USRE39341E1 - Apparatus for lighting fluorescent lamp - Google Patents
Apparatus for lighting fluorescent lamp Download PDFInfo
- Publication number
- USRE39341E1 USRE39341E1 US10/654,857 US65485703A USRE39341E US RE39341 E1 USRE39341 E1 US RE39341E1 US 65485703 A US65485703 A US 65485703A US RE39341 E USRE39341 E US RE39341E
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- voltage
- signal
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- generation circuit
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
- H05B41/14—Circuit arrangements
- H05B41/26—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc
- H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters
- H05B41/282—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices
- H05B41/2825—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices by means of a bridge converter in the final stage
- H05B41/2828—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices by means of a bridge converter in the final stage using control circuits for the switching elements
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
- H05B41/14—Circuit arrangements
- H05B41/26—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc
- H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters
- H05B41/295—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices and specially adapted for lamps with preheating electrodes, e.g. for fluorescent lamps
- H05B41/298—Arrangements for protecting lamps or circuits against abnormal operating conditions
- H05B41/2981—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions
- H05B41/2983—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions against abnormal power supply conditions
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S315/00—Electric lamp and discharge devices: systems
- Y10S315/05—Starting and operating circuit for fluorescent lamp
Definitions
- the present invention relates to an apparatus for lighting fluorescent lamp, particularly to a bulb-type fluorescent lamp, that is, a fluorescent lamp having a shape of electric bulb.
- bulb-type fluorescent lamps have been used instead of incandescent lamps.
- a light-emitting tube, a starter and a stabilizer are integrated and accommodated in the screw base portion thereof, making the base portion large and heavy.
- FIG. 47 is a circuit diagram of a conventional bulb-type fluorescent lamp. The circuit configuration of the bulb-type fluorescent lamp will be described below referring to FIG. 47 .
- An AC power source 101 is connected to the AC input terminals of a full-wave rectifier 104 via a filter circuit comprising an inductor 103 and a capacitor 102 .
- a smoothing capacitor 105 is connected across the DC output terminals of the full-wave rectifier 104 .
- two switching devices 111 and 112 are connected in a half-bridge configuration.
- a transformer 114 for generating a resonance voltage has inductors 115 , 116 and 117 .
- One of the terminals of the inductor 115 of the transformer 114 is connected to the connection point (hereinafter simply referred to as the connection point between the switching devices) of the first switching devices 111 and the second switching device 112 .
- a starting resistor 200 and a capacitor 201 are connected in parallel between the connection point between the switching devices and the smoothing capacitor 105 .
- the parallel arrangement of a capacitor 204 and zener diodes 206 and 207 is connected between the gate terminal of the first switching device 111 and the connection point between the switching devices.
- the cathodes of the two zener diodes 206 and 207 are connected to each other in series.
- An inductor 202 is connected between the other terminal of the inductor 115 of the transformer 114 and the gate terminal of the first switching device 111 .
- An inductor 203 is connected between one of the terminals of the inductor 116 of the transformer 114 and the gate terminal of the second switching device 112 .
- a smoothing capacitor 205 is connected between the other terminal of the inductor 116 and the gate terminal of the second switching device 112 .
- two zener diodes 208 and 209 are directly connected between the other terminal of the inductor 116 and the gate terminal of the second switching terminal 112 in parallel with the smoothing capacitor 205 .
- the cathodes of these two zener diodes 208 and 209 are connected to each other.
- a resistor 210 is connected between the connection point of the two zener diodes 208 and 209 and the other terminal of the second switching device 112 .
- the other terminal of the second switching terminal 112 is connected to the smoothing capacitor 205 via a capacitor 213 .
- One of the terminals of the inductor 117 of the transformer 114 is connected to the connection point between the switching devices, and a pair of filament terminals in a light-emitting tube 135 and a capacitor 134 are connected in series between the other terminal of this inductor 117 and a capacitor 133 .
- the starter of the conventional bulb-type fluorescent lamp shown in FIG. 47 includes the two switching devices 111 and 112 , the inductor 117 used as the secondary winding of the transformer 114 and the capacitors 133 and 134 connected to the light-emitting tube 135 .
- the two switching devices 111 and 112 turn on and off alternatively at high speed, thereby converting the DC voltage across the smoothing capacitor 105 into a high-frequency signal.
- the light-emitting tube 135 is set in a lighting state by the high-frequency signal.
- the capacitor 134 inserted and connected across the pair of filament electrodes of the light-emitting tube 135 forms the current path of the preheating current for filaments of the light-emitting tube 135 , and is also used as a resonance capacitor in combination with the inductor 117 .
- the capacitor 133 is a coupling capacitor used to cut DC components in the power source.
- the inductors 115 and 116 of the transformer 114 detect the timing of on/off operation, and the inductors 202 and 203 carry out driving.
- the starting resistor 200 turns on the first switching device 111 at the time of power-on to start the starter. In this way, until the starter is started by power-on and the light-emitting tube 135 is lit, resonance is caused at the inductor 117 and the capacitor 134 constituting a resonance circuit by the two switching devices 111 and 112 , thereby generating a high voltage and lighting the light-emitting tube 135 .
- the impedance across the light-emitting tube 135 becomes low.
- the resonance capacitor 134 becomes nearly short-circuited. For this reason, self-oscillation occurs at the low resonance frequency determined by the capacitor 133 and the inductor 117 , whereby the light-emitting tube 135 can continue high-frequency lighting operation at high efficiency.
- the preheating time for the filaments cannot be taken sufficiently, thereby causing a problem of making the luminous flux small because the temperature of the external tube is low immediately after lighting, and making the luminous flux larger as the temperature of the external tube rises.
- the present invention provides an apparatus for lighting fluorescent lamp, that is a fluorescent lamp lighting apparatus, configured to sufficiently provide a preheating time at the time of lighting and capable of carrying out control at a level not applying stress to the filaments of the light-emitting tube thereof.
- the present invention is intended to provide a fluorescent lamp lighting apparatus having a smaller mounting area by significantly reducing the number of components by using a one-chip monolithic IC accommodating an oscillator, and capable of maintaining a constant luminous flux immediately after lighting.
- the power source circuit portion has the DC-voltage generation circuit, the drive-signal generation circuit and the drive control circuit, and the need for a transformer coil is eliminated; therefore, the mounting area of the power source circuit portion is decreased significantly, and the number of components is reduced.
- a fluorescent lamp lighting apparatus in accordance with the present invention from another aspect comprises:
- the power source circuit portion has the DC-voltage generation circuit, the drive-signal generation circuit and the drive control circuit, and the need for a transformer coil is eliminated by providing a semiconductor integrated circuit; therefore, the mounting area of the power source circuit portion is decreased significantly, and the number of components is reduced.
- a fluorescent lamp lighting apparatus in accordance with the present invention from another aspect comprises 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 the above-mentioned pair of filament electrodes, wherein
- a signal having a frequency different from the resonance frequency of the resonance circuit network can be generated at the time of power on, whereby a desired voltage can be applied to the filament electrodes without abruptly applying a high voltage caused by resonance.
- the frequency to be supplied to the resonance circuit network is changed with the passage of time and passed through the resonance frequency band, whereby the light-emitting tube can be lit securely in the vicinity of the resonance frequency.
- the signal having the phase corresponding to the signal of the signal detection terminal is supplied to the resonance circuit network after the predetermined time has passed from power on, thereby to form a closed loop for driving the resonance circuit network, whereby the resonance state can be maintained, and the light emission of the light-emitting tube can be continued.
- a fluorescent lamp lighting apparatus in accordance with the present invention from another aspect comprises 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 the above-mentioned pair of filament electrodes, wherein
- the power source circuit portion has the DC-voltage generation circuit, the drive-signal generation circuit and the drive control circuit, and the need for a transformer coil is eliminated; therefore, the mounting area of the power source circuit portion is decreased significantly, and the number of components is reduced.
- a signal having a frequency different from the resonance frequency of the resonance circuit network can be generated at the time of power on, whereby a desired voltage can be applied to the filament electrodes without abruptly applying a high voltage caused by resonance.
- the frequency to be supplied to the resonance circuit network is changed with the passage of time and passed through the resonance frequency band, whereby the light-emitting tube can be lit securely in the vicinity of the resonance frequency.
- the signal having the phase corresponding to the signal of the signal detection terminal is supplied to the resonance circuit network after the predetermined time has passed from power on, thereby to form a closed loop for driving the resonance circuit network, whereby the resonance state can be maintained, and the light emission of the light-emitting tube can be continued.
- the resonance connection portion of the first and second switching means can be driven by the voltage across the output terminals of the DC-voltage generation circuit, whereby it is possible to generate a voltage required to drive the filament electrodes.
- abrupt stress is not applied to the filament electrodes and the light-emitting tube, whereby the service life of the light-emitting tube can be extended; in addition, the temperature of the light-emitting tube is raised and light is emitted, whereby the change in the luminous flux immediately after light emission can be suppressed.
