JP4479559B2 - Discharge lamp lighting device and lighting device - Google Patents

Description

  The present invention relates to a discharge lamp lighting device capable of dimming and lighting a discharge lamp, and an illumination device using the same.

  FIG. 9 is a circuit block diagram of a conventional discharge lamp lighting device (Japanese Patent Laid-Open No. 5-326185). The discharge lamp lighting device includes a high-frequency power source 22 that supplies high-frequency power to the discharge lamp 21 via a first impedance element Z1, and a DC power source that supplies DC power to the discharge lamp 21 via a second impedance element Z2. 25, a temperature detection unit 26 for detecting the ambient temperature, and increasing the DC power according to the ambient temperature detected by the temperature detection unit 26 at a low temperature. A dimming control unit 23 is provided.

In this discharge lamp lighting device, DC power at a level that can maintain discharge during low beam dimming is superimposed on the high frequency power and applied to the discharge lamp. , And the discharge lamp can be stably dimmed to the low luminous flux range.Furthermore, a temperature detection unit is provided to increase the DC superimposed power during low luminous flux lighting at low temperatures. Even when a low luminous flux is lit at a low temperature, the discharge lamp does not disappear or flicker, and a stable lighting state can be maintained.
JP-A-5-326185

  However, in the conventional technique, a lamp in an unstable state, for example, a new lamp in which the cumulative lighting time is short and the gas in the tube is not stable, or a lamp in a state where the extinguishing time is long and impurities are present in the tube is described above. When the dimming control is performed by the lighting device of the configuration and the lamp is in the low luminous flux lighting state, the electrical characteristics (lamp current, lamp voltage, etc.), illuminance, The input power of the lighting device is unstable, and there is a disadvantage that it is difficult to achieve stable lighting in the lighting device having the above configuration.

  In the present invention, in order to solve the above-described problem, a low luminous flux dimming lighting comprising a high frequency power source for supplying high frequency power to the discharge lamp and a dimming control means for performing dimming control of the discharge lamp. In the discharge lamp lighting device for the above, a lighting time monitoring unit for monitoring the cumulative lighting time of the discharge lamp and a control means for limiting the lower limit range of dimming lighting within a predetermined cumulative lighting time are provided. Is.

  According to the present invention, during the period when the lamp is in an unstable state, by controlling the low luminous flux dimming lighting level by the lighting device to the dimming level at which the lamp can be stably lit, the cumulative lighting time is short and the gas in the tube However, there is an effect that a stable lighting state can be maintained even when a new lamp which is not stable or a lamp which has a long turn-off time and which has impurities in the tube is dimmed. In addition, if the cumulative lighting time becomes long and the lamp can be stably lit even in the low luminous flux dimming lighting state, the lighting device performs control to lower the low luminous flux dimming lighting level to a predetermined level. There is an effect that the original low luminous flux dimming control function can be exhibited.

(Embodiment 1)
FIG. 1 is a circuit diagram of Embodiment 1 of the present invention. The discharge lamp lighting circuit 1 is an electronic ballast circuit that turns on the fluorescent lamp FL by converting the commercial power supply AC into a high frequency, and is roughly composed of a power factor correction circuit 2, a power conversion circuit 3, and a control circuit 4. Is done.

  First, the power factor correction circuit 2 is a well-known step-up chopper circuit, which includes a diode bridge DB connected to a commercial power supply AC, a series circuit of a chopper choke L1 connected in parallel to the rectified output terminal and a switching element Q1, The switching element Q1 includes a smoothing capacitor C1 connected in parallel to both ends of the switching element Q1 via a chopper diode D1. Since the switching element Q1 is turned on / off at high frequency, the input power factor from the commercial power supply AC is improved, and a DC voltage obtained by boosting the rectified output is obtained at both ends of the smoothing capacitor C1.

