JP4735521B2 - Discharge lamp lighting device and lighting fixture - Google Patents

Description

  The present invention relates to a discharge lamp lighting device and a lighting fixture equipped with the discharge lamp lighting device.

  In general, it is known that the luminous flux of a discharge lamp such as a fluorescent lamp used for illumination decreases with the passage of time of use. Therefore, a discharge lamp lighting device that suppresses a decrease in luminous flux (illuminance) with the passage of time of use of the discharge lamp has been conventionally provided (see, for example, Patent Documents 1 and 2).

  In such a conventional example, the illuminance at the initial stage of use of the discharge lamp is suppressed to about 70 to 80% of the value at the time of rated lighting, and the dimming control is performed so as to increase the luminous flux as the usage time elapses. The apparent illuminance during the use period can be kept almost constant, and there is an advantage that power can be saved by dimming the discharge lamp with less power than the rated value in the initial stage of use.

  By the way, the rated value of the electric power supplied to the discharge lamp (for example, the fluorescent lamp) is regulated by the manufacturer of the discharge lamp, and increases almost in proportion to the shape of the discharge lamp. For example, a straight tube fluorescent lamp has a tube length of about 600 mm and a tube diameter of about 25.5 mm and a rated power of about 23 W. A tube length of about 1200 mm and a tube diameter of about 25.5 mm has a rated power of about It is regulated to about 45W. Regarding the luminous flux characteristics of fluorescent lamps when the rated power is supplied, the initial luminous flux (the luminous flux after 100 hours from the start of use) has been announced by the manufacturer. It is defined as the time until the decrease reaches 70% of the initial characteristic or the time until the filament breaks, whichever comes first.

  Further, in indoor lighting, in order to obtain illuminance necessary for a work surface, the number of luminaires to be installed is determined using variables such as floor area, lamp luminous flux (the initial luminous flux), number of lamps, maintenance rate, and the like. Here, the maintenance rate is determined so that the required illuminance can be obtained at the rated life time, taking into account the reduction in luminous flux of the fluorescent lamp itself and the decrease in reflectance due to contamination of the fluorescent lamp and the lighting fixture. For example, in the case of an open-type lighting fixture, the maintenance rate is 0.7 in a general usage environment, and 0.74 in a place where the generation of dust is small and the air is always kept clean. The smaller the number, the greater the number of lighting fixtures to be installed, and the equipment cost will increase. Therefore, assuming that the fluorescent lamps used are the same and the installation environment of the luminaire is the same, the illuminance at the end of the lamp life when a general discharge lamp lighting device is used and the decrease in illuminance are anticipated in advance. The illuminance at the end of the lamp life of the conventional example that controls the illuminance to be substantially constant so that the illuminance of 70 to 80% of the initial luminous flux is always obtained is almost equal, and the number of luminaires to be installed is also equal. However, in the above-described conventional example, it is necessary to add a configuration for controlling the illuminance to be substantially constant with respect to the configuration of a general discharge lamp lighting device, which increases the cost of the device or the lighting fixture, and consequently A user's capital investment cost will become large.

  In the above conventional example, by suppressing the illuminance at the initial stage of use to about 70 to 80%, the power consumption is reduced by about 10 to 15% compared to a general discharge lamp lighting device in the period from the initial stage of use to the rated life. Therefore, the running cost of the user can be reduced. However, in order to obtain the required illuminance on the work surface, further power saving and resource saving cannot be desired.

On the other hand, the applicant of the present application pays attention to the fact that the light / power ratio from 41 W to 55 W (rated power 45 W) is substantially constant in the high-frequency lighting-only fluorescent lamp (FHF 32), and the lamp supply power at the initial stage of use. Lamp supply power by changing the dimming signal according to the cumulative lighting time so that it will be higher than the rated power of 45W after the rated life time There has already been proposed a discharge lamp lighting device that can adjust the light intensity without impairing the light emission efficiency of the discharge lamp, and as a result, can maintain the apparent illuminance substantially constant (Japanese Patent Application). 2006-9182).
JP-A-9-97683 JP 2001-15275 A

  By the way, when power is continuously supplied from the discharge lamp lighting device even after the thermoelectron emitting material (emitter) applied to the filament is consumed and disappears, the filament breaks due to the supplied power or the discharge lamp is airtight. Leakage should occur and the discharge should stop, but the discharge may continue very rarely. When the discharge continues in this manner, in the invention according to the above-mentioned patent application (Japanese Patent Application No. 2006-9182), since the discharge lamp supplies power higher than the rated power to the discharge lamp as it approaches the end of its life, high energy is required. May continue to be injected into the filament and heated to a high temperature at which the glass tube and stem glass near the filament are deformed and melted.