- FIG. 1 is a perspective view showing an appearance of a bulb-type fluorescent lamp of Embodiment 1 in accordance with the present invention
- FIG. 2 is a circuit diagram showing a configuration of the bulb-type fluorescent lamp of Embodiment 1 shown in FIG. 1 ;
- FIG. 3 is a circuit configuration diagram showing an operation of a DC-voltage generation circuit 10 in Embodiment 1;
- FIG. 4 is waveform diagrams showing voltage waveforms at each portion in the DC-voltage generation circuit 10 in Embodiment 1;
- FIG. 5 shows pulse signal waveforms input to gates of power MOS transistors M 1 and M 2 in Embodiment 1, a part ( 1 ) shows a pulse signal waveform (the pulse signal on the high-voltage side) to be input to the gate of the first power MOS transistor M 1 , and a part ( 2 ) shows a pulse signal waveform (the pulse signal on the low-voltage side) to be input to the gate of the second power MOS transistor M 2 ;
- FIG. 6 is a graph showing a progress of an output frequency in a drive control circuit 30 in Embodiment 1;
- FIG. 7 is a waveform diagram showing various signals in the drive control circuit 30 ;
- FIG. 8 is a graph showing a relationship between a current
- FIG. 9 is a block diagram showing a configuration of the semiconductor integrated circuit 21 in Embodiment 1;
- FIG. 10 is a circuit diagram showing a configuration of a timer circuit 212 in the semiconductor integrated circuit 21 of Embodiment 1;
- FIG. 11 is a circuit diagram showing a configuration of a separate-excitation/self-excitation selection switch circuit 214 in the semiconductor integrated circuit 21 of Embodiment 1;
- FIG. 12 is a circuit diagram showing a configuration of a separate-excitation oscillator in the semiconductor integrated circuit 21 of Embodiment 1;
- FIG. 13 is a waveform diagram showing signal states in the separate-excitation oscillator of Embodiment 1;
- FIG. 14 is a circuit diagram showing a configuration of a trigger input circuit in the semiconductor integrated circuit 21 of Embodiment 1;
- FIG. 15 is a waveform diagram showing a signal states of the trigger input circuit in the semiconductor integrated circuit 21 of Embodiment 1;
- FIG. 16 is a waveform diagram showing the signal states in the semiconductor integrated circuit 21 of Embodiment 1;
- FIG. 17 is a waveform diagram showing a signal states in the semiconductor integrated circuit 21 of Embodiment 1;
- FIG. 18 is a waveform diagram showing the signal states in the semiconductor integrated circuit 21 of Embodiment 1;
- FIG. 19 is a circuit diagram showing a configuration of a level shift circuit 218 in the semiconductor integrated circuit 21 of Embodiment 1;
- FIG. 20 is a circuit diagram showing a configuration of a timer circuit of a semiconductor integrated circuit in a bulb-type fluorescent lamp of Embodiment 2 in accordance with the present invention.
- FIG. 21 is a view for illustrating methods of sweeping a frequency in a separate-excitation oscillator 211 of Embodiment 3 in accordance with the present invention.
- FIG. 22 is a configuration view showing concrete circuits for sweeping frequency in a bulb-type fluorescent lamp of Embodiment 3;
- FIG. 23 is a circuit diagram showing a concrete configuration for sweeping frequency in the bulb-type fluorescent lamp of Embodiment 3;
- FIG. 24 is a frequency curve showing method of sweeping a frequency in a separate-excitation mode in the bulb-type fluorescent lamp of Embodiment 3;
- FIG. 25 is a circuit diagram showing a configuration of a separate-excitation oscillator 211 b of Embodiment 4 in accordance with the present invention.
- FIG. 26 is a graph showing a relationship between a resonance frequency at the time of lighting and the current
- FIG. 27 is a graph showing a relationship between the resonance frequency before lighting and current
- FIG. 28 is a circuit diagram of a trigger input circuit as an example wherein diodes are used to delay the operation speed of the comparator of the trigger input circuit in Embodiment 5 at low temperature;
- FIG. 29 is a circuit diagram showing an example of a delay circuit in Embodiment 5.
- FIG. 30 is a waveform diagram showing an input signal, a signal at point a, a signal at point b, a signal at point c and an output signal in the circuit shown in FIG. 29 ;
- FIG. 31 is a block diagram showing a configuration of a semiconductor integrated circuit in Embodiment 6 in accordance with the present invention.
- FIG. 32 is a graph showing a progress of a frequency output from a separate-excitation oscillator in Embodiment 6 in accordance with the present invention.
- FIG. 33 is a circuit diagram showing a configuration in a bulb-type fluorescent lamp of Embodiment 7 in accordance with the present invention.
- FIG. 34 is a block diagram showing a configuration of a semiconductor integrated circuit in Embodiment 7.
- FIG. 35 is a circuit diagram of a separate-excitation oscillator of the semiconductor integrated circuit in Embodiment 7.
- FIG. 36 shows frequency characteristic curves at the time of non-lighting in Embodiment 7.
- FIG. 37 is a circuit diagram showing a configuration of a separate-excitation oscillator 211 e in a bulb-type fluorescent lamp of Embodiment 8 in accordance with the present invention.
- FIG. 38 is a concrete circuit diagram of a delay circuit 251 used for a bulb-type fluorescent lamp of Embodiment 9 in accordance with the present invention.
- FIG. 39 is a circuit diagram showing a configuration of a bulb-type fluorescent lamp of Embodiment 10 in accordance with the present invention.
- FIG. 40 is a circuit diagram showing a configuration of a delay circuit in Embodiment 10.
- FIG. 41 is a block diagram showing a configuration of a first example of a semiconductor integrated circuit in Embodiment 11 in accordance with the present invention.
- FIG. 42 is a circuit diagram showing a configuration of a separate-excitation oscillator 511 in Embodiment 11;
- FIG. 43 is a block diagram showing a configuration of a second example of a semiconductor integrated circuit in Embodiment 11,
- FIG. 44 is a circuit diagram showing a configuration of a separate-excitation oscillator 611 in Embodiment 11;
- FIG. 45 is a block diagram showing a configuration of a semiconductor integrated circuit in Embodiment 12 in accordance with the present invention.
- FIG. 46 is a circuit diagram showing a configuration of a separate-excitation oscillator 711 in a bulb-type fluorescent lamp of Embodiment 12;
- FIG. 47 is a circuit diagram of a conventional bulb-type fluorescent lamp.
- a bulb-type fluorescent lamp in accordance with Embodiment 1 an embodiment of a fluorescent lamp lighting apparatus in accordance with the present invention, will be described below referring to the accompanying drawings.
- FIG. 1 is a perspective view showing the appearance of a bulb-type fluorescent lamp of Embodiment 1 in accordance with the present invention
- FIG. 2 is a circuit diagram showing the configuration of the bulb-type fluorescent lamp of Embodiment 1 shown in FIG. 1 .
- a bulb-type fluorescent lamp 1 of Embodiment 1 has a light-emitting portion 2 having a diameter substantially similar to the shape of a conventional electric bulb and a power source circuit portion 3 .
- the power source circuit portion 3 is made smaller and lighter than a conventional bulb-type fluorescent lamp, and has a shape replaceable with the conventional electric bulb.
- the power source circuit portion 3 is accommodated in the bottom portion near the base portion, and large components, such as an electrolytic capacitor 6 , are disposed at the central portion of the bulb-type fluorescent lamp to raise mounting efficiency.
- FIG. 2 is a circuit diagram showing the circuit configuration of the power source circuit portion 3 in the bulb-type fluorescent lamp 1 of Embodiment 1.
- the power source circuit portion 3 comprises a DC-voltage generation circuit 10 , a drive-signal generation circuit 20 and a drive control circuit 30 .
- the DC-voltage generation circuit 10 of Embodiment 1 is a circuit for forming a DC voltage (about 141 V) across terminals 100 and 101 from an AC power source (100 V AC, 50 Hz/60 Hz).
- a resistor R 1 is a circuit protection resistor against overcurrent
- an electronic capacitor C 2 is a smoothing capacitor and represented by the numeral 6 .
- a conventionally-used, general AC/DC converter can be used as the DC-voltage generation circuit 10 in the bulb-type fluorescent lamp 1 .
- the voltage of the AC power source is in the range of 200 V to 240 V depending on regions; in this case, the output voltage (the voltage across the terminals of C 2 ) of the DC-voltage generation circuit 10 differs depending on the input voltage of the AC power source.
- FIG. 3 is a circuit configuration diagram showing the operation of the DC-voltage generation circuit 10 in Embodiment 1.
- FIG. 4 is waveform diagrams showing voltage waveform at each portion in the DC-voltage generation circuit 10 .
- a part (a) of FIG. 4 is a waveform of a voltage applied across the input terminals 300 and 301 of the DC-voltage generation circuit 10 .
- a part (b) of FIG. 4 is a voltage waveform across the output terminals 100 and 101 in the case where the electrolytic capacitor 6 (C 2 ) is not provided for the DC-voltage generation circuit.
- a part (c) of FIG. 4 is a voltage waveform output from the DC-voltage generation circuit 10 in the case where the electrolytic capacitor 6 (C 2 ) is provided for the DC-voltage generation circuit 10 .
- a current flows along the path indicated by arrows ih in FIG. 3 , and the electrolytic capacitor 6 (C 2 ) is charged up to about 141 V.
- the rectifying diodes 110 and 120 of a rectifying portion 11 are turned off.
- the charge charged in the electrolytic capacitor 6 (C 2 ) is input to the drive-signal generation circuit 20 and the drive control circuit 30 through the output terminals 100 and 101 .
- the drive-signal generation circuit 20 is a circuit for generating pulse signals to be input to the gates of the two power MOS transistors M 1 and M 2 of the drive control circuit 30 .
- the voltage output across the terminals 100 and 101 from the DC-voltage generation circuit 10 is applied to a series connection arrangement comprising a resistor (R 2 ) and a zener diode (Z 1 ).
- the voltage generated across both ends of the zener diode (Z 1 ) is applied between the power source (Vcc) terminal of the pin terminal No. 1 and the ground (GND) terminal of the pin terminal 3 of the semiconductor integrated circuit 21 .
- FIG. 5 is an explanatory view showing the timing of the pulse signals formed in the semiconductor integrated circuit 21 of the drive-signal generation circuit 20 .
- FIG. 5 is an explanatory view showing the timing of the pulse signals formed in the semiconductor integrated circuit 21 of the drive-signal generation circuit 20 .
- a part ( 1 ) shows the pulse signal waveform (the pulse signal on the high-voltage side) to be input to the gate of the first power MOS transistor M 1 . Furthermore, a part ( 2 ) shows the pulse signal waveform (the pulsed signal on the low-voltage side) to be input to the gate of the second power MOS transistor M 2 .
- FIG. 6 is an example of a graph showing the progress of the output frequency in the drive control circuit 30 .
- a pulse signal having a frequency formed by an oscillator in the semiconductor integrated circuit 21 is output. This period is referred to as a separate-excitation mode in the following descriptions.
- the signal from the oscillator in the semiconductor integrated circuit 21 stops.
- the signal from the filament-side terminal the terminal indicated by code A in FIG.
- the LC resonance frequency of the drive control circuit 30 is detected on the basis of the signal output from the filament-side terminal of the coil L 1 . Then, the pulse signals are input from the light-voltage side output terminal H and the low-voltage side output terminal L of the semiconductor integrated circuit 21 to the gates of the two power MOS transistors M 1 and M 2 in the drive control circuit 30 , respectively.