  The power conversion circuit 3 is a well-known half-bridge inverter circuit, and includes a series circuit of switching elements Q2 and Q3 connected in parallel to both ends of the capacitor C1, and the capacitor C2 and the preheating transformer T1 are connected to both ends of the switching element Q3. And a series circuit of a resonant choke L2 and a resonant capacitor C3 are connected in parallel. The series circuit of the capacitor C2 and the preheating transformer T1 is a preheating resonance circuit that supplies a preheating current to the filament of the fluorescent lamp FL. The secondary winding of the preheating transformer T1, terminals d and e, the preheating capacitor C5, and the high voltage side filament Power is supplied to the filaments at both ends of the lamp FL through a closed circuit of the third winding of the preheating transformer T1, terminals f and g, a preheating capacitor C6 and a low voltage side filament. The resonance choke L2 and the resonance capacitor C3 are resonance circuits for stably lighting the fluorescent lamp FL, and the fluorescent lamp FL is connected to both ends of the resonance capacitor C3 via a DC cut capacitor C4.

  Each of the switching elements Q1 to Q3 is driven by a drive signal output from terminals a, b, and c of a control IC 5 in the control circuit 4 (for example, MCZ series manufactured by Shindengen). This control IC 5 switches the switching element Q1 of the power conversion circuit 3 at high frequency by switching the switching element Q1 of the power factor improvement circuit 2 at high frequency, while suppressing the input current distortion. The fluorescent lamp FL is turned on. Each switching element has a dimming signal input terminal and realizes a desired dimming level by a dimming signal (generally a value of an on-duty ratio of a rectangular wave of 1 KHz) that determines the dimming level. Q1 to Q3 are controlled.

  The control circuit 4 includes a control microcomputer (MPU) 6. The microcomputer 6 outputs a dimming signal from the dimming signal output unit 63. The variable range of the dimming signal is set so that the lower limit at the time of low luminous flux dimming lighting is increased during a period in which the cumulative lighting time is short.

  For example, from the line of the commercial power supply AC, an energization detection circuit composed of a diode D2 and resistors R1 and R2 is used to detect the presence or absence of energization by the energization detection unit 61 of the microcomputer 6 and energized by the counter unit 62 in the microcomputer 6 Count the cumulative time counter. In a period in which the cumulative lighting time counted by the counter unit 62 is less than the predetermined time, the lower limit of the dimming signal that can be output from the dimming signal output unit 63 at the time of low luminous flux dimming lighting is set high. . The dimming signal given from the outside to the control circuit 4 may be configured such that, for example, an analog voltage set by a variable resistor is read by the microcomputer 6 or input to the microcomputer 6 from the remote control receiver. Such a configuration may be used.

  The microcomputer 6 is connected to an output of a lamp abnormality detection circuit such as end of life detection. For example, in the example shown in FIG. 2, when the ramp voltage is detected by a circuit including a diode D3, resistors R4 and R5, and a capacitor C7, and the detected voltage exceeds the threshold voltage Vr, the output of the comparator CP1 is inverted. When the lamp abnormality detection circuit as exemplified here detects an abnormality in the lamp voltage, the microcomputer 6 performs a protective operation such as output stop.

  FIG. 3 shows the temporal transition characteristics of the lamp voltage, lamp current, illuminance, and input power of several tens of FHD85 lamps when the ambient temperature is 25 ° C. In the figure, ◆ is a characteristic at low luminous flux dimming lighting, and ■ is a characteristic at rated lighting.

  From FIG. 3, it is clear from the measurement result that, for example, when the aging time is 0 hour, particularly the lamp voltage and the illuminance, the variation due to the individual difference of the lamp is large. In addition, the lamp current and the input power vary greatly compared to the measurement data having a long aging time. It can be seen that when the aging time is increased to 5 hours, 15 hours, and 50 hours, the individual difference variation of the lamp is reduced.

  From these measurement results, from the characteristics of the relationship between the lamp voltage, lamp current, illuminance, input power and aging time, the lighting time until the lamp stabilizes is, for example, about 15 to 50 hours in the characteristics of the FHD85 lamp. If it is less than that, each lamp characteristic is in an unstable state, and each electric characteristic varies, causing flickering at the time of lamp lighting, failure to start, etc. at the time of low luminous flux dimming lighting.