  Further, even different types of discharge lamps have the same outer shape and dimensions (for example, FHF32 and FLR40S / 36), and the impedance of the filament is different in these types of discharge lamps. Therefore, for example, when the FLR40S / 36 is mounted on a discharge lamp lighting device for FHF32 and used, excess current is supplied to the filament, so that the vicinity of the filament, that is, the end of the glass tube and the stem glass are relatively There is a risk of being heated to a high temperature, and conversely, there is a risk that the emitter will be scattered due to a shortage of the pre-heating current, resulting in a shortened life.

  The present invention has been made in view of the above circumstances, and its purpose is to reduce the initial investment cost and running cost of the user while keeping the apparent illuminance substantially constant and to realize resource saving. Further, it is an object of the present invention to provide a discharge lamp lighting device and a lighting fixture that can continue to use a discharge lamp at the end of its life and can prevent the occurrence of problems due to misuse of different types of discharge lamps.

In order to achieve the above object, an invention according to claim 1 is provided with an inverter circuit that includes one or more switching elements and converts the DC input into a high-frequency AC output by switching the switching elements at a high frequency, and a discharge lamp. Together with one or more resonance inductors and resonance capacitors connected between the output terminals of the inverter circuit and constituting the resonance circuit, and by controlling the switching of the switching element, the inverter circuit passes through the resonance circuit to the discharge lamp. In a discharge lamp lighting device comprising a dimming control circuit that adjusts the supplied high-frequency power, the dimming control circuit is used from the start of use of the discharge lamp to a predetermined time after reaching the rated life of the discharge lamp. Power correction means for controlling the high-frequency power of the inverter circuit to gradually increase as the usage time elapses during the period; After a predetermined time, power suppression means for controlling the high-frequency power of the inverter circuit to be equal to or lower than a predetermined value, life detection means for detecting that the discharge lamp has reached the end of life, and the life detection means for determining the life of the discharge lamp Control means for controlling to stop or suppress the power supply from the inverter circuit to the discharge lamp when the voltage is detected , the life detecting means is a voltage level according to the DC voltage superimposed on the lamp current If the detected voltage exceeds a predetermined threshold voltage, the discharge lamp is considered to have reached the end of its life, and the discharge lamp has a straight tube shape having a tube length of about 1200 mm and a tube diameter of about 25.5 mm. In the case of a fluorescent lamp, the predetermined value is set to a value greater than 55W and less than or equal to 65W.

According to a second aspect of the present invention, there is provided an inverter circuit that includes one or more switching elements and converts the DC input into a high-frequency AC output by switching the switching elements at a high frequency, and a discharge lamp. Together with one or more resonance inductors and resonance capacitors connected between the output terminals of the inverter circuit and constituting the resonance circuit, and by controlling the switching of the switching element, the inverter circuit passes through the resonance circuit to the discharge lamp. In a discharge lamp lighting device comprising a dimming control circuit that adjusts the supplied high-frequency power and a preheating circuit that supplies a preheating current to the filament of the discharge lamp, the dimming control circuit starts from the start of use of the discharge lamp. The frequency of the inverter circuit increases with the passage of time during the period up to the specified time after reaching the rated life of the discharge lamp. Power correction means for controlling the force to gradually increase, power suppression means for controlling the high-frequency power of the inverter circuit to be a predetermined value or less after the predetermined time, and preheating current detection for detecting the preheating current and means, the preheating current which the preheating current detecting means detects that and a control means for the inverter circuit so as to control stopping or reducing power supply to the discharge lamp when it is out of the predetermined range, the release When the electric lamp is a straight tube fluorescent lamp having a tube length of about 1200 mm and a tube diameter of about 25.5 mm, the predetermined value is set to a value greater than 55 W and less than or equal to 65 W.

According to a third aspect of the present invention, in the second aspect of the present invention, the control means includes a preheating detected by the preheating current detection means during a period from when the supply of the high frequency power from the inverter circuit is started until the discharge lamp is started. It is determined whether or not the current is out of a predetermined range.

In order to achieve the above object, a fourth aspect of the present invention provides a discharge lamp lighting device according to any one of the first to third aspects, a fixture main body to which the discharge lamp lighting device is attached, The electric lamp is detachably mounted and includes a discharge lamp lighting device and a socket for electrically connecting the discharge lamp.

