JP4711127B2 - Discharge lamp lighting device and lighting device - Google Patents

Description

  The present invention relates to a discharge lamp lighting device for lighting a hot cathode discharge lamp, and an illumination device using the discharge lamp lighting device.

  In the hot cathode type discharge lamp, the emitter of the filament is worn out as the lighting time elapses, and eventually the emitter is depleted and the lifetime is reached. However, in the process of reaching the complete life, that is, the point of failure, the lighting may continue to be performed in a state that does not change from the stable lighting in appearance. However, in this state, the wear of the emitter of the filament has progressed considerably, which can cause overloading and damage to the lighting device, or the filament can rise in temperature excessively, and this heat can cause the glass to be made of glass or resin at the end of the bulb. In some cases, secondary sockets such as falling and bursting may be caused by melting the socket. For this reason, many proposals have been made to prevent the above-described problems by electrically detecting the end of life of the discharge lamp and reducing or stopping the energization of the discharge lamp.

  In addition, in order to prevent the above problems due to unexpected turn-off due to the life of the discharge lamp or continued lighting in the end-of-life state (including half-wave lighting and blinking repeated lighting state) A technique has also been proposed in which the lamp life is estimated and the lamp replacement is promoted by measuring it before actually reaching the point of failure.

  Furthermore, in order to compensate for the attenuation of light output due to the aging of the discharge lamp, a technique that measures the accumulated lighting time and increases the light output according to the accumulated lighting time, thereby making the light output constant during the life of the discharge lamp. Has also been proposed.

  However, since most of the conventional end-of-life detection means detects the lamp voltage value and the lamp current value, there is still room for improvement in terms of detection accuracy. In other words, at the end of the lifetime when the lamp is lit in a state where it does not change from the stable lighting, the degree of change is not so great whether it is the lamp voltage or the lamp current, and detection may be difficult. Also, the lamp voltage value and lamp current value vary depending on the type of discharge lamp and manufacturer, and even the same discharge lamp varies depending on the usage environment such as ambient temperature. If the determination level to be detected is set high, the accuracy of abnormality detection is reduced.

  On the other hand, Patent Document 1 focuses on the resistance value of the filament and detects the time until the ratio (Rh / Rc) between the cold resistance value (Rc) and the preheated warm resistance value (Rh) reaches a predetermined value. A technique for determining that the discharge lamp is at the end of its life when this time is less than a preset minimum preheating time is shown. The predetermined value of the ratio of the resistance values (Rh / Rc) is a temperature resistance value and a cold resistance value when the filament is preheated to such a state that the starting voltage of the discharge lamp can be reduced and the damage to the filament can be reduced. It is said that this value does not depend much on the specification of the filament. Therefore, applying the starting voltage in the vicinity of the predetermined value is effective for extending the life of the filament, that is, the discharge lamp. Patent Document 1 uses the phenomenon that if the emitter is worn, the heat capacity of the filament is reduced and the temperature rises quickly, and the discharge lamp has a function of reaching the predetermined value of the resistance value ratio (Rh / Rc). It detects the end of life.

  In addition, the technique of Patent Document 1 also shows a configuration in which the end of the life of the discharge lamp is detected before the discharge lamp is turned on, and the output of the discharge lamp lighting device is controlled so that the discharge lamp is not turned on. It is also excellent in that the occurrence of the above problems caused by turning on the electric lamp can be prevented as much as possible.

Japanese Patent Application Laid-Open No. H10-228561 discloses a method for measuring the cumulative lighting time of a discharge lamp using timer means and storage means.
JP 2004-221027 A JP 2001-15276 A

  However, Patent Document 1 has not yet been sufficient for the types of discharge lamps, variations among individual discharge lamps, or differences in filament design among manufacturers. That is, recently, a discharge lamp lighting device has been realized in which different discharge lamps such as fluorescent lamps FL40, FLR40, FHF32 are lit by the same lighting device, but the cold resistance value (Rc) of these discharge lamps and after preheating The time until the ratio (Rh / Rc) to the resistance value (Rh) reaches a predetermined value may differ depending on the type of the discharge lamp and the manufacturer.