  The reason why it is difficult for the lamp to be stably lit while the lamp aging time is short is that impurities are mixed in the lamp tube in the lamp manufacturing process, and the discharge becomes unstable due to these impurities. Immediately after the discharge lamp is turned on, impurities gradually adhere to the tube wall, and these phenomena result in a stable lighting direction.

  However, if the lamp is left unlit for a long time, impurities adhering to the lamp tube wall gradually return into the lamp tube, making it difficult to stably light the lamp.

  In the unstable state of the lamp, there is a large variation in the electrical characteristics of the lamp. For example, the detection circuit (see FIG. 2) that detects the lamp abnormality causes a non-defective product due to variations in the lamp voltage, There is a possibility that it is erroneously detected as the end of lamp life in an unstable time region regardless of the lamp.

  It can be seen that when the lighting time when the lamp is stabilized, for example, about 15 to 50 hours or more from the characteristics of FHD85, each lamp characteristic is in a stable state, and the variation range of the lamp electrical characteristics is reduced.

  Therefore, when the cumulative energization time counted by the counter unit 62 is a stable lighting time of the lamp, for example, about 15 to 50 hours or less from the characteristics of the FHD85, the lamp characteristics vary depending on the low luminous flux dimming level. Since the lamp becomes unstable and the lamp becomes unstable, the dimming level for stable lighting, for example, about 20% in the case of FHD85, during the period until the variation in lamp characteristics becomes small to some extent at the time of low beam dimming lighting Limit to be above. With these controls, the lamp is used in a stable state, so that it is possible to avoid lamp flickering and failure to start the lamp, and since the lamp voltage is low, erroneous detection of lamp abnormality can be avoided.

  When the accumulated time during which the lamp is stably lit, for example, about 15 to 50 hours or more due to the characteristics of FHD85, the dimming range of the lamp can be expanded to a desired dimming lower limit level.

  These controls increase the dimming level during periods when the lamp is unstable, and stabilize the lamp during dimming regardless of the lamp state by setting the dimming level to a desired level during periods when the lamp is stable. A discharge lamp lighting device can be realized.

(Embodiment 2)
The main circuit configuration of this embodiment is basically the same as that of the first embodiment. From the lamp characteristics when the ambient temperature of the lamp shown in FIG. 3 is 25 ° C., each electrical characteristic of the FHD85 lamp is in a direction of stabilizing over an aging time of 0 hours to about 50 hours. In addition, the lower the dimming level, the longer the time during which the lamp is stably lit.

  Considering these lamp characteristics, for example, in the case of FHD85, the dimming lower limit level with an aging time of up to 15 hours is set to about 20% or more as in the first embodiment. Thereafter, the dimming lower limit level at an aging time of 15 hours to 50 hours is set to about 15% or more, and when the aging time is 50 hours or more, dimming is possible to a desired dimming level (less than about 15%).

  In this way, the dimming level of the lamp that stably lights up changes according to the aging time of the lamp.Therefore, in accordance with the change, the dimming lower limit level is set in the direction of expanding the dimming range in which the lamp can be stably lit. Change in time series.

  With these controls, it is possible to gradually lower the dimming lower limit level within a desired period from the lamp lighting time, and to extend the dimming range even during a period when the lamp aging time is short, and to enable stable lighting. An electric lighting device can be realized.

(Embodiment 3)
The circuit configuration of the present embodiment is basically the same as that of the first embodiment. However, as shown in FIG. 4, a circuit 7 for determining a stable lamp lighting state is connected. The determination circuit 7 has the same configuration as the lamp abnormality detection circuit shown in FIG. 2, and can be used in whole or in part. However, although the threshold voltage Vr is fixed in FIG. 2, the threshold voltage Vr is variable by the microcomputer 6 in the determination circuit 7 of FIG. 4.

