JP2001250699A - Electric discharge lamp lighting device and lighting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electric discharge lamp lighting device which prevents a blacking of the electric discharge lamp, and a lighting apparatus using this by making an amount of heating of a filament electrode to be controllable in a reactance heating circuit system. SOLUTION: The electric discharge lamp lighting device is provided with a current limiting impedance L2, the electric discharge lamp DL equipped with a pair of filament electrode E1 and E2 powered from a power supply means HFG through the current limiting impedance L2, a load circuit LC including the filament heating circuit FHC, and a filament switch means FS to control the amount of filament heating by turning on or off periodically.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a discharge lamp lighting device using a discharge lamp provided with a filament electrode and a lighting device using the same.

[0002]

2. Description of the Related Art For example, when a discharge lamp having a filament electrode, such as a fluorescent lamp for general illumination, is started by hot cathode, unless the filament electrode is preheated sufficiently before starting, an electron-emitting substance is sputtered and spontaneously starts. There is a problem that blackening occurs. A circuit system using a filament heating circuit formed by connecting a non-power supply side terminal of a pair of filament electrodes of a discharge lamp via a capacitor (hereinafter referred to as a "reactance heating circuit system") can be obtained at low cost. It is often used from that. In this reactance heating circuit system, when an inductive reactance is used as a current limiting impedance, a capacitor is used as a capacitive reactance.In general, by increasing the capacitance of the capacitor, it is possible to shorten the time. Sufficient preheating of the filament electrode is performed.

[0003]

However, when the discharge lamp is dimmed in the reactance heating circuit system, the lamp voltage increases as the lamp current decreases due to the load characteristics of the discharge lamp. Tends to be excessive. For this reason, there is a problem that blackening occurs in the discharge lamp. For this reason, conventionally, when dimming a discharge lamp, a circuit method of heating a filament electrode using a filament heating transformer (hereinafter, referred to as a “winding heating method”) has been adopted. By reducing the current, blackening is prevented.

However, the winding heating method has a problem that it is expensive.

SUMMARY OF THE INVENTION An object of the present invention is to provide a discharge lamp lighting device in which the amount of heating of a filament electrode can be controlled in a reactance heating circuit system to prevent blackening of a discharge lamp, and a lighting device using the same. And

Another object of the present invention is to provide a discharge lamp lighting device in which the tube end of the discharge lamp is protected from abnormal temperature rise at the end of the life of the discharge lamp, and a lighting device using the same. Aim.

[0007]

According to a first aspect of the present invention, there is provided a discharge lamp lighting apparatus comprising: a power supply means; a current limiting impedance; and a discharge lamp having a pair of filament electrodes which are energized from the power supply means via the current limiting impedance. A load circuit including a lamp and a filament heating circuit in which the non-power-supply-side terminals of the pair of filament electrodes are connected via a reactance; filament switch means for periodically turning on and off to control the filament heating amount; It is characterized by having.

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

<Power Supply Means> The power supply means is a means for supplying power to the discharge lamp in order to energize and light the discharge lamp. In order to stably perform a series of control of preheating, starting, and lighting of the discharge lamp, the power source is preferably a controllable power source. In addition, it is preferable that control for performing a required protection operation when an abnormality occurs, such as when the discharge lamp is not mounted or at the end of its life, is also possible.

[0010] The power supply means supplies AC power to the discharge lamp. However, the frequency is not limited. Therefore, it may be either a low frequency such as a commercial frequency or a high frequency such as several tens of kHz. However, when the discharge lamp is lit at a high frequency, the luminous efficiency is increased, and the discharge lamp lighting device can be reduced in size and weight and the control is easy. Therefore, a high-frequency power source is suitable as a controllable power source.

When a high-frequency power supply is used, it is advisable to use a high-frequency inverter that converts direct current or low-frequency alternating current to high frequency. Known high-frequency inverters of various circuit types can be used. For example, inverters of various circuit types such as a full-bridge type, a half-bridge type, a parallel type, and a single-stone type can be used alone, or a high-frequency inverter can be used in combination with a switching regulator as an active filter. Also, by using the switching means of the high-frequency inverter as the switching means of the active filter, a so-called composite high-frequency inverter having an active filter can also be used. In the present invention, “high frequency” refers to a frequency of 10 kHz or more.

In order to control the high-frequency output so that the discharge lamp of the load circuit can be preheated, started and lit by using the high-frequency power supply, and to perform a required protection operation, for example, the oscillation frequency must be controlled. This can be realized by changing the effective value of the output voltage by changing the duty ratio of high-frequency switching, or by changing the DC output voltage of the active filter to change the high-frequency output voltage of the high-frequency inverter.

<Load Circuit> The load circuit includes at least a current limiting impedance, a discharge lamp energized via the current limiting impedance, and a filament heating circuit of the discharge lamp.

(Current limiting impedance) The current limiting impedance is used to compensate for the negative characteristics of the discharge lamp and to allow a constant lamp current to flow through the discharge lamp to stably light the discharge lamp. Although any of inductive reactance, capacitive reactance, and resistance may be used, it is common to use the former which theoretically does not generate power consumption. Further, in order to improve the lamp current waveform, it is preferable to use an inductive reactance. However, even if an inductive reactance or a capacitive reactance is shown as a whole, a complex circuit including a capacitive reactance or an inductive reactance as a reactance component can be adopted as the current limiting impedance.

When an inductive reactance is used as the current limiting impedance, any of a single choke coil and a leakage transformer may be used.

(Discharge Lamp) The discharge lamp may be of any configuration, and includes at least a translucent discharge vessel in which a discharge medium is sealed and a pair of filament electrodes for causing discharge of the discharge medium. ing. Discharge lamps having a filament electrode include a germicidal lamp in addition to a fluorescent lamp. In addition to fluorescent lamps that generate visible light, for example, in addition to fluorescent lamps for general certification,
There are black lights and chemical lamps that generate long wavelength ultraviolet light. To start and turn on this type of discharge lamp,
It is necessary to appropriately heat the filament electrode using a filament heating circuit. The discharge lamp can be lit by connecting not only one lamp but also a plurality of lamps in series or in parallel as desired.

(Regarding Filament Heating Circuit) In the filament heating circuit, a non-power supply side terminal of a pair of filament electrodes is connected by a reactance, and a power supply side terminal of the pair of filament electrodes is connected between output terminals of power supply means. That is, a reactance heating circuit system is employed. This makes the circuit configuration simple and inexpensive.
In this case, the reactance has an appropriate impedance value for flowing the required value of the filament heating current. If a reactance that mainly forms a current limiting impedance and a series resonance circuit of the load circuit is used, a high starting voltage due to series resonance is generated in the filament heating circuit at the time of starting, and this starting voltage is applied to the discharge lamp. Thereby, the starting and lighting of the discharge lamp can be promoted. When the current limiting impedance is composed of inductive reactance, it is preferable to use a capacitor having capacitive reactance in the filament heating circuit. Conversely,
If the current limiting impedance is a capacitive reactance,
Inductive reactance may be used in the filament heating circuit.

<Regarding Filament Switching Means> The filament switching means is a switching means for controlling the amount of heating of the filament, and is turned on and off periodically. A non-contact switch such as a transistor or a thyristor can be used as the filament switch. As the transistor, a unipolar transistor such as an FET or a bipolar transistor can be used.
Further, as the thyristor, an SCR, GTO, SI thyristor, or the like can be used. Further, by using a light control non-contact switch such as an optical trigger thyristor or a photocoupler transistor as the filament switch means, in the case of a filament heating circuit of a reactance heating circuit type, a filament switch means is provided by a conductively insulated low voltage control circuit. Switching can be controlled. Note that an AC power coupler can be used as the light trigger thyristor.

To control the amount of filament heating, the filament switch means can be connected in parallel with the filament electrode or in series with the filament heating circuit.

When the filament switch is connected in parallel to the filament electrode, when the filament switch is turned on, the filament electrode is short-circuited by the filament switch during that time. Also,
When the filament switch is turned off, the filament electrode is in a state in which electricity can be supplied during that time. Therefore, if the filament switch means is turned on and off, that is, switched at an appropriate cycle, the amount of filament heating decreases in proportion to the on-duty as compared to the case where switching is not performed. Therefore, in this case, the voltage applied to the filament electrode, that is, the filament heating voltage is effectively controlled.

On the other hand, when the filament switching means is connected in series to the filament heating circuit, the filament heating current can flow when the filament switching means is turned on, and the filament heating current is cut off when the filament switching means is turned off. . Therefore, in this case, the current flowing through the filament electrode, that is, the filament heating current is controlled in an effective value.

