JP4711148B2 - Discharge lamp lighting device and lighting device - Google Patents

Description

  The present invention relates to a discharge lamp lighting device in which control means is digitized and an illumination device using the same.

  A discharge lamp lighting device in which the control means is digitized is described in, for example, Japanese Patent Application Laid-Open No. 5-207756.

  In general, a discharge lamp lighting device including an inverter type lighting circuit means controls the switching frequency of the switching means or the on-duty of the switching according to the lighting state of the discharge lamp and the power supply voltage, so that the discharge lamp has a constant brightness. It is configured to be able to light up.

  In order to digitize the discharge lamp lighting device, the control means is generally digitized. By digitizing the control, desired control characteristics can be easily obtained, and a quick response control can be expected.

By the way, in order to digitize the control means, a control signal to be supplied to the lighting circuit means is formed by digital arithmetic processing. When performing digital arithmetic processing, the power supply voltage and the lighting state of the discharge lamp are detected in analog form, and the detected output is converted to digital form by A / D conversion, and the digitized lighting state detection signal and power supply voltage detection are detected. A signal or the like is input to the arithmetic processing means. An arithmetic program is set in advance in the arithmetic processing means, and a digital control signal is obtained by performing arithmetic processing according to the arithmetic program based on control inputs such as a lighting state detection signal and a power supply voltage detection signal. Necessary conversion such as direct or D / A conversion to analog format is performed and control input is made to the lighting circuit means. Thus, for example, the discharge lamp is stably lit by controlling the lighting frequency, the on-duty of the output voltage, and the like.
Japanese Patent Laid-Open No. 5-207756

  However, the discharge lamp lighting device varies in lighting state even if a constant control signal is supplied due to variations in characteristics of circuit components used.

  Therefore, in the past, when performing fine adjustment of the switching frequency mainly to absorb characteristic variations of circuit components and negative feedback adjustment to changes in lighting state, the resolution is generally increased by increasing the clock oscillation frequency. It was necessary to increase.

  However, as the oscillation frequency of the clock oscillator increases, it causes an increase in power consumption and cost.

  It is an object of the present invention to provide a discharge lamp lighting device and an illumination device using the same, which can easily adjust the oscillation frequency without increasing power consumption and increasing costs for adjusting a control signal. .

  A discharge lamp lighting device according to a first aspect of the present invention is a lighting circuit means for controlling a lighting state of a discharge lamp according to a control signal described later; a lighting state detection for detecting a lighting state of the discharge lamp and generating a lighting state detection signal Means; Built-in timer function, part of the timer operation can be temporarily stopped using interrupt processing, and then the operation can be started again, and according to the lighting state detection signal Arithmetic processing means for forming a control signal by calculation and supplying the control circuit means to the lighting circuit means; the arithmetic processing means temporarily stops part of the timer operation using interrupt processing and then operates again To extend the time width of the pulse that is the control signal, and to mix the pulses with the extended time width for every appropriate number of pulses that do not extend the time width. Ri, and controlling so that the frequency is reduced when viewed as an average value.

  In the present invention and each of the following inventions, the definitions and technical meanings of terms are as follows unless otherwise specified.

  (Regarding Lighting Circuit Means) The lighting circuit means may have any configuration as long as lighting of the discharge lamp can be controlled. However, since the luminous efficiency can be increased by lighting at high frequency, and fine control by electronic control is easy, a high frequency inverter is suitable.

  The lighting circuit means includes a current limiting impedance when the discharge lamp requires an external current limiting impedance like a fluorescent lamp or a high-intensity discharge lamp. In contrast, a discharge in which at least one of the pair of electrodes is provided with an external electrode disposed in close contact with the outer surface of the translucent discharge vessel, and an ionized medium mainly containing a rare gas is enclosed therein. Since the lamp performs dielectric barrier discharge, and an electrostatic capacity is formed with the wall of the translucent discharge vessel as a dielectric, and the lamp is connected in series with the discharge lamp, external connection of the current limiting impedance can be omitted. Therefore, in such a case, the current limiting impedance is not necessarily required.

  When the current limiting impedance has a current limiting function inside the high frequency inverter, the current limiting function, for example, the leakage inductance of the output transformer can be used as the current limiting impedance. Further, a current limiting function connected separately from the high frequency inverter may be used as the current limiting impedance.

  Further, when a high frequency inverter is used as the lighting circuit means, known high frequency inverters of various circuit types can be used. For example, a full bridge type, a half bridge type, a parallel type, a single stone type inverter, etc. are allowed.

