JP2007213871A - Discharge lamp lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device, capable of correcting, even with dispersion of characteristic values of part of a discharge load circuit, the dispersion without adding an adjustment part. <P>SOLUTION: The discharge lamp lighting device 1000 comprises an inverter circuit 3000 driven by a drive signal and supplying high frequency power to a discharge lamp 110; a drive frequency reference instruction value storage part 315 storing a reference instruction value, a value corresponding to a drive frequency of the inverter circuit 300; a nonvolatile memory 400a storing a correction value for correcting the reference instruction value; an inverter control circuit 310a calculating the driving frequency of the inverter circuit 300 based on the reference instruction value and the correction value, and generating and outputting a control signal corresponding to the calculated drive frequency; and an inverter driving circuit 320 generating a drive signal for driving the inverter circuit 300 from the control signal outputted by the inverter control circuit 310a and outputting the generated drive signal to the inverter circuit 300. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a discharge lamp lighting device for lighting a discharge lamp by converting a DC power source into a high frequency power source, and more particularly to a discharge lamp lighting device having a function of adjusting variation of components of a discharge lamp load circuit. is there.

  Japanese Patent Application Laid-Open No. 5-190291 (Patent Document 1) states that “in a discharge lamp lighting device that performs dimming of the discharge lamp by controlling the timing of current supplied to the discharge lamp by on / off control of a switching element” Oscillating means having the above oscillating frequency, frequency converting means for converting and outputting the oscillating frequency of the oscillating means into a plurality of frequencies, frequency control means for controlling the conversion frequency of the frequency oscillating means, and the conversion frequency of the frequency converting means And a discharge lamp lighting device comprising output means for controlling on / off of the switching element.

  A circuit diagram of the embodiment of Patent Document 1 is shown in FIG. 1 of Patent Document 1 (not attached to the present application). Also, a circuit portion corresponding to the control circuit 40 of FIG. 1 of Patent Document 1 is shown in FIG. 8 of this Patent Document 1 (not attached to the present application). Further, the relationship between “S1 to S4 output” in FIG. 8 of this Patent Document 1 and the conversion frequency is shown in Table 1 of the Patent Document 1 (not attached to the present application). That is, Table 1 shows the correspondence between the 16 combinations of S1 to S4 and the conversion frequency.

  Further, the 16 combinations are selected by the selection switch group 42 of FIG. For example, it is possible to reduce the discharge current of the discharge lamp 3 when driven at the conversion frequency of 55.6 kHz in stage 10 than when driven at the conversion frequency of 48.8 kHz in stage 5. That is, if the selection switch group 42 selects a combination of S1 to S4 and selects a conversion frequency, the discharge lamp 3 can be dimmed.

  However, the components constituting the discharge lamp load circuit such as the choke coil 4 and the capacitor 8 have variations in characteristics. Even if it is driven at the conversion frequency of 48.8 kHz in stage 5, there is a problem that the same discharge current cannot be obtained if the characteristics of the components of the discharge lamp load are not the same. That is, it is possible to control the relative change in which the discharge current of the discharge lamp decreases and increases if the conversion frequency is increased or decreased, but the discharge current of the discharge lamp also varies due to the characteristic variation of the components of the discharge lamp load circuit. There is a problem.

Therefore, for example, in the case of an application in which the light output of a large number of discharge lamps on the same floor is approximately the same and is corrected in accordance with the change over time of the light output of the discharge lamp, it cannot be practically handled. There is.
JP-A-5-190291

  A first object of the present invention is to provide a plurality of release signals in the case of command values (corresponding to S1 to S4 selected by the selection switch group of the conventional example) of the same drive frequency (corresponding to the conversion frequency of the conventional example). It is an object of the present invention to provide a discharge lamp lighting device that can make the light output of the lamp lighting device substantially the same.

  A second object of the present invention is to provide a discharge lamp lighting device that corrects the light output of a discharge lamp in response to a change with time.

The discharge lamp lighting device of the present invention is
In a discharge lamp lighting device for lighting a discharge lamp,
An inverter circuit that supplies high-frequency power corresponding to the driving frequency to the discharge lamp by driving at a predetermined driving frequency according to the drive signal;
A drive frequency corresponding value storage unit that stores a drive frequency corresponding value that is a value corresponding to the drive frequency of the inverter circuit;
A correction value storage unit that stores a correction value for correcting the drive frequency correspondence value stored in the drive frequency correspondence value storage unit;
The drive frequency of the inverter circuit is calculated based on the drive frequency corresponding value stored in the drive frequency corresponding value storage unit and the correction value stored in the correction value storage unit, and a control signal corresponding to the calculated drive frequency is generated. A control signal output unit for outputting
A drive signal for driving the inverter circuit from the control signal output by the control signal output unit; and an inverter drive circuit for outputting the generated drive signal to the inverter circuit.

The discharge lamp lighting device further includes:
A clock oscillation circuit that oscillates a clock signal of a predetermined frequency is provided.
The control signal output unit is
A frequency obtained by dividing the frequency of the clock signal oscillated by the clock oscillation circuit by the sum of the drive frequency corresponding value stored in the drive frequency corresponding value storage unit and the correction value stored in the correction value storage unit. The value is a drive frequency of the inverter circuit.

The drive frequency corresponding value storage unit is
A drive frequency corresponding value corresponding to a reference drive frequency predetermined as a reference among drive frequencies of the inverter circuit is stored as a reference command value.

The discharge lamp lighting device of the present invention is
In a discharge lamp lighting device for lighting a discharge lamp,
An inverter circuit that supplies high-frequency power corresponding to the driving frequency to the discharge lamp by driving at a predetermined driving frequency according to the drive signal;
A cumulative lighting time recording unit that records the lighting time of the discharge lamp as a cumulative lighting time;
A drive frequency corresponding value storage unit for storing a plurality of drive frequency corresponding values corresponding to the drive frequency of the inverter circuit and any one of which is determined from the cumulative lighting time recorded in the cumulative lighting time recording unit;
By selecting a predetermined driving frequency corresponding value as a selection value from among a plurality of driving frequency corresponding values stored in the driving frequency corresponding value storage unit by referring to the cumulative lighting time recorded in the cumulative lighting time recording unit, A control signal output unit that calculates a drive frequency of the inverter circuit based on the selected selection value, generates and outputs a control signal corresponding to the calculated drive frequency, and
A drive signal for driving the inverter circuit from the control signal output by the control signal output unit; and an inverter drive circuit for outputting the generated drive signal to the inverter circuit.

The discharge lamp lighting device further includes:
A clock oscillation circuit that oscillates a clock signal of a predetermined frequency is provided.
The control signal output unit is
The frequency of the clock signal oscillated by the clock oscillation circuit is divided by a selected value, and the value obtained by the division is used as the drive frequency of the inverter circuit.

The discharge lamp lighting device further includes:
A correction value storage unit that stores a correction value for correcting at least one of the plurality of drive frequency corresponding values stored in the drive frequency corresponding value storage unit;
The control signal output unit is
If the correction value stored in the correction value storage unit exists in the drive frequency corresponding value selected as the selection value, the drive frequency of the inverter circuit is calculated based on the selection value and the correction value for correcting the selection value. It is characterized by doing.

The discharge lamp lighting device further includes:
A clock oscillation circuit that oscillates a clock signal of a predetermined frequency is provided.
The control signal output unit is
When there is a correction value stored in the correction value storage unit in the drive frequency corresponding value selected as the selection value, the frequency of the clock signal oscillated by the clock oscillation circuit is selected and the correction value for correcting the selection value. And the value obtained by the division is used as the drive frequency of the inverter circuit.

The drive frequency corresponding value storage unit is
A plurality of drive frequency corresponding values respectively corresponding to a plurality of different reference drive frequencies that are determined in advance as a reference among the drive frequencies of the inverter circuit are stored as reference command values.

  According to the present invention, it is possible to provide a discharge lamp lighting device capable of correcting a variation without adding an adjustment component even when the characteristic value of the component of the discharge lamp load circuit varies. In addition, according to the present invention, it is possible to provide a discharge lamp lighting device capable of correcting the light output of the discharge lamp corresponding to a change with time.

Embodiment 1 FIG.
The first embodiment will be described with reference to FIGS.

  The discharge lamp lighting device 1000 according to the first embodiment stores a value (correction value to be described later) corresponding to the variation in the components of the discharge lamp lighting circuit to which the discharge lamp is mounted in the nonvolatile memory, and is caused by the variation in the components. The structure which correct | amends the dispersion | variation in the discharge lamp lighting current to perform is provided. Note that the variation in the components of the discharge lamp lighting circuit is an example, and the value stored in the volatile memory may be, for example, a value corresponding to the variation in the voltage boosted by the boost chopper circuit.