- a self-excitation mode a loop for continuing LC resonance is formed in the drive control circuit 30 and the filaments 51 and 52 of the light-emitting tube 4 . Therefore, the resonance state continues until power is turned off (OFF state).
- the resistor R 2 , the zener diode Z 1 and the capacitor C 3 of the drive-signal generation circuit 20 form a circuit wherein a DC power source voltage of 15 V to be supplied to the pin terminal No. 1 (Vcc) of the semiconductor integrated circuit 21 is generated from a DC voltage of about 141 V, i.e., the output of the DC-voltage generation circuit 10 .
- a current always flows through the zener diode Z 1 , and the resistor R 2 is set to maintain the voltage on the zener diode at 15V. Therefore, the resistance value of the resistor R 2 is set depending on the currents flowing at the terminal of the pin terminal No. 1 and at the terminal of the pin terminal No. 8 of the semiconductor integrated circuit 21 .
- the terminals of the pin terminal Nos. 6 , 7 and 8 in the semiconductor integrated circuit 21 of the drive-signal generation circuit 20 are the terminal group of the high-pressure-pulse generation circuit portion, and a high-voltage pulse signal is output from the terminal (the high-voltage side) of the pin terminal No. 7 .
- FIG. 7 shows various signals in the drive control circuit 30 .
- a part ( 1 ) of FIG. 7 shows the voltage signal across the terminals of the coil L 1
- a part ( 2 ) shows a signal input to be gate of the first power MOS transistor M 1
- a part ( 3 ) shows a signal input to the gate of the second power MOS transistor M 2
- a part ( 4 ) shows a signal input into the terminal of the pin terminal No. 6
- the pulse signal shown in the part ( 4 ) of FIG. 7 is the output signal of the half bridge, and is the signal at the source (the drain of the second power MOS transistor M 2 ) of the fist power MOS transistor M 1 .
- the terminal of the pin terminal No. 6 is connected to the common connection portion of the power MOS transistors M 1 and M 2 of the drive control circuit 30 .
- the pulse signal shown in the part ( 4 ) of FIG. 7 is input to the terminal of the pin terminal No. 6 .
- the capacitor C 7 of the drive-signal generation circuit 20 is a capacitor for setting the time of the separate-excitation mode immediately after power on.
- a constant current of 6 ⁇ A for example, is output from the terminal of the pin terminal No. 5 of the semiconductor integrated circuit 21 , and the capacitor C 7 is charged with the current.
- the voltage across the terminals of the capacitor C 7 rises from 0 V; when the capacitor C 7 reaches a predetermined voltage, the semiconductor integrated circuit 21 is switched from the separate-excitation mode to the self-excitation mode.
- the bulb-type fluorescent lamp of Embodiment 1 of the present invention has a filament preheating function described next.
- the pulse signal having the frequency shown in the part ( 4 ) of FIG. 7 is input to the connection portion of the source of the first power MOS transistor M 1 and the drain of the second power MOS transistor M 2 , i.e., the terminal of the pin number No. 6 of the semiconductor integrated circuit 21 .
- the resonance frequency f 0 of the capacitor C 5 , the capacitor C 6 and the coil L 1 of the drive control circuit 30 is represented by the following equation (1).
- the resistor R 3 of the drive-signal generation circuit 20 is sufficiently large.
- C 5 and C 6 represent the capacitances of the capacitors C 5 and C 6
- L 1 represents the inductance of the coil L 1 .
- FIG. 8 is a graph showing the relationship between the current
- flowing in the resonance circuit becomes maximum, and the voltage across the filaments becomes maximum.
- becomes smaller, and the voltage across the filaments (across both terminals of the capacitor C 6 ) becomes smaller.
- the resonance circuit has such a resonance curve as shown in FIG. 8 . Therefore, the start frequency (lighting frequency) at the time of power on in the separate-excitation mode is set at frequency fstt wherein the light-emitting tube 4 it not lit securely, and this frequency is lowered gradually.
- the stop frequency fstp wherein the separate-excitation mode is switched to the self-excitation mode is set at a frequency lower than the resonance frequency f 0 .
- the lighting voltage is applied across the filaments.
- the impedance across the filaments becomes low (about 100 ⁇ ).
- the separate-excitation mode is switched to the self-excitation mode.
- the resonance frequency in the self-excitation mode is determined by the resonance circuit of the capacitor C 5 , the capacitor C 6 and the coil L 1 , the impedance of the light-emitting tube 4 at the time of lighting and the phase of the feedback loop from the resonance circuit.
- FIG. 9 is a block diagram showing the semiconductor integrated circuit in the bulb-type fluorescent lamp of Embodiment 1.
- a low-voltage-side and under-voltage lockout circuit (written as a low-voltage-side UVLO in FIG. 9 ; UVLO is an acronym of Under-Voltage Lockout) 232 is configured so that no signal is output from the terminal of the pin terminal No. 4 when the power voltage is a setting voltage (10 V for example) or less.
- a high-voltage-side under-voltage lockout circuit (written as a high-voltage-side UVLO in FIG. 9 ) 231 is configured so that no signal is output from the terminal of the pin terminal No. 7 when the voltage across the terminals of the pin terminal No. 8 and the pin terminal No. 6 is the setting voltage or less.
- the low-voltage-side under-voltage lockout circuit 232 and the high-voltage-side under-voltage lockout circuit 231 are provided for the bulb-type fluorescent lamp of Embodiment 1 as described above, thereby preventing abnormal operation at the time of power on/off. Furthermore, the low-voltage-side and under-voltage lockout circuit 232 has a function of resetting a timer circuit 212 at the time of power on/off, and a function of stopping the operation of a separate-excitation oscillator 211 operating usually at a frequency of 75 kHz to 100 kHz, for example.
- the setting voltage in the low-voltage-side under-voltage lockout circuit 232 and the setting voltage at the high-voltage-side under-voltage lockout circuit 231 are provided with hysteresis between the value at the time of voltage rising and the value at the time of voltage lowering, thereby being set to have different voltages.
- FIG. 10 is a circuit diagram showing a preferred configuration of the timer circuit 212 in the semiconductor integrated circuit 21 .
- the timer circuit 212 is a circuit for setting the time of switching from the separate-excitation mode to the self-excitation mode after power on.
- the voltage across the terminals of the capacitor C 7 is initialized to 0 V by the MOS transistor M 3 of the timer circuit 212 .
- the capacitor C 7 is charged with a constant current Ia.
- the output (OUT 1 ) of the timer circuit 212 is switched from LOW to HIGH.
- the setting voltage of the timer circuit 212 is provided with hysteresis between the value at the time when the voltage across the terminals of the capacitor C 7 rises and the value at the time when the voltage lowers, thereby being set to have different voltages.
- the voltage across the terminals of the capacitor C 7 is also initialized to 0 V by the low-voltage-side under-voltage lockout circuit 232 .
- UVLO Under-voltage lockout circuits
- low-voltage-side under-voltage lockout circuit hereinafter simply referred to as low-voltage-side UVLO
- high-voltage-side UVLO high-voltage-side UVLO
- the high-voltage-side UVLO 231 When the high-voltage-side UVLO 231 operates (carries out reset output) earlier than the low-voltage side UVLO 232 at the time of power off, only the power MOS transistor M 1 becomes open at the time when the high-voltage-side UVLO 231 operates. Then, the resonance state of the LC resonance circuit of the drive control circuit 30 stops. As a result, the charge of the 141 V power source from the DC-voltage generation circuit 10 loses all means of escape, and the voltage drop of the 141 power source stops. Then, the 15 V power source of the semiconductor integrated circuit 21 also stops. By this operation of the high-voltage-side UVLO 231 , the non-operating state of the low-voltage-side UVLO 232 is maintained.
- the timer terminal voltage at the pin terminal No. 5 is not reset to 0 V by the low-voltage-side UVLO 232 , but is maintained at a certain voltage.
- start is carried out in the self-excitation mode, instead of the separate-excitation mode, thereby causing a malfunction of no lighting.
- the setting voltages thereof are adjusted so that the low-voltage side UVLO 232 operates earlier than the high-voltage-side UVLO 21 at the time of power off.
- the operation voltage of the low-voltage side UVLO 232 is set at 10 V
- the operation voltage of the high-voltage-side UVLO 231 is set at 9 V.
- the low-voltage side UVLO 232 operates earlier than the high-voltage-side UVLO 231 at the time of power off.
- the bulb-type fluorescent lamp of Embodiment 1 lights securely even at the time of the re-lighting operation.
- the power source voltage on the low-voltage side is 15 V
- the power source voltage on the high-voltage side is 14.3 V. Since noise is apt to mix into the signal on the high-voltage side at this time, a filter is provided to prevent the mixture of noise.
- FIG. 11 is a circuit diagram of the separate-excitation/self-excitation selection switch circuit 214 in the semiconductor integrated circuit 21 .
- the separate-excitation/self-excitation selection switch circuit 214 is a circuit for outputting either the output (OUT 2 ) from the separate-excitation oscillator 211 or the output (OUT 3 ) from a trigger input circuit 213 as OUT 4 depending on the output (OUT 1 ) of the timer circuit 212 .
- the separate-excitation/self-excitation selection switch circuit 214 outputs the signal (OUT 2 ) from the separate-excitation oscillator 211 in the separate-excitation mode immediately after power.
- the signal (OUT 3 ) from the trigger input circuit 213 is output as OUT 4 to a high-voltage-side dead time generation circuit 216 and a low-voltage-side dead time generation circuit 217 .
- the separate-excitation oscillator 211 is a circuit for generating a pulse signal having a preset frequency in the period of the separate-excitation mode after power on. As the terminal voltage at the pin terminal No. 5 connected to a timer circuit 212 rises, the frequency of the separate-excitation oscillator 211 lowers.
- FIG. 12 is a circuit diagram showing the configuration of the separate-excitation oscillator 211 in the semiconductor integrated circuit 21 of Embodiment 1.
- C 8 is a charging/discharging capacitor
- Ib is a constant current source current
- Ic is a constant current to be subtracted from the charging or discharging current supplied to the charging/discharging capacitor C 8 depending on the terminal voltage at the pin terminal No. 5
- Vb is an upper-side reference voltage for repeating charging/discharging to the charging/discharging capacitor C 8
- Vc is a lower-side reference voltage.