  In FIG. 4, the lamp FL is divided according to the lamp voltage divided by the resistors R4 and R5 via the diode D3 from the high voltage side of the lamp and the dimming signal level of the lamp FL output from the terminal Po of the microcomputer 6. The comparator CP1 compares the threshold voltage Vr for determining that the lighting state is stable. The output of the comparator CP1 is connected to the terminal Pi of the microcomputer 6. The threshold voltage Vr is set in consideration of the lamp voltage value due to the variation of each lamp from the lamp voltage value at an aging time of 15 to 50 hours or more according to the lamp voltage characteristics shown in FIG.

  The detected value Vs of the lamp voltage is compared with the threshold voltage Vr corresponding to each dimming level. If Vs> Vr, the output of the comparator CP1 becomes H level, and this H level signal is input to the terminal Pi of the microcomputer 6. Is done. Accordingly, the microcomputer 6 determines that the lamp is not stably lit and increases the lower limit value of the dimming level.

  Next, the dimming level increases by one, and the on-duty of the rectangular wave of the dimming signal output from the terminal Pd of the microcomputer 6 changes. The control IC 5 receives this signal, changes the drive frequency of the switching elements Q2, Q3, and changes the lamp output.

  The threshold voltage Vr ′ when the dimming level of the lamp becomes high is output from the terminal Po of the microcomputer, and compared with the divided voltage value Vs ′ of the lamp voltage at the dimming level at that time. If Vr ′> Vs ′, it is determined that stable lighting is possible at the dimming level, and lighting at the dimming level is maintained.

Further, as another means, detects a change in a very short period of the lamp voltage due to flickering of the lamp, as compared to the threshold voltage Vr, and detecting the presence or absence of lamp flickering state, if the detected lamp flickering state Needless to say, increasing the light control level has the effect of reducing flicker.

  In the second embodiment, the lower limit value of the dimming level is changed in a time series by the cumulative counter of the lighting time, whereas in this embodiment, the amount of electricity of the lamp is directly detected and the state of the lamp is detected. A determination is made, and if the lighting state is not stable, the dimming level is increased until the lighting state is stabilized.

  In the illustrated embodiment, the detected value compared is the lamp voltage. For example, the lamp current is detected by connecting a detection resistor in series with the lamp, or the electrical value such as the electrical characteristics of the input terminal is set. It goes without saying that the same result can be obtained even if the same control as described above is performed by detecting and comparing each detection value with the threshold value of each dimming level.

  As described above, it is possible to share all or part of the determination circuit 7 of FIG. 4 and the lamp abnormality detection circuit of FIG. That is, the electrical path for detecting the electrical parameter of the discharge lamp and the electrical path for detecting the abnormal parameter of the discharge lamp may be the same.

  With these controls, it is possible to realize a discharge lamp lighting device that can be controlled to an appropriate dimming level according to the low luminous flux dimming level of the lamp that is stably lit during the aging time until the lamp is stably lit due to individual lamp differences.

(Embodiment 4)
The circuit configuration of the present embodiment is basically the same as that of the first embodiment, and the description of the configuration is omitted. The configuration of the detection circuit unit of this embodiment is shown in FIG. The detection circuit unit of this embodiment installs the illuminance meter 8 at a certain distance from the lamp FL, and converts the measurement value of the illuminance meter 8 into a voltage value.

  According to the relationship between the aging time and the lamp illuminance shown in FIG. 3, the lamp illuminance varies greatly during rated lighting in the period when the lamp lighting state is unstable, and the illuminance becomes larger than when the lamp is stably lit. However, when the dimming level is lowered, on the contrary, compared to the illuminance at the time of stable lamp lighting, the illuminance value in the period with a short aging time becomes more variable, so in particular, at the time of low luminous flux dimming, When the lamp illuminance is smaller than the threshold corresponding to the light control level of the lamp, the light control ratio of the lamp is increased and the light control ratio is increased until the lamp is in a stable lighting state.

  Also, when the temperature at the coldest spot of the lamp or the ambient temperature of the lamp is low, the illuminance of the lamp is different and the lighting state of the lamp becomes unstable. A discharge lamp lighting device capable of controlling the dimming level of the lamp so as to maintain a stable lighting state can be realized.