  FIG. 1 is a circuit diagram showing a configuration of a discharge lamp lighting device 1000 according to the first embodiment. The configuration of the discharge lamp lighting device 1000 will be described with reference to FIG.

As shown in FIG. 1, the discharge lamp lighting device 1000 includes:
(1) Diode bridge 20,
(2) Boost chopper circuit 200,
(3) Boost chopper control circuit 210,
(4) Inverter circuit 300,
(5) Inverter drive circuit 320,
(6) Inverter control circuit 310a,
(7) Non-volatile memory 400a,
(8) Discharge lamp load circuit 330 on which the discharge lamp is mounted
Is provided.

(DC power supply)
The diode bridge 20 supplies a direct current power by full-wave rectifying the alternating current power supply 10 such as a commercial power supply. The output voltage of the diode bridge 20 as a DC power supply is boosted and smoothed by the boost chopper circuit 200.

(Boost chopper circuit 200, boost chopper control circuit 210)
The step-up chopper circuit 200 is controlled by a step-up chopper control circuit 210. The control power supply of the boost chopper control circuit 210 is not shown. In the step-up chopper circuit 200, the choke coil 30 is connected between the positive output of the diode bridge 20 (DC power supply) and the anode of the diode 40. The cathode side of the diode 40 is connected to the negative electrode side of the diode bridge 20 (DC power supply) via the capacitor 60. A switching element 50 made of a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) is connected between the anode of the diode 40 and the negative side of the diode bridge 20 (DC power supply). A step-up chopper control circuit 210 is connected to the control terminal of the switching element 50 (the gate of the switching element 50 which is a MOSFET). The output of the boost chopper circuit 200 is connected to the inverter circuit 300.

(Inverter circuit 300)
The inverter circuit 300 includes switching elements 70 and 80. The switching elements 70 and 80 of the inverter circuit 300 are driven by a drive signal generated and output by an inverter drive circuit 320 that receives an output control signal (hereinafter also referred to as a control signal) from the inverter control circuit 310a. The inverter circuit 300 supplies high-frequency power corresponding to the driving frequency to the discharge lamp 110 by driving at a predetermined driving frequency according to the drive signal output from the inverter driving circuit 320. The control power supplies for the inverter control circuit 310a and the inverter drive circuit 320 are not shown. In the inverter circuit 300, a switching element 70 and a switching element 80 made of MOSFETs are connected in series and connected to the output of the boost chopper circuit 200. A discharge lamp load circuit 330 is connected between a connection point between the switching element 70 and the switching element 80 and the negative side of the step-up chopper circuit 200. The diodes built in antiparallel between the drain and source of the switching element 70 and the switching element 80 are not shown.

(Discharge lamp load circuit 330)
The discharge lamp load circuit 330 has a configuration in which a coupling capacitor 90, a choke coil 100, and a discharge lamp 110 are connected in series, and a capacitor 120 is connected in parallel to the discharge lamp 110. The other end of the coupling capacitor 90 is connected to a connection point between the switching element 70 and the switching element 80, and the other end of the discharge lamp 110 is connected to the negative electrode side of the boost chopper circuit 200.

(Inverter drive circuit 320)
The inverter drive circuit 320 drives the gates of the switching element 70 and the switching element 80. That is, the inverter drive circuit 320 generates a drive signal from the control signal output from the inverter control circuit 310a, outputs the generated drive signal to the inverter circuit 300, and drives the switching element 70 and the switching element 80.

(Nonvolatile memory 400a)
The nonvolatile memory 400a (an example of a correction value storage unit) stores a correction value of the drive frequency reference command value. The “drive frequency reference command value” and “correction value” will be described in detail later.

(Inverter control circuit 310a)
The inverter control circuit 310a will be described. The inverter control circuit 310a is realized by, for example, a microcomputer (hereinafter referred to as a microcomputer). As shown in FIG. 1, the inverter control circuit 310 a includes a drive frequency reference command value storage unit 315, a correction value temporary storage unit 313, a clock oscillation circuit 312, a drive frequency generation output circuit 311, and an operation mode switching circuit 314.

(1) The drive frequency reference command value storage unit 315 (an example of a drive frequency corresponding value storage unit) stores a drive frequency reference command value (an example of a drive frequency corresponding value) and a program, which will be described later. The “drive frequency reference command value” may be simply referred to as “reference command value”. The drive frequency reference command value storage unit 315 is realized by, for example, a ROM (Read Only Memory).
(2) The correction value temporary storage unit 313 reads the correction value from the outside of the inverter control circuit 310a and transfers the read correction value to the nonvolatile memory 400a in the case of the adjustment mode described later. In the normal operation mode, the correction value stored in the nonvolatile memory 400a is read and transferred to the drive frequency generation output circuit 311. The “correction value” of the drive frequency reference command value will be described later. The correction value temporary storage unit 313 is realized by, for example, a RAM (Random Access Memory) incorporated in a microcomputer.
(3) The clock oscillation circuit 312 is a circuit that oscillates a reference clock.
(4) The drive frequency generation output circuit 311 (an example of the control signal output unit) is transferred from the non-volatile memory 400a to the correction value temporary storage unit 313 and the drive frequency reference command value stored in the drive frequency reference command value storage unit 315. The drive frequency of the inverter circuit 300 is calculated based on the corrected value, and a control signal corresponding to the calculated drive frequency is generated and output.
(5) The operation mode switching circuit 314 inputs “correction value input 500 for the adjustment frequency driving frequency reference command value” and “normal operation / adjustment mode switching input 600”. These will be described later.

(Drive frequency reference command value: n _STD )
The inverter control circuit 310a will be described in more detail. In the inverter control circuit 310a, the clock oscillation circuit 312 is an oscillation circuit that oscillates the reference clock of the microcomputer as described above, and the oscillator is not shown. The drive frequency reference command value storage unit 315 stores a “reference command value” of the drive frequency f _STD (reference drive frequency) that serves as a reference for the inverter circuit 300. The “reference command value” in this embodiment is the drive frequency of the inverter circuit 300 given when the characteristic value of each component constituting the discharge lamp load circuit 330 is at the center value of variation (correction value nc = 0). It is a numerical value corresponding to f _INV (hereinafter referred to as inverter drive frequency or drive frequency), and has the following relationship (Equation 1).
Drive frequency used as a reference for the inverter circuit 300: f _STD ,
Reference clock frequency of microcomputer (clock oscillation circuit 312): f _MIC ,
Drive frequency reference command value: n _STD
As
f _STD = f _MIC ÷ n _STD (Formula 1)
It is.

For example,
Microcontroller reference clock frequency f _MIC = 6.0000 MHz,
Drive frequency reference command value n _STD = 141
And
In this case, the reference drive frequency f _{STD which} is the reference of the inverter circuit 300 is
From (Equation 1), f _STD = f _MIC ÷ n _STD = 6.00 MHz ÷ 141 = 42.553 kHz
It becomes.

(Correction value: n _c )
Correction value _{n c} of the drive frequency reference command value _{n STD} is a value for correcting the driving frequency reference command value _{n STD.} Correction value n _c is the variation of components constituting the discharge lamp load circuit 330 is a numerical value given as a positive or negative value.

(Calculation command value: N _CAL )
The sum of the correction value _{n c} and the drive frequency reference command value _{n STD} will be referred to as a calculation command value _{N CAL.}
That is,
N _CAL = n _STD + n _c
far.

(Control signal generation)
Drive frequency generation output circuit 311, when the correction value n _c is present, the operation command value N _CAL calculates calculates the inverter driving frequency f _INV indicated by the following equation (2), was calculated drive A control signal corresponding to the frequency f _INV is generated and output to the inverter drive circuit 320.
That is,
Inverter driving frequency _{f INV = f MIC ÷ (n} STD + n c) = f MIC ÷ N CAL ( Equation 2)

For example,
Microcomputer reference clock frequency f _MIC = 6.000 MHz
Drive frequency reference command value n _STD = 141,
Correction value n _c = 4 for the drive frequency reference command value
And
In this case, the inverter drive frequency f _INV calculated by the drive frequency generation output circuit 311 is
f _INV = 141 MHz ÷ 145 = 41.379 kHz
It becomes.

For example,
Microcontroller reference clock frequency f _MIC = 6.0000 MHz,
Drive frequency reference command value = 141,
Correction value n _c = −4 for the drive frequency reference command value
And
In this case, the inverter drive frequency f _INV calculated by the drive frequency generation output circuit 311 is
f _INV = 6.0000 MHz ÷ 137 = 43.796 kHz
It becomes.

Next, correction value writing will be described. The “normal operation / adjustment mode switching input 600” shown in FIG. 1 is a signal of “H” or “L” level. The mode of the operation mode switching circuit 314 is switched according to “H” or “L” of the “normal operation / adjustment mode switching input 600”.
(1) When “normal operation / adjustment mode switching input 600” is “adjustment mode”, the operation mode switching circuit 314 of the inverter control circuit 310a is switched to “adjustment mode”, and “adjustment mode drive frequency reference command value” Ru correction value input 500 "is fetched (i.e. the correction value n _c is input). Captured correction value n _c is stored in the correction value temporary storage section 313, is further transferred to the nonvolatile memory 400a, it is stored by the nonvolatile memory 400a.
(2) when switching to the "normal operation" by the "normal operation / adjustment mode switching input 600", the correction value n _c stored in the nonvolatile memory 400a is transferred to the correction value temporary storage unit 313, the drive frequency The generation output circuit 311 uses this to perform the arithmetic processing of (Expression 2).

Figure 2 is a graph showing the relationship between the discharge current _{I L} of the voltage Vc120 and the discharge lamp 110 of the capacitor 120 of the inverter driving frequency _{f INV} and the discharge lamp load circuit 330. The horizontal axis indicates the drive frequency of the inverter circuit 300. The vertical axis indicates the current _{I L} flowing through the voltage VC120 or discharge lamp 110, the capacitor 120.
Also,
(1) Graph 1 (dashed line), the capacitance _{C 120} of the capacitor 120, the value of which is the product of the inductor _{L 100} of choke coil 100 _{"C 120} × _{L 100"} is, the discharge lamp 110 in the case of the variation maximum The characteristic of the voltage VC120 of the capacitor 120 at the time of preheating is shown.
(2) Graph 2 (solid line) shows the characteristics of the voltage VC120 of the capacitor 120 when the discharge lamp 110 is preheated when the value of “C ₁₂₀ × L ₁₀₀ ” is a variation type (typical).
(3) Graph 3 (dotted line) shows the characteristics of the voltage VC120 of the capacitor 120 during preheating of the discharge lamp 110 when the value of “C ₁₂₀ × L ₁₀₀ ” is the smallest in variation.
Also,
(4) Graph 11 shows the characteristic of the discharge current _{I L} corresponding to the graph 1 at the time of lighting of the discharge lamp 110.
(5) The graph 12 shows the characteristics of the discharge current _{I L} corresponding to the graph 2 during lighting of the discharge lamp 110.
(6) The graph 13 shows the characteristics of the discharge current _{I L} corresponding to the graph 3 at the time of lighting of the discharge lamp 110.

(Graph 2)
In FIG.
Graph 2 shows a case where the characteristic values of the components of the discharge lamp load circuit 330 are at the center value of the variation. Graph 2 is a characteristic diagram showing the voltage Vc120 generated in the capacitor 120 when the discharge lamp 110 is not discharged. The natural vibration frequency f0typ, which is the frequency that brings about the maximum value of the voltage Vc120, is expressed by the following (Expression 3) under the condition of the following (Expression 4).
That is

C ₉₀ >> C ₁₂₀ (Formula 4)
However,
L ₁₀₀ : inductance of the choke coil 100,
C ₉₀ : capacitance of the capacitor 90,
C ₁₂₀ is the capacitance of the capacitor 120.

(Graph 1)
Similarly, the graph 1 is a characteristic diagram similar to the graph 2 in the case where the product of L ₁₀₀ and C ₁₂₀ is the maximum (variation max). (Natural vibration frequency is minimum: f0min)

(Graph 3)
Similarly, the graph 3 is a characteristic diagram similar to the graph 2 in the case where the product of L ₁₀₀ and C ₁₂₀ is the minimum (variation min). (The natural vibration frequency is maximum: f0max)

(Graph 12)
Further, the graph _12, in the case the product of _{L 100} and _{C 120} is the center value of the fluctuation of (typ), a characteristic view showing discharge currents _{I L} in the case where the discharge lamp 110 is lighted, corresponding to the graph 2. Graph 12 and the one-dot chain line shows the _{I L} at 100% output of the "100% power at _I L 18""intersection 12a 'is driven when lit output power of the discharge lamp 110 is 100% of the specified value It shows the discharge current _{I L} corresponding to the frequency f21.

(Graph 11)
Similarly, the graph 11 is a characteristic diagram corresponding to the graph 12 when the product of L ₁₀₀ and C ₁₂₀ is maximum (variation max) (the natural vibration frequency is minimum: f0 min). In addition, the “intersection 11a” between the graph 11 and the alternate long and short dash line “100% output I _L 18” indicates the discharge current corresponding to the drive frequency f11 when the output power when the discharge lamp 110 is turned on is 100% of the specification value. _IL is shown.

(Graph 13)
Similarly, the graph 13 is a characteristic diagram corresponding to the graph 12 when the product of L ₁₀₀ and C ₁₂₀ is minimum (variation min) (the natural vibration frequency is maximum: f0max). Further, the “intersection 13a” between the graph 13 and the alternate long and short dash line “100% output I _L 18” indicates a discharge current corresponding to the drive frequency f31 when the output power when the discharge lamp 110 is turned on is 100% of the specification value. _IL is shown.

Next, FIG. 3 will be described. FIG. 3 is a table for explaining the principle of the generation method for generating the inverter drive frequency _fINV .

(Line No. 1)
Line number 1 indicates the natural vibration frequency f 0 of the discharge lamp load circuit 330. The line number f0min and the like are those shown in FIG.

(Line number 2)
Row number 2 is the drive frequency f _INV of the inverter circuit 300.

(Line number 3)
Line number 3 is the operation command value N _CAL . Calculating the command value _{N CAL} row number 3, as described above, by the drive frequency generation output circuit 311, it is calculated as the sum of the _{n c} of the _{n STD} and line number 4 of the line number 5. The inverter drive frequency f _INV for driving the inverter circuit 300 is obtained by dividing the microcomputer clock frequency f _MIC by the drive frequency command value (calculation command value N _CAL ) of line number 3.
That is,
f _INV = f _MIC ÷ N _CAL
It is.

(Line No. 4)
Further, the correction value n _C of line number 4 is a numerical value stored in the correction value temporary storage unit 313 of the microcomputer (inverter control unit 310a) from the nonvolatile memory 400a.

(Line No. 5)
In FIG. 3, the drive frequency reference command value n _STD that is the value of line number 5 is stored in the drive frequency reference command value storage unit 315 of FIG. As described above, the drive frequency reference command value storage unit 315 is, for example, a ROM that is a kind of nonvolatile memory. The drive frequency reference command value n _STD is stored in the ROM in advance.

The correction value n _C of the drive frequency reference command value of line number 4 is obtained in the process of adjusting the output power in the manufacturing process of the discharge lamp lighting device 100 as described later, and is recorded in the nonvolatile memory 400a.

  FIG. 4 is a diagram corresponding to FIG. 3 and shows test data when an actual circuit is designed. Line numbers 1 to 5 in FIG. 4 correspond to line numbers 1 to 5 in FIG. Line numbers 6 to 7 in FIG. 4 show test data of discharge lamp power and discharge lamp current. Line numbers 8 to 11 indicate test conditions (design conditions) of the inverter circuit 300.

  The operation of the discharge lamp lighting device 1000 according to the first embodiment will be described with reference to FIGS.

  First, the case where the natural vibration frequency of the discharge lamp load circuit 330 is f0typ, which is the center value, will be described. In FIG. 2, the graph 2 and the graph 12 correspond to each other, and in FIG. 3 and FIG. 4, the column of f0typ corresponds to the graph.

  In FIG. 1, when the AC power supply 10 is turned on, the control power supply of each circuit, which saves the illustration, starts up, and the microcomputer program of the inverter control circuit 310a also starts operation. A CPU (Central Processing Unit) of the drive frequency generation output circuit 311 reads the program. The microcomputer program of the inverter control circuit 310a is stored in the drive frequency reference command value storage unit 315, which is a ROM, for example. Alternatively, it is stored in the non-volatile memory 400a.

Thereafter, the discharge lamp 110 is turned on through a preheating operation of the filament of the discharge lamp 110 and a start voltage application program, which saves explanation. Inverter driving frequency f21 at this time is generated by the principle described in FIG. 3, the discharge lamp current I _L shown in "intersection 12a 'flows.

Here, it is assumed that driving is performed at the same inverter driving frequency f21 in the case of the characteristics of the graph 11 and the characteristics of the graph 13 as well. In that case, the variation range of the discharge lamp current is a value in the range of [Delta] I _L in FIG.

Therefore, by providing an appropriate correction value n _c corresponding to the product of the inductance L ₁₀₀ and capacitance C ₁₂₀ of the discharge lamp load circuit 330, in the case of a low natural frequency of the (Graph 1, Graph 11 Characteristics ), The inverter drive frequency is set to f11 lower than f21. Conversely, when the natural vibration frequency is large (characteristics of graphs 3 and 13), the inverter drive frequency is set higher than f21 as f31. By doing so, it is possible, as shown in FIG. 2, to reduce variations in the discharge lamp current I _L due to a variation in part characteristics of the inverter circuit 300.

Next, how to determine the correction value n _C (the numerical value of line number 4 in FIGS. 3 and 4) of the drive frequency reference command value n _STD will be described.

  In FIG. 1, “normal operation / adjustment mode switching input 600” of the inverter control circuit 310a is set to “adjustment mode”. In this state, the discharge lamp 110 is turned on and the electric power of the discharge lamp 110 is measured.

The measured power of the discharge lamp 110 is compared with the discharge lamp power whose natural vibration frequency is the center value. If there is a difference as a result of the comparison, a positive or negative correction value from the “correction value input 500 of the adjustment frequency driving frequency reference command value” via the operation mode switching circuit 314 and the correction value temporary storage unit 313. to enter a n _C. Then, while executing the program in accordance with the principle described with reference to FIG. 3, the correction value input is increased or decreased so that the natural vibration frequency substantially matches the discharge lamp power when driven by the discharge lamp lighting device having the center value (correction value input). Increase or decrease by human power or automatic machine).

When the electric power of the discharge lamp 110 matches the electric power whose natural vibration frequency is the center, the “normal operation / adjustment mode switching input 600” is switched to the “normal mode” and the drive stored in the correction value temporary storage unit 313 is stored. The correction value n _C of the frequency reference command value n _STD is also recorded in the nonvolatile memory 400. After the adjustment, when the AC power supply 10 is turned off and the AC power supply 10 is turned on again, the correction value n _C even stored in the nonvolatile memory 400a is written in the correction value temporary storage unit 313 (RAM area). .

  Note that the input power is the sum of the power of the discharge lamp 110, the power of the control circuit, and the circuit loss, and the sum of the power of the control circuit and the power of the circuit loss does not vary greatly within the adjustment range of the correction value. Alternatively, the correction value may be obtained so that the input powers roughly match.

Further, test data of a specific design example will be described with reference to FIG.
(1) Line numbers 1 to 5 correspond to line numbers 1 to 5 in FIG.
(2) As shown in line number 9, the type name of the suitable discharge lamp is “FHF32EX-W (manufactured by MITSUBISHI / OSRAM)”.
(3) Line numbers 6 and 7 indicate the power and current of the discharge lamp 110.
(4) Line number 8 indicates the product of the characteristic values of the choke coil 100 and the capacitor 120.
(5) Line number 10 indicates the voltage of the capacitor 60.
(6) Line number 11 indicates the clock oscillation frequency of the clock oscillation circuit 312.
(7) line number 12, in the line number 7 shows a discharge lamp current _{I L} when driving the driving frequency at a driving frequency of the variation center 42.553KHz. The difference [Delta] I _L of the maximum value and the minimum value of the discharge lamp current I _L corresponds to [Delta] I _L shown in FIG.

As is clear from the results of FIG. 4, the variation in power when the discharge lamp 110 is turned on is substantially zero. That is, the discharge lamp power of line number 6 is 41.1 (W) in any case, and there is no variation. The row number 7 shows the discharge current I _L when calculating the driving frequency f _INV using the correction value n _C. As shown in line number 7, in the case of using the correction value n _C, the variation of the discharge current I _L has remained 5 (mA). On the other hand, the line number 12 is the case where the driving frequency is the same (42.553 kHz) in any of the characteristics of min, typ, and max. In this case, the variation of the discharge current I _L is 18 (mA), and ΔI _L = 36 (mA). Thus, when using the correction value n _C, which is considerably smaller variation in the discharge current I _L. Needless to say, the nonvolatile memory 400a may be provided inside the microcomputer (inside the inverter control circuit 310a).

3 and 4, the principle and actual test data for correcting the variation of components (mainly the resonance capacitor and the resonance coil) constituting the discharge lamp load circuit 330 have been described. Even in the case where the output voltage fluctuates due to variations in the components of the chopper circuit, an appropriate drive frequency reference command value n _STD correction value n _C is given to roughly illustrate the variation in power when the discharge lamp 110 is turned on. Can be zero.

  In addition, about the case of FIG. 3, FIG. 4, the operation | movement as a concrete discharge lamp lighting device is as follows. It is assumed that the discharge lamp lighting device 1000 corresponds to the case of “f0 min” in FIG.

(1) The drive frequency reference command value storage unit 315 stores a drive frequency reference command value n _STD that is a value corresponding to the drive frequency f _INV of the inverter circuit 300. As shown in FIG. 4, n _STD = 141
It is.
(2) non-volatile memory 400a, the drive frequency reference command value storage unit 315 stores a correction value _{n C} for correcting the driving frequency reference command value _{n STD} storing. The correction value n _C are stores "normal operation / adjustment mode switching input 600" as described above, the "correction value of the adjustment mode drive frequency reference command value input 500", the correction value n _C is in the non-volatile memory 400a Is done. Therefore, the nonvolatile memory 400a stores a correction value n _C that is a value for correcting the drive frequency reference command value n _STD in a nonvolatile manner.
In this case, n _C = “+ 4” as shown in FIG.
(3) The drive frequency generation output circuit 311 of the inverter control circuit 310a is based on n _STD = 141 stored in the drive frequency reference command value storage unit 315 and n _C = “+ 4” stored in the nonvolatile memory 400a. The drive frequency f _INV of the inverter circuit 300 is calculated, a control signal corresponding to the calculated f _INV is generated and output to the inverter drive circuit 320. As described above, the drive frequency generation output circuit 311 divides the frequency (6 MHz in FIG. 4) of the clock signal oscillated by the clock oscillation circuit 312 by the sum of n _STD = 141 and n _C = “+ 4”. The value obtained in this way is used as the drive frequency of the inverter circuit 300. That is, the drive frequency generation output circuit 311
6 MHz / (141 + 4) = 41.379 kHz
And a control signal corresponding to 41.379 kHz is generated and output to the inverter drive circuit 320.
(4) The inverter drive circuit 320 receives the control signal output from the drive frequency generation output circuit 311 and generates a drive signal for driving the inverter circuit 300 from the input control signal corresponding to 41.379 kHz. Of course, the generated drive signal is also a signal corresponding to the inverter drive frequency of 41.379 kHz. The inverter drive circuit 320 outputs the generated drive signal to the inverter circuit 300.
(5) The inverter circuit 300 is driven at a drive frequency of 41.379 kHz according to a drive signal corresponding to the inverter drive frequency of 41.379 kHz, thereby supplying the discharge lamp 110 with high-frequency power corresponding to this drive frequency. To do. Thereby, the output of the discharge lamp 110 can be adjusted easily and accurately.

  As described above, according to the discharge lamp lighting device 1000 of the first embodiment, even when there are variations in the characteristic values of the components of the discharge lamp load circuit 330, the variations are made by the microcomputer program without adding the adjustment components. Can be provided, and the variation in power when the discharge lamp 110 is turned on can be made substantially zero. That is, the light output between a plurality of lighting fixtures equipped with the present discharge lamp lighting device can be made substantially the same. Such a small and inexpensive discharge lamp lighting device can be provided.

  In the discharge lamp lighting device 1000 according to the first embodiment, the drive frequency generation output circuit 311 calculates the inverter drive frequency based on the correction value, and generates a control signal from the inverter drive frequency. Can be corrected. Therefore, variation in electric power of the discharge lamp during lighting can be suppressed.

  In the discharge lamp lighting device 1000 according to the first embodiment, the drive frequency generation output circuit 311 includes a clock oscillation circuit that oscillates a clock signal, and the frequency of the clock signal is divided by the sum of the reference command value and the correction value. Then, the value obtained by the division is set as the inverter driving frequency. Therefore, it is possible to easily cope with variations in the discharge lamp output by correcting only the correction value.