  According to the present invention, the initial investment cost and running cost of the user can be kept low while keeping the apparent illuminance substantially constant, and resource saving can be realized. Further, the discharge lamp at the end of life can be continuously used. It is possible to provide a discharge lamp lighting device and a lighting fixture that can prevent the occurrence of problems due to misuse of different types of discharge lamps.

(Embodiment 1)
FIG. 1 shows a circuit configuration diagram of Embodiment 1 of the present invention. The AC output of the commercial AC power supply AC is full-wave rectified by the diode bridge DB and input to the DC power supply circuit 1. The DC power supply circuit 1 includes a DC / DC converter (for example, a step-up chopper circuit) that converts a pulsating current output input from the diode bridge DB into a DC output having a desired voltage. The inverter circuit 2 is a conventionally known half-bridge type, and is configured by connecting a pair of switching elements Q1 and Q2 made of MOSFETs in series between the output terminals of the DC power supply circuit 1. Input resistors R1 and R2 are connected to the gates of the switching elements Q1 and Q2, and a detection resistor R3 is connected to the low-side switching element Q2.

  In the series circuit of the low-side switching element Q2 and the detection resistor R3, a resonance inductor L1 and a resonance capacitor C1 that form the resonance circuit 3 together with the discharge lamp La are connected in series via a DC cut capacitor, and the resonance circuit 3 A discharge lamp La is connected in parallel to the capacitor C1. A preheating circuit 8 for supplying a preheating current to the filament of the discharge lamp La is connected in parallel with the resonance circuit 3. The preheating circuit 8 includes a resonance inductor L1 (primary winding) constituting the resonance circuit 3 and each filament (not shown) of the discharge lamp La through a DC cut capacitor that is magnetically coupled to the resonance inductor L1. A pair of secondary windings L2 and L2.

  The dimming control circuit 4 includes an inverter control unit 5 that performs switching control of the pair of switching elements Q1 and Q2 included in the inverter circuit 2, and a correction control unit 6 that performs light amount correction according to the cumulative lighting time of the discharge lamp La. And a rewritable nonvolatile memory 7 that stores the cumulative lighting time. The inverter control unit 5 supplies the preheating current from the preheating circuit 8 to the filament of the discharge lamp La by switching the switching elements Q1, Q2 at a frequency (preheating frequency) sufficiently higher than the no-load resonance frequency of the resonance circuit 3. A preceding preheating mode, a starting mode in which a starting voltage is applied to the discharge lamp La by switching the switching elements Q1, Q2 at a frequency (starting frequency) lower than the preheating frequency and higher than the no-load resonance frequency, and the discharge lamp La And a lighting mode in which the discharge lamp La is stably lit at a frequency (lighting frequency) higher than the resonance frequency at the time of lighting after starting, and the lighting frequency is increased or decreased by the correction control unit 6 to be supplied to the discharge lamp La. This adjusts the high frequency power.

  The inverter control unit 5 includes an inverter control signal generation circuit 11 that generates an inverter control signal for switching control of the switching elements Q1 and Q2, and the switching element Q1 according to the inverter control signal output from the inverter control signal generation circuit 11 , Q2 and a preheating timer circuit 10 that limits the period of the preceding preheating mode (preceding preheating period). The inverter control signal generation circuit 11 includes an integrated circuit (IC) including a constant voltage buffer circuit, a constant voltage mirror circuit, an oscillation capacitor (none of which is shown), and the output terminal of the constant voltage buffer circuit. A series circuit of resistors R6 and R7 and a series circuit of a switch circuit SW1 and a resistor R8 included in the inverter controller 5 are connected between the terminal Ro of the inverter controller 5 connected to the ground and the ground. That is, a constant voltage is applied to the terminal Ro, and the inverter control signal generation circuit 11 increases the frequency of the inverter control signal (= the switching frequency of the switching elements Q1 and Q2) as the current flowing through the terminal Ro increases. Operate. After the AC power supply AC is turned on and the inverter control unit 5 is activated, the preheating timer circuit 10 turns on the switch circuit SW1 and starts the time limit of the preceding preheating period. Since the current flowing through the terminal Ro increases when the switch circuit SW1 is turned on, the frequency of the inverter control signal becomes relatively high and the pre-preheating mode is set. When the preheating timer circuit 10 completes the time limit of the preceding preheating period and turns off the switch circuit SW1, the current flowing through the terminal Ro decreases, the frequency of the inverter control signal becomes relatively low, and the operation mode is shifted to the start mode. Further, the switch circuit SW2 is turned on by the preheating timer circuit 10, and the power correction circuit 13 is connected to the connection point of the resistors R6 and R7 via the resistor R9, the diode D1, and the switch circuit SW2.

