JP4985408B2 - Discharge lamp lighting device and lighting device - Google Patents

Description

  The present invention relates to a discharge lamp lighting device that controls the amount of heating of a filament when dimming and lighting a hot cathode discharge lamp, and an illumination device using the discharge lamp lighting device.

  When dimming and lighting a hot cathode discharge lamp, it is known that changing the amount of heating of the filament according to the dimming degree is preferable from the viewpoint of life of the discharge lamp or power saving. As an example of responding to such a request, one described in Japanese Patent Laid-Open No. 2005-235619 has been proposed.

  The technique described in Japanese Patent Laid-Open No. 2005-235619 is provided with switch means for turning on and off a preheating transformer provided at the output end of an inverter circuit, and controls the on-duty of the switch means in accordance with the dimming degree. .

  However, in the thing of Unexamined-Japanese-Patent No. 2005-235619, it only responds to the actual lamp current of a discharge lamp, since it only turns on / off the switch means with the on-duty fixed beforehand according to the light control degree. In some cases, the filament heating amount cannot be optimized. That is, the actual heating amount of the filament cannot be confirmed, and the heating amount of the filament may not be optimized. For example, the filaments of each discharge lamp are not all of the same quality and have deviations, but the filament heating amount may be inappropriate for filaments with large deviations.

  Further, it is conceivable that the filament heating cannot be optimized by the uniform on-duty control set in advance due to factors such as manufacturing deviation of the preheating transformer, power supply voltage fluctuation, and ambient temperature fluctuation.

  Therefore, the present invention provides a discharge lamp lighting device and an illumination device capable of optimizing the heating amount of the filament according to the dimming degree even when there is a filament deviation, a preheating transformer manufacturing deviation, or other disturbances as described above. The purpose is to provide.

A discharge lamp lighting device according to a first aspect of the present invention is a variable output lighting device that turns on a hot cathode discharge lamp by converting an output of a DC power supply device to a high frequency voltage; and heating a filament of the discharge lamp. Heating means with variable output; Detection means for detecting the heating amount of the filament; Filament heating amount according to the dimming degree of the discharge lamp is stored in advance, and the output of the lighting device according to the dimming signal controls and control means for controlling the output of said heating means such that the filament heating amount heating amount of filament which is detected by the detecting means are stored in advance; provided, said control means Has a ratio of each filament heating amount in a plurality of filaments, and the detection means detects the filament heating amount in any filament of the discharge lamp. A facilities available, the control means to set the heating amount of filaments is calculated by using the detected position and the ratio of said detecting means.
In the invention of the first aspect and the following invention, the definitions or technical meanings of terms are as follows.

  The DC power supply device also allows a battery, a commercial power supply voltage that is rectified, smoothed as necessary, or others. When rectifying and smoothing the commercial power supply voltage, using an active filter mainly composed of a boost chopper is effective in that the harmonic component of the input current can be reduced and the output voltage can be controlled arbitrarily.

  The hot cathode discharge lamp is typically a fluorescent lamp, but is not limited to this, and may be used for general illumination, sterilization, decoration, display, etc. Good.

  The lighting device only needs to convert the output voltage of the DC power supply device into a high-frequency voltage, and can be configured using, for example, an inverter, a converter, or a chopper. Moreover, even if it is these inverters, converters, or choppers, the circuit system is not limited.

  The heating means may be energized by a part of the output of the lighting device, energized by the output of the DC power supply or the commercial power supply, or energized from another power source. Good. In addition, the specific configuration may be any of a component in which a filament heating winding is provided on a component part of a transformer or a lighting device, or a component that forms a circuit through which a filament heating current flows.

  The detection means detects the heating amount of the filament, and can be configured to detect the current and voltage of the filament, or to detect the filament temperature.

  The control means stores in advance a filament heating amount corresponding to the degree of dimming. In this case, the heating amount of the filament is within a range in which it is possible to prevent the discharge lamp from being shortened due to insufficient heating and to prevent blackening of the discharge lamp bulb due to excessive heating. Such a range can be set according to the type or application of the discharge lamp and the cumulative lighting time of the discharge lamp. Preliminarily storing the filament heating amount according to the dimming degree may be a form in which the filament heating amount according to the dimming degree is stored in the data table, or an arithmetic expression is stored and You may make it obtain | require by calculation each time according to the light control degree. However, in the present invention, the stored content itself is not characteristic, but is characterized in that the actual filament heating state is fed back and optimized according to the degree of dimming.

  The control means changes the output of the lighting device in accordance with the dimming signal. Specifically, the control means can change the output by changing the output voltage value of the DC power supply device or controlling the operation of the lighting device. . For example, when the lighting device is configured by an inverter, a converter, a chopper, or the like, the output can be changed by controlling the switching frequency and on-duty of these switching devices.

  The control means controls the output of the heating means. In this case, the control structure can be formed according to the structure of the heating means. For example, when the transformer is used as described above, the input voltage of the transformer may be controlled, and when the filament winding is provided in the component part of the inverter, the applied voltage of the component part may be controlled. In addition, when a component that forms a flow path for heating current is used, the impedance value of the component may be controlled or the flow path may be opened and closed with a switch.

  The control means as described above are not particularly limited in terms of structure, such as being configured integrally, and a part for controlling the lighting device and a part for controlling the heating means are configured separately. Is sufficient if it performs the above-mentioned action.

  As the control means as described above, for example, an IC, a microcomputer, a DSP (digital signal processor) or the like configured to perform arithmetic processing is advantageous in terms of processing speed and miniaturization. In particular, in the case of a DSP, the calculation speed is fast, which is suitable for controlling the heating amount within about 0.5 seconds.