  The discharge lamp lighting device 1000 according to the first embodiment stores a reference command value corresponding to the reference drive frequency of the inverter circuit 300. For this reason, the light output of the some lighting fixtures which mount the discharge lamp lighting device 1000 can be made substantially the same.

Embodiment 2. FIG.
Next, the discharge lamp lighting device 2000 according to the second embodiment will be described with reference to FIGS. The discharge lamp lighting device 2000 according to the second embodiment stores variations in the components of the discharge lamp lighting circuit to which the discharge lamp is mounted in the nonvolatile memory in the same manner as the discharge lamp lighting device 1000 according to the first embodiment. A configuration that compensates for variations in the discharge lamp lighting current caused by variations, and further maintains a constant light output of the discharge lamp by changing the dimming rate of the discharge lamp according to the cumulative lighting time of the discharge lamp. Is provided.

  FIG. 5 is a circuit diagram showing a configuration of a discharge lamp lighting device 2000 according to the second embodiment.

  As in the first embodiment, the discharge lamp lighting device 2000 reduces the variation in the light output of the lighting fixture on which the present lighting device mounted due to the characteristic variation of the components of the discharge lamp load circuit 330 is reduced, and further uses the discharge lamp. Reduces the decrease in illuminance over time (cumulative lighting time). In FIG. 5, elements having the same or equivalent functions as those in FIG.

  The discharge lamp lighting device 2000 further includes a lighting time counter 2001 with respect to the discharge lamp lighting device 1000, and the nonvolatile memory 400b (an example of a cumulative lighting time recording unit) records the cumulative lighting time of the discharge lamp. The difference is that it has a “cumulative lighting time recording area 2002”. In contrast to the discharge lamp lighting device 1000, in the discharge lamp lighting device 2000, "reference symbol b" is used to denote the inverter control circuit 310b and the nonvolatile memory 400b.

  In the inverter control circuit 310b, the drive frequency generation output circuit 311 obtains a signal from the “end-of-life protection detection circuit” of the discharge lamp 110 (not shown), and only when the discharge lamp 110 is normally lit, the inverter drive circuit Assume that output is sent to 320.

The lighting time counter 2001 of the inverter control circuit 310b outputs a control signal to the inverter drive circuit 320 based on the clock oscillation frequency f _MIC of the clock oscillation circuit 312 and the presence / absence of the operation signal of the drive frequency generation output circuit 311b. The time when the discharge lamp 110 is normally lit, that is, the time when the discharge lamp 110 is normally lit, is accumulated and sent to the nonvolatile memory 400b. The nonvolatile memory 400b accumulates the lighting time of the discharge lamp 110 and records it in the cumulative lighting time recording area 2002 as the cumulative lighting time.

  At that time, the inverter control circuit 310b adds the current accumulated lighting time to the lighting time already accumulated in the nonvolatile memory 400b, and records it as a new accumulated lighting time at a predetermined timing in the nonvolatile memory 400b. To do. The predetermined timing is, for example, when the lighting time counter 2001 of the inverter control circuit 310b reaches 1 hour, or when the AC power supply 10 is shut off.

FIG. 6 is a characteristic diagram corresponding to FIG. Graph listed is the same as that in FIG. 2, the horizontal axis represents the driving frequency of the inverter circuit 300, the vertical axis is the discharge current I _L of the voltage and the discharge lamp 110 of the capacitor 12 of the discharge lamp load circuit 330 . Figure 6 is added to the characteristic diagram of FIG. 2, further discharge in the case where the output power of the discharge lamp 110 is about 70% (about 70% dimming) current _{I L} operating points 15 of the operating point 16, the operation point 17 It is a thing.

In FIG. 6, “operating point 16” corresponds to the inverter drive frequency f23 when the natural vibration frequency of the discharge lamp load circuit 330 is the center value of the variation and the output power of the discharge lamp 110 is about 70%. it is an operation point of the discharge current I _L.

Similarly, "operating point 15" is the variation in the natural frequency indicates an operating point of the drive frequency f13 and the discharge current I _L in the case of the minimum value.

"Operating point 17" is the variation of the natural frequency is indicative of the operating point of the drive frequency f33 and the discharge current I _L when the maximum value.

FIG. 7 is a table for explaining the principle of the driving frequency generation method corresponding to FIG. In FIG. 7, the value of line number 5 (drive frequency reference command value n _STD ) is a numerical value given by the program and is the same as in the case of FIG. When the electric power of the discharge lamp 110 is reduced from 100% of the total light, that is, when the luminous flux is reduced, the drive frequency reference command value n _STD is made smaller than that at the time of 100% of the total light. The value of the drive frequency reference command value n _STD is set in advance corresponding to the cumulative lighting time of the discharge lamp 110, and is selected and set by the CPU of the drive frequency generation output circuit 311 based on the program.

FIG. 8 is a graph showing an example of the relationship between the cumulative lighting time (horizontal axis) of the discharge lamp 110 and the dimming rate (vertical axis). For example, as shown in FIG. 8, the drive frequency reference command value n _STD is set by a program so that the initial value at which the cumulative lighting time is zero time is 70 dimming (30% dimming), and then cumulative The drive frequency reference command value n _STD is set to decrease by a program so that the dimming rate increases by 2% every time the lighting time increases by 1000 hours. That is, as the cumulative lighting time increases by 1000 hours, the dimming rate decreases as 30% → 28% → 26%. Then, when the cumulative lighting time has passed 15000 hours (t15 in FIG. 8), the dimming rate becomes 100% (0% dimming). In FIG. 8, 5000 hours is expressed as t5, 10,000 hours as t10, and the like. Also, for example, if the microcomputer program is set so that the 1% dimming rate increases every 0.5000 hours of cumulative lighting time, the change in the dimming rate with respect to the increase of the cumulative lighting time becomes smoother. can do. That is, since the decreasing increment in FIG. 8 is halved (the 1% attenuation rate decreases every 500 hours), the change in the dimming rate becomes smooth.

By reducing the drive frequency reference command value n _STD , the inverter drive frequency is increased and the electric power of the discharge lamp 110 is decreased. This is for the following reason.
Inverter drive frequency f _INV = f _MIC ÷ n _STD
And
When n _STD → small, f _INV → large.
When f _INV is increased, due to the discharge current _{I L} decreases as shown in the graph 11 to 13 of FIG.

Further, the description of FIG. 7 is continued. The line number 4 in FIG. 7 is the correction value n _C described in the first embodiment. As described in the first embodiment, the numerical values are transferred from the nonvolatile memory 400b and stored in the correction value temporary storage unit 313 (RAM). The value of the correction value n _C is determined by the characteristic variation of the components of the discharge lamp load circuit 330. The correction value n _C is normally set to the same value as when 100% of all light is output regardless of the cumulative lighting time of the discharge lamp 110. Further, as described in the first embodiment, the sum of the correction value n _C of line number 4 and the drive frequency reference command value n _{STD of} line number 5 is calculated as the numerical value of the operation command value N _CAL of line number 3. Is done.

The drive frequency f _INV of the inverter circuit 300 is obtained as a value obtained by dividing the clock frequency of the clock oscillation circuit 312 by the operation command value N _CAL of row number 3. This is the same as in the first embodiment.

The correction value n _C of line number 4 is obtained in the process of adjusting the output power of the discharge lamp 110 in the manufacturing process of the discharge lamp lighting device 2000 and the like by the same procedure as described in the first embodiment. Recorded in the memory 400b.

  FIG. 9A is a characteristic diagram showing the relationship between the cumulative lighting time and the luminous flux when the electric power during lighting of the discharge lamp 110 is constant. The horizontal axis indicates the cumulative lighting time, and the vertical axis indicates the luminous flux. As shown in FIG. 9A, the luminous flux of the discharge lamp 110 decreases as the cumulative lighting time elapses. In addition, as time passes, the amount of light also decreases due to dirt on the discharge lamp 110, dirt on the mounted lighting fixture, and the like.

FIG. 9B is a diagram showing that the electric power of the discharge lamp is increased as the cumulative lighting time elapses. The horizontal axis indicates the cumulative lighting time, and the vertical axis indicates the power of the discharge lamp. In order to prevent the light quantity of the discharge lamp 110 from decreasing with the cumulative lighting time, the power of the discharge lamp 110 is suppressed to less than 100% of the total light when the cumulative lighting time is short as shown in FIG. 9B. However, the electric power of the discharge lamp 110 is increased as the cumulative lighting time of the discharge lamp elapses (for example, 70%: 70% dimming). As a result of such control, as shown in FIG. 9C, the light output of the discharge lamp becomes substantially constant as the cumulative lighting time elapses. In this way, when the cumulative lighting time reaches the rated life of the discharge lamp, the drive frequency reference command value n _STD is given by the program so that the power is 100% of the total light.

That is, every time the predetermined cumulative lighting time increases (for example, every 500 hours) so that the electric power of the discharge lamp 110 with respect to the cumulative lighting time has the characteristics of FIG. The drive frequency reference command value n _STD is set by the microcomputer program so that the power of 1 is obtained. As a result, the light output of the discharge lamp 110 can be controlled so as to have the characteristics shown in FIG. 9C as the cumulative lighting time elapses. When the cumulative lighting time reaches the rated life of the discharge lamp or when the discharge lamp 110 becomes defective before the rated life, the replacement work with a new discharge lamp and the corresponding nonvolatile memory 400b The accumulated lighting time is cleared (RESET) to the initial value (not shown).

  That is, as shown in FIG. 9B, immediately after the discharge lamp 110 is new or replaced with a new one, for example, the dimming lighting of 70% of the discharge lamp power is performed, and the discharge lamp 110 gradually increases as the cumulative lighting time elapses. Control power to 100% of total light.

  The operation of the discharge lamp lighting device 2000 according to the second embodiment will be described with reference to FIGS.

First, the case where the natural vibration frequency of the discharge lamp load circuit 330 is f0typ, which is the center value of the variation, will be described. and a graph 2 and Graph 12 in FIG. 6 correspond to F0typ, 7, in the FIG. 10, "column of F0typ" in the natural vibration frequency _{f 0} is equivalent to this F0typ.

  When the AC power supply 10 is turned on in FIG. 5, the discharge lamp 110 is lit as described in the first embodiment.

(F0typ: 70% dimming)
Here, if the discharge lamp 110 is new or just replaced with a new one, as shown in FIG. 9B, for example, the power of the discharge lamp is 70% (70% dimming),
Drive frequency reference command value n _STD = n3 (line number 5 in FIG. 7)
Is given by the microcomputer program. The drive frequency f _{INV in} this case is f23 (FIG. 7, second row). Discharge current I _L shown by "operating point 16 'in FIG. 6 correspond to this f23 is flowing to the discharge lamp 110.

(F0type: 85% dimming)
Then, as the cumulative lighting time elapses, the discharge lamp power is increased from 70% dimming in an appropriate dimming step.
For example, in the case of 85% dimming,
Drive frequency reference command value n _STD = n2
As shown in FIG.

(F0typ: 100% dimming)
In addition, at 100% output of all light,
Drive frequency reference command value n _STD = n1
As shown in FIG. In this case, the discharge lamp current _IL is controlled to be the “operating point 12a” in FIG. As a result, the light output of the discharge lamp 110 can be controlled to be substantially constant with the lapse of the cumulative lighting time as shown in FIG.

(F0max: 70% dimming)
Similarly, when the natural vibration frequency of the discharge lamp load circuit 330 is the maximum (f0max), with 70% dimming, as shown in FIG.
Drive frequency reference command value n _STD = n3,
Correction value n _C = −nc1 (nc1> 0) of the drive frequency reference command value,
Drive frequency f _INV = f33
It becomes.
In FIG. 6, the discharge lamp current _IL is “operating point 17”.

(F0max: 85% dimming)
In 85% dimming,
Drive frequency reference command value n _STD = n2,
Correction value n _C = −nc1,
Drive frequency f _INV = f32
It becomes.

(F0max: 100% light control)
At 100% output of all light,
Drive frequency reference command value n _STD = n1,
Correction value n _C = −nc1,
The drive frequency f _INV = f31.
In FIG. 6, the discharge lamp current _IL is controlled to be the “operating point 13a”.

(In the case of f0min)
Similarly, when the natural vibration frequency of the discharge lamp load circuit 330 is minimum (f0 min), control is performed in the same manner except that + nc1 is selected as the correction value of the drive frequency reference command value, and the light output of the discharge lamp 110 is as shown in FIG. As shown in (c), the natural vibration frequency can be controlled to be substantially constant with the same value as the central value with the lapse of the cumulative lighting time.

  If the cumulative lighting time reaches the rated life of the discharge lamp 110 or the discharge lamp 110 becomes defective before the rated life, etc., the replacement work with a new discharge lamp and the nonvolatile memory 401 that responds to the replacement work are performed. The accumulated lighting time is cleared (RESET) to the initial value (not shown).

Test data of a specific design example will be described with reference to FIG. FIG. 10 corresponds to FIG. 7 and shows test data when an actual inverter circuit 300, discharge lamp load circuit 330, and the like are designed.
(1) Line numbers 1 to 5 in FIG. 10 correspond to line numbers 1 to 5 in FIG.
(2) As shown in line number 9, the type name of the suitable discharge lamp is “FHF32EX-W (manufactured by MITSUBISHI / OSRAM)”.
(3) Line numbers 6 and 7 indicate the power and current of the discharge lamp 110.
(4) Line number 8 indicates the product of the characteristic values of the choke coil 100 and the capacitor 120.
(5) Line number 10 indicates the voltage of the capacitor 60.
(6) Line number 11 indicates the clock oscillation frequency of the clock oscillation circuit 312.
(7) line number 12, in the line number 7 shows a discharge lamp current _{I L} when driving the driving frequency at a driving frequency of the variation center 42.553KHz. The difference [Delta] I _L of the maximum value and the minimum value of the discharge lamp current I _L corresponds to [Delta] I _L shown in FIG.

As is apparent from the result of the electric power of the discharge lamp 110 shown in row number 6 of FIG. 10, the variation in electric power when the discharge lamp 110 is turned on is substantially zero. The electric power of the discharge lamp 110 is controlled to increase as the cumulative lighting time elapses according to the drive frequency reference command value n _STD given in correspondence with the cumulative lighting time. As indicated by line number 6, by giving an appropriate reference frequency reference command value n _STD at each passing point of the cumulative lighting time, the light output of the discharge lamp 110 can be made the characteristic of FIG. 9C.

(When correction value n _C is used)
Further, by using the driving frequency f _INV obtained by adding the correction value n _C of the drive frequency reference command value n _STD for correcting a characteristic variation of components of the discharge lamp load circuit 330, is at full light course, release during the dimming The lamp power can be made approximately the same.

(When dimming rate is 70%)
For example, at 70% dimming ratio, the variation [Delta] I _L of the discharge current _{I L} in the control method of the second embodiment (calculates a driving frequency _{f INV} using the correction value _{n C)} are, 1mA (= 221-220 : FIG. 10, line number 7). In contrast, [Delta] I _L in the case of a constant frequency and the driving frequency _{f INV} and 53.097kHz is greatly increased and 74MA (10, line number 12).

(When dimming rate is 85%)
Similarly, in the case of the dimming ratio 85%, [Delta] I _L of the discharge current _{I L} in the control method of the second embodiment (calculates a driving frequency _{f INV} using the correction value _{n C)} is, 6 mA (= 293 -287: FIG. 10, line number 7). In contrast, [Delta] I _L in the case where the driving frequency _{f INV} is constant, 47 mA (FIG. 10, line number 12) is greatly increased and.

That is, according to the control method according to the second embodiment (calculating the drive frequency f _INV using the correction value n _C ), the light control rate is set for each dimming rate regardless of the characteristic variation of the components of the discharge lamp load circuit 330. The light output of the discharge lamp 110 can be made substantially the same. Of course, the nonvolatile memory may be stored in the microcomputer.

In the case of FIG. 10, the specific operation of the discharge lamp lighting device 2000 is as follows. It is assumed that the characteristic of the discharge lamp lighting device 2000 corresponds to the case of “f0 min” in FIG.
(1) (Drive frequency reference command value storage unit 315)
When the discharge lamp lighting device 2000 corresponds to “f0min” in FIG. 6, the characteristic corresponds to the graph of FIG. 6 and the graph 11. The drive frequency reference command storage unit 315 has n _STD = 113 (70% output) and n _STD = 123 (85% output), which are the drive frequency reference values n _STD of “f0min” in row number 5 in FIG. , N _STD = 141 (100% output) is stored in relation to the cumulative lighting time. FIG. 11 is a correspondence table 2003 showing a correspondence relationship between the cumulative lighting time and the reference command value n _STD described by the drive frequency reference command value storage unit 315.
The correspondence table 2003 shows that the cumulative lighting time is t.
If 0 ≦ t <t1, n _STD = 113,
In the case of t1 ≦ t <t2, n _STD = 123,
When t is t2 or more, n _STD = 141 corresponds.
FIG. 9D shows the correspondence relationship of the correspondence table 2003 in FIG. 11 in a graph. According to the correspondence table 2003, one of a plurality of drive frequency reference command values n _STD of 113, 123, and 141 is determined by the cumulative lighting time t recorded in the nonvolatile memory 400b.
(2) (Driving frequency generation output circuit 311)
Specifically, the drive frequency generation output circuit 311 refers to the cumulative lighting time t recorded in the non-volatile memory 400b to thereby store a plurality of drive frequency reference command values n _STD stored in the drive frequency reference command value storage unit 315. The drive frequency reference command value n _STD that matches the range of the cumulative lighting time in the correspondence table 2003 is selected as a selection value from among 113, 123, and 141. For example, the drive frequency generation output circuit 311 selects n _STD = 123 as the selection value when the cumulative lighting time t recorded in the nonvolatile memory 400b belongs to the range of t1 ≦ t <t2 (85% output range). . In this example, since the correction value n _C is not taken into consideration, the drive frequency generation output circuit 311 calculates the inverter drive frequency f _INV as 48.780 kHz as follows.
That is,
f _INV = clock frequency f _MIC ÷ n _STD
It is. In this example, the clock frequency f _MIC = 6 MHz as indicated by line number 11 in FIG.
Therefore,
f _INV = 6MHz ÷ 123 = 48.780kHz
It becomes.
The drive frequency generation output circuit 311 generates a control signal corresponding to the calculated inverter drive frequency f _INV = 48.780 kHz and outputs it to the inverter drive circuit 320.
The subsequent operation is the same as that in the first embodiment.
(3) In the case of “f0min” described above, the case where the correction value n _C described in the first embodiment is not considered has been described. Next, a case corresponding to “f0min” and a case where the correction value n _C is considered will be described. This corresponds to “f0min” (correction value = + 4) in FIG.

(Corresponding to “f0min” and considering the correction value n _C )
(1) (Drive frequency reference command value storage unit 315)
Also in this case, it is assumed that the drive frequency reference command value storage unit 315 stores the correspondence table 2003 of FIG. In this example, the non-volatile memory 400b further stores correction values n _C for correcting each of the reference command values 113, 123, and 141 described in the correspondence table 2003. The correction value n _C is “+4” as indicated by line number 4 in FIG. In this example, the correction value n _C of “+4” is set uniformly for all of the reference command values 113, 123, 141, but this is an example. A different correction value n _C may be set for each reference command value. Further, there may be a reference command value (that is, no correction) having a correction value of 0 (zero). In these cases, the correction value stored in the nonvolatile memory 400b may be associated with the reference command value described in the correspondence table 2003. As described above, if the nonvolatile memory 400b stores a correction value for correcting at least one of the reference command values, the effect described in the first embodiment can be obtained.
(2) (Driving frequency generation output circuit 311)
In the same manner as in the case where the correction value n _C is not taken into account, the drive frequency generation output circuit 311 refers to the cumulative lighting time t recorded in the nonvolatile memory 400b, and matches the drive frequency from the correspondence table 2003. The reference command value n _STD is selected as the selection value. Assume that n _STD = 123 is selected as the selection value. The drive frequency generation output circuit 311 calculates the drive frequency _fINV of the inverter circuit 300 based on the selection value and the correction correction value of the selection value when a correction value exists in the selection value.
In this example,
For n _STD = 123, the correction value n _C = “+ 4”
Exists.
Therefore,
The drive frequency generation output circuit 311 calculates the drive frequency f _INV based on the selection value n _STD = 123 and the correction value = “+ 4”.
In this example, the drive frequency generation output circuit 311 calculates the inverter drive frequency f _INV as 47.244 kHz by taking the correction value n _C into consideration.
f _INV = clock frequency f _MIC ÷ (n _STD + n _C )
It is. In this example, the clock frequency f _MIC = 6 MHz as indicated by the line number 11 in FIG.
Therefore,
f _INV = 6 MHz ÷ (123 + 4) = 47.244 kHz
It becomes.
The drive frequency generation output circuit 311 generates a control signal corresponding to the calculated inverter drive frequency f _INV = 47.244 kHz and outputs it to the inverter drive circuit 320.
The subsequent operation is the same as that in the first embodiment.

  As described above, according to the second embodiment, even if the characteristic values of the components of the discharge lamp load circuit 330 vary as in the case of the first embodiment, the adjustment components are not added. A correction value for correcting the variation can be given by the program of the microcomputer, and there is an effect that the electric power of the discharge lamp 110 can be made substantially the same at the time of each dimming as well as the variation of the power when the discharge lamp 110 is turned on.

  Further, by giving an appropriate drive frequency reference command value at each passing point of the cumulative lighting time, the light output of the discharge lamp 110 is substantially constant with respect to the cumulative lighting time as shown in FIG. 9C. There is an effect that it is possible to make such a characteristic. That is, there is an effect that it is possible to provide a small and inexpensive discharge lamp lighting device that can make the light output between a plurality of lighting fixtures equipped with the present lighting device substantially the same from the beginning of the cumulative lighting time to the end of the lifetime.

  In the discharge lamp lighting device 2000 according to the second embodiment, the driving frequency generation command circuit 311 refers to the cumulative lighting time t recorded in the nonvolatile memory 400b, and the correspondence table stored in the driving frequency reference command value storage unit 315. A predetermined reference command value corresponding to the cumulative lighting time t is selected as a selection value from a plurality of reference command values described in 2003, and the drive frequency of the inverter circuit 300 is calculated based on the selected selection value. A control signal corresponding to the driven frequency is generated and output. For this reason, the discharge lamp lighting device 2000 can make the light output of the discharge lamp 110 substantially the same from the beginning of the cumulative lighting time to the end of the lifetime.

In the discharge lamp lighting device 2000 according to the second embodiment, the drive frequency generation output circuit 311 includes:
A clock oscillation circuit that oscillates the clock signal is provided, the frequency of the clock signal is divided by the reference command value, and a value obtained by the division is set as an inverter drive frequency. Therefore, the output of the discharge lamp output can be easily adjusted by changing only the reference command value with the lapse of the cumulative lighting time.

The discharge lamp lighting device 2000 of Embodiment 2 is
A non-volatile memory 400b for storing a correction value for correcting at least one of the plurality of reference command values stored in the drive frequency reference command value storage unit 315;
The drive frequency generation output circuit 311 calculates the inverter drive frequency based on the selected reference command value and the correction value for correcting the reference command value when the correction value exists in the reference command value selected as the selection value. To do.
Therefore, even when the reference command value is selected according to the accumulated lighting time, the variation in the discharge lamp output can be easily corrected.

The discharge lamp lighting device 2000 of Embodiment 2 is
When the correction value exists in the reference command value selected as the selection value by the drive frequency generation output circuit 311, the frequency of the clock signal oscillated by the clock oscillation circuit is divided by the sum of the selection value and the correction value. The value obtained by the division is set as the inverter drive frequency. Therefore, since the reference command value and the correction value need only be written in the memory, the light output of the discharge lamp can be adjusted without requiring any parts.

  In the discharge lamp lighting device 2000 according to the second embodiment, the drive frequency reference command value storage unit 315 stores a plurality of reference command values corresponding to a plurality of different reference drive frequencies. As the time elapses, the light outputs of a plurality of lighting fixtures equipped with the discharge lamp lighting device 2000 can be made substantially the same.

  The discharge lamp lighting device described in the first embodiment and the second embodiment has the following effects.

  Even if there are variations in the characteristic values of the components of the discharge lamp load circuit, it is possible to give a correction value to correct the variations in the microcomputer program without adding adjustment components. As a matter of course, there is an effect that the discharge lamp power can be made substantially the same at the time of all dimming and at the time of each dimming. Further, by giving an appropriate drive frequency reference command value at each passing point of the cumulative lighting time, there is an effect that the light output of the discharge lamp can be made substantially constant with respect to the cumulative lighting time of the discharge lamp. . That is, there is an effect that it is possible to provide a small and inexpensive discharge lamp lighting device capable of making the light output between a plurality of lighting fixtures equipped with the present discharge lamp lighting device approximately the same from the beginning of the cumulative lighting time to the end of the lifetime. .