  Even in the same discharge lamp, since the heat capacity of the filament changes according to the cumulative lighting time, that is, the degree of wear of the emitter, the time for the resistance value ratio (Rh / Rc) to reach a predetermined value also changes.

  The data shown in FIG. 10 shows that the filament preheating is performed at a voltage of 4 V at room temperature on three prototype lamps having different filament emitter amounts of 20%, 50%, and 100%, respectively, and the ratio of the resistance value of each pair of filaments. It shows an average value (black circle) and upper and lower limit values as a result of measuring the time until (Rh / Rc) reaches a predetermined value (4 as an example). As is clear from FIG. 10, the variation due to the lamp is large, and even if the emitter amount is the same, the variation in the minimum preheating time until (Rh / Rc) reaches the predetermined value, in other words, the emitter amount is the same even when the time reaching the predetermined value is the same. It can be seen that the distribution range of the different discharge lamps is large.

  Therefore, the different types of discharge lamps as described above cannot be sufficiently covered by the technology of Patent Document 1, or are limited by the type of discharge lamp to be determined.

  In addition, the device described in Patent Document 2 requires a timer means for measuring the lighting time and a processing means for measuring time such as resetting of the timer means necessary every time the lamp is replaced, which increases the cost of the apparatus. It will end up.

  The present invention is less affected by the type of discharge lamp, and can detect the worn state of the filament emitter and estimate the cumulative lighting time without using any special timer means. An object is to provide a discharge lamp lighting device.

  In addition, by using the detection result of the worn state of the emitter, for example, the discharge lamp can control the output of the lighting device at the end of the life of the discharge lamp to prevent the lighting device from being damaged, the bulb of the discharge lamp being melted, etc. An object is to provide a lighting device.

  In addition, by using the detection result of the worn state of the emitter, it is possible to detect the cumulative lighting time and display a prompt to replace the lamp or to stabilize the light output during the life of the discharge lamp. An object is to provide an electric lighting device.

  Moreover, it aims at providing the illuminating device provided with the same effect | action as any or all of said discharge lamp lighting device.

  A discharge lamp lighting device according to a first aspect of the present invention is a lighting means for lighting a hot cathode discharge lamp; a preheating means for preheating a filament of the discharge lamp; and a heat capacity for detecting a heat capacity value of the filament during a preheating period of the discharge lamp. Detecting means; storing data indicating a relationship between the heat capacity value of the filament and the degree of wear of the filament; and filament state determining means for determining the worn state of the filament of the discharge lamp from the detected value of the heat capacity detecting means. It is characterized by that.

  In the invention described in claim 1 and the following invention, the definitions and technical meanings of terms are as follows.

  The hot cathode type discharge lamp has a preheated filament electrode, and may be used for general lighting, sterilization, decoration, etc. Any shape such as a so-called compact shape may be used.

  The lighting means and the preheating means may be configured separately, respectively, or the main part may be configured in common. The typical examples that are configured separately have separate power supplies or frequency converters, and the typical examples that are configured to share the main part are common for the power supply or frequency converter and for lighting. The circuit part and the preheating circuit part are configured separately.

  The lighting means or the preheating means preferably includes a high-frequency generator from the viewpoint of ease of output control, but may be one that outputs a DC voltage or one that outputs a commercial frequency AC voltage. .

  The preheating means supplies preheating power so that the temperature resistance value of the filament increases after the filament preheating starts, and a constant current type or a constant voltage type that is generally used can be used. Further, stopping or reducing the supply of preheating power after starting and lighting the discharge lamp is effective for power saving, but is not limited thereto.

  The filament heat capacity detection means may be any means as long as it can detect the heat capacity value. For example, the filament resistance value is detected using the detection values of the filament current value detection means and the filament end-to-end voltage value detection means. Can be obtained by dividing the electric power supplied to the filament during this time by the time until this resistance value reaches a predetermined value set in advance. In this case, the detection values of the current detection means and the voltage detection means can be converted from analog to digital and arithmetically processed by, for example, an IC, a microcomputer, or a DSP (digital signal processor).