  In the invention of the first aspect, the amount of power supplied to the discharge lamp is changed by controlling the output of the lighting device in accordance with the dimming signal. As a result, the discharge lamp is lit at a dimming degree corresponding to the dimming signal. The filament heating amount at this time is detected by the detecting means and controlled so as to be a filament heating amount corresponding to the dimming degree stored in advance. Therefore, the filament is controlled to a preset filament heating amount regardless of the deviation of the filament, the manufacturing deviation of the heating means, and other disturbance factors.

Therefore, according to the first aspect of the invention, the filament of the discharge lamp is heated at a preset heating amount according to the degree of dimming regardless of the deviation of the filament, the manufacturing deviation of the heating means, and other disturbance factors. Thus, it is possible to provide a discharge lamp lighting device that can achieve a long life of the discharge lamp and can also save power.
Moreover, according to the discharge lamp lighting device of the first aspect, when a plurality of discharge lamps are connected in series between the high potential side and the low potential side, the heating amount of each filament is estimated as the high potential side and the low potential. When the lamp current is detected, the leakage current can be estimated and the lamp current in each filament can be estimated based on the leakage current. Then, the amount of heating of each filament is estimated using the estimation of the lamp current in each filament, and the ratio is held in advance. Under such a premise, for example, when it is desired to adjust the heating amount to the low potential side, if any one is detected, then control may be performed according to the ratio, or any one may be detected. For example, the heating amount of the other filaments can be adjusted to an optimum range by varying the heating rate according to the ratio.

A discharge lamp lighting device according to a second aspect of the present invention is the discharge lamp lighting device according to the first aspect, wherein the control means includes means for determining the type of the discharge lamp, The calculation is performed according to the dimming degree and the determination result of the type of the discharge lamp.

According to the discharge lamp lighting device of the second aspect, the type of the discharge lamp can be determined using the identification signal, and the target filament heating amount can be obtained according to the type of the discharge lamp.

The discharge lamp lighting apparatus of the third aspect of the present invention, in the discharge lamp lighting apparatus of the first or second aspect, wherein the lighting device, switching the pair of switching devices and the switching devices that are serially connected to each other A series resonant circuit to which an output is supplied, and the heating unit heats the filament by arranging a resonant capacitor of the series resonant circuit in series on a non-power supply side of a pair of filaments of the discharge lamp, The control means controls the heating amount of the filament by increasing or decreasing the current flowing through the filament.

According to the discharge lamp lighting device of the third aspect, the discharge lamp is made to flow from the high potential side to the low potential side of the discharge lamp by flowing the filament heating current through the filament and the resonance capacitor which is a part of the series resonance circuit. Leakage current when current flows is eliminated, and efficient filament heating control can be performed.

A discharge lamp lighting device according to a fourth aspect of the present invention is the discharge lamp lighting device according to the third aspect, wherein the control means is arranged in parallel with the filament of the discharge lamp and in series with the resonance capacitor. An impedance; and a switching means that is arranged in series with the impedance and that controls an inflow current; and a filament heating amount control means that controls the heating amount of the filament by turning on and off the switching means. Features.

According to the discharge lamp lighting device of the fourth aspect, a part of the filament heating current that flows through the filament and the resonant capacitor is divided through the series circuit of the impedance and the switch means, so that the divided current is supplied to the switch means. The amount of current flowing through the filament can be controlled, and the amount of heating of the filament can be controlled.

A lighting device according to an aspect of the present invention includes a lighting fixture body; a hot cathode discharge lamp mounted on the lighting fixture body; and the discharge lamp according to any one of the first to fourth modes for lighting the discharge lamp. And a lighting device.

According to this aspect of the invention, it is possible to provide an illuminating device that exhibits the same effects as the discharge lamp lighting device of any one of the first to fourth aspects.

The circuit diagram which shows 1st Embodiment of the discharge lamp lighting device by this invention. FIG. 2 is an enlarged view illustrating a filament terminal current by cutting out a part of FIG. 1. The figure which shows the relationship between the lamp current of FIG. 1, and a filament heating amount. The circuit diagram which shows 2nd Embodiment of the discharge lamp lighting device by this invention. The circuit diagram which shows 3rd Embodiment of the discharge lamp lighting device by this invention. The figure which shows the relationship between the lamp electric current and filament heating amount with respect to a different discharge lamp. The circuit diagram of 4th Embodiment of the discharge lamp lighting device by this invention. The figure which shows an example of the discrimination means of a discharge lamp kind. The figure which concerns on 5th Embodiment of the discharge lamp lighting device of this invention, and shows the control flow of a discharge lamp lighting device. Explanatory drawing which shows the mode of control with respect to 5th Embodiment with respect to the discharge lamp kind A. FIG. Explanatory drawing which shows the mode of control with respect to 5th Embodiment with respect to the discharge lamp kind B. FIG. The circuit diagram which shows 6th Embodiment of the discharge lamp lighting device of this invention. Explanatory drawing of the filament terminal current detection which expands and shows a part of FIG. The figure which shows the upper limit and minimum of a filament heating amount. The figure which shows the position of the lamp current detection point for the heating amount detection in 2 lamp | ramp serial lighting. The circuit diagram which shows 7th Embodiment of the discharge lamp lighting device of this invention. FIG. 17 is a circuit diagram in which the impedance in FIG. 16 is a capacitor. The figure which shows the filament electric current at the time of controlling the switch of a filament in each of FIG. The perspective view which shows one Embodiment of the illuminating device by this invention.

  Embodiments of the invention will be described with reference to the drawings.

[First Embodiment]
Hereinafter, a first embodiment of a discharge lamp lighting device according to the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a block diagram showing a first embodiment of a discharge lamp lighting device according to the present invention, FIG. 2 is an enlarged view illustrating a filament terminal current by cutting out a part of FIG. 1, and FIG. Hereinafter, it is a figure which shows the relationship between lamp current) and a filament heating amount.

  Reference numeral 1 denotes a DC power supply device, and a lighting device 2 is connected to the DC power supply device 1. The lighting device 2 converts the output voltage of the DC power supply device 1 into a high-frequency AC voltage of several kHz to several hundred kHz. In addition, the lighting device 2 is configured to be capable of changing its output, and includes current limiting means for stably lighting the discharge lamp. The hot cathode discharge lamp 3 is lit by the output of the lighting device 2.

  Reference numeral 4 denotes a heating means for heating the filament of the discharge lamp 3 and is energized by the output of the lighting device 2 in this embodiment.

  One filament of the discharge lamp 3 is provided with detection means 5 for detecting the heating amount of the filament. In this embodiment, the filament current is detected. Specifically, as shown in FIG. 2, the sum of the square of the sum (Il + If) of the lamp current Il and the filament heating current If and the square of the filament heating current If is obtained. 2 is an enlarged view of a part of FIG. 1. In FIG. 2, reference numeral 21 represents a power source equivalent to the output of the heating means 4. FIG.

  Returning to FIG. 1, the discharge lamp 3 is provided with current detection means 6 in series with the lamp current supply path so as to detect the lamp current value. The current detection unit 6 may be used as a lighting detection unit for the discharge lamp 3. Further, the heating means 4 is provided with a heating amount control switch 7 in series so that the input to the heating means 4 can be controlled.

Next, reference numeral 8 is a control means for controlling the output of the lighting device 2 and controlling the on / off of the switch 7, and the filament heating amount corresponding to the dimming degree of the discharge lamp 3 is set. It is something that is remembered. As shown in FIG. 3, the stored contents of the present embodiment are a correspondence relationship between the lamp current Il and the sum of the square of (Il + If) and the square of the filament heating current If. In other words, the lamp current value of the discharge lamp 3 changes according to the dimming degree, and an appropriate filament heating amount for this lamp current value is defined by the sum of the square of (Il + If) and the square of the filament heating current If. is doing. In FIG. 3, the shaded area is an appropriate range for filament heating, and the appropriate range is controlled to increase as the lamp current increases. However, it may be defined simply by the relationship between the lamp current Il and the filament heating current If. In short, what is necessary is just to prescribe | regulate by the relationship between the signal which shows a filament heating state, and the signal which shows the light control lighting state of a discharge lamp. As a form to be stored, a data table or an arithmetic expression may be used.

  The control means 8 can be constituted by an IC, a microcomputer, a digital signal processor (DSP), etc., and its functions include an arithmetic control unit (CPU), a main memory, a program memory, a nonvolatile memory, an analog / digital conversion. Device (AD converter), interface circuit (I / F circuit) and the like. And this control means 8 memorize | stores the control sequence according to the control sequence at the time of starting of the discharge lamp 3, and the detection signal from the electric current detection means 6 as needed, and it performs control according to the memory | storage content It may be.

  A dimming signal is input to the control unit 8 and detection signals from the filament heating amount detection unit 5 and the current detection unit 6 are input to the control unit 8. Then, according to the dimming signal, the output of the lighting device 2 is changed so that the discharge lamp 3 has a predetermined dimming degree. Further, the lamp current is obtained from the detection signal of the current detection means 6, and the ON period of the switch 7 is controlled (on-duty control) so that the filament heating amount corresponding to the lamp current is obtained.

  Further, the control unit 8 controls the output of the lighting device 2 when the lamp current value detected from the current detection unit 6 deviates from the value corresponding to the dimming degree set by the dimming signal, as necessary. Then, control may be performed so that a predetermined lamp current value is obtained.

  Next, the operation of this embodiment will be described. When the discharge lamp 3 is started, the lighting device 2 outputs a filament heating output and a starting voltage by starting sequence control of the control means 8. When the lighting of the discharge lamp 3 is detected by the detection signal of the current detecting means 6, the control means 8 controls the output of the lighting device 2 so that it is fully lit or lit at the set dimming degree.

  In this state, since the lamp current value is detected by the current detection means 6, the control means 8 can know the filament heating amount corresponding to the lamp current value at this time from the stored data or arithmetic expression. On the other hand, since the heating amount of the filament is detected by the filament heating amount detection means 5, it is possible to determine the coincidence or mismatch by comparison with the stored filament heating amount. For example, when the detected filament heating amount is outside the shaded area in FIG. 3, the on / off duty of the switch 7 is controlled so as to be within the shaded area. That is, the on-duty is increased when it is determined that the filament heating amount is insufficient, and the on-duty is decreased when it is determined that the filament heating amount is excessive.

  Thereby, the heating amount of the filament is always within the shaded portion in FIG. 3, and the life of the discharge lamp can be shortened due to insufficient heating, and the blackening of the bulb and the power loss due to scattering of the emitter due to excessive heating can be eliminated.

[Second Embodiment]
A second embodiment of the present invention will be described. FIG. 4 is a circuit diagram showing a second embodiment of the discharge lamp lighting device according to the present invention. In FIG. 4, the same or corresponding parts as those in FIG.

  In the present embodiment, a half-bridge type inverter is used as the lighting device 40. In this inverter, a pair of MOS FETs 41 and 42 connected in series with each other are connected between the output terminals of the DC power supply device 1, and a series resonance circuit 43 is provided in parallel with one FET 42. The series resonance circuit 43 includes a DC cut capacitor 44, a current limiting and resonance inductor 45, and a resonance capacitor 46. The inductor 45 originally functions as a ballast.

  The heating means 47 of the present embodiment is formed by a series circuit of a DC cut capacitor 48 and a filament heating transformer 49. Symbols a and b indicate current detection points necessary for heating amount detection in the filament heating amount detection means 5.

  Next, the operation of this embodiment will be described. The control means 8A controls the switching frequency of the pair of MOS FETs 41 and 42 according to the dimming signal. Thereby, since the frequency of the switching output supplied to the series resonant circuit 43 changes, the resonant output changes and the power supplied to the discharge lamp 3 changes. That is, the discharge lamp 3 is lit at a predetermined dimming degree set by the dimming signal. The lamp current value in this state is detected by the current detection means 6, the filament heating amount is detected by the filament heating amount detection means 5, and the control means 8A has a filament heating amount corresponding to the lamp current value at this time. Controls on / off of the switch 7. Therefore, the operation is the same as in FIG.

[Third Embodiment]
A third embodiment of the present invention will be described. FIG. 5 is a circuit diagram showing a third embodiment of a discharge lamp lighting device according to the present invention. In FIG. 5, the same or corresponding parts as those in FIG. 1 or FIG.

  The DC power supply device 50 of the present embodiment uses an active filter composed of a boost chopper. That is, the DC power supply 50 includes a rectifier 52 that rectifies the output of the commercial AC power supply 51, a MOS FET 54 that can short-circuit the output terminals of the rectifier 52 via the inductor 53, and the FET 54 and the diode 55. And a smoothing capacitor 56 connected in parallel.

  In the present embodiment, the switch 7 in the first and second embodiments is omitted, and the on-duty of the MOS FET 54 can be controlled by the control means 8B so that the output voltage value of the DC power supply device 50 can be varied. I have to.

  The operation of this embodiment will be described. The control means 8B controls the switching frequency of the pair of MOS FETs 41 and 42 of the lighting device 40 according to the dimming signal. Thereby, the electric power supplied to the discharge lamp 3 is changed, and the discharge lamp 3 is lit at a predetermined dimming degree set by the dimming signal. The lamp current value in this state is detected by the current detection means 6, the filament heating amount is detected by the filament heating amount detection means 5, and the control means 8B has a filament heating amount corresponding to the lamp current value at this time. The on-duty of the MOS FET 54 is controlled. Since the output of the DC power supply device 50 changes when the ON duty of the MOS FET 54 is controlled by the control means 8B, the voltage applied to the heating means 47 also changes. Thereby, the filament heating current is controlled, and the filament heating amount can be controlled.

  Note that when the output voltage of the DC power supply device 50 changes, the resonance voltage value also changes and the power supplied to the discharge lamp 3 also changes. In contrast, the control means 8B has a pair of lighting devices 40. By controlling the switching frequency of the MOS FETs 41 and 42 so that the detection value of the current detection means 6 has a predetermined dimming degree, it is possible to stabilize the lamp power to a set value.

[Fourth Embodiment]
A fourth embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a graph showing the relationship between lamp current and filament heating amount for different discharge lamps.

  In FIG. 6, the horizontal axis represents the lamp current Il of the discharge lamp, and the vertical axis represents the sum of the square of the current (Il + If) and the square of the filament heating current If corresponding to the filament heating amount. FIG. 6 shows the upper limit value and the lower limit value of the filament heating amount with respect to the dimming lamp current Il of each of the 40 watt class discharge lamps FLR40S, FL40SS, and FHF32. Accordingly, when these discharge lamps are lit in common in the embodiments of FIGS. 1, 4 and 5, the shaded portion in FIG. 6 is the appropriate filament heating range for all discharge lamps (common to all discharge lamps). Therefore, the heating amount of the filament is controlled so as to be within this proper range.

  In FIG. 6, no shaded portion exists in the region where the lamp current is small. Therefore, ideally, the dimming operation should be limited by setting the portion where the shaded portion is eliminated as the lower limit of the dimming lamp current Il. Alternatively, a means for detecting the type of the discharge lamp may be provided, and the filament heating may be performed in an appropriate range of each discharge lamp.

FIG. 7 shows a circuit diagram of a fourth embodiment of a discharge lamp lighting device according to the present invention, and FIG. 8 shows an example of a discharge lamp type discriminating means. 7 is substantially the same as the configuration of FIG. 4 described above.
For example, in FIG. 7, the DC power source 1 is converted to AC by an inverter that is the lighting device 40, and a high voltage necessary for lighting the discharge lamp 3 is obtained using the series resonance circuit 43. As one form of the filament heating circuit which is the heating means 47, a heating circuit capable of controlling the heating amount by a switch 7 using a MOSFET as shown in FIG. 7 is shown. The detection circuit 60 including the filament heating amount detection means detects electrical characteristics such as a discharge current or voltage, a filament current or voltage. The control circuit 8C, which is a control means, can control the filament heating circuit 47 in addition to the lighting control for controlling the inverter 40 in accordance with the dimming signal. Regarding reference signs A, B, and C, A is a lamp voltage detection point, B is a lamp current detection point, and C is a filament heating amount detection point. As the current detection point, a very small resistance means that can ignore a voltage drop with respect to the heating circuit 47 and the resonance circuit 43 can be used.

  The filament heating circuit 47 is controlled so that a target value of the filament heating amount corresponding to the dimming degree is given and the heating amount of the filament is set accordingly. In FIG. 7, the heating amount control connected to the heating circuit 47 so that the detected value of the filament heating amount given by the detection circuit 60 approaches the target value of the heating amount set by the control circuit 8C (or the detection circuit 60). The on period of the switch 7 is controlled. At this time, the optimum value of the filament heating amount is generally determined according to the dimming level given by the dimming signal, and in the prior art Japanese Patent Application Laid-Open No. 2005-235619, etc., the dimming level is also set. The circuit is controlled to give a corresponding filament current value. However, in the conventional technique, it has not been possible to confirm by feedback to the control means that the filament has actually reached the optimum value. Further, the optimum filament heating value itself varies depending on the type of the discharge lamp 3 and the cumulative lighting time, but control taking these into consideration has not been performed.

  For example, when the filament heating amount is determined from the amount of current flowing into the terminal of the discharge lamp 3, the difference between the upper limit and the lower limit of the heating amount depending on the type of the discharge lamp is as shown in FIG. For example, if the target heating amount of the FHF32 lamp is set on the circuit side of the control circuit 8C (or the detection circuit 60) and is set near the lower limit of FIG. 6 for power saving, the same discharge lamp with 40W output can be obtained. In some FLR40 and FL40, the filament heating is set below the lower limit of each, which leads to a shortened life of the discharge lamp. Further, in all three types shown in FIG. 6, the region giving the optimum filament heating amount is a shaded portion in the drawing, and therefore optimization is performed over the entire range of the dimming lamp current Il. I can't. Similarly, the elapse of a long cumulative lighting time, for example, exceeding 1000 hours in the discharge lamp promotes the wear of the filament emitter, and therefore the filament heating characteristics vary depending on the length of the cumulative lighting time. For this reason, even in the same discharge lamp, it is necessary to determine the target value of the heating amount according to the cumulative lighting time.

  Therefore, in the present embodiment, the discharge lamp lighting device is provided with a discharge lamp type determination unit or a cumulative lighting time estimation unit so that the filament heating amount target value according to the discharge lamp type and the cumulative lighting time is obtained. The filament heating circuit 47 is controlled.

  As shown in FIG. 8, the discharge lamp type discriminating means is provided with means for enabling the control circuit 8C to recognize the type of the discharge lamp 3 using an external setting switch or the like. FIG. 8 shows an example of the dip switch 61 for setting 0 or 1 (black is a set value). Here, a 2-bit DIP switch is shown, but if the number of bits is increased, the corresponding type of discharge lamp can be a value obtained by raising 2 to the power of the number of bits. By performing switch setting corresponding to the types of discharge lamps A, B, and C from the outside as shown in FIG. 8, the target value of the filament heating amount can be set according to the type of discharge lamp. The discharge lamp type discriminating means is not limited to this. When the type of the discharge lamp is limited to some extent, the discharge lamp type is also determined by detecting the discharge lamp voltage (referred to as lamp voltage) according to the tube diameter. Can do.

  Regarding the estimation of the cumulative lighting time, a spot progress method is known in which the degree of filament wear is known from the filament voltage during lighting. Also, a technique that includes a means for measuring the cumulative lighting time inside or outside the control circuit is widely known because of the requirement for initial illuminance correction. By utilizing these, it is possible to set a target value of the filament heating amount according to the cumulative lighting time.

  According to the present embodiment, it is possible to prevent the discharge lamp from shortening its life and premature blackening by optimizing the filament heating amount even at the time of dimming the discharge lamp. The target value of the filament heating amount can be set according to the dimming level and the discharge lamp type or the cumulative lighting time of the discharge lamp, and the filament heating amount can be further optimized.

[Fifth Embodiment]
A fifth embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a control flow for explaining a fifth embodiment of the discharge lamp lighting device of the present invention, and FIGS. 10 and 11 are diagrams for explaining the control of the filament heating amount for different types of discharge lamps. Since the configuration of the discharge lamp lighting device is the same as that of FIG. 7, it will be described with reference to the circuit diagram of FIG.

  In FIG. 7, the output voltage of the DC power supply device 1 can be converted into AC using an inverter that is the lighting device 40, and a high-frequency discharge voltage can be obtained through the series resonance circuit 43. As shown in FIG. 7, the filament heating circuit 47 has a configuration in which electric power is transmitted to the filament using a transformer, and the on / off of the heating current or voltage is controlled by the switch 7. By controlling the ON period of the switch 7, the heating amount of the filament can be controlled.

  The detection circuit 60 in FIG. 7 detects electrical characteristics such as the current or voltage of the discharge lamp, the filament current or voltage. The control circuit 8C turns on the switch 7 connected to the heating circuit 47 so that the difference between the filament heating amount obtained based on the detection value of the detection circuit 60 and the target heating amount set in the control circuit 8C is minimized. Control the duty.

  FIG. 9 is a diagram showing a control flow. The filament heating amount obtained by the heating amount detection circuit of the detection circuit 60 is the difference between the heating amount target value obtained by the control circuit 8C from factors such as the dimming signal, the type of discharge lamp, and the cumulative lighting time of the discharge lamp. The control circuit 8C controls the on-duty of the switch connected to the heating circuit 47 so as to minimize it. In FIG. 9, the target value of the filament heating amount described above is given as the reference value (Ref) of the error amplifier 62, and control is performed so that the difference from the detected value of the filament heating amount detected by the detection circuit 60 is minimized. To do.

  The configuration shown in FIG. 9 may be a hardware configuration or a configuration that performs software arithmetic processing in that control for detecting the heating amount and feeding back the difference from the target heating amount is performed. . Since general feedback control is used here, Error = (target value)-(detected value) and (control amount) = Kp * Error + Ki∫Error * dt (where Kp and Ki are feedback gains) It is also possible to perform control using a general-purpose feedback method such as PI control for controlling so as to be a coefficient giving * and * means multiplication.

For example, consider a method for optimizing the amount of filament heating based on the terminal inflow current of the discharge lamp. Here, the terminals refer to terminals at both ends of the filament disposed at the end of the discharge lamp. 10 and 11, the horizontal axis represents the lamp current Il, and the vertical axis represents the square sum ILH ² + ILL ² of the terminal inflow current. Discharge lamps A and B are different types of discharge lamps. ILH is a terminal inflow current on the side where the lamp current Il flows in at both ends of the filament, and ILL is a terminal inflow current on the side where Il does not flow. At this time, a target line corresponding to the type of the discharge lamp can be drawn as in the discharge lamps A and B of FIGS. As the target value shown in FIG. 9, such a target function, that is, a target function of (ILH ² + ILL ² ) = a * Il + b (a and b are constants and * is a multiplication) is obtained. Here, (ILH ² + ILL ² ) corresponds to the heating amount of the filament. After obtaining the detection amount of (ILH ² + ILL ² ), the target function shown in FIG. 9 is given as the target value in FIG. 9 and feedback control is performed, which is indicated by a black circle in FIG. 10 and FIG. The detected value (measured value) of the filament heating amount is feedback-controlled to a target line that is an appropriate value. FIG. 10 shows a state of feedback control for the discharge lamp A, and FIG. 11 shows a state of feedback control for the discharge lamp B. In the feedback control of the two different types of discharge lamps A and B, it can be seen that the amount of increase in the heating amount, which is the control amount, differs for each type of discharge lamp.

  According to the present embodiment, it is possible to prevent the filament heating from becoming too large or too small during dimming of the discharge lamp, and to shorten the life of the discharge lamp and prevent the tube wall from being blackened quickly. By performing feedback control of the filament heating amount, it is possible to control the heating means corresponding to the actual heating amount. It is possible to set the target value of the optimum filament heating amount according to the dimming degree, that is, the lamp current, and the optimum filament heating amount target value considering the change in the heating amount depending on the type of discharge lamp and the length of the cumulative lighting time Can be set.

[Sixth Embodiment]
A sixth embodiment of the present invention will be described with reference to FIGS. FIG. 12 is a circuit diagram showing a sixth embodiment of the discharge lamp lighting device of the present invention. FIG. 13 is an explanatory diagram of filament terminal current detection showing a part of FIG. 12 in an enlarged manner, FIG. 14 is a diagram showing upper and lower limits of the filament heating amount with respect to changes in lamp current, and FIG. It is a figure which shows the position of the lamp current detection point for a detection.

  The configuration of the discharge lamp lighting device shown in FIG. 12 is the same as that of FIG. As a means for detecting the filament heating amount, there is a method using the sum of the lamp current Il and the filament current If. In FIG. 12, when the sum of Il and If is detected as the filament heating amount, the sum of Il and If is detected on the low potential side (stable potential side) filament in the discharge lamp lighting device. Show.

  In FIG. 12, the DC power supply device 1 is converted to AC by an inverter that is a lighting device 40, and a high-frequency and high-frequency voltage is supplied to the discharge lamp 3 through the series resonance circuit 43. Filament heating is performed using a heating circuit 47. The control circuit 8C controls the inverter 40 according to the dimming signal, dims the discharge lamp 3, and controls the switch 7 of the heating circuit 47, thereby controlling the optimum filament heating amount.

  As shown in FIG. 12, a detection circuit for Il + If is provided as a detection circuit for the filament heating amount. By simultaneously detecting Il, If can be calculated from the detected value of Il + If. At the detection point a on the low potential side (stable potential side) filament in FIG. 12, the sum of Il and If is obtained, and the sum of the currents at the detection point a on the lowest potential filament is detected. If the detected value exceeds the lower limit, it is presumed that the heating amount exceeding the lower limit is assumed for all other filaments (the filament on the high potential side in FIG. 12), and the optimization control of the filament becomes easy. . The same can be said for the detection of Il at the detection point b. For the detection of Il + If and the detection of Il, for example, a minute resistance means that can ignore a voltage drop with respect to the heating circuit 47 and the resonance circuit 43 can be used.

The optimum filament heating amount can be given as the appropriate range in the hatched area in FIG. 14 by using the terminal inflow current of the discharge lamp as shown in FIG. In FIG. 13, if the design is such that the discharge current Il does not shunt to the illustrated heating circuit 47 side, ILH = Il + If and ILL = If. At this time, if the value of ILH ² + ILL ^{2 with} respect to Il is controlled between the lower limit and the upper limit (shaded area) of FIG. 14, the filament heating amount during lighting of the discharge lamp is optimized. If the lamp current Il with respect to the dimming level setting is detected, the heating amount detection may be performed by looking at ILH ² + ILL ² . Here, the sum of Il + If is detected and used for feedback control.

Since ILH ² + ILL ² = (Il + If) ² + If ² can be written, when Il + If = a, ILH ² + ILL ² = 2a ² −2aIl + Il ² can be written. For this reason, ILH ² + ILL ² is given as a function of the detected amount a = Il + If and Il, and the control amount of the heating circuit 47 may be set so that this value is between the upper limit and the lower limit. . Thereby, the optimum value of the filament heating amount can be obtained while simplifying the filament heating amount detection circuit 60A.

  In general, the filament heating amount can be detected by detecting Il + If in an arbitrary filament. As shown in FIG. 15, when the discharge lamps of the load are two lamps and are lit in series, Il + If may be detected for the high potential side filament (detection point 1), and the low potential side filament is detected. It may be performed (detection point 3). Alternatively, it may be detected at a position corresponding to an intermediate potential (detection point 2). However, especially during dimming of a discharge lamp, the current leaks from the high potential side through the capacitive component (this capacitive component is a stray capacitance that exists between the high potential side and the low potential side). The magnitude of the discharge current measured on the low current side decreases with respect to the magnitude of the discharge current measured on the potential side, and the discharge current contributing to filament heating becomes smaller as the potential becomes lower. For this reason, by detecting the value of the detection point 3 having the lowest potential and controlling the detected value so as to exceed the lower limit shown in FIG. 14, filament heating that does not fall below the lower limit shown in FIG. The amount can be secured. Thereby, it is possible to prevent the life of the discharge lamp from being shortened due to a shortage of heating amount in any filament.

  For example, when a plurality of (two in the figure) discharge lamps are connected in series between the high potential side and the low potential side as shown in FIG. 15, the control means sets the ratio of the heating amount of each filament in the plurality of filaments. The heating amount detecting means is capable of detecting the filament heating amount in any filament of the discharge lamp, and the control means uses the detection location of the heating amount detecting means and the ratio. The heating amount of the filament may be set by calculation. This is due to the following reason. That is, when a plurality of discharge lamps are connected in series between the high potential side and the low potential side, if the lamp currents on the high potential side and the low potential side are detected as an estimate of the heating amount of each filament, the leakage current is estimated roughly. Based on this, the lamp current in each filament can be estimated. Then, the amount of heating of each filament is estimated using the estimation of the lamp current in each filament, and the ratio is held in advance. In this way, for example, if it is desired to adjust the heating amount to the low potential side, if any one is detected, then control may be performed according to the ratio, or if any one is detected, the other is detected. The heating amount of the filaments can be adjusted to an optimum range by varying the heating rate according to the ratio.

  According to the present embodiment, it is possible to prevent the discharge lamp from being shortened in life and to be quickly blackened by optimizing the filament heating during the dimming of the discharge lamp. The filament heating amount of the discharge lamp can be detected with a simple circuit configuration. The amount of heating of the discharge lamp filament can be detected for each filament, but if the detected value exceeds the lower limit by detecting Il + If on the low potential side (stable potential side) filament, otherwise These filaments can be optimized by providing an optimum filament heating amount exceeding the lower limit. Therefore, even if the detection point of the filament heating amount is limited to one point, it is possible to perform heating control that does not shorten the life of the discharge lamp. In addition, when a plurality of discharge lamps are connected in series between the high potential side and the low potential side, each filament heating amount is estimated using the estimation of the lamp current in each filament, and the ratio is held in advance. If the heating amount of any one of the filaments is detected, the heating amount of the other filaments can be controlled or varied in accordance with the respective ratios so that the optimum heating amount range can be obtained.

[Seventh Embodiment]
A seventh embodiment of the present invention will be described with reference to FIGS. FIG. 16 is a circuit diagram showing a seventh embodiment of the discharge lamp lighting device of the present invention. FIG. 17 is a circuit diagram in which the impedance in FIG. 16 is a capacitor, and FIG. 18 is a diagram showing the filament current when the filament switch in FIG.

  In FIG. 16, a lighting device 40 includes a pair of switching devices connected in series with each other and a series resonance circuit 43 to which a switching output of the switching device is supplied (reference numeral 43 is not shown, but is similar to FIG. 7). The heating means includes the resonance capacitor 46 of the series resonance circuit 43 arranged in series on the non-power supply side of the pair of filaments of the discharge lamp 3 to heat the filament. The control means performs control to increase or decrease the current flowing through the filament using the impedance Zf (Zf is at least one of Zf1 and Zf2) and the switch SWf (SWf is at least one of SWf1 and SWf2). It is possible to control the heating amount of the filament. Compared with the configuration of FIG. 7, in FIG. 16, the heating means 47 using the preheating transformer of FIG. 7 is eliminated, the resonant capacitor 46 is arranged in series on the non-power supply side of the pair of filaments of the discharge lamp 3, and each filament A series circuit of an impedance Zf and a switch SWf is connected in parallel at both ends.

  In the present embodiment, the half-bridge inverter as the lighting device 40 has a pair of MOS FETs 41 and 42 connected in series to each other connected between the output terminals of the DC power supply device 1 and is parallel to one FET 42. In addition, a series resonance circuit 43 is provided. The series resonance circuit 43 includes a DC cut capacitor 44, a current limiting and resonance inductor 45 (hereinafter abbreviated as Lr), and a resonance capacitor 46 (hereinafter abbreviated as Cr).

  The direct current power supply device 1 is converted into alternating current using an inverter that is a lighting device 40, and high-pressure high-frequency power is applied to the discharge lamp 3 using a series resonance circuit 43. The discharge lamp 3 is lit using high-pressure high-frequency generated at both ends of Cr. At this time, since the filament of the discharge lamp 3 is in series with Cr, it is heated by the alternating current flowing through Cr.

  Therefore, the heating means of this embodiment arranges Cr of the series resonance circuit 43 and the filament of the discharge lamp 3 in series, and heats the filament.

  Further, the control circuit 8D as a control means has a function of controlling the output of the inverter 40 in accordance with the dimming signal and controlling the heating amount of the filament by increasing or decreasing the current flowing through the filament. Regarding reference signs A, B, and C, A is a lamp voltage detection point, B is a lamp current detection point, and C is a filament heating amount detection point. As the current detection point, it is possible to use a very small resistance means that can ignore a voltage drop with respect to the resonance circuit 43 or the like.

  In the configuration of FIG. 16, the current leaking from the high potential side via the stray capacitance is suppressed as shown in FIGS. 7 and 12, and both filaments have a current as a filament heating current via the resonance capacitor Cr in addition to the lamp current. Flows.

  The control means including the control circuit 8D is arranged in parallel with the filament of the discharge lamp 3, and has an impedance Zf arranged in series with the resonance capacitor Cr, and a switch arranged in series with the impedance Zf to control the inflowing current. SWf and filament heating amount control means (a part of the control circuit 8D) for controlling the heating amount of the filament by turning on and off the switch SWf are included.

  When the dimming of the discharge lamp 3 is controlled by the frequency of the inverter 40, the current flowing through Cr is also controlled. As a result, when the light is adjusted, the filament heating amount changes in accordance with the increase or decrease in the amount of current flowing through Cr. In this system, the current flowing through the filament and the discharge lamp filament is determined by the impedance component of Cr given by 1 / 2πfCr from the values of the frequency f and Cr during dimming. For this reason, the electric current which flows through a filament changes by controlling the frequency of an inverter by dimming control. It is necessary that a value of Cr, a frequency to be controlled, and the like are given so that the filament current can obtain an optimum heating amount.