In the above embodiment, in a discharge lamp lighting device for lighting a discharge lamp by converting a DC power source to a high frequency power source,
A microcomputer control circuit (inverter control circuit) capable of outputting a plurality of drive frequencies divided from a predetermined oscillation frequency corresponding to the command value, and a memory for storing the cumulative lighting time of the discharge lamp in a nonvolatile manner The discharge lamp lighting device that lights the discharge lamp by outputting the driving frequency corresponding to the command value and the cumulative lighting time from the microcomputer control circuit has been described.

  In the above embodiments, in a discharge lamp lighting device that turns on a discharge lamp by converting a direct current power source to a high frequency power source, a microcomputer that can output a plurality of drive frequencies divided from a predetermined oscillation frequency corresponding to a command value A control circuit and a memory for recording the variation of the discharge lamp load circuit in a nonvolatile manner as a correction value of the command value of the drive frequency, and the microcomputer controls the drive frequency corresponding to the command value and the correction value of the command value There has been described a discharge lamp lighting device characterized in that a discharge lamp is lit by outputting from a circuit.

  In the above embodiments, in a discharge lamp lighting device that turns on a discharge lamp by converting a direct current power source to a high frequency power source, a microcomputer that can output a plurality of drive frequencies divided from a predetermined oscillation frequency corresponding to a command value A control circuit; and a memory for non-volatilely recording a correction value of a driving frequency command value for correcting variations in the discharge lamp load circuit and a cumulative lighting time of the discharge lamp, the correction value of the command value and the command value The discharge lamp lighting device for lighting the discharge lamp by outputting the driving frequency corresponding to the cumulative lighting time from the microcomputer control circuit has been described.

  In the above embodiment, the discharge lamp lighting device has been described in which the driving frequency of the discharge lamp is a frequency obtained by dividing the reference clock frequency of the microcomputer by the command value.

  In the above embodiment, the discharge lamp driving device has been described in which the driving frequency of the discharge lamp is a frequency obtained by dividing the reference clock frequency of the microcomputer by the sum of the command value and the correction value of the command value. .

  In the above embodiment, the discharge lamp lighting device has been described in which the command value is increased as the cumulative lighting time elapses.

  In the above embodiment, the discharge lamp lighting device has been described in which the correction value of the command value is made constant with the lapse of the cumulative lighting time.

  In the above embodiment, the discharge lamp lighting device has been described in which the normal lighting time of the discharge lamp is the cumulative lighting time.

1 is a circuit diagram of a discharge lamp lighting device 1000 according to Embodiment 1. FIG. Explanatory drawing for demonstrating operation | movement of the discharge lamp lighting device 1000 in Embodiment 1. FIG. FIG. 3 shows a method for generating a drive frequency in the first embodiment. 7 is a test data table of actual operation of the discharge lamp lighting device 1000 according to the first embodiment. FIG. 6 is a circuit diagram of a discharge lamp lighting device 2000 according to Embodiment 2. Explanatory drawing for demonstrating operation | movement of the discharge lamp lighting device 2000 in Embodiment 2. FIG. Explanatory drawing for demonstrating operation | movement of the discharge lamp lighting device 2000 in Embodiment 2. FIG. FIG. 6 illustrates light control in Embodiment 2. The figure which shows the relationship between the cumulative lighting time in Embodiment 2, and the light output of a discharge lamp. 10 is a test data table of actual operation of the discharge lamp lighting device 2000 according to the second embodiment. FIG. 10 shows a correspondence table in the second embodiment.

Explanation of symbols

  10 AC power supply, 20 diode bridge, 30 choke coil, 40 diode, 50 switching element, 60 capacitor, 70, 80 switching element, 90 coupling capacitor, 100 choke coil, 110 discharge lamp, 120 capacitor, 200 step-up chopper circuit, 210 Boost chopper control circuit, 300 inverter circuit, 310a, 310b inverter control circuit, 311 drive frequency generation output circuit, 312 clock oscillation circuit, 313 correction value temporary storage unit, 314 operation mode switching circuit, 315 drive frequency reference command value storage unit, 2001 lighting time counter, 2002 cumulative lighting time recording area, 2003 correspondence table, 320 inverter drive circuit, 330 discharge lamp load circuit, 400a, 400b nonvolatile memory, 500 Correction value input of drive frequency reference command value in adjustment mode, 600 Normal operation / adjustment mode switching input, 1000, 2000 Discharge lamp lighting device.

Claims (8)

In a discharge lamp lighting device for lighting a discharge lamp,
An inverter circuit that supplies high-frequency power corresponding to the driving frequency to the discharge lamp by driving at a predetermined driving frequency according to the drive signal;
A drive frequency corresponding value storage unit that stores a drive frequency corresponding value that is a value corresponding to the drive frequency of the inverter circuit;
A correction value storage unit that stores a correction value for correcting the drive frequency correspondence value stored in the drive frequency correspondence value storage unit;
The drive frequency of the inverter circuit is calculated based on the drive frequency corresponding value stored in the drive frequency corresponding value storage unit and the correction value stored in the correction value storage unit, and a control signal corresponding to the calculated drive frequency is generated. A control signal output unit for outputting
A discharge lamp lighting device comprising: an inverter drive circuit that generates a drive signal for driving the inverter circuit from the control signal output by the control signal output unit, and outputs the generated drive signal to the inverter circuit . The discharge lamp lighting device further includes:
A clock oscillation circuit that oscillates a clock signal of a predetermined frequency is provided.
The control signal output unit is
A frequency obtained by dividing the frequency of the clock signal oscillated by the clock oscillation circuit by the sum of the drive frequency corresponding value stored in the drive frequency corresponding value storage unit and the correction value stored in the correction value storage unit. The discharge lamp lighting device according to claim 1, wherein the value is a drive frequency of the inverter circuit. The drive frequency corresponding value storage unit is
3. The discharge lamp lighting device according to claim 1, wherein a driving frequency corresponding value corresponding to a reference driving frequency predetermined as a reference among driving frequencies of the inverter circuit is stored as a reference command value. 4. . In a discharge lamp lighting device for lighting a discharge lamp,
An inverter circuit that supplies high-frequency power corresponding to the driving frequency to the discharge lamp by driving at a predetermined driving frequency according to the drive signal;
A cumulative lighting time recording unit that records the lighting time of the discharge lamp as a cumulative lighting time;
A drive frequency corresponding value storage unit for storing a plurality of drive frequency corresponding values corresponding to the drive frequency of the inverter circuit and any one of which is determined from the cumulative lighting time recorded in the cumulative lighting time recording unit;
By selecting a predetermined drive frequency correspondence value as a selection value from among a plurality of drive frequency correspondence values stored in the drive frequency correspondence value storage unit by referring to the cumulative lighting time recorded in the cumulative lighting time recording unit, A control signal output unit that calculates a drive frequency of the inverter circuit based on the selected selection value, generates and outputs a control signal corresponding to the calculated drive frequency, and
A discharge lamp lighting device comprising: an inverter drive circuit that generates a drive signal for driving the inverter circuit from the control signal output by the control signal output unit, and outputs the generated drive signal to the inverter circuit . The discharge lamp lighting device further includes:
A clock oscillation circuit that oscillates a clock signal of a predetermined frequency is provided.
The control signal output unit is
5. The discharge lamp lighting device according to claim 4, wherein a frequency obtained by dividing the frequency of the clock signal oscillated by the clock oscillation circuit by a selected value is used as the drive frequency of the inverter circuit. The discharge lamp lighting device further includes:
A correction value storage unit that stores a correction value for correcting at least one of the plurality of drive frequency corresponding values stored in the drive frequency corresponding value storage unit;
The control signal output unit is
If the correction value stored in the correction value storage unit exists in the drive frequency corresponding value selected as the selection value, the drive frequency of the inverter circuit is calculated based on the selection value and the correction value for correcting the selection value. The discharge lamp lighting device according to claim 4, wherein: The discharge lamp lighting device further includes:
A clock oscillation circuit that oscillates a clock signal of a predetermined frequency is provided.
The control signal output unit is
When there is a correction value stored in the correction value storage unit in the drive frequency corresponding value selected as the selection value, the frequency of the clock signal oscillated by the clock oscillation circuit is selected and the correction value for correcting the selection value. The discharge lamp lighting device according to claim 6, wherein a value obtained by dividing the sum by the sum is used as a drive frequency of the inverter circuit. The drive frequency corresponding value storage unit is
8. A plurality of drive frequency corresponding values respectively corresponding to a plurality of different reference drive frequencies determined in advance as a reference among the drive frequencies of the inverter circuit are stored as reference command values. A discharge lamp lighting device according to claim 1.

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