- FIG. 13 shows the voltage ( 1 ) across the terminals of the charging/discharging capacitor C 8 in the separate-excitation oscillator 211 and the output signal (OUT 2 ) of the separate-excitation oscillator 211 .
- the relationship between the constant current Ic determined by the terminal voltage Ic at pin terminal No. 5 in the separate-excitation oscillator 211 and the oscillator frequency f (Ic) of the separate-excitation oscillator 211 is represented by the following equation (2).
- f ⁇ ( lc ) lb - lc 2 ⁇ ( C8 ) ⁇ ( Vb - Vc ) ( 2 )
- the constant current Ic changes depending on the terminal voltage at the pin terminal No. 5
- the constant current source current Ib and the constant current Ic has a relationship of Ib>Ic.
- the preheating current flowing through the filaments 51 and 52 before the lighting of the light-emitting diode 4 becomes larger.
- the duty ratio can be set by adjusting the ratio of the gate width of the MOS transistor M 8 and that of the MOS transistor M 9 and the ratio of the gate width of the MOS transistor M 10 and that of the MOS transistor M 11 as described above.
- the signal from the high-voltage-side terminal A (the terminal on the opposite side of the ground) of the coil L 1 shown in the above-mentioned FIG. 2 is input to the trigger input circuit 213 via a high-resistance resistor R 3 (510 k ⁇ ).
- FIG. 14 is a circuit diagram showing the configuration of the trigger input circuit 213 .
- a part ( 1 ) Of FIG 15 shows the signal at the high-voltage-side terminal of the coil L 1 ( FIG. 2 ) to be input to the trigger input circuit 213 and a part ( 2 ) shows the signal to be output.
- the input signal shown in the part ( 1 ) is converted into a pulse waveform with its 0 V as the threshold level.
- the trigger input circuit 213 of Embodiment 1 is set to have hysteresis. For this reason, at the rising time of the input signal, conversion is carried out into a pulse waveform, with 0.2 V, slightly higher than 0 V, used as the threshold level. However, in reality, the phase of the output signal (OUT 3 ) is slightly shifted from that of the input signal by the delay operation of the circuit in the trigger input circuit 213 .
- a noise canceler 213 b is provided at the output of the comparator 213 a of the trigger input circuit 213 , thereby having a configuration wherein when noise is included in the input signal, the noise can be canceled.
- a part ( 1 ) of FIG. 16 shows an example of the input signal, including noise, from the high-voltage-side terminal A of the coil L 1 (FIG. 2 ), a part ( 2 ) shows the signal output from the comparator 213 a in that case, and a part ( 3 ) shows the signal output from the noise canceler 213 b.
- the signal is canceled.
- the output signal (OUT 3 ) becomes a signal with no noise.
- the signal (OUT 4 ) from the separate-excitation/self-excitation selection switch circuit 214 is input to the high-voltage-side dead time generation circuit 216 and the low-voltage-side dead time generation circuit 217 .
- the high-voltage-side dead time generation circuit 216 and the low-voltage-side dead time generation circuit 217 form and output signals wherein a one-side edge (rising or falling) of the input signal waveform is delayed (750 ns).
- a part ( 1 ) of FIG. 17 shows the signal (OUT 4 ) from the separate-excitation/self-excitation selection circuit 214 .
- a part ( 2 ) of FIG. 17 shows the output signal (OUT 6 ) of the high-voltage-side dead time generation circuit 216 .
- a part ( 3 ) of FIG. 17 shows the output signal (OUT 7 ) of the low-voltage-side dead time generation circuit 217 .
- the output signal (OUT 6 ) of the high-voltage-side dead time generation circuit 216 is formed to rise 750 ns laster than the rising of the signal (OUT 4 ) from the separate-excitation/self-excitation selection circuit 214 .
- the output signal (OUT 7 ) of the low-voltage-side dead time generation circuit 217 is an inversion of the signal (OUT 4 ) from the separate-excitation/self-excitation selection circuit 214 as shown in the part ( 3 ) of FIG. 17 . Furthermore, the output signal (OUT 7 ) is generated to rise 750 ns later than the falling of the signal of OUT 4 .
- a narrow pulse generation circuit 215 is a circuit wherein when the output signal (OUT 6 ) of the high-voltage-side dead time generation circuit 216 is input, a pulse signal having a narrow pulse width is formed in response to the rising and falling of the output signal (OUT 6 ).
- FIG. 18 shows an example of the output signal from each circuit.
- a part ( 1 ) shows the output signal of the high-voltage-side dead time generation circuit 216
- a part ( 2 ) shows a pulse signal having a width of about 50 ns formed by the narrow pulse generation circuit 215 in response to the falling of the output signal (OUT 6 ).
- a part of FIG. 18 shows a pulse signal having a width of about 50 ns formed by the narrow pulse generation circuit 215 in response to the rising of the output signal (OUT 6 ) of the high-voltage-side dead time generation circuit 216 .
- a level shift circuit 218 is a circuit wherein the signals (OUT 8 and OUT 9 ) from the narrow pulse generation circuit 215 are converted into the signals (OUT 10 and OUT 11 ) of the high-voltage circuit by the 15 V power source (the terminal voltage as the pin terminal No. 1 of the semiconductor integrated circuit 21 shown in FIG. 9 ).
- Parts ( 4 ) and ( 5 ) of FIGS. 18 show the output signals (OUT 10 and OUT 11 ) from the level shift circuit 218 .
- the signal (OUT 10 ) of the part ( 4 ) of FIG. 18 is formed by the signal (OUT 8 ) shown in the part ( 2 ) from the narrow pulse generation circuit 215 .
- the signal (OUT 11 ) shown in the part ( 5 ) of FIG. 18 is formed by the signal (OUT 9 ) shown in the part ( 3 ) from the narrow pulse generation circuit 215 .
- the signals (OUT 10 and OUT 11 ) from the level shift circuit 218 are input to the high-voltage circuit, that is, a high-voltage circuit 234 comprising a high-voltage-side pulse reproduction circuit 219 , a high-voltage-side output circuit 230 and the high-voltage-side under-voltage lockout circuit (high-voltage-side UVLO) 231 .
- the minimum potential thereof is determined when the pulse signal shown in the above-mentioned part ( 4 ) of FIG. 7 is applied from the terminal of the pin terminal No. 6 .
- the maximum potential (power source voltage) of the high-voltage-side pulse reproduction circuit 219 , the high-voltage-side output circuit 230 and the high-voltage-side under-voltage lockout circuit (high-voltage-side UVLO) 231 and the level shift circuit 218 is applied from the terminal of the pin terminal No. 8 .
- the terminal voltage at the pin terminal No. 8 is set at a voltage about 14.3 V higher than the terminal voltage at the pin terminal No. 6 .
- FIG. 19 is a circuit diagram showing the configuration of the level shift circuit 218 .
- the level shift circuit 218 has two N-channel MOS transistors M 4 and M 5 .
- the signal OUT 8 is input to the gate of one of the N-channel MOS transistor, M 4
- the signal OUT 9 is input to the gate of the other N-channel MOS transistor M 5 .
- the sources of the N-channel MOS transistors M 4 and M 5 of Embodiment 1 are configured so as to be grounded, it may be possible to use a source follower configuration wherein a resistor is inserted between the source and GND to limit current.
- resistors R 4 and R 5 are inserted between each of the drains of the N-channel MOS transistors M 4 and M 5 and the terminal of the pin terminal No. 8 , respectively.
- the signals from the drains of the MOS transistors M 4 and M 5 are output as OUT 10 and OUT 11 .
- the resistor R 4 and the resistor R 5 are set at desired values so that the drain voltages of the MOS transistors M 4 and M 5 can activate the high-voltage-side pulse reproduction circuit 219 of the next stage.
- zener diodes Z 2 and Z 3 are inserted between the drain of the MOS transistor M 4 and the terminal of the pin terminal No. 6 . Furthermore, zener diodes Z 4 and Z 5 are inserted between the drain of the MOS transistor M 5 and the terminal of the pin terminal No. 6 . It is desired that the inserted zener diodes Z 2 , Z 3 , Z 4 and Z 5 have large current capacities in the forward direction, and that the zener diodes, wherein the zener voltage for the two (zener voltage ⁇ 2) is higher than the voltage between the pin terminal No. 8 and the pin terminal No. 6 so that when the gate levels of the MOS transistors M 4 and M 5 become the L level, the drain voltage can rise to the voltage at the pin terminal No. 8 of the semiconductor integrated circuit 21 of FIG. 9 , are selected.
- the high-voltage-side pulse reproduction circuit 219 is a circuit wherein a pulse signal (OUT 12 ) having the same timing as that of the output signal (OUT 6 ) of the high-voltage-side dead time generation circuit 216 is reproduced from the signals (OUT 10 and OUT 11 ) from the level shift circuit 218 .
- the pulse signal (OUT 12 ) generated by the light-voltage-side pulse reproduction circuit 219 differs from the output signal (OUT 6 ) of the high-voltage-side dead time generation circuit 216 in the potential thereof.
- the object of the series of operations in the range from the narrow pulse generation circuit 215 to the high-voltage-side pulse reproduction circuit 219 is to reduce a time-average current flowing through the level shift circuit 218 to which a high voltage is applied, thereby to reduce power consumption.
- the output current at the terminal of the pin terminal No. 7 is increased, and in a low-voltage-side output circuit 233 , the output current at the terminal of the pin terminal No. 4 is increased.
- a 16 V zener diode is connected between the terminal (Vcc) of the pin terminal No. 1 and the terminal of the pin terminal No. 3 (GND), and its purpose is to prevent a voltage of 16 V or more from applying to the terminal of the pin terminal No. 1 .
- the zener diode Z 1 of the drive-signal generation circuit 20 of FIG. 2 can be eliminated.
- the pin terminal No. 1 can be used, whereby the number of components can be reduced.