Regardless of the control mode of the filament heating voltage and the filament heating current described above, in order to control the amount of filament heating by switching, the positive and negative polarities of the filament heating current flowing through the filament electrode are halved. It is possible to select whether to control the waves together or only the half-wave of either polarity. Further, even when the latter is selected, it is possible to select whether to cut off the half-wave of the polarity not controlled or to conduct all the half-waves.

The switching frequency of the filament switch means can be set appropriately as long as there is no decisive problem with the filament heating operation. For example, if the switching frequency is set to about 1 Hz or less, the human eyes do not feel flickering.

Further, it is possible to select a mode in which the amount of heating of the filament is changed depending on whether or not the filament switching means is periodically switched. On the other hand, the duty of the filament switch means may be changed to change the filament heating amount.

Further, in the reactance heating circuit system, when the lighting state of the discharge lamp changes, for example, from all light to the dimming state, the filament heating amount changes. Therefore, by controlling the filament switch means such as changing the on-duty of switching in accordance with the lighting state, it is possible to keep the filament heating amount substantially constant through the change in the lighting state. Further, even if the filament heating amount does not become constant, an undesired change in the filament heating amount may be suppressed by keeping the filament heating current or the filament voltage constant. Further, by keeping the filament heating current and the filament voltage constant, the resistance value of the filament electrode can be controlled to be constant.

Further, as the lighting state of the discharge lamp for which the heating amount of the filament is to be controlled, there is a blinking frequency other than the dimming as described above. That is, if the discharge lamp is blinking frequently, blackening tends to occur early. In this case, if the filament heating amount is increased, blackening can be suppressed. Therefore, it is possible to configure so that the heating amount of the filament is controlled according to the blinking frequency. In this case, if it is known in advance that the blinking frequency is high, the filament heating amount may be increased from the beginning. If the blinking frequency is not fixed, a blinking frequency detecting means may be provided to automatically change the filament heating amount according to the detection signal. In this case, the change may be continuous or may be changed intermittently. In the latter case, it may be configured to change in at least two stages.

Furthermore, the filament switching means can be controlled so as not to reduce the amount of filament heating during filament preheating of the discharge lamp. Thereby, the filament electrode can be sufficiently preheated.
Furthermore, in order to ensure this, the reactance can be set smaller than in a conventional filament heating circuit. As a result, the starting voltage can be greatly reduced.

Further, when the power supply means of the discharge lamp is constituted by a high-frequency AC power supply having a variable operating frequency, the duty of the filament switch means is changed in accordance with the operation frequency of the high-frequency AC power supply. be able to. When the inductance is used as the current limiting impedance of the load circuit, when the operating frequency of the power supply increases, the lamp current decreases and the discharge lamp enters a dimming state, and the duty of the filament switch changes accordingly. Therefore, it is possible to control the filament heating current so as to be substantially constant or to reduce the change.

Next, in order to control the filament switch means as required, a means for detecting the lighting state of the discharge lamp may be provided and controlled in accordance with the detection signal. As a lighting state detecting means of the discharge lamp, for example, a current detecting means is inserted in a portion where the discharge current of the load circuit and the filament heating current flow in a superimposed manner, and a first detection indicating a current value at the moment when the discharge current becomes almost zero is performed. The data and second detection data indicating the current value at the moment when the filament heating current becomes substantially zero are extracted based on the detection signal, and the lighting state of the discharge lamp is determined based on the first and second detection data. be able to. Then, the ment heating current can be detected based on the first detection data.

Further, in order to determine an appropriate control amount according to the detection signal, the detection signal is recorded using programmable digital processing means configured using a central processing unit, a read-only memory, a temporary storage memory, and the like. In addition to performing the determination, the required control amount can be obtained by calculation. Further, by using a microcomputer in which such programmable digital processing means is integrated into one chip, downsizing, weight reduction, and simplification of circuit connection can be achieved.

<Other Configurations> In order to determine a required control amount for the filament switch means for controlling the filament heating amount, when a digital processing means is employed using a central processing means and an associated memory, etc. The power supply means can be controlled using the digital processing means. For example, in a case where the power supply means includes a switching means and its drive circuit, if the digital processing means constitutes an oscillator to excite the drive circuit, the control means for the power supply means is constituted, and the lighting state is changed. , And a series of controls such as control of the filament switch means based on the determination result can be easily and reliably performed.

<Function of the Present Invention> In the present invention, in the configuration in which the filament heating circuit of the reactance heating circuit system is used to heat the filament of the discharge lamp, the filament heating amount is controlled by the filament switch means that is turned on and off periodically. Therefore, the filament can be heated to a required degree according to the lighting state of the discharge lamp. For example, when dimming the discharge lamp, the filament heating means is turned on and off periodically to reduce one or both of the filament voltage and the filament heating current, so that the filament heating amount is almost the same as at the time of all light spots. Can be maintained. Further, if necessary, by adjusting the degree of filament heating control, the amount of filament heating can be appropriately increased or reduced as compared to the all-lights-on state. . For this reason, the filament heating can be appropriately performed for a wide range of changes in the lighting state, and at the time of starting and lighting, so that blackening is reduced and the life of the discharge lamp is prolonged.

Further, by setting the switching frequency of the filament switch means to an appropriate value, it is possible to reduce the temperature change of the filament electrode so that the thermoelectron emission of the filament electrode is not adversely affected.

Further, by lowering the starting voltage so that sufficient filament preheating can be performed at the time of starting, the cost can be reduced by using circuit components having a low withstand voltage.

Further, the adoption of the reactance heating circuit system simplifies the circuit configuration of the filament heating circuit.
Since the number of circuit components is reduced, the cost can be reduced.

The discharge lamp lighting device according to the second aspect of the present invention
2. The discharge lamp lighting device according to claim 1, wherein the filament switching means has a switching cycle shorter than a thermal time constant of the filament electrode.

The filament electrode is brought into a thermionic emission state when the electron-emitting substance carried thereon is heated. Since it has a certain heat capacity, it has a thermal time constant.

Thus, in the present invention, the filament switch means is turned on and off within a time shorter than the thermal time constant of the filament electrode, so that the temperature distribution of the filament electrode is always substantially constant, and the heat generated by the filament switch means is reduced. The electron emission action is not adversely affected.

Further, since the filament switch means can be switched at a frequency lower than the operating frequency of the switching means of the power supply means, a low-speed and inexpensive switch can be used.

According to a third aspect of the present invention, there is provided a discharge lamp lighting device,
Power supply means for converting a low-frequency AC power supply voltage into a controllable output voltage; current limiting impedance, a discharge lamp having a pair of filament electrodes energized from the power supply means via the current limiting impedance, and a pair of filament electrodes A load circuit including a filament heating circuit in which the non-power supply side terminals are connected via a reactance; and a filament switch means for switching at a frequency twice the power supply frequency of the low-frequency AC power supply to control the amount of filament heating. ;
It is characterized by having.

According to the present invention, when a controllable power source is obtained by using a low-frequency AC power source to light a discharge lamp,
The switching frequency of the filament switch means for controlling the filament heating amount is specified to be twice the frequency of the low-frequency AC power supply.

Thus, in the present invention, the filament switch means can be switched in synchronization with the low-frequency AC power supply. For this reason, the switching control of the filament switch means is facilitated.

Further, by controlling the filament switch means near the peak of the low-frequency AC power supply voltage waveform, ie, near the peak value, to cut off the filament current, and passing the filament heating current near the valley, ie, near the zero value, the low-frequency Since the peak value of the input current from the power supply can be reduced, the crest factor can be improved, and the input current waveform can be made closer to a sine wave.

According to a fourth aspect of the present invention, there is provided a discharge lamp lighting device comprising:
Power supply means for converting a low-frequency AC power supply voltage into a controllable output voltage by using switching of the switching means; current limiting impedance; and a pair of filament electrodes energized from the power supply means via the current limiting impedance. A discharge lamp and a load circuit including a filament heating circuit in which a non-power supply side terminal of the pair of filament electrodes is connected via a reactance; and a filament heating amount by switching at a frequency lower than the switching frequency of the switching means of the power supply means. And filament switching means for controlling the

The switching frequency of the filament switch means may be lower than the switching frequency of the power supply means, and there is no numerical limit. Preferably, the switching frequency is equal to or higher than a frequency having a cycle shorter than the thermal time constant of the filament electrode. . However, if necessary, a frequency having a period longer than the thermal time constant is allowed. If the power supply means has a high frequency of, for example, 40 kHz or more, the switching frequency of the filament switch means is set to, for example, 20 kHz.
As described above, the frequency can be reduced to less than 40 kHz. Thus, the switching of the filament electrode causes an audible sound and no noise is generated.