(Embodiment 5)
Since the main circuit configuration of the present embodiment is basically the same as that of the third embodiment, a duplicate description is omitted. FIG. 6 shows the detection circuit unit of this embodiment. The detection circuit unit of the present embodiment measures the lowest zero point temperature measurement point of the lamp or an arbitrary tube wall temperature and the ambient temperature of the lamp with the thermometer 9, and converts the measured value of the thermometer 9 into a voltage value. , Input to the temperature input terminal of the microcomputer 6.

  FIG. 7 shows the aging time and characteristics of each lamp at a low temperature (ambient temperature: 0 ° C.). From this, it is apparent that the lamp characteristics in the stable lighting state of the lamp greatly change depending on the ambient temperature.

  Therefore, as in the third embodiment, the threshold value of each electrical characteristic for determining whether the lamp is in a stable state is the threshold value for each electrical characteristic for determining whether the lamp is in a stable state according to FIG. Need to change.

  Specifically, for example, as shown in FIG. 6, the temperature characteristics detected by arranging a thermocouple Tp in the vicinity of the lamp FL are used to determine whether each matching electric characteristic is in a stable state. A threshold value is selected, and the threshold voltage Vr in FIG. Subsequent control is the same as in the third embodiment.

  In this way, the threshold corresponding to the dimming level of the lamp is selected according to the temperature of the coldest spot of the lamp, etc., and it is accurately determined whether the lighting state of the lamp is stable lighting even when the lamp temperature is low, A discharge lamp lighting device capable of stable lighting can be realized.

(Embodiment 6)
The circuit configuration of the present embodiment is basically the same as that of the first embodiment, and the description of the configuration is omitted. Moreover, the structure of the filament presence detection circuit of this embodiment is shown in FIG. In the present embodiment, the detection circuit unit is a lamp voltage abnormality detection circuit, and is detected as a lamp abnormality at the end of the lamp life, resulting in lamp failure. An abnormality detection signal by this detection circuit is input to the microcomputer 6 and the count value of the lighting cumulative counter is automatically reset by this signal.

  According to this embodiment, when the lamp of the lighting device is replaced with a new lamp, it is automatically recognized, the count value of the lighting cumulative counter is reset, and in the period when the lamp cumulative lighting time is short, as in the first to fifth embodiments. A discharge lamp lighting device capable of controlling the above can be realized.

(Embodiment 7)
The circuit configuration of this embodiment is basically the same as that of Embodiment 6, and the description of the configuration is omitted. The reason why it is difficult for the lamp to be stably lit while the lamp aging time is short is that impurities are mixed inside the lamp tube in the lamp manufacturing process, and the discharge becomes unstable due to these impurities. Immediately after the discharge lamp is turned on, impurities gradually adhere to the tube wall, and these phenomena result in a stable lighting direction.

  However, if the lamp is left unlit for a long time, impurities adhering to the lamp tube wall gradually return into the lamp tube, making it difficult to stably light the lamp. For example, in the FHD85, there is a lamp that is difficult to stably light a discharge lamp at low luminous flux dimming at low temperatures when left for about two weeks.

  In order to cope with these situations, a lamp extinguishing time counter is provided in advance, and a function that automatically resets the cumulative lighting counter when it has been left untouched for more than two weeks, for example, has been added. It is a form.

  The lamp extinguishing time counter according to the present embodiment can be realized by using, for example, the configuration shown in FIG. 1, and the energization detection unit for a predetermined time (for example, two weeks) after the energization detection unit 61 of the microcomputer 6 detects the last energization. If 61 does not detect energization, the count value of the cumulative lighting time of the counter unit 62 may be reset.

  According to the present embodiment, when the lamp is not lit for a long time, the possibility that the lamp is steadily lit is reduced. Therefore, the cumulative lighting time is reset, and in the period when the lamp cumulative lighting time is short, the same as in the first to fifth embodiments. A discharge lamp lighting device capable of controlling the above can be realized.