  The power correction circuit 13 includes an operational amplifier OP1 in which a dimming signal (described later) is input to the non-inverting input terminal and the voltage (detection voltage) across the detection resistor R3 is input to the inverting input terminal via the input resistor R4. The feedback resistor R5 and the capacitor C3 are connected in parallel between the inverting input terminal and the output terminal of the operational amplifier OP1, and the output terminal of the operational amplifier OP1 is connected to the cathode of the diode D1 via the switch circuit SW2. Further, the anode of the diode D1 is connected to the connection point of the resistors R6 and R7 via the resistor R9. That is, when the current flowing through the switching elements Q1 and Q2 of the inverter circuit 2 is substantially proportional to the lamp power consumed by the discharge lamp La, the detection voltage of the detection resistor R3 does not match the signal voltage of the dimming signal In addition, negative feedback is applied to the output voltage of the operational amplifier OP1, and the oscillation frequency of the inverter circuit 2 (= switching frequency of the switching elements Q1 and Q2) is adjusted by increasing or decreasing the current at the terminal Ro via the resistor R9 and the diode D1. The power correction circuit 13 operates so that the lamp power becomes a value corresponding to the dimming signal. However, the control operation of the power correction circuit 13 is prohibited by turning off the switch circuit SW2 until the switch circuit SW2 is turned on by the preheating timer circuit 10, that is, in the preceding preheating period and the starting period.

  Here, the dimming control circuit 4 is provided with a stop circuit 18 that detects the no-load state, the end-of-life state of the discharge lamp La (half-wave discharge state described later), and the like, and stops the operation of the inverter circuit 2. Yes. The stop circuit 18 stops the operation of the inverter control signal generation circuit 11 and the preheating timer circuit 10 when a signal is received from a no-load detection circuit (not shown) or a comparison circuit 22 described later, or is output from the drive circuit 12. The operation of the inverter circuit 2 is stopped by stopping the drive signal.

  The correction control unit 6 includes a timer unit 14 that receives a mode signal output from the inverter control signal generation circuit 11 via the terminal Mode of the inverter control unit 5 and measures the cumulative lighting time of the discharge lamp La. The mode signal is a signal that is H level when the drive signal is output from the drive circuit 12, and is L level when the drive signal is not output, and the mode timer 14 is at the H level. The clocking operation is performed only during the period.

  In addition, the correction control unit 6 includes a signal generation unit 15 that generates a dimming signal for adjusting the light amount of the discharge lamp La according to the cumulative lighting time output from the timing timer unit 14. The signal generation unit 15 stores a correction table that represents a correspondence relationship between the cumulative lighting time and the DC voltage level of the dimming signal (a level corresponding to the light amount ratio when the rated lighting is 100%). The dimming signal corresponding to the cumulative lighting time output from the timer unit 14 is read from the correction table and output to the dimming control circuit 4 (power correction circuit 13). However, the dimming signal output from the signal generator 15 has an upper limit value for the power supplied to the discharge lamp La (for example, 55 W as described later when a fluorescent lamp of FHF 32 is used as the discharge lamp La). It is limited by the power suppression unit 16 so as not to exceed. The accumulated lighting time stored in the nonvolatile memory 7 is reset (initialized) by the reset unit 17 when the discharge lamp La is replaced.

  Next, the operation of the correction control unit 6 will be described. When the AC power supply AC is turned on and the correction control unit 6 is activated, the signal generation unit 15 first reads the accumulated lighting time stored in the nonvolatile memory 7 and temporarily stores it in the memory (not shown). The dimming signal corresponding to the cumulative lighting time is read from the correction table and output to the inverter control unit 5. On the other hand, the timekeeping timer unit 14 starts timekeeping from the time of activation, and the signal generation unit 15 adds the time counted by the timekeeping timer unit 14 to the accumulated lighting time stored in the memory, and the stored contents of the nonvolatile memory 7 Update. As a result, the DC voltage level of the dimming signal is monotonously increased by the correction control unit 6 so as to gradually increase the high-frequency power supplied to the discharge lamp La as the cumulative lighting time of the discharge lamp La increases. Become.