Thus, in the present invention, the switching frequency of the filament switch means is switched at a lower frequency than the switching frequency of the switching means of the power supply means, so that a low-speed switching means can be used. Therefore, the filament switch means can be obtained at low cost.

A discharge lamp lighting device according to a fifth aspect of the present invention
According to a fourth aspect of the present invention, in the discharge lamp lighting device, the filament switching means has a switching frequency that is an integer fraction of the switching frequency of the switching means in the power supply means.

In the present invention, the switching means of the power supply means and the filament switch means can be synchronously switched. In addition, it becomes possible to obtain a drive signal for the power supply means using a common oscillator and a drive signal for the filament switch means by further dividing the frequency. For example, a microcomputer can be used as control means for driving the switching means of the power supply means, and the output pulse from the internal timer can be divided to obtain a drive signal for the filament switch means. This makes it possible to share circuit elements or circuit components and programs.

According to a sixth aspect of the present invention, there is provided a discharge lamp lighting device,
Power supply means for converting a low-frequency AC power supply voltage into a controllable output voltage by using switching of the switching means; current limiting impedance; and a pair of filament electrodes energized from the power supply means via the current limiting impedance. A discharge lamp and a load circuit including a filament heating circuit in which the non-power-supply-side terminals of the pair of filament electrodes are connected via a reactance; a frequency equal to the switching frequency of the switching means of the power supply means, and a phase shifted therefrom And a filament switch means for controlling the amount of heating of the filament by switching at the same time.

The present invention specifies a configuration in which the switching frequency of the filament switch means is made equal to the switching frequency of the switching means of the power supply means.

The arrangement of the filament switch means for controlling the heating of the filament is the same as in the preceding claim. In the present invention, the switching is synchronized with the switching of the switching means of the power supply means, but the phase is changed. The difference is that the filament switch means is driven by being shifted.
The degree of the phase shift can be varied depending on the degree of filament heating. Therefore, the manner of connection of the filament switch means to the filament can be the same as in the preceding claim. When the filament switch is connected in series to the filament, the filament switch is turned on a predetermined time after the switching of the power supply is turned off. When the filament switching means is connected in parallel to the filament, the filament switching means is turned on when the switching means of the power supply means is turned on, and the filament switching means is provided a predetermined time after the switching means of the power supply means is turned off. Off.

In order to control the filament heating, for example, a filament current is detected, a filament voltage or a lamp voltage is detected, and a required filament heating amount is obtained by calculation based on the detected value. , The switching phase of the filament switch means can be determined. The switching phase of the filament switch means can also be calculated. These calculations can be performed using a programmable element such as a CPU.

Thus, in the present invention, since the switching phase of the switching means of the power supply means and the switching phase of the filament switch means are shifted, noise due to the switching of the switching means is reduced.

The starting voltage can be reduced by increasing the reactance connected to the filament heating circuit and performing sufficient preheating at the time of filament preheating.
Therefore, inexpensive circuit components having relatively low withstand voltage can be used, and cost can be reduced.

A discharge lamp lighting device according to a seventh aspect of the present invention
The discharge lamp lighting device according to any one of claims 1 to 6, wherein the filament switching means has a variable switching duty.

According to the present invention, by varying the duty of the filament switch means, it is possible to control the heating amount of the filament to be within a required range even if the lighting state of the discharge lamp is variously changed.

In order to control the amount of heating of the filament, a detecting means for detecting the filament voltage or the filament heating current is provided, and a signal calculated and processed in the microcomputer so that the average value of the detected signals is constant. By driving the filament switch, the duty of the filament switch can be controlled. Further, the configuration is such that the filament voltage and the filament heating current are detected, and the microcomputer performs arithmetic processing so that the filament resistance becomes constant to form a drive signal for the filament switch means to control the duty of the switching means. Can also.

The discharge lamp lighting device according to the invention of claim 8 is:
The discharge lamp lighting device according to any one of claims 1 to 7, wherein the filament switching means has a variable switching duty in accordance with a dimming signal.

When the discharge lamp is dimmed and lit, the lamp voltage rises as described above, and it is necessary to reduce the filament heating current. In the present invention, however, the duty of the filament switch means is controlled based on the dimming signal. To control the heating amount of the filament to an appropriate value. This can prevent excessive preheating at the time of dimming.

When a control amount is obtained by calculation using a programmable element such as a microcomputer, an appropriate control amount can be obtained by using a dimming signal and table data set in the microcomputer in advance.

Thus, in the present invention, the duty of the filament switch means is controlled according to the dimming signal, so that the amount of heating of the filament can be easily controlled.

According to a ninth aspect of the present invention, there is provided a discharge lamp lighting device comprising:
The discharge lamp lighting device according to any one of claims 1 to 8, wherein the filament switch means controls switching so that a filament heating current becomes substantially constant.

In the present invention, the filament heating current can be made substantially constant by making the filament heating current substantially constant.

In order to make the filament heating current substantially constant, for example, a means for detecting the filament heating current is provided, the detection signal is compared with a preset reference value, and arithmetic processing is performed so as to eliminate the difference. Then, a drive signal may be formed to drive the filament switch means.

Thus, according to the present invention, an appropriate filament heating amount can be set according to the lighting state of the discharge lamp.

According to a tenth aspect of the present invention, in the discharge lamp lighting device according to any one of the first to ninth aspects, the filament switch means makes the filament voltage applied to the filament electrode substantially constant. The switching is controlled as described above.

In the present invention, the filament heating amount becomes substantially constant by making the filament voltage substantially constant.

To make the filament voltage almost constant,
For example, a filament voltage detecting means may be provided, the detected signal may be compared with a preset reference value, and a processing signal may be processed so as to eliminate the difference, a drive signal may be formed, and the filament switch means may be driven. .

Thus, according to the present invention, an appropriate filament heating amount can be set according to the lighting state of the discharge lamp.

In the discharge lamp lighting device according to the eleventh aspect of the present invention, in the discharge lamp lighting device according to any one of the first to tenth aspects, the filament switch means is provided so that the filament voltage / filament heating current becomes substantially constant. Switching is controlled.

The present invention defines a configuration for controlling the filament switch means so that the filament voltage / filament heating current, that is, the filament resistance, becomes substantially constant.

That is, if the filament temperature is too high, the damage to the filament electrode increases, so it is desirable to maintain the filament temperature at an appropriate value. The filament electrode is made of tungsten, and its resistance has a positive temperature characteristic. Thus, the filament temperature can be expressed as a function of the filament resistance. If the filament resistance is kept constant, the filament temperature can be kept constant.

In order to keep the filament resistance constant in accordance with the present invention, a filament voltage detecting means and a filament heating current detecting means are respectively provided, and the filament voltage detecting signal and the filament heating current detecting signal are calculated by using arithmetic means. Then, the filament resistance is calculated based on the calculation. Then, the on-duty of the filament switch means may be feedback-controlled in accordance with the calculation result.

Thus, in the present invention, by controlling the filament resistance to be constant, the filament temperature can be kept constant and the damage to the filament electrode can be reduced.

A discharge lamp lighting device according to a twelfth aspect of the present invention provides a discharge lamp lighting device comprising: a power supply means; a current limiting impedance; a discharge lamp having a pair of filament electrodes energized from the power supply means via the current limiting impedance; A load circuit including a filament heating circuit in which the non-power-supply-side terminals of the electrodes are connected via a reactance; switch means for periodically turning on and off to control the amount of filament heating; It is characterized by comprising: lighting integrated time measuring means for measuring; and control means for controlling the filament switch means so as to control the filament heating amount as required according to the lighting integrated time.

The discharge lamp has a tendency that the lamp voltage gradually increases as the lighting time increases. For this reason, when the filament heating circuit of the reactance heating circuit type is provided, the amount of filament heating increases with the progress of the life, and the filament heating tends to be excessive.

In the present invention, since the integrated lighting time measuring means is provided and the filament switch means is controlled in accordance with the integrated lighting time, the amount of heating of the filament during the life of the discharge lamp can be controlled as required.

The lighting integrated time measuring means can, for example, write the data in the RAM in the microcomputer to integrate the lighting time. Then, a program of the filament heating amount with respect to the lighting time may be incorporated in the microcomputer in advance, and the filament heating amount may be determined by this program to control the filament switch means.

A discharge lamp lighting device according to a thirteenth aspect of the present invention is the discharge lamp lighting device according to any one of the first to twelfth aspects, further comprising end-of-life detection means for detecting the end of life of the discharge lamp; The filament switching means is controlled based on the detection signal of the end-of-life detecting means at the end of the life of the discharge lamp so as to substantially prevent the filament heating current from flowing.

The present invention defines a configuration in which a protective operation is performed using the filament switch means when the discharge lamp reaches the end of its life.

When the filament electrode is at the end of its life, an electron-emitting substance is deposited on the flare stem located at both ends of the light-transmitting discharge vessel and supporting the electrode, and the resistive electrode connected in parallel with the filament electrode is formed. A conductive path is formed.
Then, since the filament heating current flows through the resistive conductive path in a bypass manner, heat is generated, and the tube end of the discharge lamp is overheated and the temperature rises abnormally, which is likely to cause inconvenience.

In the present invention, since the filament heating current does not flow to the filament electrode at the end of the life of the discharge lamp, the above-mentioned inconvenience can be prevented.

By the way, when the filament switching means performs the protection operation, the case where the filament switching means is connected in series to the filament heating circuit and the case where it is connected in parallel to the filament electrode are different.

When the filament switching means is connected in series to the filament heating circuit, by turning off the filament switching means, the filament heating circuit can be opened and the filament heating current can be interrupted to perform a protection operation. .

When the filament switch is connected in parallel to the filament electrode, the filament switch is turned on to short-circuit the filament electrode, and the filament heating current flowing through the filament electrode is cut off. A protection operation can be performed.

In order to detect the end of life of the discharge lamp, for example, a lamp voltage appearing between a pair of filament electrodes of the discharge lamp is monitored to detect an abnormal increase in lamp voltage at the end of life. It is possible to detect the half-wave discharge current flowing at the time, or to detect the temperature of the base of the discharge lamp with a temperature sensor.

A lighting device according to a fourteenth aspect of the present invention is the lighting device main body;
And a discharge lamp lighting device according to any one of the above.

The lighting device of the present invention is a broad concept including any device that uses the light emitted from a discharge lamp for some purpose, and a device corresponding to this is generally called a lighting device.
For example, various lighting fixtures, display devices, image forming devices, and the like.

The lighting equipment includes indoor and outdoor lighting equipment.

The display device includes an internally illuminated display device and an externally illuminated display device.

The image forming apparatus is a copying machine, a scanner or the like.

The “illumination device main body” means a remaining portion obtained by removing the discharge lamp lighting device from the illumination device.

[0093]

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

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

FIG. 2 is a block circuit diagram showing the digital processing means.

In each figure, AS is a low-frequency AC power supply,
W is a power switch, NF is a noise filter, RDC is a rectified DC power supply, HFG is power supply means, LC is a load circuit, D
PY is digital processing means, FS is filament switch means, FVD is filament voltage detection means, SSL is a blinking signal line, and DML is a dimming operation line.

<Regarding the Low Frequency AC Power Supply AS> The low frequency AC power supply AS is a commercial AC power supply.

<Power Switch SW> The power switch SW is connected in series between the low-frequency AC power supply AS and the noise filter NF. Then, it is closed when the power is turned on. Therefore, the power switch SW may be either a contact or a non-contact as long as the power switch SW has a power disconnection function.

<Regarding Noise Filter NF> The noise filter NF is interposed between the low-frequency AC power supply AS and the rectified DC power supply RDC, and converts the high-frequency noise generated by the high-frequency switching in the power supply means HFG described later into the low-frequency AC power supply. It is prevented from flowing out to the AS side.

<Regarding Rectified DC Power Supply RDC> The rectified DC power supply RDC is constituted by a full-wave rectifier circuit FBR interposed between a noise filter NF and an active filter AF described later, and rectifies a low-frequency AC voltage. To output a non-smooth DC voltage.

<Regarding Power Supply Means HFG> Power Supply Means HF
G includes an active filter AF and a high-frequency inverter HFI.

The active filter AF comprises a boost chopper interposed between the rectified DC power supply RDC and the high frequency inverter HFI. Then, the DC voltage that has been smoothed and boosted as required is output at a high power factor and under low harmonic distortion. That is, the active filter AF
Is composed of an inductor L1, a switching means Q1, a gate drive circuit GDC1, a diode D1, and a smoothing capacitor C1. The inductor L1 and the switching means Q1 form a series circuit to form a rectified DC power supply RDC.
Connected between the DC output terminals. Gate drive circuit G
DC1 is connected so as to apply a gate drive signal between the gate and source of the switching means Q1.
The diode D1 and the smoothing capacitor C1 form a series circuit and are connected between both ends of the switching means Q1. Then, smoothing is performed, which is proportional to the ON time + OFF time of the switching means Q1, that is, the switching cycle,
A variable DC voltage which is inversely proportional to the off time is obtained between both ends of the smoothing capacitor C1.

The high-frequency inverter HFI operates using the smoothed direct current obtained from the active filter AF as a power supply, and outputs a high-frequency voltage to its output terminal by alternate high-frequency switching of the first and second switching means Q2 and Q3. That is, the high-frequency inverter HFI is:
It comprises first and second switching means Q2, Q3, and a gate drive circuit GDC2 for supplying a gate voltage to these switching means Q2, Q3. The first and second switching means Q2, Q3 are:
It is composed of N-channel MOSFETs, connected in series with each other and connected so that a DC power supply voltage is applied between the output terminals of the active filter AF. The gate drive circuit GDC2 performs high-frequency switching alternately by applying a gate voltage having an opposite phase relationship between the gate and source of the first and second switching means Q2 and Q3.
A high-frequency AC voltage of a rectangular wave proportional to the DC input voltage is output between both ends of the switching means Q3. Then, the gate drive circuit GDC2 generates a gate drive signal according to a control signal from the control means CC described later and supplies the gate drive signal to the gates of the switching means Q1 and Q2.

<About Load Circuit LC> Load Circuit LC
Is the DC cut capacitor C2, the current limiting impedance L
2. Discharge lamp DL and filament heating circuit FH
C. DC cut capacitor C2 is
A capacitor having a relatively large capacitance is used, and cut off so that a DC component does not flow into the load circuit LC from the high frequency inverter HFI of the high frequency generating means HFG. The current limiting impedance L2 is constituted by a choke coil type inductor. The discharge lamp DL includes a fluorescent lamp having a pair of filament electrodes E1 and E2. The filament heating circuit FHC is configured in an impedance preheating circuit system by connecting a capacitor C3 between the non-power-supply-side terminals of the pair of filament electrodes E1 and E2 of the discharge lamp DL, and connects the pair of filament electrodes E1 and E2. At least at the time of preheating, heating to thermionic emission state is performed.

<Regarding Digital Processing Unit DPY> As shown in FIG. 2, the digital processing unit DPY includes a central processing unit CPU, a rewritable nonvolatile memory EEPROM, a read-only memory ROM, and a temporary storage memory RAM connected to a bus line B. And includes functions of a determination unit, a recording unit, a control unit, and a protection unit. The read-only memory ROM stores data such as filament heating amount reference data, dimming data, blinking frequency reference data, a determination program, and a control program.

Further, since the filament voltage detecting means FVD, the blinking signal line SSL and the dimming operation line MDL are individually input to the central processing means CPU, the end of the life of the discharge lamp DL and the absence of the lamp are determined. Perform a required protection operation, determine a filament heating amount, a dimming degree, and a blinking frequency, and generate a required control signal for a filament switch means FS, which will be described later, and a required control signal for the high frequency generation means HFG. Send out.

Further, the central processing means CPU has a lighting integrated measurement function, and a rewritable nonvolatile memory EEPROM stores lighting integrated time data. The central processing means CPU reads out the accumulated lighting time data, generates a control signal for the filament switch means FS so as to perform the corresponding filament heating, and sends the control signal to the filament switch means FS.

Therefore, the digital processing means DP
The dimming degree and the blinking frequency of the discharge lamp DL are determined using Y, and the filament heating amount can be controlled based on the determination result. Further, by controlling the high-frequency generating means HFG, the control sequence of filament preheating, starting and lighting of the discharge lamp DL can be automatically performed, or dimming control can be performed.

<Regarding Filament Switching Means FS> The filament switching means FS is constituted by voltage variable circuits connected in parallel to a pair of filament electrodes E1 and E2 of the discharge lamp DL, respectively. That is, the filament switch FS is configured by connecting a pair of a series circuit of the switch element Tr and the diode D2 in anti-parallel. Then, M is used as the switch element Tr.
Since the OSFET is used and the potential of the gate is controlled by a control signal from the digital processing means CPU, the ON / OFF and duty change and the voltage applied to the filament electrodes E1 and E2 is variable. The filament heating current flowing through E1 and E2 increases and decreases, and thus the filament preheating amount can be changed.

<Regarding Filament Voltage Detecting Means FVD> The filament voltage detecting means FVD is connected to both ends of the filament electrode E2 to detect the voltage applied to the filament electrode, and converts the detection signal into digital processing means. Control input is made to the DPY, where the amount of filament heating of the discharge lamp DL and the presence / absence of lamp installation are determined.

<Regarding the Blinking Signal Line SSL> The blinking signal line SSL can obtain blinking frequency data from the load side of the power switch SW, and can be connected to the control input terminal of the digital processing means DPY to provide digital processing means. D
The frequency of blinking is recorded and determined inside the PY.

<Regarding the dimming operation line DML> The dimming operation line DML is controlled by inputting an operation signal to the digital processing means DPY and supplying dimming instruction information as an arithmetic element when determining the heating amount of the filament. A control signal corresponding to the dimming degree is formed by the digital processing means DPY and sent to the high frequency inverter HFI. The dimming operation line DML is connected to a dimming operation unit whose base end (not shown) is disposed at a position separated from the discharge lamp lighting device.

<Circuit Operation> At the time of filament preheating of the discharge lamp, power is supplied from the power supply means HFG so that the reduced voltage at the time of preheating is applied to the discharge lamp DL. At this time, the filament switch means FS
Is off. For this reason, the filament electrodes E1, E
2, a filament heating current of a magnitude determined by the filament resistance and the reactance of the capacitor C3 and the starting voltage flows, and the filament electrodes E1 and E2
Is sufficiently preheated to a thermionic emission state.

At the time of starting, since the power is supplied from the power supply means HFG so that a high starting voltage is applied to the discharge lamp DL, the discharge lamp DL starts and lights up. In this case, the filament switch means FS is in the same state as during preheating.

When the discharge lamp DL is turned on,
Power is supplied from the power supply means HFG so that a reduced lighting voltage required for maintaining lighting is applied to the discharge lamp DL. In the lighting state, the filament switch means FS performs switching with a relatively small on-duty, and the filament heating amount becomes a value as the lighting state.

Power supply means HFG in each of the above steps
The control of the filament switch means FS is performed by a control signal sent from the digital processing means DPY.

Next, when a dimming operation signal arrives at the dimming operation line DML, power is supplied from the power supply means HFG so as to reduce the light output to the discharge lamp DL, and
The filament switch means FS performs switching with a relatively large on-duty. However, since the lamp voltage of the discharge lamp DL increases due to the dimming, the filament heating amount is maintained at a value that is almost the same as when the all light is turned on.

On the other hand, when the digital processing means DPY determines that the blinking data inputted from the blinking signal line SS to the digital processing means DPY exceeds a predetermined frequency, the control signal for the filament switching means FS is increased to relatively increase the filament heating amount. And send it out.

The central processing means CPU measures the integrated lighting time, generates a control signal whose on-duty is gradually increased in accordance with the integrated lighting time, and supplies it to the filament switch means FS. As a result, the on-duty of the filament switch means FS relatively gradually increases, but the lamp voltage gradually increases during that time, so that the filament heating amount is maintained substantially constant throughout the lighting integration time.

In the filament switching means FS, since a pair of the switching elements Tr are connected in anti-parallel, the filament voltage applied to the filament electrodes E1 and E2 with respect to the positive and negative half-waves of the high-frequency AC current. Is controlled.

On the other hand, when the discharge lamp DL reaches the end of its life, a half-wave discharge occurs. Therefore, by providing an end-of-life detection means (not shown), this is detected, and the detection signal is sent to the digital processing means DPY. Control input. As a result, the control signal supplied from the digital processing means DPY to the gate drive circuit GDC2 of the high-frequency inverter HFI is cut off.
Stops the operation, the application of the high-frequency voltage to the discharge lamp DL is stopped, and the protection operation is performed.

Further, the filament voltage detecting means FVD
Detects that the discharge lamp DL is not mounted, the detection signal is control-input to the digital processing means DPY. As a result, the gate drive circuit GDC of the high-frequency inverter HFI is supplied from the digital processing means DPY in the same manner as at the end of the life.
2, the high-frequency inverter HFI stops operating, the high-frequency voltage is not applied to the discharge lamp DL, and the protection operation is performed.

FIG. 3 is a graph showing the relationship between the light output and the on-duty of the switching means of the high-frequency inverter in the first embodiment of the discharge lamp lighting device of the present invention.

In the figure, the horizontal axis represents the light output, and the vertical axis represents the on-duty.

The on-duty of the switching means Q2, Q3 of the high-frequency inverter HFI is variable by a control signal sent from the digital processing means DPY. Therefore, the discharge lamp DL can be continuously changed from the all-light state to the dimming state.

FIG. 4 is a graph conceptually showing the relationship between the filament heating current and the starting voltage in the first embodiment of the discharge lamp lighting device of the present invention.

In the figure, the horizontal axis represents the filament heating current, and the vertical axis represents the starting voltage. That is, when the filament heating current is increased during preheating, the starting voltage decreases, and becomes substantially saturated at a certain value or more.

FIG. 5 is a graph conceptually showing an optimum operating region and an underheated region in the relationship between the lamp current and the filament heating current in the first embodiment of the discharge lamp lighting device of the present invention.

In the figure, the horizontal axis represents the lamp current, and the vertical axis represents the filament heating current. That is, the drawing shows that when the lamp current is small, the filament can be lit in an optimum operating range within a certain limit by increasing the filament heating current.

FIG. 6 is a circuit diagram showing a discharge lamp lighting device according to a second embodiment of the present invention.

In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, the load circuit LC and the filament switch means FS are different.

That is, in the load circuit LC, a pair of discharge lamps DL1 and DL2 are connected in series. The filament switch means FS includes a capacitor C3, a primary winding p of the transformer T, and a filament switch means F between the non-power supply side terminals of the filament electrode E11 of the discharge lamp DL1 and the filament electrode E22 of the discharge lamp DL2.
A series circuit of S is connected, and a filament electrode E21 of the discharge lamp DL1 and a filament electrode E12 of the discharge lamp DL2 are connected in series to both ends of the secondary winding s of the transformer T.

The filament switch means FS comprises a switching element Tr, a series circuit of a gate drive circuit GD3 of the switching element Tr and a diode D2.

Then, the filament switch means FS
By changing the on-duty of the switch element Tr with respect to the half-wave of one polarity, the filament heating current can be increased or decreased to increase or decrease the filament heating amount. The half wave of the other polarity flows through the diode D2 without control.

FIG. 7 is a waveform diagram showing voltage waveforms at various parts in the third embodiment of the discharge lamp lighting device according to the present invention.

In the figure, (a) is a low-frequency AC power supply voltage waveform, (b) is a control voltage of the filament switch means,
(C) shows the filament heating voltage, respectively.

In this embodiment, the filament switch means FS is switched at twice the frequency of the low-frequency AC power supply voltage, and is turned off at the peaks of the low-frequency AC power supply voltage waveform and turned on at the valleys. It is configured as follows.

FIG. 8 is a circuit diagram showing a fourth embodiment of the discharge lamp lighting device according to the present invention.

In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, the filament switch means FS and the lamp voltage detection means LV
D is different. That is, the filament switch means FS
Consists of an AC power coupler PC and is inserted in series into the filament heating circuit FHC.

The AC power coupler PC connects the light trigger thyristor PTS and the photodiode PD to the light shielding case K.
The light trigger thyristor PTS is inserted into the filament heating circuit FHC, and the photodiode PD is connected to the digital processing means DPY via the switch means Q4.
It is configured to be controlled by:

The lamp voltage detecting means LVD is connected in parallel with the discharge lamp DL, and its detection signal is control-input to the digital processing means DPY via the analog / digital converter A / D.

FIG. 9 is a circuit diagram showing a discharge lamp lighting device according to a fifth embodiment of the present invention.

In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description is omitted. This embodiment includes a current detection unit CD and an individual data extraction unit IDS instead of the filament voltage detection unit FVD,
The filament switch means FS is different.

The current detecting means CD comprises a resistor R1, and the resistor R1 is inserted between the source of the second switching means Q3 and the power supply terminal of the filament electrode E2 of the discharge lamp DL. Then, a voltage drop proportional to the current flowing through the resistor R1 occurs, and a current in which the discharge current and the filament heating current are superimposed is detected.