  Furthermore, the lighting circuit means includes a starting means for starting the discharge lamp as needed, and a power conversion means for converting the low-frequency alternating current to direct current and supplying, for example, direct-current power to the high-frequency inverter. Allow.

  By using a chopper as the power conversion means, the power factor of the input current can be increased and the harmonic distortion can be reduced. In addition, when a chopper operation function is incorporated in the high-frequency inverter to form a composite type, a separate chopper can be omitted.

  Furthermore, the lighting circuit means can be configured to directly control and input a control signal such as a pulse format supplied from the arithmetic processing means, but if necessary, a D / A converter is provided and a control analog signal is obtained. The control analog signal may be input to the control terminal. Then, for example, the output frequency or the on-duty of the output voltage of the lighting circuit means can be changed.

  Furthermore, in order to amplify the control signal from the arithmetic processing means as required, to drive or to perform high-side insulation, an appropriate conversion means is interposed between the arithmetic processing means and the control input terminal of the lighting circuit means. Can do.

  (On Lighting State Detection Unit) The lighting state detection unit detects the lighting state in order to form a control signal by performing negative feedback control on the lighting state of the discharge lamp in the arithmetic processing unit. In order to convert the lighting state detection signal from the analog format to the digital format, an A / D converter may be provided in the lighting state detection means, or an A / D converter function in the arithmetic processing means may be used. Also good.

  The lighting state can be detected in various forms. For example, the lighting state can be detected by detecting lamp voltage and lamp current, lamp power or light emission. These can be appropriately selected as necessary.

  (Regarding Arithmetic Processing Unit) The arithmetic processing unit dims the discharge lamp by sending a dimming control signal from the arithmetic processing unit to the lighting circuit unit and reducing the lamp power supplied from the lighting circuit unit to the discharge lamp. You may let them.

  The arithmetic processing program is configured to determine a control amount according to a lighting state, including a required control pattern such as constant power, constant voltage, or constant current for the discharge lamp.

  The arithmetic processing means can be constituted by, for example, a read-only memory ROM, a temporary storage memory RAM, a central processing unit CPU, an electrically writable nonvolatile memory EEPROM and the like in order to achieve the function. The main role of each element in such a configuration is as follows.

  The read-only memory ROM stores a control program and reference data such as a voltage value, a current value, a conversion table, and a coefficient of an arithmetic expression.

  The temporary storage memory RAM temporarily stores data.

  The central processing unit CPU performs calculations according to a program.

  The electrically writable nonvolatile memory EEPROM stores standard lighting state data.

  (Other Configurations) The discharge lamp may be either a low-pressure discharge lamp such as a fluorescent lamp or a high-pressure discharge lamp called a high-intensity discharge lamp. Further, a dielectric barrier discharge lamp or the like may be used.

  Further, if necessary, the power supply voltage detection means can be provided, and the power supply voltage detection data can be input to the arithmetic processing means to remove the influence on the lighting state with respect to the fluctuation of the power supply voltage.

  In the present invention, a part of the operation of the CPU of the arithmetic processing means is temporarily stopped, and then the operation is started again, thereby extending the time width of the pulse. The frequency is reduced when viewed as an average value by mixing the pulses whose time width is extended in this way for every appropriate number of pulses not extending the time width.

  Thus, in the present invention, the frequency of the pulse can be adjusted within a required range by changing the degree of extension of the time width of the pulse and the mixing ratio of the pulses having the extended time width. It is easy to make the frequency adjustable range about 10%. If necessary, the adjustable range can be set to exceed 10%.

  Therefore, for example, in the manufacturing stage, by applying the present invention and changing the frequency of the pulse of the control signal to adjust to the standard lighting state, it is possible to absorb the characteristic variation of the circuit components. In this case, the frequency adjustable range may be about 5%.

  In normal lighting, the discharge lamp lighting state detection signal detected by the lighting state detection means is A / D converted, compared with the standard lighting state data inside the arithmetic processing means, and calculated according to the difference. By controlling the frequency of the control signal supplied from the processing means to the lighting circuit means in a negative feedback manner, the discharge lamp can be lit in the standard lighting state. In this case, if the lighting frequency is about 50 kHz, which is an average frequency, for example, a frequency adjustable range of 5 to 10% is sufficient.

  Furthermore, in the present invention, the discharge lamp can be dimmed by changing the frequency.

  In any of the above aspects, the lighting circuit means is controlled by a control signal in which pulses having different time widths are mixed, so that the time width of light emission of the discharge lamp changes. It is not actually a visual problem.

  Further, as described above, in the present invention, the frequency of the control signal can be finely adjusted without increasing the resolution of the clock signal, which is effective in reducing the cost of the discharge lamp lighting device.

  Thus, by temporarily stopping the timer function of the single-chip microcomputer incorporating the timer function and then starting the operation again, the time width of the pulse can be extended with a simple configuration.

  In the present invention, since the frequency of the control signal can be finely adjusted without increasing the resolution of the clock signal, a single chip microcomputer can be used as the arithmetic processing means, and therefore the discharge lamp lighting device can be configured at low cost.

  Further, in the present invention, a part of the operation of the CPU is stopped using interrupt processing, so that the arithmetic processing is simplified.

  A lighting device according to a second aspect of the present invention includes: a lighting device main body; and the discharge lamp lighting device according to the first aspect disposed in the lighting device main body.

  The illuminating device of the present invention is a broad concept including all devices that use the light emission of a discharge lamp for some purpose. For example, various lighting fixtures, display devices, and image reading devices.

  The lighting fixture includes indoor and outdoor lighting fixtures.

  The display device includes an internal illumination display device and an external illumination display device. Moreover, the backlight apparatus used for the former is also included in an illuminating device.

  The image reading apparatus includes OA equipment such as a copying machine, a scanner, and a facsimile machine in which the image reading apparatus is incorporated.

  According to each aspect of the present invention, the time of the control signal supplied from the arithmetic processing means to the lighting circuit means is configured by temporarily stopping the timer operation and then starting the operation again. When the width is extended, it is possible to provide a discharge lamp lighting device in which the frequency of the control signal is reduced as an average value and the frequency can be finely adjusted.

  According to invention of Claim 2, the illuminating device which has the effect of Claim 1 can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a circuit block diagram showing a first reference embodiment of a discharge lamp lighting device according to the present invention.

  In the figure, 1 is an AC power source, 2 is a lighting circuit means, 3 is a discharge lamp, 4 is a lighting state detection means, 5 is an arithmetic processing means, and 6 is a setting means.

  The AC power source 1 is a low-frequency AC power source, for example, a commercial power source.

  (About the lighting circuit means 2) The lighting circuit means 2 includes a rectifier circuit 2a, a DC stabilized power supply circuit 2b, a high-frequency inverter 2c, and a current-limiting impedance 2d, and generates a high frequency.

  The rectifier circuit 2a is a full-wave rectifier circuit.

  The DC stabilized power supply circuit 2b is used to obtain a stabilized DC voltage with a full-wave rectified output at a required voltage.

  The high-frequency inverter 2c is a half-bridge type inverter including a pair of switching means Q1 and Q2 connected in series to a DC power supply, and is provided with a gate drive circuit 2c1.

  The gate drive circuit 2c1 generates a drive signal having a voltage of about 0 to 10V by voltage conversion of a control signal supplied from the arithmetic processing means 5 to be described later, and alternately applies this to the gates of the pair of switching means Q1 and Q2. Then, inverter operation is performed.

  The current limiting impedance 2d is composed of an inductor, and is connected in series with the discharge lamp 3 and the DC cut capacitor C1 between the high frequency output terminals of the high frequency inverter 2c.

  (About the discharge lamp 3) The discharge lamp 3 is a fluorescent lamp, and is lit by being energized by the high-frequency output of the lighting circuit means 2.

  C2 is a filament heating capacitor, which is connected between the non-power supply side terminals of a pair of filament electrodes of the discharge lamp to form a filament heating circuit.

  (About the lighting state detection means 4) The lighting state detection means 4 is comprised by the lamp voltage detection part 4a and the lamp current detection part 4b.

  Although not shown, the lamp voltage detector 4a detects the voltage across the discharge lamp 3.

  Although not shown, the lamp current detection unit 4 b includes a current detection current transformer connected in series with the discharge lamp 3.

  (Regarding Arithmetic Processing Unit 5) The arithmetic processing unit 5 includes a read-only memory ROM, a temporary storage memory RAM, a central processing unit CPU, and an electrically writable nonvolatile memory EEPROM. Reference numeral 5a denotes a bus line that connects each of the above-described components to an information exchange relationship.

  The read only memory ROM stores an arithmetic processing program. The program includes at least an inspection mode and a normal lighting mode. In the inspection mode, a control signal is sent so as to sequentially change the lighting state of the discharge lamp 3, and when the setting is changed from the setting means 6 described later to the normal lighting state, the control signal at that time is changed to the control signal. The program is configured to store corresponding data as standard lighting state data.

  The control signal supplied from the CPU of the arithmetic processing means 5 to the lighting circuit means 2 is a pulse voltage of about 0 to 3V to 0 to 5V.

  (Regarding Setting Unit 6) The setting unit 6 sets the operation mode of the arithmetic processing unit 5 to either the inspection mode or the normal lighting mode.

  (Operation) First, the inspection mode will be described.

  When the setting means 6 is operated to set the inspection mode, the CPU of the arithmetic processing means 5 reads the arithmetic processing program for the inspection mode from the ROM, generates a control signal composed of pulses that sequentially change in the frequency decreasing direction, and lights up. The signal is sent to the gate drive circuit 2c1 of the circuit means 2. The gate drive circuit 2c1 converts the control signal into a voltage to generate a gate drive signal, which is alternately applied to the gates of the pair of switching means Q1 and Q2, so that the high frequency inverter 2c operates to generate a high frequency voltage. To do.

  On the other hand, a standard load is connected as the discharge lamp 3 to the output terminal of the discharge lamp lighting device. Further, a high-frequency voltage is applied to the standard load after connecting a power meter that measures the load current corresponding to the lamp current flowing through the standard load and the terminal voltage of the standard load to calculate the load power. Then, since the frequency of the high frequency voltage is sequentially reduced in response to the above operation, the current limiting impedance 2d is reduced accordingly. For this reason, the load current flowing through the standard load increases sequentially.

  Therefore, the wattmeter is monitored by an operator, for example, and when the predetermined load power corresponding to a predetermined lighting state determined in advance is reached, the setting means 6 is operated to set the normal lighting mode. Thereby, the data corresponding to the control signal at the time when the setting is changed is stored in the EEPROM as the standard lighting state data.

  Next, modes stored in the normally lit EEPROM will be described.

  When the AC power supply 1 is turned on while the setting means 6 is in the normal lighting state mode, the CPU of the arithmetic processing means 5 reads out the normal lighting mode arithmetic processing program stored in the ROM. Next, the CPU reads out the standard lighting state data stored in the EEPROM, sets the initial state, generates a control signal corresponding to the standard lighting state data, and sends it to the lighting circuit means 2.

  The gate drive circuit 2c1 that has received the supply of the control signal generates a gate drive signal corresponding to the control signal by conversion and switches the pair of switching means Q1 and Q2 alternately. Therefore, the high frequency inverter 2b starts operation. A high frequency voltage is applied to the discharge lamp 3.

  When the discharge lamp 3 is lit, the lamp current and lamp voltage are detected from the lighting state detection means 4 and sent to the CPU. After the lighting state detection signal is converted from the analog format to the digital format by the A / D converter function in the CPU, the CPU calculates whether or not there is a difference from the control signal data and the degree thereof. As a result, if there is a difference, a control signal corrected in a negative feedback according to the degree is formed and sent to the lighting circuit means, so that the discharge lamp 3 is eventually maintained in the standard lighting state by the negative feedback control. It will be.

  FIG. 2 is a circuit block diagram showing a second reference embodiment of the discharge lamp lighting device of the present invention.

  In the figure, the same parts as those in FIG.

  This reference embodiment is different in that the CPU includes an external input unit 5b.

  That is, when the external input unit 5b is provided, when the switching signal is input to the external input unit 5b, the arithmetic processing program is configured to store the data corresponding to the control signal at that time in the EEPROM as the standard lighting state data. ing.

  The switching signal to be input to the external input unit 5b is formed, for example, when an operator monitors a meter indicating a lighting state and operates a switch when a predetermined lighting state is reached.

  FIG. 3 is a circuit block diagram showing a third reference embodiment of the discharge lamp lighting device of the present invention.

  In the figure, the same parts as those in FIG.

  This reference embodiment is different in that data corresponding to a control signal when the lighting state detection signal becomes a predetermined value is stored as standard lighting state data.

  That is, the lighting state detection means 4 built in the discharge lamp lighting device is provided with the external input terminal 4c. In the inspection mode, a standard lighting state detection means (not shown) having the same specifications as the built-in lighting state detection means 4 is connected to the external input terminal 4c in advance, and the standard lighting state detection means is connected thereto. The standard lighting state detection signal is input to the external input terminal 4c.

  Then, the data corresponding to the control signal transmitted when the standard lighting state detection signal is input is stored in the EEPROM as the standard lighting state data.

  FIG. 4 is a circuit diagram showing a first embodiment of a discharge lamp lighting device according to the present invention.

  In the figure, the same parts as those in FIG.