- the power source circuit portion 3 thereof comprises the DC-voltage generation circuit 10 , the drive-signal generation circuit 20 an the drive control circuit 30 . Therefore, the power source circuit portion of the fluorescent lamp lighting apparatus of Embodiment 1 has a significantly smaller mounting area and is made lighter than that of the conventional bulb-type fluorescent lamp. For this reason, the bulb-type fluorescent lamp, that is, Embodiment 1 of the fluorescent lamp lighting apparatus in accordance with the present invention, can be used in place with incandescent lamps used at various locations as lighting fixtures, without limitations in size and weight, whereby the present invention can provide a lighting fixture that can be used at various locations and can require less power consumption.
- the fluorescent lamp lighting apparatus of Embodiment 1 in accordance with the present invention eliminates the need for a transformer coil that has been used for the conventional bulb-type fluorescent lamp. Therefore, the mounting space for the power source circuit portion can be reduced significantly, and the fluorescent lamp lighting apparatus can be made smaller significantly.
- the fluorescent lamp lighting apparatus of Embodiment 1 in accordance with the present invention comprises fewer number of components by using the semiconductor integrated circuit. Therefore, the device is excellent in the rising characteristic, takes shorter time from power on to lighting, thereby having an effect of becoming bright instantaneously.
- the fluorescent lamp lighting apparatus of Embodiment 1 in accordance with the present invention is configured so as to be highly resistant against power source fluctuation.
- the power source is connected only to the resistor (R 2 ) and the drain of the power MOS transistor (M 1 ), whereby when the resistor (R 2 ) is small to a certain extent, the zener diode Z 1 and the capacitor C 1 operate stably. Therefore, no fluctuation occurs at the terminal voltage (Vcc) at the pin terminal No. 1 of the semiconductor integrated circuit.
- the power source voltage in the above-mentioned Embodiment 1 is 14 V, even in the case where the power source voltage is 100 V AC, it is obvious that the configuration is also highly resistivity against power source fluctuation.
- Embodiment 2 an embodiment of a fluorescent lamp lighting apparatus in accordance with the present invention, will be described below referring to the accompanying drawings.
- Embodiment 2 is configured so that the temperature characteristic of the timer circuit 212 in the bulb-type fluorescent lamp of the above-mentioned Embodiment 1 can be changed. Therefore, the configuration of the bulb-type fluorescent lamp of Embodiment 2 is substantially the same as that of the above-mentioned Embodiment 1 except for the timer circuit; thus, the descriptions and numeral codes of Embodiment 1 are also applied to the configurations other than the timer circuit, and their descriptions are omitted.
- the preheating time for the filaments 51 and 52 is required to be made longer as the outside-air temperature lowers.
- the separate-excitation time becomes longer as the temperature lowers in order to extend the preheating time for the filaments 51 and 52 .
- FIG. 20 is a circuit diagram showing the configuration of the timer circuit of the semiconductor integrated circuit in the bulb-type fluorescent lamp of Embodiment 2.
- the timer circuit 212 a of Embodiment 2 is a circuit for setting the time of switching from the separate-excitation mode to the self-excitation mode after power is on, just as in the case of the above-mentioned Embodiment 1.
- the voltage across the terminals of the capacitor C 7 is initialized to 0 V by the MOS transistor M 3 of the timer circuit 212 a.
- the capacitor C 7 is charged with a constant current 1 a.
- the output (OUT 1 ) of the timer circuit 212 a is switched from the L level (LOW) to the H level (HIGH).
- a plurality ( 3 pieces in Embodiment 2) of diodes, Da, Db and Dc, are connected in series between resistors Ra and Rb for determining the setting voltage Va.
- the voltage across the terminals of the diodes usually has a characteristic of becoming larger at low temperature. Therefore, in the timer circuit 212 a of Embodiment 2, the setting voltage Va becomes higher at low temperature, whereby the separate-excitation time becomes longer.
- the timer circuit 212 a of Example 2 uses the plural diodes Da, Db and Dc to form the setting voltage Va, whereby the fluctuation in the setting voltage Va depending on the power source voltage fluctuation of the semiconductor integrated circuit can be reduced. As a result, the fluctuation in the timer time set by the timer circuit 212 a can also be suppressed small. However, in this case, it is affected by the fluctuation portion of the constant current Ia; therefore,, the above is applicable when the fluctuation in this portion has been suppressed sufficiently.
- the plural diodes are connected in series between the resistors Ra and Rb for determining the setting voltage Va as described above, whereby the fluctuation in the timer time because of the fluctuation in the temperature characteristic of the constant current Ia can be canceled.
- a countermeasure can be taken by connecting plural diodes in series between the power source side with respect to the setting voltage Va and the resistor Ra.
- the setting voltage of the timer circuit 212 a of Embodiment 2 is provided with hysteresis between the value at the time when the voltage across the terminals of the capacitor C 7 rises and the value at the time when the voltage lowers, thereby being set to have different voltages.
- Embodiment 3 an embodiment of a fluorescent lamp lighting apparatus in accordance with the present invention, will be described below referring to the accompanying drawings.
- Embodiment 3 is obtained by changing the method of frequency sweeping in the separate-excitation oscillator 211 in the bulb-type fluorescent lamp of the above-mentioned Embodiment 1. Therefore, the configuration of the bulb-type fluorescent lamp, an example of the fluorescent lamp lighting apparatus of Embodiment 3, is substantially the same as that of the bulb-type fluorescent lamp of the above-mentioned Embodiment 1; thus, the descriptions of the bulb-type fluorescent lamp of Embodiment 1 are also applied, and the same numeral codes are used in the following description.
- FIG. 21 is a view for illustrating methods of sweeping the frequency in the separate-excitation oscillator 21 of Embodiment 3.
- the upper graph of a part (a) in FIG. 21 shows a case wherein the frequency of the separate-excitation oscillator 211 is lowered linearly with the passage of time, and illustrates a method of sweeping the frequency of the separate-excitation oscillator 211 of the above-mentioned Embodiment 1.
- the middle graph of the part (a) in FIG. 21 shows the progress of the voltage across the filaments at the time when sweeping is carried out as shown in the upper graph of the part (a) in FIG. 21
- the lower graph of the part (a) in FIG. 21 shows the increasing state of the preheating current of the filaments.
- the upper graph of a part of FIG. 21 shows a case wherein the frequency of the separate-excitation oscillator 211 is lowered gradually so that the frequency curve with respect to time becomes concave downward.
- the middle graph of the part in FIG. 21 shows the progress of the voltage across the filaments when sweeping is carried out as shown in the upper graph of the upper part (b).
- the preheating current until the time of lighting can be increased in the case where the changing width of the frequency is decreased as the frequency becomes lower with the passage of time as shown in the part (b) of FIG. 21 in comparison with the case when the frequency in the separate-excitation mode is swept at a constant ratio as shown in the part (a) of FIG. 21 . Furthermore, since the voltage across the filaments can be maintained for a longer time in the period while the voltage is high, the light-emitting tube can be lit securely.
- a part (a) of FIG. 22 is an example of a circuit configuration of the bulb-type fluorescent lamp of Embodiment 3 wherein the frequency is swept as shown in part (b) of FIG. 21 (b).
- a resistor R is provided between the terminal of the pin terminal No. 5 of the semiconductor integrated circuit 21 and the power source.
- This example is a configuration wherein a preheating current is flown securely for a long time at a filament voltage not lighting the light-emitting tube so that the lighting time from the power on to lighting is almost unchanged and substantially constant.
- a method of sweeping the frequency in the sequence-excitation mode in this example is shown in a part (c) of FIG. 21 .
- the upper graph of the part (c) of FIG. 21 shows a case wherein the frequency of the separate-excitation oscillator 211 is lowered gradually so that the frequency curve with respect to time becomes convex upward.
- the middle graph of the part (c) in FIG. 21 shows the progress of the voltage across the filaments when the frequency curve is set as shown in the upper graph of the part (c).
- a part (b) of FIG. 22 is an example of a circuit configuration ration of the bulb-type fluorescent lamp wherein the frequency is swept as shown in the part (c) of FIG. 21 .
- a resistor R is provided between the terminal of the pin terminal No. 5 for the timer circuit 212 of the semiconductor integrated circuit 21 and ground in parallel with a capacitor C 7 .
- FIG. 24 is a frequency curve showing a method of sweeping the frequency in the separate-excitation mode.
- plural diodes are provided between the timer terminal of the pin terminal No. 5 of a semiconductor integrated circuit 21 a and the base of the NPN transistor Q 1 of the separate-excitation oscillator 211 .
- the frequency is changed as shown in FIG. 24 , whereby a preheating current is flown at such a voltage across the filaments as not causing lighting for a constant period after power on. Then, a low constant frequency is output linearly. This low frequency is set at the resonance frequency of the resonance circuit in the drive control circuit. With this configuration, the preheating current can be securely flown through the filaments.
- FIG. 24 shows an example wherein the frequency is reduced linearly; however, it may be possible to use a configuration wherein the frequency is reduced in a curve as shown in the above-mentioned parts (b) and (c) of FIG. 21 .
- Embodiment 4 an embodiment of a fluorescent lamp lighting apparatus in accordance with the present invention, will be described below referring to the accompanying drawings.
- Embodiment 4 is configured so that the setting of the temperature characteristic of the frequency in the separate-excitation mode of the separate-excitation oscillator 211 in the bulb-type fluorescent lamp of the above-mentioned Example 1 can be changed.
- the separate-excitation oscillator of Embodiment 4 is used to set the temperature characteristic of the frequency in the separate-excitation mode at a proper condition, thereby to configure a fluorescent lamp lighting apparatus capable of securely carrying out lighting regardless of ambient temperature.
- FIG. 25 shows the configuration of a separate-excitation oscillator 211 b of Embodiment 4, and the other configurations are the same as those of the separate-excitation oscillator ( FIG. 12 ) of the above-mentioned Embodiment 1; therefore, these descriptions are omitted.
- diodes are connected in series with a resistor Rb and provided between a point at which an upper reference voltage Vb is specified and a point at which a lower reference voltage Vc is specified.
- the start frequency (lighting frequency) exerts an effect on the temperature characteristic of the constant current Ib.
- the stop frequency exerts effects on the temperature characteristics of the constant current Ib, the voltage between the base and emitter of the NPN transistor Q 1 and the emitter resistor R 6 (see FIG. 12 ) of the NPN transistor Q 1 .
- the output frequency is shifted downward at low ambient temperature.