The individual data extracting means IDS is an analog data extracting means.
Digital converter A / D and timing circuit TC
Consists of The analog / digital converter A / D is
The voltage drop of the resistor R1 is input, and the digital output is controlled and input to digital processing means DPY described later. The timing circuit TC is controlled by the digital processing means DPY to supply a timing output to the analog / digital converter A / D. The supply timing is both the moment when the discharge current becomes substantially zero and the moment when the filament heating current becomes substantially zero.

At the moment when the discharge current becomes almost zero, the first digital method corresponding to the filament heating current is used.
Is output to the digital processing means DPY.
At the moment when the filament heating current becomes almost zero, the digital second detection data corresponding to the discharge current is similarly output.

The filament switching means FS has the same configuration as that of the second embodiment shown in FIG. 6 except for the transformer T.

Next, the circuit operation will be described.

FIG. 10 is a waveform diagram showing the phase relationship between the discharge current and the filament heating current in the discharge lamp lighting device according to the fifth embodiment of the present invention.

In the drawing, Il indicates a discharge current, and If indicates a filament heating current. Since the filament heating current If is advanced in phase with respect to the discharge current Il, when the discharge current Il is 0, the current flowing through the resistor R1 is essentially only the filament heating current. At the moment when the filament heating current is 0, the current flowing through the resistor R1 is essentially only the discharge current.

Therefore, when the timing signal is supplied from the timing circuit TC to the analog / digital converter A / D under the control of the digital processing means DPY at the moment when the discharge current is almost zero, the current data corresponding to the filament heating current is converted to the first data. Is obtained as detection data. Similarly, by supplying a timing signal at the moment when the filament heating current is almost zero, current data corresponding to the discharge current is obtained as the second data.

The first and second detection data are temporarily stored in the temporary storage memory RAM via the central processing unit CPU, then read out and read out by the central processing unit CP.
Inside U, the first and second data are multiplied to obtain lamp power data.

Next, the lamp power data is compared with the reference data, and a control signal corresponding to the difference is generated in the central processing unit CPU and supplied to the controllable power supply HFG. Therefore, in the high-frequency inverter HFI of the controllable power supply HFG, its gate drive circuit GDC2 generates a gate drive signal corresponding to the control signal and applies the gate drive signal to the first and second switching means Q2 and Q3 alternately. , Their on-duty changes in response to the control signal.

As a result, the lamp current increases and decreases, and constant power is input to the discharge lamp DL.

It should be noted that the controllable power supply HFG can be controlled to automatically execute a control sequence of filament preheating, starting and lighting of the discharge lamp DL, or to perform dimming control. In addition, it is possible to determine the end of life or whether the lamp is not mounted and perform a required protection operation.

FIG. 11 is a circuit diagram showing a sixth embodiment of the discharge lamp lighting device according to the present invention.

In the figure, the same parts as those in FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, the individual data extraction means IDS 'is different. That is, the individual data extraction means IDS ′ includes the first and second sample and hold circuits SH1, SH2, and the timing circuit TC
It is composed of

The first and second sample-and-hold circuits SH1 and SH2 have their input terminals connected so as to input the voltage drop of the resistor R1, but their output terminals are connected to the respective ports of the digital processing means DY. It is connected.

The timing circuit TC is provided so as to input respective timings of the first and second sample and hold circuits SH1 and SH2.

FIG. 12 is a waveform diagram showing a gate drive signal of the filament switch means in the discharge lamp lighting device according to the seventh embodiment of the present invention.

In this embodiment, in the circuit configuration of the filament switch means FS as shown in FIG. 1, when the end of life is detected by the end of life detecting means not shown in FIG. The drive signal is configured to be continuously supplied.
Therefore, at the end of life, the filament switch means F
Since the S gate drive signal becomes the continuous ON signal COS, the filament electrodes E1 and E2 are short-circuited, and the filament heating current is cut off.

FIG. 13 is a waveform diagram showing a gate drive signal of the filament switch means in the eighth embodiment of the discharge lamp lighting device of the present invention.

In the present embodiment, in the circuit configuration of the filament switch means FS as shown in FIG. 6, when the end of life is detected by the end of life detecting means not shown in FIG. The drive signal is continuously cut off.
Therefore, at the end of life, the filament switch means F
Since the gate drive signal of S becomes the continuous off signal CFS, the filament heating circuit FHC is opened.

FIG. 14 is a circuit diagram showing a ninth embodiment of the discharge lamp lighting device according to the present invention.

FIG. 15 is a circuit diagram showing a circuit configuration of the current detecting means CD.

In each figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. This embodiment is different in that the filament switch means FS is configured to switch in synchronization with the switching of the switching means Q1 and Q2 of the power supply means HFG.

In order to detect a current flowing through the load circuit LC, current detecting means CD is inserted in series with the load circuit LC. As shown in FIG. 15, the current detecting means CD includes a current transformer CT, a voltage doubler rectifier circuit DRC, and an A / D converter ADC. The current transformer CT is
A secondary winding is inserted in series with the load circuit LC. The voltage doubler rectifier circuit DRC includes capacitors C4 and C5, diodes D3 and D4, and a resistor R2. Capacitor C4
The diode D3 forms a series circuit and is connected between both ends of the secondary winding of the current transformer CT. The capacitor C5 and the diode D4 form a series circuit and are connected between both ends of the diode D3 so as to be in the forward direction with respect to the polarity of the charge of the capacitor C4. Resistor R2
Are connected to both ends of the capacitor C5. The A / D converter ADC inputs the pulsating DC voltage appearing at both ends of the resistor R2, converts the pulsating DC voltage into a digital signal, and outputs the digital signal.

Next, the circuit operation in this embodiment will be described.

After the power switch SW is turned on, the filament switch means FS is turned off as a preheating period for a predetermined time preset in the digital processing means DPY. Since the capacity of the capacitor C3 of the filament heating circuit FHC in the load circuit LC is relatively large, a sufficient filament heating current flows to lower the starting voltage. When the discharge lamp DL is started and turned on, the filament heating current and the lamp current flow in the load circuit LC in a superimposed manner.

FIG. 16 is a waveform diagram conceptually illustrating a current flowing through a load circuit during lighting of the discharge lamp in the ninth embodiment of the discharge lamp lighting device of the present invention.

In the figure, (a) shows the waveform of each current flowing through the load circuit, (b) shows the output voltage waveform of the voltage doubler rectifier circuit,
Are respectively shown. i _LC is the load circuit current, i _L is the lamp current, i _F is the filament heating current, and V _CD is the output voltage of the voltage doubler rectifier circuit.

The load circuit current i _LC is the lamp current i
And _L, and the vector sum of the filament heating current i _F. The phases of the lamp current i _L and the filament heating current i _F are shifted by approximately 90 °.

The current detecting means CD shown in FIG. 14 detects the load circuit current _iLC . However, in FIG. 16, since the zero-crossing filament heating current _{i F} at time t1, the instantaneous value i1 of the load circuit current _{i LC} at that time represents the lamp current _{i L.} Similarly, since the zero-crossing time t2, the lamp current i _L, the instantaneous value i2 of the load circuit current i _LC at that time indicates the filament heating current i _F. Therefore, the output voltage V _{CD of the} voltage doubler rectifier circuit
The instantaneous value at time t1 corresponds to the lamp current. Likewise, the instantaneous value at time t2 of the output voltage V _CD voltage doubler rectifier circuit corresponds to a filament heating current.

Therefore, the output voltage V _{CD of the} voltage doubler rectifier circuit
Is converted into digital data by the A / D converter ADC and then calculated by the digital processing means DPY, whereby the lamp current i _L and the filament heating current i _F can be individually determined.

In the digital processing means DPY, appropriate values of the lamp current i _L and the filament heating current i _F are set in a table in advance in accordance with the level of the dimming signal. The switching phase of the switching means Q1, Q2, Q3 of the power supply means HFG is determined by calculation, and the drive signal generation circuit GD
A gate pulse is sent to G1 and GDC2. Drive signal generation circuits GDG1 and GDC2 generate gate drive signals in response to gate pulses to generate switching means Q.
Drive 1, Q2 and Q3.

The digital processing means DPY simultaneously synchronizes with the gate pulses of the switching means Q2 and Q3 and generates a gate pulse of a phase necessary for performing the required filament heating to generate the filament switching means FY.
Control the switching of S.

FIG. 17 is a waveform diagram showing waveforms of a current flowing through the switching means of the power supply means and a filament heating current in the ninth embodiment of the discharge lamp lighting device of the present invention.