(Embodiment 8)
FIG. 8 shows a configuration of the lighting apparatus according to the eighth embodiment. The present embodiment is a ceiling direct-mounted illumination device for home use. In FIG. 8, 10 is a main body chassis, 11 is a translucent cover, 12 is a reflector, 13 is a discharge lamp lighting device, and LA1 is an annular double tube lamp such as FHD70, 85, 100, for example. The main body chassis 10 has a circular shallow dish shape, includes means for attaching to the ceiling, and includes a mechanism to which the translucent cover 11 can be attached. The reflection plate 12 is formed as shallow as possible, and is shaped to reflect the light emitted from the lamp LA1 so that the luminance of the surface of the light-transmitting cover 11 is as uniform as possible. The discharge lamp lighting device 13 has the configuration described in any of Embodiments 1 to 7, and is disposed in a space formed between the main body chassis 10 and the reflection plate 12. The translucent cover 11 is provided on the lower surface of the main body chassis 10 and surrounds the lamp LA1 and the reflection plate 12.

  In the present embodiment, by including the discharge lamp lighting device according to any one of Embodiments 1 to 7, it is possible to provide a lighting device having the effects described in each embodiment.

It is a circuit diagram which shows the whole structure of Embodiment 1 of this invention. It is a circuit diagram which shows the structure of the abnormality detection circuit of Embodiment 1 of this invention. It is explanatory drawing which shows the characteristic at the normal temperature of Embodiment 1 of this invention. It is a circuit diagram which shows the principal part structure of Embodiment 2 of this invention. It is a circuit diagram which shows the principal part structure of Embodiment 4 of this invention. It is a circuit diagram which shows the principal part structure of Embodiment 5 of this invention. It is explanatory drawing which shows the characteristic at the time of low temperature of Embodiment 5 of this invention. It is a figure which shows schematic structure of the illuminating device of this invention, (a) is a perspective view, (b) is a sectional side view. It is a block diagram which shows the structure of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Discharge lamp lighting circuit 2 Power factor improvement circuit 3 Power conversion circuit 4 Control circuit 5 Control IC
6 Microcomputer (MPU)
7 Discrimination circuit 8 Illuminance meter 9 Thermometer

Claims (8)

In a discharge lamp lighting device for low luminous flux dimming lighting comprising a high frequency power source for supplying high frequency power to a discharge lamp and a dimming control means for performing dimming control of the discharge lamp, the cumulative lighting time of the discharge lamp is determined. A discharge lamp lighting device comprising: a lighting time monitoring unit for monitoring; and a control means for limiting a lower limit range of dimming lighting within a predetermined cumulative lighting time. 2. The discharge lamp lighting device according to claim 1, wherein the control means switches the lower limit range of the dimming lighting step by step according to the cumulative lighting time. 3. A discharge lamp detecting means for detecting an electrical parameter of a lighting state of the discharge lamp, wherein the control means switches the lower limit range limitation of dimming lighting according to the electrical parameter. The discharge lamp lighting device described. The illuminance detection means for detecting the illuminance parameter of the discharge lamp is provided, and the control means switches the lower limit range limitation of dimming lighting according to the illuminance parameter. Discharge lamp lighting device. The temperature detecting means for detecting a thermal parameter of the discharge lamp is provided, and the control means switches the lower limit range limitation of the dimming lighting according to the thermal parameter. The discharge lamp lighting device described. The discharge lamp lighting device according to any one of claims 1 to 3, further comprising detection means for detecting flicker of the discharge lamp, wherein the control means changes the dimming level to a higher level when flicker is detected. . 2. The discharge lamp lighting according to claim 1, further comprising a discharge lamp abnormality detecting means for detecting an electric abnormality parameter of the discharge lamp, wherein the control means resets the cumulative lighting time in accordance with the abnormal parameter. apparatus. An illumination device comprising: the discharge lamp lighting device according to any one of claims 1 to 7, a main body on which the discharge lamp lighting device is mounted, and a discharge lamp to which electric power is supplied from the discharge lamp lighting device. .

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