- the fluctuation in the voltage [Vb ⁇ Vc] becomes small with respect to the fluctuation in the power source voltage of the semiconductor integrated circuit 21 , whereby the fluctuation in the output frequency becomes small.
- the diodes are connected between the point at which the lower reference voltage Vc is specified and ground, or between the power source and the point at which the upper reference voltage Vb is specified.
- the temperature characteristic of the frequency in the separate-excitation mode can be adjusted to a desired proper condition.
- Embodiment 5 an embodiment of a fluorescent lamp lighting apparatus in accordance with the present invention, will be described below referring to the accompanying drawings.
- a bulb-type fluorescent lamp in accordance with Embodiment 5 is configured so that when fluorescent lamp lighting in the separate-excitation mode ended in failure, the voltage applied across the filaments of the fluorescent lamp in the self-excitation mode is made larger to facilitate lighting in a short time. Furthermore, the bulb-type fluorescent lamp of Embodiment 5 is configured so that the resonance frequency and the power configuration in the self-excitation mode can be adjusted.
- the filament voltage of the light-emitting tube is input from the high-voltage-side terminal (the terminal opposite to ground) of the terminals of the coil L 1 to the terminal (IN terminal) of the pin terminal No. 2 of the semiconductor integrated circuit 21 via the resistor R 3 as shown in FIG. 2 .
- the filament voltage is input to the drive-signal generation circuit 20 to carry out feedback control in the drive control circuit 30 .
- the phase of the voltage across the terminals of the coil L 1 advances ahead of that of the current flowing through the coil L 1 by 90°.
- the phase of the voltage across the terminals of the coil L 1 advances in the feedback loop from the terminal of the coil L 1 to the source (the terminal of the pin terminal No.
- FIG. 26 is a graph showing the relationship between the resonance frequency, which is determined by the capacitors C 5 , C 6 and the coil L 1 of the drive control circuit 30 shown in the above-mentioned FIG. 1 and the impedance of the fluorescent lamp at the time of lighting, and the current [I] flowing through the resonance circuit.
- the phase advances in the feedback loop from the terminal of the coil L 1 to the source of the power MOS transistor M 1 . Therefore, stabilization is attained at a frequency f 2 higher than the original resonance frequency f 1 (the frequency determined by C 5 , C 6 , L 1 and the impedance of the fluorescent lamp at the time of lighting).
- a capacitor between the terminal of the pin terminal No.
- stabilization can be attained at a frequency f 3 lower than the above-mentioned frequency f 2 . Therefore, the current
- FIG. 27 is a graph showing a frequency characteristic before lighting in the self-excitation mode in the case where lighting in the self-excitation mode ended in failure.
- the frequency characteristic shown in FIG. 27 shows the relationship between the resonance frequency determined by the capacitors C 5 , C 6 and the coil L 1 before lighting and the current
- stabilization can be attained at a frequency f 4 higher than the original resonance frequency f 0 (the frequency determined by C 5 , C 6 and L 1 ).
- the bulb-type flowchart lamp of Embodiment 5 has a configuration wherein lighting is attained securely in a short time in the self-excitation mode.
- phase temperature characteristic setting of the feedback loop in the self-excitation mode will be described.
- the bulb-type fluorescent lamp of Embodiment 5 is configured so that the current
- the voltage across the terminals of a diode is characterized to usually become larger as the temperature lowers. Therefore, by using a diode, the rate of phase advance in the feedback loop is decreased (the amount of delay in the semiconductor integrated circuit is increased) as the temperature lowers, thereby to apply a large voltage across the filaments (across the terminals of C 6 ).
- FIG. 28 is a circuit diagram of a trigger input circuit as an example wherein diodes are used to delay the operation speed of the comparator of the trigger input circuit at low temperature.
- diodes are used to delay the operation speed of the comparator of the trigger input circuit at low temperature.
- the emitter voltage Vd of the transistor Q 2 is lowered at low temperature.
- the resistor R 7 connected to the emitter the current source current Id becomes smaller at low temperature.
- the current source current Id becomes smaller at low temperature
- the currents Ie, If and Ig in FIG. 28 also become smaller.
- the bias current of the comparator in the trigger input circuit 213 c is reduced, and the operation speed is lowered.
- the phase of the signal input from the terminal of the pin terminal No. 2 is more delayed than that of the output signal (OUT 5 ) of the trigger input circuit.
- the rate of phase advance in the feedback loop is decreased as the temperature lowers, and a large voltage is applied across the filaments (across the terminals of C 6 ), whereby lighting is securely attained in a short time in the self-excitation mode even at low temperature.
- FIG. 29 is a circuit diagram showing an example of a delay circuit wherein the rate of phase advance in the feedback loop is decreased as the temperature lowers.
- FIG. 30 is a waveform diagram showing the input signal, the signal at point a, the signal at point b, the signal at point c and the output signal in the circuit shown in FIG. 29 .
- the rate of phase advance in the feedback loop can be decreased as the temperature lowers.
- Embodiment 6 an embodiment of a fluorescent lamp lighting apparatus in accordance with the present invention, will be described below.
- the bulb-type fluorescent lamp of Embodiment 6 is not provided with the trigger input circuit 213 ( FIG. 9 ) and the separate-excitation/self-excitation selection switch circuit 214 ( FIG. 9 ) in the above-mentioned Embodiment 1.
- the output signal (OUT 2 ) from the separate-excitation oscillator is output to the high-voltage-side dead time generation circuit and the low-voltage-side dead time generation circuit.
- FIG. 31 is a block diagram showing the configuration of the semiconductor integrated circuit 21 in the bulb-type fluorescent lamp of Embodiment 6.
- the configuration of the bulb-type fluorescent lamp of Embodiment 6 is the same as that of bulb-type fluorescent lamp of Embodiment 1 shown in the above-mentioned FIG. 9 , except that the trigger input circuit 213 and the separate-excitation/self-excitation selection switch circuit 214 are omitted. Therefore, FIG. 31 and the drawings and numeral codes used for the description of the above-mentioned Embodiment 1 are also applied in the following description.
- the resonance frequency determined by the capacitors C 5 , C 6 and the coil L 1 of the drive control circuit 30 before lighting is assumed to be f 0
- the resonance frequency determined by the capacitors C 5 , C 6 and the coil L 1 of the drive control circuit 30 and the impedance across the filaments of the fluorescent lamp after lighting is assumed to be f 1 (f 1 ⁇ f 0 ).
- flowing through the filaments has such a convex characteristic curve as shown in the above-mentioned FIG. 8 , at the resonance frequency, the maximum current flows, and the voltage across the filaments becomes maximum.
- FIG. 32 shows the progress of the frequency output from the separate-excitation oscillator.
- the frequency is reduced linearly to the resonance frequency f 1 (until time t 1 ), and the resonance frequency f 1 is output continuously after time t 1 . Therefore, the voltage applied across the filaments becomes maximum at time t 0 when the frequency output from the separate-excitation oscillator becomes the resonance frequency f 0 ; and the fluorescent lamp lights at least until this voltage is reached.
- a pulse signal having the same frequency as the resonance frequency f 1 at the time of lighting is output from the separate-excitation oscillator, whereby the fluorescent lamp emits light efficiently.
- the bulb-type fluorescent lamp of Embodiment 6 is configured so that the accurate resonance frequency f 1 is output continuously from the separate-excitation oscillator. Therefore, even when lighting is not attained at the time of the frequency sweep operation in the above-mentioned separate-excitation mode, a large voltage is continuously applied across the filaments even after time t 1 , whereby the fluorescent lamp lights securely.
- Embodiment 7 an embodiment of a fluorescent lamp lighting apparatus in accordance with the present invention, will be described below.
- the bulb-type fluorescent lamp of Embodiment 7 is not provided with the trigger input circuit 213 ( FIG. 9 ) and the separate-excitation/self-excitation selection switch circuit 214 ( FIG. 9 ) in the above-mentioned Embodiment 1.
- the output signal (OUT 2 ) from the separate-excitation oscillator is output to the high-voltage-side dead time generation circuit and the low-voltage-side dead time generation circuit.
- the separate-excitation oscillator of Embodiment 7 is configured to output a signal having a fixed frequency.
- the configuration of the bulb-type fluorescent lamp of Embodiment 7 is the same as that of bulb-type fluorescent lamp of Embodiment 1 shown in the above-mentioned FIG. 9 , except that the trigger input circuit 213 and the separate-excitation/self-excitation selection switch circuit 214 are omitted. Therefore, the drawings and numeral codes used for the description of Embodiment 1 are also applied in the following descriptions.
- the frequencies output from the separate-excitation oscillator of Embodiment 7 are the fixed frequency f 1 and the resonance frequency determined by the capacitors C 5 , C 6 , the coil L 1 and the impedance across the filaments of the fluorescent lamp after lighting.
- FIG. 33 is a diagram showing the circuit configuration in the bulb-type fluorescent lamp of Embodiment 7.
- FIG. 34 is a block diagram showing the configuration of the semiconductor integrated circuit in Embodiment 7.
- FIG. 35 is a circuit diagram of the separate-excitation oscillator (75 kHz) of the semiconductor integrated circuit in Embodiment 7.
- a capacitor C 9 is provided between the coil L 1 and the source of the power MOS transistor M 2 , and the drain of the MOS transistor M 30 is connected to the connection point of the capacitor C 9 and the coil L 1 .
- the timer signal from the timer terminal (pin terminal No. 2 ) of the semiconductor integrated circuit 21 d is input to the gate of the MOS transistor M 30 .
- the output signal of the timer circuit 212 d of the semiconductor integrated circuit 21 d is configured to be output from the timer terminal of the pin terminal NO. 2 .
- the separate-excitation oscillator 211 d ( FIG. 35 ) of Embodiment 7 is configured to output only the fixed frequency (75 kHz).
- the period during which the output of the timer terminal (pin terminal No. 2 ) after power on is an L-level signal is a preheating period, and the MOS transistor M 30 is in an open state (off state).
- the timer circuit 212 d is switched, and an H-level signal is output from the timer terminal (pin terminal No. 2 ), the MOS transistor M 30 becomes a closed state (on state), and a short-circuit state occurs across both terminals of the capacitor C 9 .
- FIG. 36 shows frequency characteristic curves at the time of the non-lighting of the light-emitting tube when the MOS transistor M 30 is in the open and close operations.