In the figure, (a) shows the current waveform of the switching means Q2 of the power supply means, and (b) shows the waveform of the filament heating current.

After a time T from when the switching means Q2 of the power supply means HFG is turned off, the filament switching means FS
Is turned on, the filament is short-circuited and the filament heating current is interrupted.

FIG. 18 is a circuit diagram showing a tenth embodiment of the discharge lamp lighting device according to the present invention.

In the figure, the same parts as those in FIG. 8 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, the filament voltage detecting means FVD and the lamp voltage detecting means L
VD is provided so as to perform filament heating control so that the filament voltage is constant, and to perform end-of-life protection of the discharge lamp DL.

That is, the filament voltage detecting means FV
D has a detection input terminal connected to detect the voltage of the filament electrode E2 of the discharge lamp DL, and a detection output terminal A.
It is connected to the analog input terminal of the / D converter ADC.

The digital processing means DPY comprises a central processing means CPU, a memory M, an interface I / O and an A / D converter ADC, which are functionally connected to a bus line. Note that the memory M includes a rewritable nonvolatile memory, a read-only memory, and a temporary storage memory.

The lamp voltage detecting means LVD is provided with capacitors C6, C7, C8, diodes D5, D6, and its detection input terminal is connected so as to detect the lamp voltage of the discharge lamp DL, and the detection output. The terminal is connected to the analog input terminal of the A / D converter ADC. That is, the capacitors C6 and C7 are connected in series between both ends of the discharge lamp DL. The diode D5 is connected in parallel with the capacitor C7. A series circuit of a diode D6 and a capacitor C8 is connected across the diode D5.

The filament voltage detecting means FV
The detection output of D is converted into digital data by an A / D converter ADC and input to the central processing unit CPU, which generates a control signal for the filament switch means FS by calculation, and the control signal passes through the interface I / O. Then, the filament heating means is sent to the filament switch means FS. As a result, the filament heating current is controlled so that the filament voltage becomes constant.

On the other hand, the memory M holds lamp voltage data of the discharge lamp DL. The central processing unit CPU periodically monitors the lamp voltage of the discharge lamp DL. That is, the central processing unit CPU outputs the detection output of the lamp voltage detection unit LVD to the A / D converter ADC.
In step (1), the data is converted into digital data, read into the central processing unit CPU, and compared with the lamp voltage data stored in the memory M. As a result, when the observation data is lower than the ramp voltage data of the memory M, the data held in the memory M is rewritten. If the observation data is higher than the lamp voltage data in the memory M, it is determined that the discharge lamp DL is at the end of its life, and the protection operation is performed. In the protection operation, the output of the power supply means HFG is stopped or is generated intermittently. According to the present embodiment, since a reference value for determining the end of life is not required, there is no need to perform adjustment in advance. Further, even if the type of the discharge lamp is different, it is possible to reliably determine the end of life and perform the protection operation.

FIG. 19 is a circuit diagram showing an eleventh embodiment of the discharge lamp lighting device according to the present invention.

In the figure, the same parts as those in FIG. 18 are denoted by the same reference numerals, and description thereof will be omitted. This embodiment is different from the first embodiment in that the second embodiment is configured to additionally protect the lamp from non-mounting.

That is, a lamp mounting detecting means LFD is provided to protect the lamp mounting. The lamp attachment detecting means LFD connects the resistor R3 between the non-power supply side terminals of the discharge lamp DL and sets the potential of the electrode E2 to A.
The digital data is converted into digital data by the / D converter ADC and read into the central processing unit CPU.

Thus, when the discharge lamp DL is mounted, the potential of the filament electrode E2 is low, but when the discharge lamp DL is not mounted, the high unloaded state of the power supply means HFG via the resistor R3. Since the voltage appears, the central processing unit CPU can determine that the discharge lamp DL is not mounted, and perform the protection operation.

FIG. 20 is a circuit diagram showing a twelfth embodiment of the discharge lamp lighting device according to the present invention.

In the figure, the same parts as those in FIG. 14 are denoted by the same reference numerals, and description thereof will be omitted. The present embodiment is different in that the amount of heating of the filament is controlled as required so that the filament resistance is constant.

That is, in order to make the filament resistance constant, the filament voltage / filament heating current is made constant. A filament voltage detecting means FVD for detecting a filament voltage and a current detecting means CD for detecting a filament heating current are provided. The filament voltage detection means FVD is connected so as to detect the voltage across the filament electrode E2 in the discharge lamp DL. Then, the detection output is controlled and input to the digital processing means DPY via the A / D converter ADC. Also,
In order to detect the filament heating current, a current detecting means CD is provided as in FIG.
Digital processing means DP via a / D converter ADC
Y is input.

Then, the filament heating current is calculated by the digital processing means DPY based on the detection output data of the current detecting means CD, and further, the filament heating current data and the filament voltage data are calculated to obtain the filament voltage / filament heating data. A current, that is, a filament resistance is obtained, and a control signal is sent from the digital processing means DPY to the filament switch means FS so as to make the current constant, thereby performing feedback control.

FIG. 21 is a bottom view showing a ceiling-mounted luminaire as one embodiment of the luminaire of the present invention.

In the figure, 1 is a lighting fixture body, 2 and 2 are fluorescent lamps, and HS is a human sensor.

The lighting fixture main body 1 is provided with a rectangular frame 1a on the lower surface, and a reflection plate 1b inside the decorative frame 1a. Although not shown, the discharge lamp lighting device shown in FIG. 6 is provided on the back side of the reflector 1b except for the fluorescent lamps 2 and 2.

Further, a pair of lamp sockets (not shown) are provided at both ends of the lower surface of the lighting fixture body 1 in the longitudinal direction.

The fluorescent lamps 2, 2 are mounted between the lamp sockets so as to be located in the concave portions of the reflector 1b.

The human sensor HS is inserted in place of the power switch SW in FIG. The sensing area of the human sensor HS substantially coincides with the lighting area below the lighting fixture body 1.

[0201]

According to the first to thirteenth aspects of the present invention,
A current limiting impedance, a discharge lamp including a pair of filament electrodes energized from a power supply means via the current limiting impedance, and a load circuit including a filament heating circuit, and periodically turning on and off to control a filament heating amount. And a filament switch means for controlling the amount of heating of the filament so as to be appropriate in accordance with the lighting state of the discharge lamp, thereby reducing the blackening and extending the life of the discharge lamp. A lighting device can be provided.

According to the second aspect of the present invention, in addition, the filament switch means switches within a time shorter than the thermal time constant of the filament electrode, whereby the temperature distribution of the filament electrode becomes constant, and the thermionic emission effect is adversely affected. It is possible to provide a discharge lamp lighting device which is not affected by the discharge lamp.

According to the third aspect of the present invention, by switching the filament switch means at twice the frequency of the low-frequency AC power supply frequency, the switching control of the filament switch means is easy and the phase is set. Can provide a discharge lamp lighting device capable of approximating a crest factor and an input current waveform to a sine wave.

According to the fourth aspect of the present invention, the filament switching means is switched at a frequency lower than the switching frequency of the switching means provided in the controllable power supply means. It is possible to provide a discharge lamp lighting device capable of using the means.

According to the fifth aspect of the present invention, in addition, the switching frequency of the filament switch means is an integer fraction of the switching frequency of the switching means in the power supply means, so that switching is performed in synchronization with the switching means of the power supply means. This makes it possible to provide a discharge lamp lighting device that can share circuit elements, circuit components, programs, and the like.

According to the invention of claim 6, in addition, the switching of the filament switch means is at the same frequency as the switching of the switching means of the power supply means, and the phase is shifted, so that the discharge associated with the switching reduces noise. A lamp lighting device can be provided.

According to the seventh aspect of the present invention, in addition, the duty of the filament switch means is variable, so that an appropriate filament heating amount can be set according to various lighting states of the discharge lamp. Can be provided.

According to the eighth aspect of the present invention, in addition, since the duty of the filament switch means is variable according to the dimming signal, it is possible to provide a discharge lamp lighting device in which the amount of heating of the filament can be easily controlled. .

According to the ninth aspect of the present invention, in addition, the filament switching means is controlled so as to make the filament heating current substantially constant, so that an appropriate filament heating amount can be set in accordance with the lighting state of the discharge lamp. A settable discharge lamp lighting device can be provided.

According to the tenth aspect of the present invention, in addition, the filament switching means is controlled so as to make the filament voltage substantially constant, whereby an appropriate filament heating amount is set in accordance with the lighting state of the discharge lamp. A possible discharge lamp lighting device can be provided.