  When the heat capacity detection means and the filament state determination means have calculation means, it is advantageous in terms of downsizing and processing speed that the calculation means is constituted by an IC, a microcomputer, a DSP, or the like. In this case, it may be integrated with the storage means.

  The filament state determination means stores data indicating the relationship between the heat capacity value of the filament and the degree of wear of the filament. This includes all cases where functions are stored and calculated by calculation, or other cases.

  According to the first aspect of the present invention, the discharge lamp detects the heat capacity value of the filament during the preheating period, and the heat capacity value of the filament is the degree of wear of the emitter of the filament of the discharge lamp regardless of the type of the discharge lamp. Therefore, it is possible to know how much the emitter is worn (or what is the cumulative lighting time). Therefore, the accuracy of detection of the end of life of the discharge lamp and estimation of the cumulative lighting time is improved.

  A discharge lamp lighting device according to a second aspect of the present invention is a lighting means for lighting a hot cathode discharge lamp; a preheating means for preheating a filament of the discharge lamp; a current detection means for detecting a preheating current value of the filament; A voltage detecting means for detecting a voltage value between both ends during preheating; A / D converting means for analog / digital conversion of a detection signal of each of the detecting means; and a relationship between the heat capacity value of the filament and the degree of wear of the filament Stores data, calculates the resistance value of the filament from each output signal of the A / D conversion means, and supplies the filament with the time until the resistance value of the filament reaches a predetermined value. The filament heat capacity value is calculated from the calculated preheating electric energy, and the filament wear state of the discharge lamp filament is determined from the calculated heat capacity value. Characterized in that it comprises a; and cement state determining means.

  In the invention of claim 2, the definitions and technical meanings of terms are as follows.

  As the current detection means, for example, a resistance may be inserted in the filament current path to detect the voltage value across the resistance, or a current transformer may be used.

  As the voltage detection means, for example, a resistor may be connected in parallel with the filament, and the voltage across this resistor may be detected. When the preheating means is configured individually, the output voltage value of the preheating means May be detected directly. However, the current detection means and the voltage detection means can be variously modified in addition to the above example.

  In the invention according to claim 2, since the filament state determining means stores the data indicating the relationship between the heat capacity value of the filament and the degree of wear of the filament, and has a function of calculating the resistance value of the filament, the IC, the microcomputer, It is preferable to use a DSP or the like in terms of downsizing and high-speed processing.

  The time until the resistance value reaches a predetermined value set in advance may be the time until the resistance value itself reaches a predetermined value, or the ratio to the cold resistance value during non-preheating (filament resistance The time until the detection value / cold resistance value) reaches a predetermined value may be used. In this case, the cold resistance value is measured immediately after the filament preheating is started every time the discharge lamp is turned on (a period in which the filament temperature is not increased or negligible due to preheating). However, when restarting within a preset time after the light is turned off, it is excluded from detection and the previous cold resistance value is used. This can be configured by using a microcomputer, DSP, or storage means.

  However, the cold resistance value of the filament during non-preheating may not be detected. In this case, the cold resistance value data created separately may be input to the storage means.

  According to the second aspect of the invention, the resistance value of the filament is detected by dividing the voltage detection signal of the A / D conversion means by the current detection signal. Further, the time until the filament resistance value reaches a predetermined value set in advance is counted. When the predetermined value is reached, the heat capacity value of the filament is calculated by dividing the preheating power supplied to the filament by the time required to reach the predetermined value.

  Then, the worn state of the filament is determined from the calculated heat capacity value and data input in advance.

  Based on the determination result, the end of life of the discharge lamp is determined, the cumulative lighting time is estimated, and the like. It is also possible to control display, lighting means, and the like based on these determinations and estimation results.