  In the present embodiment, a single-chip microcomputer is used as the arithmetic processing means 5 so as to adjust the frequency of the control signal without changing the resolution of the clock signal oscillator, and the DC stabilization circuit 2b is configured by a boost chopper. It is different in point.

  That is, the arithmetic processing means 5 composed of a single-chip microcomputer has a timer function, but is configured so that the timer function can be temporarily stopped by interrupt processing and then the operation can be started again.

  FIG. 5 is a waveform diagram for explaining the operating principle of extending the time width of the control signal in the fourth embodiment of the discharge lamp lighting device of the present invention.

  In the figure, the horizontal axis represents time, and the vertical axis represents voltage. An arrow t1 indicates a stop start time for stopping the partial operation of the arithmetic processing means 5, and an arrow t2 indicates an operation restart time for starting the operation again.

  As is clear from the figure, the time width of the control signal is extended during the time t1-t2, so that the frequency as the average value is reduced.

  Next, returning to FIG. 4 again, the DC stabilizing circuit 2b will be described.

  That is, the boost chopper constituting the DC stabilizing circuit 2b has a pair of input terminals 2b1 connected between the DC output terminals of the rectifier circuit 2a. A pair of output terminals 2b2 are connected between the DC input terminals of the high-frequency inverter 2c.

  A series circuit of an inductor 2b3 and a switching means 2b4 is connected between the pair of input terminals.

  A series circuit of a diode 2b5 and a smoothing capacitor 2b6 is connected in parallel with the switching means 2b4.

  The switching means 2b4 has a gate drive circuit 2b7 connected to its gate.

Then, the boosting chopper assumes that the ON time of the switching means 2b4 is TON, the OFF time is TOFF, the input voltage is Vp, and the output voltage is Vo. Can be obtained.
(Equation 1) Vo = (TON + TOFF) Vp / TOFF
Also, the input power factor is high and the harmonic distortion is remarkably reduced.

  FIG. 6 is a perspective view showing a lighting fixture in one embodiment of the lighting device of the present invention.

  In the figure, 7 is a lighting fixture body, and 8 is a discharge lamp lighting device.

  The luminaire main body 7 includes a base body 7a and a lamp socket 7b. Furthermore, a reflector, a terminal block, wiring, etc. are included as needed.

  The discharge lamp lighting device 8 includes a discharge lamp lighting circuit 8a and a discharge lamp 8b.

  The discharge lamp lighting circuit 8a has the configuration shown in FIG.

  The discharge lamp 8b is a fluorescent lamp.

  Then, the lighting fixture of this embodiment can perform illumination with a constant light output of the discharge lamp 8b.

The circuit block diagram which shows 1st reference embodiment of the discharge lamp lighting device of this invention The circuit block diagram which shows 2nd Embodiment of the discharge lamp lighting device of this invention The circuit block diagram which shows 3rd Embodiment of the discharge lamp lighting device of this invention The circuit diagram which shows 1st Embodiment of the discharge lamp lighting device of this invention FIG. 6 is a waveform diagram for explaining the operating principle of extending the time width of the control signal in the first embodiment of the discharge lamp lighting device of the present invention. The perspective view which shows the lighting fixture in one Embodiment of the illuminating device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... AC power supply 2 ... Lighting circuit means 2a ... Rectification circuit 2b ... DC stabilized power supply circuit 2c ... High frequency inverter 2c1 ... Gate drive circuit 2d ... Current limiting impedance 3 ... Discharge lamp 4 ... Lighting state detection means 4a ... Lamp voltage detection part 4b ... Lamp current detector 5 ... Arithmetic processing means 5a ... Bus line 6 ... Setting means C1 ... DC cut capacitor C2 ... Filament heating capacitor Q1 ... Switching means Q2 ... Switching means

Claims (2)

Lighting circuit means for controlling the lighting state of the discharge lamp in response to a control signal described later;
Lighting state detection means for detecting a lighting state of the discharge lamp and generating a lighting state detection signal;
Built-in timer function, configured to be able to temporarily stop part of the timer operation using interrupt processing and then start the operation again , and calculate according to the lighting state detection signal Arithmetic processing means for forming a control signal and supplying it to the lighting circuit means;
Comprising
The arithmetic processing means temporarily stops part of the timer operation using interrupt processing, and then starts the operation again, thereby extending the time width of the pulse as the control signal and extending the time width. pulse by Zaisa mixed for each appropriate number of pulses does not extend the time width was, the discharge lamp lighting device and controls so that the frequency is reduced when viewed as an average value. A lighting device body;
The discharge lamp lighting device according to claim 1, which is disposed in the lighting device body;
An illumination device comprising:

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