According to the eleventh aspect of the present invention, the filament temperature is controlled to be substantially constant by controlling the switching of the filament switch means so that the filament voltage / filament heating current, that is, the filament resistance becomes substantially constant. Therefore, it is possible to provide a discharge lamp lighting device in which damage to the filament electrode is reduced.

According to the twelfth aspect of the present invention, the apparatus further comprises means for measuring the integrated lighting time of the discharge lamp, and controlling the amount of filament heating in accordance with the integrated lighting time to thereby achieve the filament heating during the life of the discharge lamp. It is possible to provide a discharge lamp lighting device that controls the amount as required.

According to the thirteenth aspect, the end of life of the discharge lamp is provided by controlling the filament switch so that the filament heating current does not substantially flow at the end of the life. It is possible to provide a discharge lamp lighting device which prevents inconvenience caused by abnormal temperature rise at the time.

According to the invention of claim 14, it is possible to provide a lighting device having the effects of claims 1 to 13.

[Brief description of the drawings]

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

FIG. 2 is a block circuit diagram showing the digital processing means.

FIG. 3 is a graph showing the relationship between the light output and the on-duty of the switching means of the high-frequency inverter in the first embodiment of the discharge lamp lighting device of the present invention.

FIG. 4 is a graph conceptually showing a relationship between a filament heating current and a starting voltage in the first embodiment of the discharge lamp lighting device of the present invention.

FIG. 5 is a graph conceptually showing an optimum operation region and a preheating under-range in a relationship between a lamp current and a filament heating current in the first embodiment of the discharge lamp lighting device of the present invention.

FIG. 6 is a circuit diagram showing a discharge lamp lighting device according to a second embodiment of the present invention.

FIG. 7 is a waveform chart showing voltage waveforms at various parts in a third embodiment of the discharge lamp lighting device of the present invention.

FIG. 8 is a circuit diagram showing a fourth embodiment of the discharge lamp lighting device of the present invention.

FIG. 9 is a circuit diagram showing a fifth embodiment of the discharge lamp lighting device of the present invention.

FIG. 10 is a waveform chart showing a phase relationship between a discharge current and a filament heating current in a fifth embodiment of the discharge lamp lighting device of the present invention.

FIG. 11 is a circuit diagram showing a sixth embodiment of the discharge lamp lighting device of the present invention.

FIG. 12 is a waveform chart showing a gate drive signal of a filament switch means in a seventh embodiment of the discharge lamp lighting device of the present invention.

FIG. 13 is a waveform chart showing a gate drive signal of a filament switch means in an eighth embodiment of the discharge lamp lighting device of the present invention.

FIG. 14 is a circuit diagram showing a ninth embodiment of the discharge lamp lighting device of the present invention.

FIG. 15 is a circuit diagram showing a circuit configuration of the current detection means CD;

FIG. 16 is a waveform diagram conceptually illustrating a current flowing in a load circuit during lighting of a discharge lamp in a ninth embodiment of the discharge lamp lighting device of the present invention.

FIG. 17 is a waveform chart showing waveforms of a current flowing through a switching means of a power supply means and a filament heating current in a ninth embodiment of the discharge lamp lighting device of the present invention.

FIG. 18 is a circuit diagram showing a tenth embodiment of the discharge lamp lighting device according to the present invention.

FIG. 19 is a circuit diagram showing an eleventh embodiment of the discharge lamp lighting device of the present invention.

FIG. 20 is a circuit diagram showing a twelfth embodiment of the discharge lamp lighting device according to the present invention.

FIG. 21 is a bottom view showing a ceiling-mounted lighting device as one embodiment of the lighting device of the present invention.

[Explanation of symbols]

 AS: Low frequency AC power supply SW: Power supply switch NF: Noise filter RDC: Rectified DC power supply FBR: Full-wave rectifier circuit HFG: Power supply means AF: Active filter L1: Inductor Q1: Switching means GDC1: Gate drive circuit D1: Diode C1 ... smoothing capacitor HFI ... high frequency inverter Q2 ... switching means Q3 ... switching means GDC2 ... gate drive circuit LC ... load circuit C2 ... DC cut capacitor L2 ... current limiting impedance DL ... discharge lamp E1 ... filament electrode E2 ... filament electrode FHC ... filament heating Circuit C3: Capacitor DPY: Digital processing means FS: Filament switch means Tr: Switch element D2: Diode FVD: Filament voltage detection means SSL: Flashing signal line ML ... dimming operation line

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yuji Takahashi 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Inside Toshiba Litec Corporation (72) Inventor Masahiko Kamada 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Toshiba Litec Co., Ltd. (72) Hideo Kozuka, Inventor 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Tokyo, Japan Inventor Toshihiko Sasai (72) 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo, Japan No. Toshiba Litec Co., Ltd. (72) Inventor Kazutoshi Mita 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo F-term (reference) 3T072 AA02 AB01 BA03 BA05 BC01 BC02 DB03 DD04 DE02 EA03 EB07 FA06 GA01 GA02 GA05 GB01 GC04 HA10 3K098 CC10 CC13 CC23 CC40 DD20 DD22 EE03 EE32 EE37 FF04

Claims (14)

[Claims] A power supply means; a current limiting impedance; a discharge lamp having a pair of filament electrodes energized from the power supply means via the current limiting impedance; and a reactance between a non-power supply side terminal of the pair of filament electrodes. A discharge lamp lighting device, comprising: a load circuit including a filament heating circuit connected via a wire; and a filament switch means for periodically turning on and off to control a filament heating amount. 2. The discharge lamp lighting device according to claim 1, wherein the switching period of the filament switch means is shorter than the thermal time constant of the filament electrode. 3. A power supply means for converting a low-frequency AC power supply voltage into a controllable output voltage; a current limiting impedance; a discharge lamp having a pair of filament electrodes energized from the power supply means via the current limiting impedance; And a load circuit including a filament heating circuit in which the non-power supply side terminals of the pair of filament electrodes are connected via a reactance; switching at a frequency twice the power supply frequency of the low-frequency AC power supply to control the filament heating amount And a filament switch means. 4. A power supply means for converting a low-frequency AC power supply voltage into a controllable output voltage by using switching of a switching means; a current limiting impedance; A discharge lamp having a filament electrode, and a load circuit including a filament heating circuit in which a non-power supply side terminal of the pair of filament electrodes is connected via a reactance; And a filament switch means for controlling the amount of heating of the filament. 5. The discharge lamp lighting device according to claim 4, wherein the switching frequency of the filament switching means is an integer fraction of the switching frequency of the switching means of the power supply means. 6. A power supply means for converting a low-frequency AC power supply voltage into a controllable output voltage by using switching of a switching means; a current-limiting impedance; A discharge lamp having a filament electrode, and a load circuit including a filament heating circuit in which the non-power-supply-side terminals of the pair of filament electrodes are connected via a reactance; And a filament switch means for controlling the amount of heating of the filament by switching at a shifted phase. 7. The discharge lamp lighting device according to claim 1, wherein the switching duty of the filament switch means is variable. 8. The discharge lamp lighting device according to claim 1, wherein the switching duty of the filament switch means is variable according to a dimming signal. 9. The discharge lamp lighting device according to claim 1, wherein the switching of the filament switching means is controlled such that the filament heating current becomes substantially constant. 10. The discharge lamp lighting device according to claim 1, wherein switching of the filament switching means is controlled so that a filament voltage applied to a filament electrode is substantially constant. . 11. The filament switching means according to claim 1, wherein switching is controlled such that filament voltage / filament heating current becomes substantially constant.
11. The discharge lamp lighting device according to any one of claims 10 to 10. 12. A power supply means; a current-limiting impedance; a discharge lamp having a pair of filament electrodes energized from the power supply means via the current-limiting impedance; A load circuit including a filament heating circuit connected via a wire; filament switch means for periodically turning on and off to control the filament heating amount; lighting integrated time measuring means for measuring the integrated lighting time of the discharge lamp; Control means for controlling the filament switch means so as to control the filament heating amount as required in accordance with the cumulative lighting time. 13. An end-of-life detecting means for detecting the end of life of the discharge lamp; the filament switch means detects a filament heating current at the end of life of the discharge lamp based on a detection signal of the end-of-life detecting means. 13. The discharge lamp lighting device according to claim 1, wherein the discharge lamp lighting device is controlled so as not to substantially flow. 14. A lighting device comprising: a lighting device main body; and the discharge lamp lighting device according to claim 1 disposed in the lighting device main body.