on and said discharge lamp (16) is started and characterized in that said control means (30) effects the control operation to raise a voltage of said switching means (Q1) to a preset level for a predetermined period of time in which the time counted by said timer means (50) reaches a preset period of time and set the voltage of said switching means (Q1) detected by said voltage detection means (40) to a con­stant level after the time counted by said timer means (50) has exceeded the preset period of time.
Claim 5
Dependent Claim 44 words
An apparatus according to claim 3, character­ized in that said timer means (50) counts a course of time from when said discharge lamp (16) is turned on by integrating voltage generated between terminals of said discharge lamp (16) after rectifying and smoothing said voltage.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Maintenance schedule is calculated for granted US utility patents.

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag