JP4207703B2 - Dimmable discharge lamp lighting device and lighting device - Google Patents

Description

  The present invention relates to a dimming discharge lamp lighting device in which the end-of-life detection sensitivity becomes substantially constant regardless of the dimming state, and an illumination device using the same.

  Patent Document 1 proposes a discharge lamp lighting device including an asymmetric component detection unit that detects a positive / negative asymmetric component of a discharge lamp tube voltage generated by half-wave discharge during one-side Emires of a discharge lamp, that is, a DC voltage component of the tube voltage. Has been.

  An example is shown in FIG. In this circuit, a DC power source E, a series circuit of first and second switching elements Q2 and Q3 connected to the DC power source E, and a drive circuit 11 for alternately turning on and off the switching elements Q2 and Q3, A series circuit of a DC cut capacitor C6, a resonance choke coil L2, and a resonance capacitor C4 connected between the connection point of the first and second switching elements Q2 and Q3 and the negative potential side of the DC power supply E; The discharge lamp load LA connected in parallel with the resonance capacitor C4, the resistor Rx connected between the connection point of the DC cut capacitor C6 and the resonance choke coil L2 and the circuit ground, DC component detection The capacitor Cx is connected in series to both ends of the DC component detection capacitor Cx, and the voltage of the DC component detection capacitor Cx is at a predetermined level. A voltage comparison circuit 12 that generates a detection output when it is present, and an output to the discharge lamp load LA by controlling the switching of the first and second switching elements Q2 and Q3 based on the detection output of the voltage comparison circuit 12 And a control circuit 13 that reduces or stops the discharge lamp, and realizes low-cost, high-safety end-of-life detection and protection of the discharge lamp with a simple configuration.

Another example is shown in FIG. In this circuit, the frequency control circuit 14 for changing the frequency for alternately turning on and off the first and second switching elements Q2 and Q3, and the frequency control circuit 14 in response to an external dimming signal are controlled. The dimming signal circuit 15 for performing signal processing for the dimming discharge lamp lighting device capable of increasing / decreasing the lighting output is provided with a simple configuration at low cost and with high safety. Provides end-of-life detection and protection.
JP 2002-83699 A

  The end-of-life detection of the discharge lamp described in Patent Document 1 detects the DC voltage component of the discharge lamp tube voltage. As a precondition, the on-duty and off-duty of the switching element of the inverter are controlled equally. Sometimes. Further, with respect to the dimming control of the discharge lamp, the inverter operating frequency is controlled on the assumption that the on-duty and off-duty of the switching element are equal. This is because if the on-duty and off-duty of the switching element are unbalanced, a DC voltage component is generated in the discharge lamp tube voltage even when a normal discharge lamp is lit.

  However, it is well known that the discharge lamp dimming means includes, for example, the control of the DC power supply voltage or the duty control of the switching element of the inverter in addition to the operating frequency control disclosed in Patent Document 1. .

  Further, as a recent trend in the lighting market, there is a demand for a dimming discharge lamp lighting device capable of controlling a wide range of discharge lamp lighting outputs for the purpose of saving energy or producing various spatial scenes. When the output is limited to a deep dimming state using various dimming means, the resonance condition including the load continuously changes due to the dimming, and thus occurs in the end-of-life discharge lamp in any dimming state There is a problem that it is difficult to stably detect the DC voltage component of the tube voltage.

  The present invention has been devised in view of the above-described problems, and in particular, in a discharge lamp lighting device that continuously adjusts light to a deep dimming state (for example, 25% or less), a direct current component generated in the discharge lamp is reduced. An object of the present invention is to provide means capable of stably detecting in any dimming state, thereby enabling more accurate end-of-life detection and providing DC component detection means suitable for various dimming methods. .

  In the dimming discharge lamp lighting device of the present invention, in order to solve the above-mentioned problem, as shown in FIGS. 1 to 5, an AC / DC conversion unit 1 that converts an AC voltage into a predetermined DC voltage. And an inverter unit 2 that converts the output of the AC / DC conversion unit 1 to a high frequency and supplies high frequency power to a load unit 3 including a resonance circuit unit and a discharge lamp, and power supplied from the inverter unit 2 to the load unit 3 A control unit 6 for controlling the light, a dimming signal processing unit 5 for receiving a dimming signal from the outside and supplying the dimming signal to the control unit 6, and a DC voltage component being superimposed on the discharge lamp at the end of its life And a load state detection unit 4 that generates a detection output to the control unit 6 when the DC voltage component exceeds a predetermined level, and the control unit 6 uses the detection output of the inverter unit 2 and the AC / DC conversion unit 1. A machine that suppresses or stops either or both outputs A dimming discharge lamp lighting device comprising: a means for controlling the power from the inverter unit 2 to the load unit 3, wherein the operating frequency of the inverter unit 2 is changed, and the load state detection unit 4 Has a means for correcting the detection voltage in accordance with the dimming state, and corrects the maximum or the minimum in the vicinity of the no-load resonance frequency of the load unit 3, thereby improving the end-of-life detection sensitivity regardless of the dimming state. It is characterized by being substantially constant.

  According to the present invention, by providing means for detecting the DC voltage component of the lamp voltage generated in the load section and correcting the detected voltage according to the dimming state, the detection sensitivity is substantially reduced regardless of the dimming state. Thus, a dimming discharge lamp lighting device capable of stably detecting the end of life in any dimming state can be obtained.

  FIG. 1 shows a basic block diagram of a discharge lamp lighting device of the present invention. An AC / DC conversion unit 1 that converts a commercial AC voltage into a predetermined DC voltage is connected to the commercial AC power source. The inverter unit 2 is connected to the output of the AC / DC conversion unit 1 and converts a predetermined DC voltage into a high frequency. The load unit 3 includes resonant circuit components such as an inductor and a capacitor, a discharge lamp, and the like, is connected to the output of the inverter unit 2, and is supplied with high-frequency power from the inverter unit 2.

  The dimming signal processing unit 5 receives the dimming signal from the outside and performs signal processing to the control unit 6. For example, a signal process is performed in which a dimming signal composed of a rectangular wave voltage having a variable duty is received, a direct current voltage corresponding to the dimming level is generated and applied to the control unit 6. The control unit 6 controls the ON / OFF operation of the switching element of the inverter unit 2. Further, depending on the circuit configuration, the configuration may also be such that the ON / OFF operation of the switching element of the AC / DC conversion unit 1 typified by an active filter (such as a boost chopper circuit) is also controlled. Further, the control unit 6 receives the processing signal from the dimming signal processing unit 5 and supplies high-frequency power to the load unit 3 according to the dimming signal to the inverter unit 2 (or AC / DC conversion unit 1). Control is performed so as to increase or decrease.

  The load state detection unit 4 detects that a DC voltage component has been generated in the lamp voltage Vla of the discharge lamp, and the detected voltage passes through the detection voltage correction unit 42 and if the corrected detection voltage is equal to or higher than a predetermined level. The detection output is transmitted to the control unit 6. Upon receiving the detection output, the control unit 6 controls the inverter unit 2 (according to circumstances, the AC / DC conversion unit 1) so as to reduce or stop the power supply to the load unit 3. The detection voltage correction unit 42 is connected to the dimming signal processing unit 5 in order to grasp the dimming state. 1 is connected to the dimming signal processing unit 5, there is no particular problem whether this is an external dimming signal or another signal source in the discharge lamp lighting device. Any configuration that can detect the dimming state is acceptable.

  FIG. 2 shows a block diagram of the detection voltage correction unit 42. As shown in the figure, the detection voltage correction unit 42 includes a correction voltage generation unit 421, a subtracter 422, and an absolute value conversion unit 423. The absolute value conversion unit 423 converts the output from the voltage detection unit 43 into an absolute value so that it always becomes a positive voltage when viewed from the circuit ground. The correction voltage generation unit 421 receives the output signal from the dimming signal processing unit 5, recognizes the dimming state, generates a correction voltage corresponding to each dimming state, and outputs the correction voltage to the subtracter 422. The relationship between the correction voltage and the dimming state is shown in FIG. 3, and is set so that the correction voltage becomes maximum near the no-load resonance frequency f0. The subtractor 422 receives the detection voltage output from the absolute value conversion unit 423 and the correction voltage, and outputs a voltage obtained by subtracting the correction voltage from the detection voltage (corrected detection voltage) to the comparator 41 as an output. The comparator 41 receives the corrected detection voltage and the threshold voltage, and outputs a detection output to the control unit 6 when the corrected detection voltage is higher than the threshold voltage. The control unit 6 receives the detection output and controls the inverter unit 2 (according to circumstances, the AC / DC conversion unit 1) so as to reduce or stop the power supply to the load unit 3.

  In this way, by detecting the DC voltage component of the lamp voltage generated in the load unit 3 and correcting the detected voltage according to the dimming state, the detection sensitivity is substantially constant regardless of the dimming state. Thus, a dimming discharge lamp lighting device capable of stably detecting the end of life in any dimming state can be obtained. In FIG. 3, the correction voltage is defined by a straight line, but it may be a curve.

  FIG. 4 shows a specific circuit example of FIG. First, the correction voltage generation unit 421 will be described. The dimming signal is a rectangular wave signal that is frequency invariant and regulates the degree of dimming by changing the duty. The dimming signal is input to the base of the transistor Q11, and the charging current to the capacitor C11 is turned on / off to generate a DC voltage corresponding to the duty in the capacitor C11. Since the inverted signal of the transistor Q11 is input to the transistor Q13 via the transistor Q12, the voltage generated in the capacitor C12 has a slope opposite to that of the capacitor C11 with respect to the duty of the dimming signal. When the voltage generated in the capacitors C11 and C12 is input to the minimum value circuit 420 (analog AND circuit), the lower voltage of the capacitors C11 and C12 is output as shown in FIG.

  In the voltage detection unit 43, the load voltage is detected by the resistors R41 to R43, and integrated by the capacitor C13 and the resistor R40 having a sufficiently large time constant with respect to the oscillation frequency. At this time, if a DC component is superimposed on the detection voltage from the load, the DC component appears in the capacitor C13.

  In the absolute value converter 423, when the detected voltage of the capacitor C13 is positive, the voltage of the capacitor C13 is generated as it is on the cathode side of the diode D7. On the contrary, in the negative case, the polarity inversion voltage of the voltage of the capacitor C13 is applied to the cathode of the diode D7 by the output of the operational amplifier OP1. The operational amplifier OP2 is a buffer circuit for stabilizing the output of the operational amplifier OP1.

In the subtracting unit 422, the output voltage from the minimum value circuit 420 is applied to the resistor R30 via the transistor Q14 as a reference of the mirror circuit, and generates a reference current. The reference current is mirrored, and a constant current corresponding to the output voltage from the minimum value circuit 420 is extracted from the output of the absolute value circuit 423 via the resistor R36. The voltage at the connection point of the resistors R35 and R36 is a voltage obtained by subtracting the voltage across the resistor R36 from the output voltage of the operational amplifier OP2. That is, the detected voltage is corrected by changing the voltage across the resistor R36 according to the output of the correction voltage generator 421.
The comparator 41 compares the corrected detection voltage with the threshold voltage to determine the end of life. Here, the threshold voltage generated by the threshold voltage generation unit 44 is a constant voltage.

In this example, analog circuit components are used. For example, the correction voltage generation unit 421 uses a data table such as a microcomputer to generate an arbitrary correction voltage for the duty of the dimming signal. It goes without saying that the effects of the present invention can be realized even if the configuration is used.
In short, any means can be used as long as it has a function of performing correction in order to keep the detection voltage of the end-of-life load that changes depending on the frequency characteristics of the resonance circuit substantially constant.

(Principle of the present invention)
FIG. 6 shows the lamp characteristics of the discharge lamp and the load characteristics of the discharge lamp lighting device. The lamp characteristics of the discharge lamp are expressed as VI characteristics (characteristics of the lamp voltage Vla and the lamp current Ila), and are characteristics specific to individual lamps. As for the load characteristics of the discharge lamp lighting device, for example, in the discharge lamp lighting device of FIG. 39, the operating frequency of the inverter was changed to 60 KHz, 85 KHz, and 94.2 KHz, and the lamp current was adjusted to 350 mA, 200 mA, and 100 mA. In case of load characteristics. However, the ambient temperature was measured at 25 ° C.

  First, when the lamp is in a normal state, the lighting state of the lamp is determined at the intersection of the VI characteristic curve unique to the lamp and the load characteristic curve of the discharge lamp lighting device. For example, when the discharge lamp lighting device is operated at an operating frequency of 60 KHz, lighting is maintained at an operating point of a lamp current of 350 mA and a lamp voltage of 247.4V. It can also be seen that when the operating frequency is operated at 85 KHz or 94.2 KHz, the operating point is shifted to a lower current side and a dimming state is obtained.

  Next, when the lamp is in the end-of-life state, the loss in the filament provided at the lamp end increases, and the lamp voltage increases. That is, the lamp-specific VI characteristic moves upward, but its operating point moves along the load characteristic.

  In such a state, the power loss in the filament part increases and causes an abnormal temperature rise in the filament part, which is not preferable for safety. Therefore, before the lamp enters such an unsafe state, It is necessary to move to a protection operation (output suppression, oscillation stop, etc.) upon detecting that the state has been reached.

However, the DC voltage component of the lamp voltage generated when the lamp reaches the end of its life and causes half-wave discharge varies greatly depending on the load characteristics when the inverter operating frequency is changed.
For example, in FIG. 6, the load characteristic (lamp current Ila: 350 mA) at the operating frequency = 60 KHz operates at the intersection voltage = 247.4 Vrms with the lamp VI characteristic when the normal lamp is lit. On the other hand, when the lamp reaches the end of its life, the lamp voltage increases, and the VI characteristic of the lamp moves upward, the maximum value having an intersection with the lamp VI characteristic is the maximum value of the load characteristic 471. .9 Vrms. Therefore, the maximum value of the DC voltage component of the lamp voltage generated at the end of the lamp life is a voltage reflected in ΔV = 471.9-247.4 = 224.5 Vrms, which is the voltage difference.

  Considering in the same manner as described above, ΔV = 811 Vrms at an operating frequency = 85 KHz (lamp current Ila: 200 mA), and ΔV = 73.3 V at an operating frequency = 94.2 KHz (lamp current Ila: 100 mA). It can be seen that there is a large difference in how the DC component detection voltage of the lamp voltage is output when the operating frequency is changed, that is, when the dimming degree of the discharge lamp is changed.

  The fact that the DC component detection voltage of the lamp voltage changes according to the inverter operating frequency will be described in more detail. FIG. 7 shows a resonance curve when the load portion is not loaded in the discharge lamp lighting device (FIG. 39) shown in the conventional example, that is, a frequency characteristic of the resonance voltage obtained from the inductor L1 and the capacitor C1. From FIG. 7, the resonance frequency f0 is 78.4 KHz. The maximum value of the lamp voltage rise at the end of the lamp life described above is equal to the voltage on the no-load resonance curve at each operating frequency. Therefore, it can be seen that the DC component detection voltage of the lamp voltage is large when the inverter operating frequency is close to the resonance frequency f0, and decreases as the distance from the resonance frequency f0 increases.

  From the above, when dimming control is performed by changing the inverter operating frequency, in order to detect the end of the lamp life in any lighting state, the dimming lighting state with the smallest voltage difference ΔV can be detected. It is necessary to set the load detector.

  However, when the threshold voltage Vth is set in consideration of a lighting state with a small voltage difference ΔV, on the other hand, in a dimming lighting condition where the generated voltage is steep, such as when the lighting frequency is operating near the resonance frequency f0, There is a possibility of malfunction of detection or degradation of noise resistance.

Therefore, in the present invention, in order to provide a means capable of stably detecting in any dimming state, it is proposed to add a correction means for the detection voltage so as to make the detection sensitivity substantially constant regardless of the dimming state. It is. The configuration shown in FIGS. 1 to 5 is an example. Hereinafter, other configuration examples will be described .

Example 1
In this embodiment, the configuration shown in FIGS. 1 to 5 is partially changed. FIG. 8 is a block diagram of the detection voltage correction unit 42, and FIG. 9 is a characteristic example of the correction voltage generation unit 421 in FIG. Note that the configuration shown in FIG. 1 is also effective in this embodiment, and redundant description is omitted. The dimming / lighting means of the discharge lamp is the operation frequency control of the inverter.

  In the detection voltage correction unit 42 of FIG. 8, the subtracter 422 used in FIG. 2 is replaced with an adder 424 in this embodiment. Further, in the correction voltage generation unit 421 in FIG. 9, the correction voltage is set to be maximum near the resonance frequency f0 in FIG. 3, but in the present embodiment, the correction voltage is corrected near the resonance frequency f0. The voltage is set to be minimum.

In short, in the basic configuration shown in FIGS. 1 to 5, the threshold voltage is set so that it can be detected without correction even in a dimming state where the DC component detection voltage of the lamp voltage is least likely to occur. The embodiment shows how to correct the detection voltage when the threshold voltage is set so that the detection voltage near the resonance frequency f0 that is most likely to occur can be detected without correction. Also in this embodiment, the same effects as those of the basic configuration shown in FIGS .

(Comparative Example 1)
In this example , in the discharge lamp lighting device using the control means for changing the DC power supply voltage that is the output of the AC / DC converter 1 as the dimming lighting means for the discharge lamp, the detection sensitivity is substantially constant regardless of the dimming state. The means for correcting will be described. The configuration shown in FIG. 1 is also effective in this example , and redundant description is omitted.

  FIG. 10 shows the lamp characteristics of the discharge lamp and the load characteristics of the discharge lamp lighting device. The lamp characteristics of the discharge lamp are expressed as VI characteristics (characteristics of the lamp voltage Vla and the lamp current Ila), and are characteristics specific to individual lamps. The load characteristics of the discharge lamp lighting device are load characteristics when the lamp current is dimmed to 350 mA and 200 mA by changing the DC power supply voltage value of the discharge lamp lighting device. However, the ambient temperature was measured at 25 ° C.

  As can be seen from FIG. 10, ΔV = 224.5 Vrms when the lamp current Ila = 350 mA is turned on, and ΔV = 82.8 rms when the lamp current Ila = 200 mA is turned on. It can be seen that the detection voltage in the lamp state changes most steeply, and the sensitivity of the detection voltage becomes worse as the dimming state is reached.

  In the case of dimming by changing the DC power supply voltage in this way, as a means for making the detection sensitivity substantially constant regardless of the dimming state, first, the configuration of the detection voltage correction unit 42 is illustrated. 2 is a means for correcting the detected voltage most during all lamps as shown in FIG. In this case, it is necessary to set the threshold voltage so that the detection operation can be performed without correction in the deepest dimming state.

Next, the configuration of the detection voltage correction unit 42 is shown in FIG. 8, and means for correcting the detection voltage most at the dimming lower limit as shown in FIG. In this case, the threshold voltage is set so that the detection operation is performed without correction when all the lamps are lit, and the detection operation is performed by adding a correction voltage during dimming. Also in this example , the same effect as the basic configuration shown in FIGS .

(Example 2)
In this embodiment, in the discharge lamp lighting device using the control means for changing the ON / OFF duty of the switching element of the inverter unit as the dimming lighting means of the discharge lamp, the detection sensitivity is made substantially constant regardless of the dimming state. A means for correcting will be described. Note that the configuration shown in FIG. 1 is also effective in this embodiment, and redundant description is omitted.

  As described above, when the ON / OFF duty of the switching element of the inverter unit is 50%: 50%, no DC voltage component is generated in the lamp voltage Vla, but normal when the duty is unbalanced. Even when a simple discharge lamp is lit, a DC voltage component is generated. This is because the electrical properties of the discharge lamp are so-called negative characteristics, that is, the characteristic that the tube voltage decreases as the lamp current increases, and the discharge lamp lighting device shown in FIG. In a configuration in which a DC cut capacitor is connected in series, a DC voltage component is always generated.

  Therefore, in order to accurately detect the end of life, it is necessary to remove only the DC voltage component of the lamp voltage Vla generated due to duty imbalance and detect only the voltage generated at the end of the net lamp life. .

  The configuration of the detection voltage correction unit 42 used in the present embodiment is as shown in FIG. Further, regarding the relationship between the correction voltage and the dimming state, the correction voltage is increased as the dimming is deeper as shown in FIG. In this way, when dimming by changing the on / off duty of the switching element of the inverter unit, the detection sensitivity can be made substantially constant regardless of the dimming state.

In general, in duty control, it can be determined whether to increase or decrease the ratio based on a duty ratio of 50% when all lamps are lit. Therefore, the DC voltage component of the lamp voltage Vla due to duty change is It only occurs either on the positive side or on the negative side. The configuration of the detection voltage correction unit 42 in FIG. 13 corresponds to the case where the normal lamp is turned on and the DC voltage component of the lamp voltage Vla is generated on the positive side due to the duty change, and conversely the lamp voltage Vla due to the duty change. When the DC voltage component is generated on the negative side, it is necessary to adopt the configuration of FIG. Also in this embodiment, the same effects as those of the basic configuration shown in FIGS .

(Example 3)
FIG. 15 shows a block diagram of the third embodiment of the present invention. In the basic configuration shown in FIG. 1 described above, the detection voltage is corrected. In this embodiment, the threshold voltage is corrected. The dimming control means of the discharge lamp lighting device in this embodiment uses means for changing the operating frequency of the inverter.

  FIG. 16 shows an internal block diagram of the threshold voltage correction unit 45. The correction voltage generation unit 451 generates a correction voltage based on the dimming signal (which may be the output of the dimming signal processing unit). The adder 452 adds the correction voltage generated by the correction voltage generation unit 451 to the reference threshold voltage generated by the reference threshold voltage generation unit 441, thereby increasing the threshold voltage in a lighting state with a large detection voltage change range. Conversely, in a lighting state with a small change width, the threshold voltage is set low, and the detection sensitivity is always kept substantially constant regardless of the dimming state. In the configuration in which the adder 452 as shown in FIG. 16 is assembled, the relationship between the correction voltage and the dimming state is set so that the correction voltage becomes maximum near the resonance frequency f0 as shown in FIG. Just do it.

Further, the threshold voltage correction unit 45 may have a configuration in which a subtracter 453 is assembled as shown in FIG. 17. In this case, the correction voltage near the resonance frequency f0 as shown in FIG. 9 described in the first embodiment. Should be set so that is minimized. Also in this embodiment, the same effects as those of the basic configuration shown in FIGS .

(Comparative Example 2)
The block diagram of this example is the same as the configuration of FIG. 15 shown in the third embodiment, and redundant description is omitted. In this example , similarly to the third embodiment, the detection voltage is not corrected, but the threshold voltage is corrected. The dimming control means of the discharge lamp lighting device in this example uses means for changing the DC power supply voltage that is the output of the AC / DC converter 1.

  In this way, when dimming by changing the DC power supply voltage, as a means for making the detection sensitivity substantially constant regardless of the dimming state, first, the configuration of the threshold voltage correction unit 45 is illustrated. 16, there is means for maximizing the correction voltage when all the lamps are lit as shown in FIG. In this case, at the lower limit of dimming, it is set so that it can be appropriately detected without correcting to the reference threshold voltage, and the more the lighting output is increased, the more the DC voltage component of the lamp voltage Vla is detected. The correction is made so as not to operate.

Next, the second configuration includes a means for maximizing the correction voltage at the dimming lower limit as shown in FIG. In this case, the reference threshold voltage is set so that the detection operation is appropriately performed when all the lamps having the highest detection sensitivity are turned on, and when the light is adjusted, the reference threshold voltage is corrected and a slight lamp voltage Vla is applied. The correction is performed so that the detection operation can be appropriately performed even with the DC voltage component. Also in this example , the same effect as the basic configuration shown in FIGS .

Example 4
FIG. 18 shows a block diagram of the fourth embodiment of the present invention. Also in the present embodiment, as in the third embodiment, the threshold voltage is corrected instead of correcting the detection voltage. Note that the dimming control means of the discharge lamp lighting device in the present embodiment changes the on / off duty of the switching element of the inverter unit 2. As described above, when the ON / OFF duty of the switching element of the inverter unit 2 is 50%: 50%, no DC voltage component is generated in the lamp voltage Vla, but normal when the duty is unbalanced. Even when a simple discharge lamp is lit, a DC voltage component is generated. Therefore, in this embodiment, in order to accurately detect the end of life, a DC voltage component of the lamp voltage Vla generated due to duty imbalance is taken into consideration, and means for reflecting it in the threshold voltage is provided.

In the block diagram of FIG. 18, the difference from FIG. 15 described in the third embodiment is that the reference threshold voltage generation units 441 a and 441, threshold voltage correction units 45 a and 45 b, and comparators 41 a and 41 b are respectively provided as the configuration related to the threshold voltage. The upper and lower limits are set individually. This is because the DC voltage component of the lamp voltage Vla generated when the discharge lamp is at the end of its life can generate both positive and negative voltages, whereas the DC voltage component of the lamp voltage Vla due to duty dimming is either positive or negative. This is because only the voltage is generated, and the absolute value of the net detected DC voltage is different between positive and negative.

As the configuration of the upper and lower threshold voltage correction units 45a and 45b when the DC voltage component of the lamp voltage Vla due to duty dimming is generated as a positive voltage, the adders 452a and 45b are set as shown in FIG. Note that the setting of the correction voltage depending on the dimming state may be as shown in FIG. 12 described in the second embodiment. The upper limit comparator 41a outputs a detection output to the control unit 6 when the detection voltage exceeds the corrected upper limit threshold voltage. The lower limit comparator 41 b outputs a detection output to the control unit 6 when the detection voltage falls below the corrected lower limit threshold voltage. 20 and 21 show corrected threshold voltages (thick lines) that are outputs from the upper and lower threshold voltage correction units 45a and 45b from the lighting of all lamps to the dimming lower limit, and respective detection areas (shaded portions). ing.

When the DC voltage component of the lamp voltage Vla due to duty dimming is generated as a negative voltage, the configuration of the upper limit and lower limit threshold voltage correction units 45a, 45b sets the subtracters 453a, b as shown in FIG. The setting of the correction voltage depending on the dimming state may be the setting as shown in FIG. 12 described in the third embodiment. 23 and 24, corrected threshold voltages (thick lines) that are outputs from the upper and lower threshold voltage correction units 45a and 45b from the lighting of all lamps to the dimming lower limit and the respective detection regions (shaded portions). Is shown.
As described above, when dimming by changing the on / off duty of the switching element of the inverter unit, the detection sensitivity can be made substantially constant regardless of the dimming state. Also in this embodiment, the same effects as those of the basic configuration shown in FIGS .

(Comparative Example 3)
In this example , in a discharge lamp lighting device using a control unit that changes both the DC power supply voltage and the inverter operating frequency as a discharge lamp dimming unit, a unit for making detection sensitivity substantially constant regardless of the dimming state will be described.

  FIG. 25 shows the lamp characteristics of the discharge lamp and the load characteristics of the discharge lamp lighting device. The lamp characteristics of the discharge lamp are expressed as VI characteristics (characteristics of the lamp voltage Vla and the lamp current Ila), and are characteristics specific to individual lamps. The load characteristics of the discharge lamp lighting device are load characteristics when the lamp current is dimmed to 350 mA, 200 mA, and 100 mA by changing both the DC power supply voltage value and the inverter operating frequency of the discharge lamp lighting device. However, the ambient temperature was measured at 25 ° C.

As can be seen from FIG. 25, the voltage difference ΔV between the normal lighting and the end of life in each lighting state is about 220 Vrms, and the detection sensitivity is substantially constant. Therefore, there is no need to correct the detection voltage or threshold voltage as described in the first to fourth embodiments. The output from the dimming signal processing unit 5 is received by the control unit 6 as shown in FIG. And the inverter operating frequency may be appropriately controlled.

As an effect of this example , as in the basic configuration shown in FIGS. 1 to 5, it is possible to stably detect the end of life in any dimming state, and in order to make it possible, the correction means includes Since it is not necessary, it is possible to reduce the size and cost of the apparatus by reducing the number of parts .

(Example 5)
In this embodiment, a means for adding a means for correcting the detection voltage or the threshold voltage input to the load state detection unit in consideration of the temperature characteristics of the discharge lamp and enabling higher detection accuracy will be described.

  As an example in FIG. 26, when the ambient temperature is 10 ° C., 25 ° C., 40 ° C., and 70 ° C., the VI characteristic unique to the discharge lamp to be lit, the DC power supply voltage value of the discharge lamp lighting device, and the inverter operating frequency The load characteristics when the lamp current is dimmed to 350 mA, 200 mA, and 100 mA by changing both of the above are shown.

  As can be seen from FIG. 26, the VI characteristic inherent to the lamp has the highest lamp voltage Vla when the temperature is 25 ° C., and the lamp voltage Vla tends to decrease regardless of whether the temperature is lower or higher. In particular, when the temperature is 70 ° C., the lamp voltage Vla is significantly reduced. Therefore, ΔV is the smallest when the temperature is 25 ° C., and ΔV increases even if the temperature is lower or higher than that, and the detection sensitivity becomes steep. This is obvious when looking at the load characteristics (lamp current 100 mA) at the operating frequency of 94.2 KHz.

  FIG. 27 shows a ratio of ΔV at each ambient temperature when ΔV at an ambient temperature of 25 ° C. is 100%. From now on, in a deep dimming state (for example, a lamp current of 100 mA), It can also be seen that the change is remarkable, for example, at 70 ° C., it is three times or more of 25 ° C.

  From the above, in order to make the detection sensitivity substantially constant regardless of the ambient temperature and to obtain a more stable detection operation, the detection voltage or threshold voltage input to the load state detection unit is corrected in consideration of the temperature characteristics of the discharge lamp. The addition of means is proposed below.

  FIG. 28 shows a block diagram of the discharge lamp lighting device of the present embodiment. The difference from FIG. 1 is that the discharge lamp ambient temperature detection unit 7 is provided, and the output is transmitted to the detection voltage correction unit 42 in the load state detection unit 4.

  FIG. 29 shows the configuration of the detection voltage correction unit 42. The difference from FIG. 2 is that an ambient temperature correction voltage generation unit 427 is provided in the detection voltage correction unit 42. The ambient temperature correction voltage generation unit 427 receives a signal from the ambient temperature detection unit 7 and also receives an output from the dimming signal processing unit 5 if necessary to generate an ambient temperature correction voltage according to the dimming state. , Output to the subtractor 422. The subtractor 422 outputs, to the comparator 41, a value obtained by subtracting the correction voltage corresponding to the dimming state and the ambient temperature correction voltage from the absolute value converted detection voltage. Further, as the ambient temperature correction voltage to be generated, for example, as shown in FIG. 30, it is set so that the correction voltage is minimized at room temperature. Further, when the ambient temperature correction voltage is changed according to the dimming state, the correction voltage is set to be relatively higher at the time of deep dimming lighting than at the time of lighting all lamps or at the time of shallow dimming lighting.

  If it does as mentioned above, the correction | amendment regarding the light control state and the ambient temperature of a discharge lamp can be performed with respect to the detection voltage at the end of life, and a more highly accurate detection is attained.

  In the above description, the ambient temperature of the lamp is described. However, in the case where it is not preferable in terms of cost and aesthetics, the temperature measurement target and the control means are used in this embodiment, such as substituting the temperature of an arbitrary part in the discharge lamp lighting device. However, it is not limited to the means described above, and other means may be used as long as the effects are the same.

Further, in this embodiment, inverter operating frequency control is used as the dimming lighting means, and the correction target is the detection voltage of the DC component of the lamp voltage Vla, but this also relates to the duty described in the previous embodiments. Needless to say, the present invention can be easily developed with respect to applications from this embodiment, such as control or correction to a threshold voltage .

(Example 6)
A circuit diagram of Embodiment 6 of the present invention is shown in FIG. Although the embodiments so far have been related to detection when the discharge lamp is lit, this embodiment will explain end-of-life detection in the process of starting and lighting the discharge lamp.

  Hereinafter, the circuit configuration of FIG. 31 will be described. A surge absorber ZNR is connected to both ends of the commercial power supply Vs to provide overvoltage protection. The capacitor C1 and the common filter LF1 constitute a noise prevention filter circuit. The diodes D1 to D4 constitute a rectifier, and the commercial power supply Vs is full-wave rectified. The capacitor C2 is a high frequency bypass capacitor.

  A step-up chopper circuit is configured by the inductor L1, the switching element Q1 (MOSFET), and the diode D5. One end of the secondary winding n12 of the inductor L1 is connected to the circuit ground GND, and the other end is input to the control unit 6 via the resistor R2 to detect the zero current of the chopper circuit. The resistor R1 is connected between the source terminal of the switching element Q1 and the circuit ground, and the voltage across the resistor R1 is input to the control unit 6 to detect an overcurrent flowing through the switching element Q1. A series circuit of resistors R3 to R5 is connected between the cathode of the diode D5 and circuit ground, and the voltage across the resistor R5 is input to the control unit 6 to detect the output voltage of the boost chopper circuit. The aluminum electrolytic capacitor C3 outputs a DC power supply voltage as a smoothing capacitor. The above is the AC / DC converter, which functions as a DC power source for the inverter circuit.

  A series circuit of switching elements Q2 and Q3 (MOSFET) is connected to both ends of the capacitor C3, and the controller 6 is controlled to repeat ON / OFF operations alternately. Thus, an inverter circuit that supplies high-frequency power to the load circuit connected to both ends of the switching element Q3 is configured.

  A series circuit of the capacitor C7 and the primary winding n31 of the transformer L3 is connected to the switching element Q3. The secondary windings n32 and n33 of the transformer L3 are connected to both ends of the discharge lamp LA via capacitors C8 and C9, respectively. The preheating circuit which supplies a preheating current to the filament installed in the both ends of the discharge lamp LA by the above is comprised.

  A series circuit of a resonance inductor L2 and a resonance capacitor C4 is connected to the switching element Q3. A series circuit of the resonance capacitor C5 and the primary winding n1 of the step-up transformer T1 is connected to both ends of the resonance capacitor C4. A series circuit of the DC cut capacitor C6, the discharge lamp LA, and the secondary winding n2 of the step-up transformer T1 is connected to both ends of the primary winding n1. The lighting load circuit of the discharge lamp LA is configured as described above.

  For starting the discharge lamp LA, a high frequency voltage is generated in the resonance capacitor C4 by the resonance operation of the resonance inductor L2 and the resonance capacitor C4, and the voltage is boosted by the step-up transformer T1 and applied to both ends of the discharge lamp LA. When the discharge lamp LA is lit, the discharge lamp LA is kept lit by a lighting resonance condition in which the resonance capacitor C5 and the discharge lamp LA are added to the resonance system of the resonance inductor L2 and the resonance capacitor C4.

  Note that T1 is an autotransformer, and the current flowing in the primary winding n1 and the current flowing in the secondary winding n2 are in opposite phases, and as a result, the primary current of the autotransformer T1 is almost cancelled. The temperature rise of the autotransformer T1 is reduced.

  Hereinafter, a detection circuit for the DC voltage component of the lamp voltage Vla will be described as end-of-life detection of the discharge lamp LA. A series circuit of resistors R11, R12, R13 and a capacitor C101 is connected between a connection point between the DC cut capacitor C6 and the discharge lamp LA and the circuit ground. A parallel circuit of a resistor R14 and a capacitor C102 is connected to both ends of the capacitor C101 via a diode D101. A connection point between the diode D101 and the resistor R14 is connected to the comparator 41 as a detection output. As a result, when a positive voltage with respect to the circuit ground is generated at the connection point between the DC cut capacitor C6 and the discharge lamp LA, the capacitor C101 is charged with a DC voltage and input to the comparator 41.

  Next, a Zener diode ZD101 is connected to a connection point between the capacitor C101 and the diode D101, and the other end of the Zener diode ZD101 is connected to the base terminal of the transistor Q101. A parallel circuit of a resistor R15 and a capacitor C103 is connected between the base and collector of the transistor Q101. The control power supply Vcc is always applied to the emitter terminal of the transistor Q101. A resistor R16 and a diode D102 are connected between the collector terminal of the transistor Q101 and the cathode terminal of the diode D101. As a result, when a negative voltage with respect to the circuit ground is generated at the connection point between the DC cut capacitor C6 and the discharge lamp LA, the connection point between the capacitor C101 and the Zener diode ZD1 becomes a negative potential, and the negative potential and the control power supply Vcc When the sum of the voltages becomes equal to or higher than the Zener potential of the Zener diode ZD1, a current flows through the Zener diode ZD101, the base current of the transistor Q101 is drawn, and the transistor Q101 is turned on. As a result, the control power supply Vcc is input to the comparator 41 via the transistor Q101, the resistor R16, and the diode D102.

  As described above, when the discharge lamp LA is at the end of its life and a positive or negative DC voltage is generated at the connection point between the DC cut capacitor C6 and the discharge lamp LA, the detection voltage is input to the comparator 41. ing. The comparator 41 has a built-in comparator, compares the threshold voltage Vth with the detection voltage, and outputs a detection output to the control unit 6 when the detection voltage is high.

As a function of the control unit 6, the ON / OFF operation of the chopper switching element Q1 and the ON / OFF operation of the inverter switching elements Q2, Q3 are controlled. Then, it receives the dimming signal from the outside and controls the ON / OFF operation according to the dimming signal. Further, when a detection output is input from the DC voltage component detection circuit of the lamp voltage Vla, control is performed so as to limit or stop power supply to the inverter.
The control power supply unit 8 is connected to the output of the capacitor C3, has a step-down chopper function, and functions as a low-voltage DC power supply for the control power supply.

Next, a process until the discharge lamp LA is turned on will be described.
FIG. 32 shows frequency characteristics of the resonance voltage applied to both ends of the discharge lamp LA and the lamp current during lighting. The resonance frequency f01 is a natural vibration frequency determined by the inductor L2 and the capacitor C4, and the resonance frequency f02 is a natural vibration frequency determined by the inductor L2, the capacitors C4 and C5 when the discharge lamp LA is short-circuited. When the discharge lamp LA is lit, a lamp current curve having a peak between the resonance frequencies f01 and f02 is obtained.

  A general discharge lamp lighting device roughly has three modes as a process until the discharge lamp is lit. Here, a case where mode control is performed by changing the inverter operating frequency will be described.

  First, the first mode is a preheating mode in which a preheating current is supplied to the filaments at both ends of the lamp. At this time, in order to prevent a cold start of the discharge lamp and a burden on the lamp filament, it is desirable to prevent voltage from being applied to both ends of the discharge lamp as much as possible. Therefore, during preheating, the inverter circuit is operated in a high frequency region that is distant from the resonance frequency f01. In FIG. 32, the tube voltage during preheating is shown as Vpre.

  Next, the second mode is a start mode in which the high voltage Vsrt is applied to both ends of the discharge lamp LA to start the lamp. In order to obtain a high voltage at the start, the inverter circuit is operated in the vicinity of the resonance frequency f01. When the discharge lamp LA is lit, the resonance system is added with the capacitor C5 and the discharge lamp LA in addition to the inductor L2 and the capacitor C4, and the lamp current Isrt flows through the discharge lamp LA.

  In the third mode, in order to obtain a desired lighting output, for example, in the case of all lamp lighting, the operating frequency is further lowered than that at the time of starting to obtain the lamp current Ifl. Conversely, if the operating frequency is increased, dimming can be performed.

  Next, FIG. 33 will be described. FIG. 33 shows the time series of the detection voltage of the DC voltage component detection circuit of the lamp voltage Vla when the upper stage is the lamp voltage Vla of the discharge lamp LA and the lower stage is when the discharge lamp LA is in the end of life state.

  It should be noted that the DC detection voltage is 0 (zero) at the time of preheating and starting and immediately before the discharge lamp LA is turned on. When the discharge lamp LA is lit at the time of starting, since the discharge lamp LA is at the end of its life, a DC voltage component of the lamp voltage Vla is generated. Finally, a direct-current voltage component of the lamp voltage Vla is generated even in the all-lamp lighting mode, but the generated voltage is lower than that at the start. This is because, as described in the above embodiment, the detection sensitivity is higher as the operation is performed in the vicinity of the natural vibration frequency f01 determined by the resonance circuit system of the load circuit.

  From the above, in the present embodiment, as means for reliably operating the end of life detection in the starting lighting process of the discharge lamp LA, at least the end of life detecting operation is enabled in the lighting transition state including the starting time, and the lighting including the starting is performed. The present invention proposes a dimming discharge lamp lighting device that detects a DC voltage component superimposed on a discharge lamp in a transition state to. Note that the threshold voltage setting value needs to be set in consideration of the steep sensitivity of the detection voltage.

As an effect of the present embodiment, it is possible to reliably detect whether the end of the lamp life is reached in the process of starting and lighting the discharge lamp without using the correction means for the detection voltage or the threshold voltage as described above. Become.
As a product development of this embodiment, a simple and reliable means for detecting an installation place where lighting / extinguishing of lamps is relatively frequent, such as a lighting apparatus equipped with a human sensor, a brightness sensor, etc. as valid.

(Comparative Example 4)
FIG. 34 shows a circuit diagram of Comparative Example 4 . Similar to the sixth embodiment, this example also describes the end of life detection in the process of starting and lighting the discharge lamp. In the circuit of FIG. 34, in the circuit configuration of FIG. 31 described in the sixth embodiment, a series circuit of resistors R17 to R19 is connected between the drain terminal of the switching element Q2 and the load side of the DC cut capacitor C6. . By connecting the resistors R17 to R19, even when a slow leak, which is one of the forms at the end of the life of the discharge lamp LA, is detected, the function of circuit protection is activated. In other words, when the discharge lamp LA cannot sustain the discharge, such as when a pinhole is formed in the discharge lamp LA and the discharge of the discharge lamp LA cannot be maintained, the switching element Q3 is turned on from the DC power source via the resistors R17 to R19. A charging current flows through the capacitor C6, and a DC voltage component is generated at both ends of the capacitor C6. The generation of this DC voltage is detected by the DC voltage component detection circuit of the lamp voltage Vla as in the case of the half-wave discharge described so far, so that output control of the AC / DC converter and inverter circuit can be performed. Become.

  Next, FIG. 35 will be described. FIG. 35 shows the detection voltage of the DC voltage component detection circuit of the lamp voltage Vla when the upper stage is the lamp voltage Vla of the discharge lamp LA, the middle stage is when the discharge lamp LA is a normal lamp, and the lower stage is when the discharge lamp LA is at the end of life. The time series of is shown.

  It should be noted here that even if it is a normal lamp, a DC detection voltage is generated immediately before the discharge lamp LA is lit at the time of preheating and starting. This is because the resistors R17 to R19 described above are added. When the discharge lamp LA is lit, the resistance component of the discharge lamp LA is lower than the impedance of the resistors R11 to R14, so that the charge of the DC cut capacitor C6 is discharged and the detection voltage becomes almost 0 (zero). . When the discharge lamp LA is at the end of its life, the detection voltage is generated even when the discharge lamp LA is lit at start-up, and further, the detection voltage is reduced even when all lamps or dimming lights. Yes.

As described above, in this example , as a means for reliably operating the end of life detection in the starting lighting process of the discharge lamp LA, the end of life detection is effective only in the period after the lighting mode after the starting mode, and in the case of dimming lighting. In addition, the present invention proposes a dimming discharge lamp lighting device that always makes a transition to a desired lighting output (dimming lighting) through all lamp states.

  In such a discharge lamp lighting device, first, the end of life detection is made effective only in the period after the lighting mode after the start mode, so that the period until the discharge lamp LA is lit even in the normal lamp ( A detection malfunction can be avoided against occurrence of a DC detection voltage in the preheating and starting modes.

  In addition, even when dimming, all lamps have relatively better detection sensitivity than deep dimming conditions by making a transition to the desired lighting output (dimming lighting) via all lighting conditions. Detection can be reliably performed in the lighting state.

In this example , the inverter operating frequency control is used as the lighting dimming means, but it may be the case of DC power supply voltage control or duty control.

As an effect of this example , detection is possible even when the discharge lamp LA is in a slow leak state by adding the resistors R17 to R19. Further, it is possible to reliably detect whether the end of the lamp life is reached in the process of starting and lighting the discharge lamp without using the correction means for the detection voltage or threshold voltage as described above.

As a product development of this example , as a means to detect easily and surely as an application to installation places where lighting / extinguishing of lamps is relatively frequent, such as lighting fixtures equipped with human sensors, brightness sensors, etc. It is effective .

(Example 7)
FIG. 36 is a perspective view showing the appearance of the lighting device. A reflector 102 is formed on the lower surface of the instrument body 101, and lamp sockets 103, 103 are provided at both ends of the reflector 102. A straight tube fluorescent lamp as a low-pressure discharge lamp is provided between the lamp sockets 103, 103. The lamp LA is attached, and any one of the above-described dimming discharge lamp lighting devices is built in the appliance main body 101.

  FIG. 37 is a perspective view showing the appearance of another type of lighting device. Any of the dimming discharge lamp lighting devices described above is built in between the fixture body 201 and the reflector 202. Reference numeral 203 denotes a lamp socket, 204 denotes a lamp support spring, 205 denotes a power adapter, and 206 denotes an instrument cover. A round tube fluorescent lamp LA is attached to the lamp socket 203 and the lamp support spring 204.

  The dimming discharge lamp lighting device and lighting device of the present invention can be used for lighting fixtures for offices and general households.

It is a block diagram which shows the basic composition of this invention. It is a block diagram which shows the internal structure of the detection voltage correction | amendment part of FIG. FIG. 3 is a characteristic diagram of a correction voltage generation unit in FIG. 2. FIG. 3 is a circuit diagram illustrating a specific configuration of a detection voltage correction unit in FIG. 2. It is a figure which shows the input-output relationship of the minimum value circuit of FIG. It is a VI characteristic figure at the time of lighting of the present invention. It is a resonance characteristic figure at the time of no load of the present invention. It is a block diagram which shows the internal structure of the detection voltage correction | amendment part of Example 1 of this invention. It is a characteristic view of the correction voltage generation part of Example 1 of this invention. It is a figure which shows the lamp characteristic of the discharge lamp of the comparative example 1 with respect to this invention, and the load characteristic of a lighting device. It is a characteristic view of the correction voltage generation part of the comparative example 1 with respect to this invention. It is another characteristic view of the correction voltage generation part of the comparative example 1 with respect to this invention. It is a block diagram which shows the internal structure of the detection voltage correction | amendment part of Example 2 of this invention. It is a block diagram which shows the other example of the internal structure of the detection voltage correction | amendment part of Example 2 of this invention. It is a block diagram which shows the whole structure of Example 3 of this invention. It is a block diagram which shows the internal structure of the threshold voltage correction | amendment part of Example 3 of this invention. It is a block diagram which shows the other example of the internal structure of the threshold voltage correction | amendment part of Example 3 of this invention. It is a block diagram which shows the whole structure of Example 4 of this invention. It is a block diagram which shows the internal structure of the threshold voltage correction | amendment part of Example 4 of this invention. FIG. 20 is a characteristic diagram showing the threshold voltage on the upper limit side after correction by the threshold voltage correction unit in FIG. 19. FIG. 20 is a characteristic diagram illustrating a lower limit side threshold voltage after correction by the threshold voltage correction unit of FIG. 19. It is a block diagram which shows the other example of the internal structure of the threshold voltage correction | amendment part of Example 4 of this invention. FIG. 23 is a characteristic diagram showing the threshold voltage on the upper limit side after correction by the threshold voltage correction unit in FIG. 22. It is a characteristic view which shows the threshold voltage of the lower limit side after correction | amendment by the threshold voltage correction | amendment part of FIG. It is a figure which shows the lamp characteristic of the discharge lamp of the comparative example 3 with respect to this invention, and the load characteristic of a lighting device. It is a figure which shows the lamp characteristic of the discharge lamp of Example 5 of this invention, and the load characteristic of a lighting device. It is a figure which shows the relationship between the lamp voltage change and ambient temperature in Example 5 of this invention. It is a block diagram which shows the whole structure of Example 5 of this invention. It is a block diagram which shows the internal structure of the detection voltage correction | amendment part of Example 5 of this invention. It is a figure which shows the relationship between the correction voltage and ambient temperature in Example 5 of this invention. It is a circuit diagram which shows the whole structure of Example 6 of this invention. It is a frequency characteristic figure of the resonant circuit of Example 6 of this invention. It is operation | movement explanatory drawing of each mode of the preheating of the Example 6 of this invention, starting, and lighting. It is a circuit diagram which shows the whole structure of the comparative example 4 with respect to this invention. It is operation | movement explanatory drawing of each mode of the preheating of the comparative example 4 with respect to this invention, starting, and lighting. It is a perspective view which shows the external appearance of the straight tube | pipe type illuminating device of Example 7 of this invention. It is a disassembled perspective view which shows the external appearance of the round tube type illuminating device of Example 7 of this invention. It is a circuit diagram of the prior art example 1 disclosed in Patent Document 1. FIG. 10 is a circuit diagram of Conventional Example 2 disclosed in Patent Document 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AC / DC conversion part 2 Inverter part 3 Load part 4 Control part 5 Dimming signal processing part 6 Load state detection part