  The discharge lamp lighting device according to claim 3 is characterized in that, in the discharge lamp lighting device according to claim 1 or 2, the output of the lighting means is controlled based on the detection result of the heat capacity detecting means.

  Controlling the output of the lighting means is, for example, to reduce the output voltage of the lighting means to such an extent that it stops or the discharge lamp does not light. As another example, the light output of the discharge lamp is controlled so as to change according to the lighting time. These can be realized by stopping the operation of the high frequency generation means or changing the output by controlling the oscillation frequency when the lighting means is constituted by high frequency generation means such as an inverter. That is, by controlling the oscillation frequency, the output of the resonance circuit normally included in the high-frequency generating means can be changed, or the output can be changed by using the impedance value change of the inductive or capacitive impedance device. it can.

  In this case, the output voltage of the high frequency generating means can be changed by changing the oscillation frequency of the high frequency generating means, and a discharge lamp starting voltage can be obtained.

  In the invention according to claim 3, the heat capacity value of the filament is detected, and based on this value, from the data indicating the correspondence between the heat capacity value stored in the storage means and the remaining amount of the emitter of the discharge lamp, Estimate end-of-life judgment and cumulative lighting time.

  When it is determined that the end of life is reached, the output of the lighting means is stopped or reduced. Alternatively, the output of the lighting means is controlled so that the light output is stored in advance according to the cumulative lighting time.

  In this case, the data stored in advance changes the dimming degree so that the light output increases as the cumulative lighting time elapses. This makes it possible to control the light output to be constant during the life of the discharge lamp. Then, when the cumulative lighting time exceeds a preset time, it may be displayed that it is a lamp replacement time. Thus, if the user replaces the lamp, the inconvenience caused by continuously lighting the end-of-life discharge lamp can be solved.

  However, the above-described light output stabilization control is based on the assumption that the discharge lamp is turned off and on repeatedly, for example, every day or every week.

  A lighting device according to a fourth aspect of the present invention comprises: a lighting fixture main body; a hot cathode discharge lamp provided in the fixture main body; and the discharge lamp according to any one of claims 1 to 3 for lighting the discharge lamp. And a lighting device.

  The lighting device may be indoor or outdoor, and the discharge lamp lighting device may or may not be built in the lighting fixture body.

  According to the first and second aspects of the invention, since the heat capacity value of the filament of the discharge lamp is detected, it is possible to know the degree of wear of the emitter of the filament more accurately than that of Patent Document 1 regardless of the type of the discharge lamp. .

  According to the third aspect of the invention, in addition to the first and second aspects of the invention, since the output of the lighting means is controlled, the start-up lighting of the discharge lamp is stopped or the discharge lamp is stopped at the end of the life of the discharge lamp. It is possible to make the light output constant during the lifetime.

  According to invention of Claim 4, the illuminating device which has an effect of the invention of any one of Claim 1 thru | or 3 can be provided.

  Hereinafter, a first embodiment of a discharge lamp lighting device of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a discharge lamp lighting device, FIG. 2 is a flowchart showing the operation of the embodiment, and FIG. 3 is a diagram showing an example of a relationship between a heat capacity value of a filament and an emitter amount.

  In FIG. 1, 1 is a hot cathode discharge lamp, 2 is a lighting means for lighting the discharge lamp, and 3 is a preheating means for preheating the filament of the discharge lamp 1. The lighting means 2 and the preheating means 3 are both composed of an inverter or the like, and supply a high frequency voltage.

  4 is a filament heat capacity detecting means, which is provided corresponding to only one filament in FIG. 1, but may be provided for both filaments. The heat capacity detecting means 4 detects the heat capacity value of the filament at least during the preheating period of the discharge lamp 1.

  The detection value of the heat capacity detection means 4 is supplied to the filament state determination means 5. The filament state determination means 5 stores data (see FIG. 3) indicating the relationship between the preliminarily inputted heat capacity value of the filament and the degree of wear of the filament, and the filament of the discharge lamp is detected from the detection value of the heat capacity detection means 4. The wear state is determined.

