Apparatus for lighting fluorescent lamp

A fluorescent lamp lighting apparatus comprising:

• a DC-voltage generation circuit for generating a DC voltage;
• a drive-signal generation circuit for generating and outputting desired high-voltage-side and low-voltage-side pulse signals by using the DC voltage from said DC-voltage generation circuit;
• and
• a drive control circuit having first switching means driven by the high-voltage-side pulse signal input from said drive-signal generation circuit, and second switching means connecting in series therewith and driven by the low-voltage-side pulse signal input from said drive-signal generation circuit, wherein an inductance device, the pair of filament electrodes of the fluorescent lamp light-emitting tube and a first capacitor are connected across both ends of said second switching means, and
• said drive-signal generation circuit having:
• a timer circuit in which the output signal thereof is altered after a predetermined time from power on;
• a separate-excitation oscillator for outputting a signal having a predetermined frequency;
• a separate-excitation/self-excitation selection switch circuit for outputting one of two input signals depending on the output signal of said timer circuit;
• a trigger input circuit for detecting the resonance frequency of a resonance circuit, wherein said resonance circuit comprises said inductance device and said first capacitor;
• a high voltage-side pulse generation circuit having a high-voltage-side dead time generation circuit, a narrow pulse generation circuit, a level shift circuit, a pulse reproduction circuit and an output circuit;
• a low-voltage-side pulse generation circuit having a low-voltage-side dead time generation circuit and an output circuit;
• and
• an under-voltage lockout circuit for outputting an output signal when the voltage of the power source is a predetermined voltage or less at the time of the rising and falling of the power source.

A fluorescent lamp lighting apparatus comprising a light-emitting portion having a light-emitting tube excited by a pair of filament electrodes and a power source circuit portion for outputting a signal for driving said pair of filament electrodes, wherein

• said power source circuit portion comprises:
• a DC-voltage generation circuit for outputting a smoothened DC voltage from an externally supplied AC power source,
• a drive-signal generation circuit operated by the application of the DC voltage of said DC-voltage generation circuit to output a signal, and
• a drive control circuit, having a resonance circuit network connected across the terminals for outputting a signal driven by the signal from said drive-signal generation circuit, for detecting the signal of this resonance circuit network and outputting the signal to a signal detection terminal, wherein
• said drive-signal generation circuit is configured to output a signal having a frequency, which is determined inside said drive-signal generation circuit, changes with the passage of time, and at least passes through the resonance frequency of said resonance circuit network in the non-lighting state of said light-emitting tube within a predetermined time from the application of said DC voltage, and to output a signal having the phase corresponding to the signal of said signal detection terminal after said predetermined time has passed.

A fluorescent lamp lighting apparatus comprising a light-emitting portion having a light-emitting tube excited by a pair of filament electrodes and a power source circuit portion for outputting a signal for driving said pair of filament electrodes, wherein

• said power source circuit portion comprises:
• a DC-voltage generation circuit for outputting a smoothened DC voltage from an externally supplied AC power source,
• a drive-signal generation circuit operated by the application of said DC voltage to output first and second drive signals individually,
• first switching means wherein the conduction between two terminals, that is, between one terminal and one of the pair of output terminals of said DC-voltage generation circuit, is turned on and off by said first drive signal,
• second switching means wherein the conduction between two terminals, that is, between one terminal and the other of the pair of output terminals of said DC-voltage generation circuit, is turned on and off by said second drive signal, and
• a resonance circuit network connected between the common connection portion of said first and second switching means and at least one of the pair of output terminals of said DC-voltage generation circuit, wherein
• said first and second drive signals are each configured to output a signal having a frequency, which is determined inside said drive-signal generation circuit, changes with the passage of time, and at least passes through the resonance frequency of said resonance circuit network in the non-lighting state of said light-emitting tube within a predetermined time from the application of said DC voltage, and to output a signal having the phase corresponding to the signal of said signal detection terminal after said predetermined time has passed.