- the curve shown in a broken line indicates the frequency characteristic at the time when the MOS transistor M 30 is open (off state), and the curve shown in a solid line indicates the frequency characteristic at the time when the MOS transistor M 30 is closed (on state).
- the MOS transistor M 30 becomes a closed state by the signal from the timer circuit 212 d when a predetermined time has passed after power on.
- the MOS transistor M 30 shifts to the characteristic curve shown in the solid line of FIG. 36 .
- flowing through the LC resonance circuit of the drive control circuit 30 d at the fixed frequency f 1 increases, and the fluorescent lamp lights.
- the output frequency of the separate excitation oscillator 211 d is fixed at the resonance frequency f 1 in the closed state of the MOS transistor M 30 . Therefore, the voltage applied across the filaments of the light-emitting tube is larger when the MS transistor M 30 is closed than when it is open.
- the light-emitting tube is set not to light at the voltage across the filaments applied when the MOS transistor M 30 is in the open state. Furthermore, the light-emitting tube is set to light without fail at the voltage across the filaments applied when the MOS transistor M 30 is in the closed state. Therefore, when the MOS transistor M 30 is in the open state, a preheating current securely flows through the filaments.
- the preheating current flows constantly during the predetermined time after power on, and the MOS transistor M 30 is switched by the signal from the timer circuit 212 d. Simultaneously with the switching, the preheating of the filaments ends, and the light-emitting tube used as a fluorescent lamp lights.
- a bulb-type fluorescent lamp of Embodiment 8 an embodiment of a fluorescent lamp lighting apparatus in accordance with the present invention, will be described below.
- the bulb-type fluorescent lamp of Embodiment 8 is configured so that the output frequency of the separate-excitation oscillator is fixed, and so that the duty ratio increases when the voltage at the timer terminal of the pin terminal No. 5 of the semiconductor integrated circuit becomes higher.
- FIG. 37 is a circuit diagram showing the configuration of the separate-excitation oscillator 211 e in the bulb-type fluorescent lamp of Embodiment 8.
- the bulb-type fluorescent lamp of Embodiment 8 is configured so that the frequency of the separate-excitation oscillator 211 e is fixed, and so that the duty increases as the voltage at the timer terminal of the pin terminal No. 5 becomes higher.
- the current flowing through the filaments of the light-emitting tube used as a fluorescent lamp before lighting increases as the duty ratio becomes larger, and the voltage applied across the filaments also becomes larger. Therefore, by using the configuration wherein the timer terminal voltage rises, it is possible to use a system similar to that used in the case where the frequency is swept.
- the bulb-type fluorescent lamp of Embodiment 8 Since the bulb-type fluorescent lamp of Embodiment 8 is configured as described above, it has the effect of carrying out preheating sufficiently without performing frequency modulations.
- the light-emitting tube may be lit by raising the voltage across the filaments by using a system for making a selection between a duty ratio of 20% (the duty ratio for not attaining lighting) during preheating and a duty ratio of 50% (the duty ratio for attaining lighting) after preheating, for example.
- the bulb-type fluorescent lamp of Embodiment 8 even a system, wherein a separate-excitation oscillator is used as a trigger circuit for causing LC oscillation at the time of power on, and the duty ratio is swept (or selected between two stages) in the full self-excitation mode, can light the fluorescent lamp by raising the voltage across the filaments.
- a bulb-type fluorescent lamp of Embodiment 9 an embodiment of a fluorescent lamp lighting apparatus in accordance with the present invention, will be described below.
- the bulb-type fluorescent lamp of Embodiment 9 has a configuration wherein a delay circuit, the delay amount of which changes depending on the timer terminal voltage of the semiconductor integrated circuit, is provided at the output of the trigger input circuit in the bulb-type fluorescent lamp of the above-mentioned Embodiment 1. Furthermore, in Embodiment 9, the separate-excitation oscillator is used as a trigger generation circuit for causing LC oscillation momentarily at the time of power on.
- the bulb-type fluorescent lamp of Embodiment 9 has a system wherein phase sweep is performed in the full self-excitation mode to light the fluorescent lamp.
- the lighting system by using the phase sweep will be described below.
- the separate-excitation oscillator in Example 9 outputs a trigger signal for causing LC oscillation momentarily at the time of power on. Therefore, the bulb-type fluorescent lamp of Embodiment 9 has a configuration wherein in the feedback loop from the terminal of the coil L 1 to the gates of the power MOS transistors M 1 and M 2 , the phase is swept in a delaying direction for a constant period after power on.
- the preheating current flowing through the filaments before lighting increases as the phase of the feedback loop delays. Furthermore, the voltage applied across the filaments also increases.
- the bulb-type fluorescent lamp of Embodiment 9 can be obtained when a system, similar to that used in the case where the frequency is swept in the separate-excitation mode, performs phase sweep in the full self-excitation mode.
- a signal being switched at short time intervals (100 msec, for example) after power on is output from the timer circuit.
- the reference voltage Va in the timer circuit is set low.
- the amount of delay increases as the timer terminal voltage rises.
- FIG. 38 is a concrete circuit diagram of the delay circuit 251 used for the bulb-type fluorescent lamp of Embodiment 9.
- the input signal in FIG. 38 is a signal from the trigger input circuit, and the output signal is input to the separate-excitation/self-excitation selection switch circuit.
- the separate-excitation oscillator is configured to output a fixed frequency as shown in FIG. 35 of the above-mentioned Embodiment 7.
- the delay circuit 251 is provided at the output of the trigger input circuit.
- the present invention is not limited to this configuration, it may be possible to use a configuration wherein a delay circuit is provided at the output of the separate-excitation/self-excitation selection switch circuit, and the amount of delay changes depending on the timer terminal voltage of the semiconductor integrated circuit.
- a system configuration so that a non-lighting phase is set at the time of preheating and a lighting phase is selected after preheating, as a system wherein phase sweep is performed in the full self-excitation mode to light the light-emitting tube used as a fluorescent lamp.
- the IC used in the above-mentioned embodiments is a component mountable in an 8-pin DIP or SMD package generally used for monolithic ICs. Therefore, it can be used in such a restricted space as found near the base portion of the bulb-type fluorescent lamp, thereby being best suited to obtain a compact fluorescent lamp lighting apparatus.
- a bulb-type fluorescent lamp of Embodiment 10 an embodiment of a fluorescent lamp lighting apparatus in accordance with the present invention, will be described below by using the accompanying FIGS. 39 and 40 .
- FIG. 39 is a circuit diagram showing the configuration of the bulb-type fluorescent lamp of Embodiment 10.
- FIG. 40 is a circuit diagram showing the configuration of the delay circuit in Embodiment 10.
- the descriptions and numeral codes of Embodiment 1 are also applied, and their descriptions are omitted.
- the bulb-type fluorescent lamp of Embodiment 10 is configured by adding a pin (pin terminal No. 9 ) to the semiconductor integrated circuit 21 in the bulb-type fluorescent-lamp of the above-mentioned Embodiment 1. Furthermore, Embodiment 10 has a configuration wherein a delay circuit is connected to the output of the trigger input circuit 213 or the output of the separate-excitation/self-excitation selection switch circuit 214 shown in FIG. 9 of the above-mentioned Example 1. An example of this delay circuit 500 is shown in the circuit diagram in FIG. 40 .
- the delay amount of the delay circuit 500 can be controlled by the signal input to the pin terminal No. 9 of the semiconductor integrated circuit 21 .
- the output signal from the trigger input circuit 213 or the separate-excitation/self-excitation selection switch circuit 214 is input to the delay circuit 500 .
- the signal input from the trigger input circuit 213 or the separate-excitation/self-excitation selection switch circuit 214 is delayed by the delay circuit 500 and output to the next stage.
- the delay amount obtained at this time is controlled by the signal input to the pin terminal No. 9 of the semiconductor integrated circuit 21 .
- a variable resistor R 8 is connected to the pin terminal No. 9 of the semiconductor integrated circuit 21 .
- the constant currents Ih and Ii of FIG. 40 increase, and the delay amount decreases.
- the constant currents Ih and Ii decrease, and the delay-amount increases. Therefore, in bulb-type fluorescent lamp of Embodiment 10, by adjusting the voltage at the pin terminal No. 9 of the semiconductor integrated circuit 21 after lighting, the phase setting in the feedback loop in the self-excitation mode can be changed. As a result, the brightness of the light-emitting tube 4 in Embodiment 10 can be changed easily.
- Embodiment 10 when the phase is advanced from the reference setting, the light-emitting tube 4 becomes dark, and when the phase is delayed from the reference setting, the light-emitting tube 4 becomes bright. In this way, the light of the bulb-type fluorescent lamp of Embodiment 10 can be adjusted to desired brightness.
- a bulb-type fluorescent lamp of Embodiment 11 an embodiment of a fluorescent lamp lighting apparatus in accordance with the present invention, will be described below by using the accompanying FIGS. 41 to 44 .
- the components of the bulb-type fluorescent lamp of Embodiment 11 having the same functions and configurations as those of the bulb-type fluorescent lamp of the above-mentioned Embodiment 1, the descriptions and numeral codes of Embodiment 1 are also applied, and their descriptions are omitted.
- the bulb-type fluorescent lamp of Embodiment 11 has a configuration wherein the frequency of the separate-excitation oscillator can be controlled after the light-emitting tube is lit.
- FIG. 41 is a block diagram showing the configuration of a first example of the semiconductor integrated circuit in Embodiment 11.
- the semiconductor integrated circuit of Embodiment 1 shown in FIG. 41 is the first example configured so that the frequency of the separate-excitation oscillator can be controlled after the light-emitting tube in the bulb-type fluorescent lamp of the above-mentioned Embodiment 6 is lit.
- FIG. 42 is a circuit diagram showing the configurations of the separate-excitation oscillator 511 and the like in Embodiment 11.
- the semiconductor integrated circuit of Embodiment 11 is a first circuit example having a configuration wherein the frequency of the separate-excitation oscillator 511 can be controlled after the light-emitting tube 4 is lit.