  FIG. 3 shows the relationship between the heat capacity value of the filament and the degree of wear of the filament, that is, the amount of emitter (the remaining amount of emitter). FIG. 3 shows that the heat capacity value of the filament decreases as the amount of emitter decreases. It is also possible to replace the emitter amount in FIG. 3 with the cumulative lighting time. That is, the cumulative lighting time increases as the emitter amount decreases.

  Moreover, in this embodiment, the filament state determination means 5 is comprised so that the output of the lighting means 2 and the preheating means 3 may be controlled according to the determination result.

  Next, the operation of this embodiment will be described with reference to FIG. When the discharge lamp 1 is started, preheating power is supplied from the preheating means 3 to the filament of the discharge lamp 1 to preheat (S1). At this time, the lighting means 2 may be operating, but should not be applied with a voltage higher than the starting voltage.

  The heat capacity detecting means 4 detects the heat capacity value of the filament (S2). This detected value is compared with the data indicating the relationship between the heat capacity value input in advance and the amount of emitter as shown in FIG. Lighting time) is determined.

  If it is determined that the discharge lamp 1 is at the end of its lifetime from the degree of emitter wear (S3) (for example, in FIG. 3, the emitter amount reaches a value set between 0% and 20%) The filament state determination means 5 stops or reduces the outputs of the lighting means 2 and the preheating means 3 so that the discharge lamp 1 is not turned on (S4). If it is determined that it is not the end of life, a high voltage for starting is applied to the discharge lamp 1 as necessary to start and light (S5).

  Next, a second embodiment of the discharge lamp lighting device of the present invention will be described with reference to FIGS. 4 is a circuit diagram showing a second embodiment of the discharge lamp lighting device, FIG. 5 is a flowchart showing the operation of the second embodiment, and FIG. 6 is a diagram showing an example of the relationship between the light output and the cumulative lighting time, FIG. 7 is a diagram showing a difference in the degree of increase in filament resistance depending on the amount of emitter, and FIG. 8 is a diagram showing measured values of heat capacity values of prototype lamps having different emitter amounts.

  In FIG. 4, the same or corresponding parts as in FIG. In the present embodiment, the lighting means 2 is composed of a high-frequency generator, and a pair of FETs 21 and 22 connected in series constituting a half-bridge inverter and a drive circuit 23 for alternately turning on and off the FETs 21 and 22. have. Further, a DC cut capacitor 24 and a current limiting / resonant inductor 25 provided in series with the discharge lamp 1 are provided. Then, by controlling the output of the drive circuit 23 and changing the switching frequency of the pair of FETs 21 and 22, the output voltage (output power) can be changed by the resonance characteristics or the impedance characteristics of the current limiting inductor 25.

  The preheating means 3 is composed of a capacitor also serving for resonance provided between the non-power supply side filaments of the discharge lamp 1. That is, the lighting means 2 operates during preheating, and the pair of FETs 21 and 22 are alternately turned on and off, whereby a series resonance circuit including the capacitor 24, the current limiting and resonance inductor 25 and the capacitor as the preheating means 3 is obtained. The filament is preheated by this series resonance current.

  In the preheating current path of the filament, a current detection means 41 for detecting the current value of the filament is provided, and a voltage detection means 42 for detecting the voltage value is provided between both ends of the filament. The detection signals of these detection means 41 and 42 are input to the A / D conversion means 43 and are subjected to analog / digital conversion. The output signal of the A / D conversion means 43 is input to the filament state determination means 50. The filament state determination unit 50 includes a calculation unit 51 and a storage unit 52 including a CPU. The calculation means 51 includes a timer means 53.

  The computing means 51 calculates the resistance value and heat capacity value of the filament. Therefore, in this embodiment, the calculation means 51 comprises a part of filament heat capacity detection means.