Claims (8)

An AC / DC converter that converts an AC voltage into a predetermined DC voltage; an inverter that converts the output of the AC / DC converter into a high frequency and supplies high frequency power to a load unit including a resonance circuit unit and a discharge lamp; A control unit for controlling power supplied from the inverter unit to the load unit, a dimming signal processing unit for receiving a dimming signal from the outside and supplying a dimming signal to the control unit, and a DC voltage applied to the discharge lamp at the end of its life A load state detection unit that detects that the component is superimposed and generates a detection output to the control unit when the DC voltage component exceeds a predetermined level, and the control unit causes the inverter unit and the AC / DC conversion by the detection output. A dimming discharge lamp lighting device having a function of suppressing or stopping the output of either or both of the units, and as means for controlling the power from the inverter unit to the load unit, the operating frequency of the inverter unit The load state detection unit has means for correcting the detection voltage according to the dimming state, and is corrected to be the largest or smallest near the no-load resonance frequency of the load unit, A dimming discharge lamp lighting device characterized in that the end-of-life detection sensitivity is substantially constant regardless of the dimming state. An AC / DC converter that converts an AC voltage into a predetermined DC voltage; an inverter that converts the output of the AC / DC converter into a high frequency and supplies high frequency power to a load unit including a resonance circuit unit and a discharge lamp; A control unit for controlling power supplied from the inverter unit to the load unit, a dimming signal processing unit for receiving a dimming signal from the outside and supplying a dimming signal to the control unit, and a DC voltage applied to the discharge lamp at the end of its life A load state detection unit that detects that the component is superimposed and generates a detection output to the control unit when the DC voltage component exceeds a predetermined level, and the control unit causes the inverter unit and the AC / DC conversion by the detection output. A dimming discharge lamp lighting device having a function of suppressing or stopping the output of one or both of the inverter units, and a switching element of the inverter unit as means for controlling power from the inverter unit to the load unit The load state detection unit has means for correcting the detection voltage according to the dimming state, and a DC voltage component generated by dimming a normal load. The dimming discharge lamp lighting device is characterized in that the detection sensitivity is made substantially constant regardless of the dimming state by correcting the above. An AC / DC converter that converts an AC voltage into a predetermined DC voltage; an inverter that converts the output of the AC / DC converter into a high frequency and supplies high frequency power to a load unit including a resonance circuit unit and a discharge lamp; A control unit for controlling power supplied from the inverter unit to the load unit, a dimming signal processing unit for receiving a dimming signal from the outside and supplying a dimming signal to the control unit, and a DC voltage applied to the discharge lamp at the end of its life A load state detection unit that detects that the component is superimposed and generates a detection output to the control unit when the DC voltage component exceeds a predetermined level, and the control unit causes the inverter unit and the AC / DC conversion by the detection output. This is a dimming discharge lamp lighting device having a function of suppressing or stopping the output of either or both of the parts, and the inverter operating frequency is changed as means for controlling the power from the inverter part to the load part. The load state detection unit has means for correcting the threshold voltage according to the dimming state, and corrects the load voltage to be the largest or smallest near the no-load resonance frequency of the load unit. Regardless of the above, the dimming discharge lamp lighting device is characterized in that the end-of-life detection sensitivity is substantially constant. An AC / DC converter that converts an AC voltage into a predetermined DC voltage; an inverter that converts the output of the AC / DC converter into a high frequency and supplies high frequency power to a load unit including a resonance circuit unit and a discharge lamp; A control unit for controlling power supplied from the inverter unit to the load unit, a dimming signal processing unit for receiving a dimming signal from the outside and supplying a dimming signal to the control unit, and a DC voltage applied to the discharge lamp at the end of its life A load state detection unit that detects that the component is superimposed and generates a detection output to the control unit when the DC voltage component exceeds a predetermined level, and the control unit causes the inverter unit and the AC / DC conversion by the detection output. A dimming discharge lamp lighting device having a function of suppressing or stopping the output of one or both of the inverter units, and a switching element of the inverter unit as means for controlling power from the inverter unit to the load unit The load state detection unit has means for correcting a threshold voltage according to the dimming state, and a DC voltage component generated by dimming a normal load. The dimming discharge lamp lighting device is characterized in that the detection sensitivity is made substantially constant regardless of the dimming state by correcting the above. The dimming discharge lamp lighting device according to any one of claims 1 to 4 , further comprising means for correcting a detection voltage or a threshold voltage of the load state detection unit in consideration of a temperature characteristic of the discharge lamp. . An AC / DC converter that converts an AC voltage into a predetermined DC voltage; an inverter that converts the output of the AC / DC converter into a high frequency and supplies high frequency power to a load unit including a resonance circuit unit and a discharge lamp; A control unit for controlling power supplied from the inverter unit to the load unit, a dimming signal processing unit for receiving a dimming signal from the outside and supplying a dimming signal to the control unit, and a DC voltage applied to the discharge lamp at the end of its life A load state detection unit that detects that the component is superimposed and generates a detection output to the control unit when the DC voltage component exceeds a predetermined level, and the control unit causes the inverter unit and the AC / DC conversion by the detection output. This is a dimming discharge lamp lighting device having a function of suppressing or stopping the output of either or both of the units, and at least starting the discharge lamp by changing the inverter operating frequency. Te, the load status detecting unit, wherein the dimming the discharge lamp lighting device that detects a DC voltage component is superimposed to the discharge lamp in the transition state to the lighting including startup. 7. The dimming discharge lamp lighting device according to claim 6, wherein a human sensor or a brightness sensor is mounted, and the discharge lamp lighting device for dimming is used in a lighting fixture that is relatively frequently turned on and off . A lighting device comprising the dimming discharge lamp lighting device according to any one of claims 1 to 7 , and a fixture main body provided with the dimming discharge lamp lighting device.

Images