  However, actually, even if the value of Cr, the control frequency, etc. are determined as described above, a difference between the actual heating amount and the optimum heating amount occurs. For this reason, in this embodiment, the detection circuit 60 detects the electrical characteristics of the discharge lamp current and voltage and the heating amount of the filament, and the control circuit controls the inverter frequency and the on / off of the switches SWf1 and SWf2 based on the detected values. It is characterized by doing. Impedance Zf is arranged in parallel on the filament of the discharge lamp. In the state where the switch SWf is OFF, the filament current of the filament is determined only by Cr as described above. On the other hand, when the switch SWf is turned on, a current diverted to the impedance Zf is generated, so that the current flowing through the filament can be reduced. As described above, in FIG. 16, the switches SWf1 and SWf2 are turned on and off, so that the heating amount of the filament can be controlled. The target value of the heating amount is determined by the dimming level, the type of discharge lamp, and the cumulative lighting time, and the on-duty of SWf1 and SWf2 is controlled so that the detected heating amount matches the target value.

  FIG. 17 shows an example in which capacitors (Cf1, Cf2) are given as impedance components arranged in parallel with the filament. When SWf1 is turned on, Cf1 and the filament are connected in parallel. For this reason, the current used for heating the filament is divided into the Cf1 side and the filament side. Thereby, the filament heating amount can be controlled. For example, the resistance value of the filament when the discharge lamp is lit is generally about 10Ω. On the other hand, if the lighting frequency f is 50 kHz and Cf1 = 0.47 uF, 1 / 2πfCf1 = 6.77Ω, which is the order of the resistance value of the filament.

  FIG. 18 illustrates the effect of SWf control. When SWf is on, the current flowing through the filament is reduced compared to when it is off. Therefore, by controlling the ON period of the switch, the current is controlled to be intermediate between the current flowing through the filament when ON and the current flowing through the filament when OFF, and the heating amount is controlled by the absolute value.

In FIG. 17, an example of a capacitor is given as the impedance arranged in parallel with the filament, but it may be an inductor or a combination of a capacitor and an inductor. The resistance components may be arranged in parallel, but in order to consume effective power, it is preferable to use a capacitor or an inductor.

  As described above, when the filament is heated by the current flowing through the resonance capacitor Cr, the effect of the current leaking from the high potential side of the discharge lamp can be ignored, so that a uniform filament heating amount can be obtained on the high potential side and the low potential side. There is also an advantage that can be.

  According to this embodiment, in the discharge lamp, it is possible to prevent the discharge lamp from having a short life and early blackening by optimally controlling the heating amount of the filament. By using the current flowing through the resonant capacitor for heating the filament, the effect of leakage current during dimming of the discharge lamp is suppressed, and variation in the heating amount according to the filament potential (high potential side, low potential side) is suppressed. it can. In addition, control of the amount of filament heating can also be realized in such a system that uses the current flowing through the resonant capacitor for heating the filament.

  Furthermore, according to the present embodiment, since the configuration of the heating means for heating the filament is configured to eliminate the loss of leakage current, the detection of the filament heating amount is released regardless of whether the filament is on the high potential side or the low potential side. It becomes possible to carry out with any filament of the electric lamp, and the degree of freedom in designing the discharge lamp circuit can be expanded.

  Next, an embodiment of a lighting device according to the present invention will be described with reference to FIG. FIG. 19 is a perspective view showing an embodiment of a lighting device according to the present invention. In the case of FIG. 19, the lighting device is a ceiling-mounted lighting fixture. Reference numeral 70 denotes a lighting fixture body, 71 denotes a socket provided in the lighting fixture body 70, 72 denotes a reflector, 73 denotes a hot cathode discharge lamp mounted in the socket 71, and 74 denotes a discharge lamp built in the lighting fixture body 70. It is an electric lamp lighting device. As the discharge lamp lighting device, the one described in any of the first to seventh embodiments is used.

  In the illuminating device having such a configuration, the filament heating of the discharge lamp 73 can always be appropriately performed, and the lifetime can be prevented and the power loss can be reduced.

  This application is filed on the basis of the priority claim of Japanese Patent Application No. 2006-016653 filed in Japan on January 25, 2006. Shall be quoted in the range.

Claims (5)

A variable output lighting device that converts the output of the DC power supply device into a high-frequency voltage to light a hot cathode discharge lamp;
Variable output heating means for heating the filament of the discharge lamp;
Detection means for detecting the heating amount of the filament;
The filament heating amount corresponding to the dimming degree of the discharge lamp is stored in advance, the output of the lighting device is controlled according to the dimming signal, and the heating amount of the filament detected by the detecting means is previously determined. Control means for controlling the output of the heating means so as to have the stored filament heating amount,
The control means has a ratio of each filament heating amount in a plurality of filaments in advance, and the detection means can detect the filament heating amount in any filament of the discharge lamp,
The discharge lamp lighting device according to claim 1, wherein the control means sets the amount of heating of the filament by calculating using the detection location of the detection means and the ratio . The control means includes means for determining the type of the discharge lamp, and calculates a filament heating amount according to the dimming degree and the determination result of the type of the discharge lamp. The discharge lamp lighting device according to 1. The lighting device has a pair of switching devices connected in series with each other and a series resonance circuit to which a switching output of the switching device is supplied,
The heating means heats the filament by arranging the resonance capacitor of the series resonance circuit in series on the non-power supply side of the pair of filaments of the discharge lamp,
The discharge lamp lighting device according to claim 1 or 2, wherein the control means controls the heating amount of the filament by increasing or decreasing the current flowing through the filament . The control means includes
An impedance arranged in parallel with the filament of the discharge lamp and arranged in series with the resonant capacitor;
Switch means arranged in series with the impedance to control the incoming current;
Filament heating amount control means for controlling the heating amount of the filament by turning on and off the switch means;
The discharge lamp lighting device according to claim 3, comprising: A lighting fixture body;
A hot-cathode discharge lamp mounted on the luminaire body;
The discharge lamp lighting device according to any one of claims 1 to 4, wherein the discharge lamp is turned on;
An illumination device comprising:

Images