  The storage means 52 includes a cold resistance value (Rc) of the filament, a predetermined value of a ratio of the warm resistance value (Rh) of the filament to the cold resistance value (Rc), a heat capacity value of the filament and an emitter amount or an accumulated lighting time. Data indicating at least one of the correspondence relationships is stored. Moreover, you may memorize | store the relationship between light output and accumulation lighting time like FIG. 6 shown as an example.

  In FIG. 6, the light output is 70% of the rated lighting when the cumulative lighting time is 0, and 100% when the cumulative lighting time is 12,000 hours. That is, at the initial stage of a discharge lamp having a high light output, the light is dimmed and turned on, and the light is increased so as to compensate for the light output that attenuates as the cumulative lighting time increases.

  The filament state determination means 5 also has an interface 54 for transmitting and receiving signals between the calculation means 51 and the drive circuit 23. That is, the drive circuit 23 is controlled based on the filament state determination result of the discharge lamp 1 or the estimation result of the cumulative lighting time.

  In FIG. 4, reference numeral 100 denotes a commercial AC power source, and reference numeral 200 denotes a rectifier that rectifies an AC voltage and smoothes it as necessary.

  Next, the operation of this embodiment will be described with reference to FIGS. The description of the same part as in FIG. 2 is omitted. First, the operation of the lighting means 2, the preheating means 3 and the starting means of this embodiment will be described. When starting the discharge lamp 1, the lighting means 2 is operated. Accordingly, the pair of FETs 21 and 22 are alternately turned on and off, and a resonance voltage is generated in the series resonance circuit including the capacitor 24, the inductor 25 for current limiting and resonance and the capacitor as the preheating means 3, and the filament of the discharge lamp 1 Preheated by series resonant current. Note that the output frequency of the drive circuit 23 is controlled so that the resonance voltage at this time becomes an insufficient value for starting the discharge lamp 1.

  The calculation means 51 of the filament state detection means 50 calculates the resistance value of the filament based on the signal obtained from the A / D conversion means 43 (S2). When the resistance value of the filament rises until reaching a predetermined value (for example, the resistance value ratio (Rh / Rc) is 4) (S4), the calculation means 51 starts preheating supplied to the filament from the start of preheating. Calculate power.

  This is obtained by integrating the product of the current detection means 41 and the voltage detection means 42 from the start of preheating until reaching the predetermined value. Further, when this preheating power is divided by the time from the start of preheating, the heat capacity value of the filament is obtained (S5).

  Here, when the amount of the emitter is small, the time required to reach a predetermined value (Rh / Rc appropriate preheating value) is short as shown in FIG. . That is, it is understood that the heat capacity value is smaller as the amount of the emitter is smaller.

  FIG. 8 shows an actual measurement value of the relationship between the emitter amount and the heat capacity value. FIG. 8 shows the preheating of each of three prototype lamps having different filament emitter amounts of 20%, 50%, and 100% at a room temperature voltage of 4 V, and the ratio of the resistance values of a pair of filaments (Rh / It shows an average value (black circle) and upper and lower limit values as a result of measuring the heat capacity value when Rc) reaches a predetermined value (4 as an example). As is apparent from the comparison between FIG. 7 and FIG. 10 described above, the heat capacity value varies depending on the lamp with respect to the time until the ratio of resistance values (Rh / Rc) reaches a predetermined value (for example, 4). It was a small one.

  The obtained heat capacity value is compared with data stored in advance (see FIG. 3), and the amount of emitter (or accumulated lighting time) is estimated. As a result of the estimation of the emitter amount, when it is determined that the discharge lamp 1 is at the end of its life (S6), the output of the drive circuit 23 is stopped and the start-up lighting of the discharge lamp 1 is stopped.

  If it is determined that the discharge lamp 1 is not yet at the end of its life, the drive circuit 23 changes the output frequency and outputs a voltage necessary for starting the discharge lamp 1 to start the discharge lamp 1 (S7). After the start-up, the drive circuit 23 again changes the output frequency to another frequency, and maintains the lighting of the discharge lamp 1 stably.