- the frequency of the separate-excitation oscillator 511 is lowered. Conversely, when the voltage at the pin terminal No. 2 is made smaller than the reference voltage of the initial setting, the frequency of the separate-excitation oscillator 511 is raised. Therefore, when the separate-excitation frequency is made close to the resonance frequency of the LC resonance circuit at the time of lighting by changing the voltage at the pin terminal No. 2 , the light-emitting tube 4 becomes bright, and when the frequency is made away from the resonance frequency, the light-emitting tube 4 becomes dark. In this way, the light of the bulb-type fluorescent lamp of Embodiment 11 can be adjusted.
- FIG. 43 is a block diagram showing the configuration of a second example of the semiconductor integrated circuit in Embodiment 11.
- the semiconductor integrated circuit of Embodiment 11 shown in FIG. 43 is the second example configured so that the frequency of the separate-excitation oscillator can be controlled after the light-emitting tube in the bulb-type fluorescent lamp of the above-mentioned Embodiment 6 is lit.
- FIG. 44 is a second circuit example showing a configuration wherein the frequency of the separate-excitation oscillator 611 can be controlled after the light-emitting tube 4 is lit.
- the frequency of the separate-excitation oscillator 611 is lowered. Conversely, by making the value of the variable resistor R 9 larger than the initial setting, the frequency of the separate-excitation oscillator 611 is raised.
- the light-emitting tube 4 becomes bright. Conversely, by making the separate-excitation frequency away from the resonance frequency, the light-emitting tube 4 becomes dark. In this way, in Embodiment 11, the light of the light-emitting tube 4 can be adjusted by adjusting the resistance value of the variable resistor R 9 .
- a bulb-type fluorescent lamp of Embodiment 12 an embodiment of a fluorescent lamp lighting apparatus in accordance with the present invention, will be described below by using the accompanying FIGS. 45 and 46 .
- the components of the bulb-type fluorescent lamp of Embodiment 12 having the same functions and configurations as those of the bulb-type fluorescent lamp of the above-mentioned Embodiment 1, the descriptions and numeral codes of Embodiment 1 are also applied, and their descriptions are omitted.
- the bulb-type fluorescent lamp of Embodiment 12 has a configuration wherein the output duty of the separate-excitation oscillator can be controlled after the light-emitting tube is lit.
- FIG. 45 is a block diagram showing the configuration of the semiconductor integrated circuit of Embodiment 12.
- the semiconductor integrated circuit of Embodiment 6 shown in the above-mentioned FIG. 31 is configured so that the output duty of the separate-excitation oscillator can be controlled after the light-emitting tube is lit.
- FIG. 46 is a circuit diagram showing the configuration of the separate-excitation oscillator 711 in the bulb-type fluorescent lamp of Embodiment 12.
- the separate-excitation oscillator 711 shown in FIG. 46 is a circuit example of the configuration wherein the output duty of the separate-excitation oscillator 711 can be controlled after the light-emitting tube 4 is lit.
- Embodiment 12 by making the voltage of the pin terminal No. 2 of the semiconductor integrated circuit larger than the reference voltage of the initial setting after the light-emitting tube 4 is lit, the output duty (OUT 2 ) of the separate-excitation oscillator 711 becomes large. Conversely, by making the voltage of the pin terminal No. 2 smaller than the reference voltage of the initial setting, the output duty (OUT 2 ) of the separate-excitation oscillator 711 becomes small. In Embodiment 12, by increasing the output duty of the separate-excitation oscillator 711 , the light-emitting tube 4 becomes bright. Conversely, by decreasing the output duty of the separate-excitation oscillator 711 , the light-emitting tube 4 becomes dark.
- Embodiment 12 by adjusting the voltage of the pin terminal No. 2 after the light-emitting tube is lit, the brightness of the light-emitting tube can be changed. In this way, in Embodiment 12, by adjusting the voltage of the pin terminal No. 2 of the semiconductor integrated circuit, the light of the light-emitting tube 4 can be adjusted.
- the power source circuit portion thereof has the DC-voltage generation circuit, the drive-signal generation circuit and the drive control circuit, and is provided with the semiconductor integrated circuit, thereby emitting the need for a transformer coil. Therefore, in the fluorescent lamp lighting apparatus of the present invention, the mounting area of the power source circuit portion is decreased significantly, and the number of components is reduced.
- the fluorescent lamp lighting apparatus of the present invention is configured just as in the case of the above-mentioned embodiments, the voltage applied to the filaments becomes large, and the rising characteristic of the fluorescent lamp is excellent, whereby lighting can be attained securely in a short time.
- the fluorescent lamp lighting apparatus of the present invention can securely light the fluorescent lamp in a predetermined constant lighting time (time from power on to lighting).
- the portions connected to the power source are only the resistor and the drain of the power MOS transistor, and when the resistor has a small resistance value to some extent, the power source terminal voltage (Vcc) of the semiconductor integrated circuit does not change. Therefore, in the fluorescent lamp lighting apparatus of the present invention, even when the input power source voltage changes, the fluorescent lamp is lit securely, and no fluctuation occurs in the lighting state of the fluorescent lamp.
- the preheating time at the time of lighting can be secured sufficiently.
- the number of components can be reduced significantly by using a one-chip IC including an oscillator for carrying out control to attain a level not causing stress to the filaments of the light-emitting tube, whereby the mounting area can be made smaller, and a constant luminous flux can be maintained immediately after lighting.
- the fluorescent lamp lighting apparatus of the present invention is configured so that the preheating time for preheating the filaments of the light-emitting tube is made longer when the ambient temperature is low, and so that the preheating time at the time of re-lighting is made shorter when the ambient temperature immediately after the light-emitting tube turning is turned off or the like is high. Therefore, the service life of the light-emitting tube is made longer than those of conventional tubes. Besides, since the filaments are sufficiently heated by the separate-excitation oscillation control, the luminous flux can be maintained constant immediately after the light-emitting tube is lit.
- the fluorescent lamp lighting apparatus of the present invention carries out self-excitation control when the light-emitting tube is lit and being lit, even if lighting is turned off because of the fluctuation in commercial power, re-lighting can be attained momentarily.
- the fluorescent lamp lighting apparatus of the present invention has a one-chip monolithic IC capable of directly driving switching devices having a half-bridge configuration, no current transformer is necessary, the number of components is reduced significantly, and the weight is decreased.
- the brightness of the light-emitting tubes can be adjusted as desired on the basis of commands and the like provided externally.
Landscapes
- Circuit Arrangements For Discharge Lamps (AREA)
Abstract
Description
-
- 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 the above-mentioned DC-voltage generation circuit, and
- a drive control circuit having switching means driven by the pulse signals input from the above-mentioned drive-signal generation circuit to output a drive signal across the output terminals thereof, wherein a resonance circuit and the filament electrodes of a fluorescent lamp light-emitting tube are connected across the output terminals of the above-mentioned switching means.
-
- 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 the above-mentioned DC-voltage generation circuit, and
- a drive control circuit having first switching means driven by the high-voltage-side pulse signal input from the above-mentioned drive-signal generation circuit, and second switching means connected in series therewith and driven by the low-voltage-side pulse signal input from the above-mentioned 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 the above-mentioned second switching means.
-
- the above-mentioned 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 the above-mentioned 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 the above-mentioned drive-signal generation circuit, for detecting the signal of this resonance circuit network and outputting the signal to a signal detection terminal, wherein
- the above-mentioned drive-signal generation circuit is configured to output a signal having a frequency, which is determined inside the above-mentioned drive-signal generation circuit, changes with the passage of time, and at least passes through the resonance frequency of the above-mentioned resonance circuit network in the non-lighting state of the above-mentioned light-emitting tube within a predetermined time from the application of the above-mentioned DC voltage, and to output a signal having the phase corresponding to the signal of the above-mentioned signal detection terminal after the above-mentioned predetermined time has passed.
- the above-mentioned power source circuit portion comprises:
-
- the above-mentioned 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 above-mentioned 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 the above-mentioned DC-voltage generation circuit, is turned on and off by the above-mentioned 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 the above-mentioned DC-voltage generation circuit, is turned on and off by the above-mentioned second drive signal, and
- a resonance circuit network connected between the common connection portion of the above-mentioned first and second switching means and at least one of the pair of output terminals of the above-mentioned DC-voltage generation circuit, wherein
- the above-mentioned first and second drive signals are each configured to output a signal having a frequency, which is determined inside the above-mentioned drive-signal generation circuit, changes with the passage of time, and at least passes through the resonance frequency of the above-mentioned resonance circuit network in the non-lighting state of the above-mentioned light-emitting tube within a predetermined time from the application of the above-mentioned DC voltage, and to output a signal having the phase corresponding to the signal of the above-mentioned signal detection terminal after the above-mentioned predetermined time has passed.
- the above-mentioned power source circuit portion comprises:
Claims (33)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/654,857 USRE39341E1 (en) | 1998-12-09 | 2003-09-03 | Apparatus for lighting fluorescent lamp |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP37497498 | 1998-12-09 | ||
US09/454,135 US6285138B1 (en) | 1998-12-09 | 1999-12-03 | Apparatus for lighting fluorescent lamp |
US10/654,857 USRE39341E1 (en) | 1998-12-09 | 2003-09-03 | Apparatus for lighting fluorescent lamp |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/454,135 Reissue US6285138B1 (en) | 1998-12-09 | 1999-12-03 | Apparatus for lighting fluorescent lamp |
Publications (1)
Publication Number | Publication Date |
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USRE39341E1 true USRE39341E1 (en) | 2006-10-17 |
Family
ID=18504749
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/454,135 Ceased US6285138B1 (en) | 1998-12-09 | 1999-12-03 | Apparatus for lighting fluorescent lamp |
US10/654,857 Expired - Lifetime USRE39341E1 (en) | 1998-12-09 | 2003-09-03 | Apparatus for lighting fluorescent lamp |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
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US09/454,135 Ceased US6285138B1 (en) | 1998-12-09 | 1999-12-03 | Apparatus for lighting fluorescent lamp |
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US (2) | US6285138B1 (en) |
CN (2) | CN1198485C (en) |
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Also Published As
Publication number | Publication date |
---|---|
CN1256608A (en) | 2000-06-14 |
CN1575086A (en) | 2005-02-02 |
CN1198485C (en) | 2005-04-20 |
US6285138B1 (en) | 2001-09-04 |
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