  In this embodiment, if the ratio of resistance values (Rh / Rc) does not reach the predetermined value 4 even after time t1 has elapsed after the start of preheating, it is determined that the discharge lamp 1 is not installed, the filament is broken, or the like. Then, the starting lighting of the discharge lamp 1 is stopped (S12).

  Further, in this embodiment, in addition to or instead of the above-described discharge lamp life determination, the cumulative lighting time is estimated, and the light output control having the relationship as shown in FIG. 6 is performed according to the cumulative lighting time. May be.

  Further, in the above embodiment, instead of the output control of the lighting means, the life display of the discharge lamp may be simply performed, and as the display means in this case, for example, the discharge lamp is forcibly blinked, An indicator lamp provided in the lighting fixture can be turned on.

  Next, an embodiment of the illumination device will be described with reference to FIG. The lighting device of the present embodiment is a ceiling-mounted lighting fixture. 81 is a lighting fixture body, 82 is a socket provided in the lighting fixture body 81, 83 is a reflector, 84 is a hot cathode discharge lamp mounted in the socket 82, and 85 is a discharge lamp built in the lighting fixture body 81. It is a lighting device.

  The illuminating device having such a configuration determines the life of the discharge lamp and estimates the cumulative lighting time in accordance with the heat capacity value of the filament during preheating of the hot cathode type discharge lamp 84, whereby the discharge lamp in the end-of-life state is obtained. Inconvenience and unexpected turn-off due to continuous lighting of 84 are reduced.

Block diagram showing a first embodiment of a discharge lamp lighting device Flow chart showing operation of the embodiment The figure which shows an example of the relationship between the heat capacity value of a filament, and the amount of emitters Circuit diagram showing a second embodiment of a discharge lamp lighting device Flow chart showing the operation of the second embodiment The figure which shows an example of the relationship between light output and accumulation lighting time The figure which shows the difference in the rise degree of the filament resistance by the size of the emitter The figure which shows the actual value of the heat capacity value of the prototype lamp with different emitter quantity The perspective view which shows one Embodiment of an illuminating device The figure which shows the measured value of resistance ratio (Rh / Rc) of the prototype lamp from which the amount of emitters differs

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 84: Hot cathode type discharge lamp, 2: Lighting means, 3: Preheating means, 4: Heat capacity detection means, 5: Filament state determination means, 41: Current detection means, 42: Voltage detection means, 43: A / D conversion means, 81: luminaire main body.

Claims (4)

Lighting means for lighting a hot cathode discharge lamp;
Preheating means for preheating the filament of the discharge lamp;
Heat capacity detecting means for detecting the heat capacity value of the filament during the preheating period of the discharge lamp;
Data indicating the relationship between the heat capacity value of the filament and the degree of wear of the filament, and filament state determination means for determining the wear state of the filament of the discharge lamp from the detection value of the heat capacity detection means;
A discharge lamp lighting device comprising: Lighting means for lighting a hot cathode discharge lamp;
Preheating means for preheating the filament of the discharge lamp;
Current detection means for detecting the preheating current value of the filament;
Voltage detecting means for detecting a voltage value between both ends during preheating of the filament;
A / D conversion means for analog / digital conversion of detection signals of these detection means;
Stores data indicating the relationship between the heat capacity value of the filament and the degree of wear of the filament, calculates the resistance value of the filament from each output signal of the A / D conversion means, and presets the resistance value of the filament. Filament state determination means for calculating the heat capacity value of the filament from the time until the predetermined value is reached and the amount of preheating power supplied to the filament during that time, and determining the worn state of the filament of the discharge lamp from the calculated heat capacity value;
A discharge lamp lighting device comprising:   The discharge lamp lighting device according to claim 1 or 2, wherein an output of the lighting means is controlled based on a determination result of the filament state determination means. A lighting fixture body;
A hot cathode type discharge lamp provided in the luminaire body;
The discharge lamp lighting device according to any one of claims 1 to 3, which energizes the discharge lamp;
An illumination device comprising:

Images