  Here, when the present inventors examined the relationship between the lamp power and the light quantity for two types of straight tube fluorescent lamps (FHF32, FLR40S / 36), the result shown in FIG. 2A was obtained. In FIG. 2A, the power supplied to the fluorescent lamp (lamp supply power) is normalized by the light quantity when the lamp supply power is the rated value (45 W for FHF32, 36 W for FLR40S / 36) (light / light). The power ratio is plotted on the vertical axis, and the characteristics of FHF32 are indicated by a solid line, and the characteristics of FLR40S / 36 are indicated by a dashed line. FHF32 is a high-frequency lighting-only fluorescent lamp with a tube length of 1200 mm and a tube diameter of 25.5 mm, with rated lamp power of 32 W and 45 W, and FLR40S / 36 has a tube length of 1200 mm and a tube diameter of 25.5 mm. A rapid start type fluorescent lamp with a rated lamp power of 36 W. As apparent from FIG. 2 (a), in the fluorescent lamp of FHF32, when the lamp supply power is 55W or less, the light / power ratio becomes approximately 1.0, and when the lamp supply power exceeds 55W, the light / power ratio is increased. As a result, the light / power ratio became about 0.98 when the lamp supply power was 65 W. On the other hand, in the FLR40S / 36 fluorescent lamp, the lamp supply power was about 40 W and the light / power ratio was about 0.98.

  Therefore, in the present embodiment, when an FHF32 fluorescent lamp is used as the discharge lamp La, the lamp supply power starts to be supplied from a value lower than the rated power of 45 W in the initial stage of use, and is rated after the rated life time of the discharge lamp La. The lamp supply power (the output of the inverter circuit 2) is adjusted by changing the dimming signal in accordance with the cumulative lighting time so that the power is higher than 45W. Specifically, as shown in FIG. 2B, the lamp supply power at the start of lighting (cumulative lighting time is 0) is 41 W, and the lamp supply power when the rated life time of the FHF 32 (= 12000 hours) has elapsed is 55 W. In such a way that the cumulative lighting time is between 0 and 12000 hours, the lamp supply power is increased linearly, and after the lamp supply power reaches 55 W, a constant power (= 55 W) is supplied. The relationship between the time and the dimming signal is set and stored in the correction table. Here, the lamp supply power (= 55 W) when the rated life time elapses is about 1.22 times the value of the rated power (= 45 W).

  Further, when the lamp supply power is adjusted as described above, the lamp current is about 0.35 A when the lamp supply power in the initial stage of use is 41 W, the lamp current when the cumulative lighting time is 3500 hours and the lamp supply power is 45 W. Is about 0.42 A, when the cumulative lighting time is 7000 hours and the lamp supply power is 49 W, the lamp current is about 0.48 A, and when the cumulative lighting time is 10,000 hours and the lamp supply power is 53 W, the lamp current is about 0. When the cumulative lighting time is 12000 hours and the lamp supply power is 55 W, the lamp current is about 0.54 A. Here, the filament temperature of the discharge lamp La increases as the lamp supply power increases, and the filament temperature when the lamp supply power is 53 W increases by about 5 to 10% compared to the case of 45 W. Since the filament temperature is suppressed to a generally low value until the time is about 7000 hours, there is no possibility that the life of the discharge lamp La is significantly impaired even if the correction control as described above is performed. Further, as shown in FIG. 2A, in the fluorescent lamp of FHF32, the light / power ratio from 41 W to 55 W is substantially constant, so that the light quantity can be increased without impairing the light emission efficiency of the discharge lamp La. It will be possible.

  By the way, in a discharge lamp La such as a fluorescent lamp, when the thermoelectron emitting material (emitter) applied to the filament is consumed, it is considered that the lifetime has been reached, and only one of the emitters of the two filaments is the first. However, the discharge should be stopped due to asymmetrical discharge (so-called half-wave discharge), and the filament breaks due to continuous supply of high-frequency power, or an airtight leak occurs in the discharge lamp La. Very rarely, discharge may continue. And when such a half wave discharge continues, if the discharge lamp La is supplying electric power higher than the rated power as the end of the life approaches, as described above, high energy continues to be injected into the filament and the vicinity of the filament There is a possibility that the glass tube and the stem glass are heated to a high temperature at which the glass tube and the stem glass are deformed and melted.

  Therefore, in the present embodiment, the DC voltage superimposed on the lamp voltage by the half-wave discharge is detected by the DC voltage detection circuit 21, and the detected voltage of the DC voltage detection circuit 21 (the voltage level corresponding to the DC voltage superimposed on the lamp current). And a predetermined threshold voltage are compared by the comparison circuit 22, and if the detected voltage exceeds the threshold voltage, it is considered that half-wave discharge has occurred, and the stop circuit 18 causes the inverter control signal generation circuit to 11 and the preheating timer circuit 10 are stopped, or the operation of the inverter circuit 2 is stopped by stopping the drive signal output from the drive circuit 12, so that the discharge lamp La that has reached the end of its life has excessive power. Is prevented from continuing to be supplied.

  Here, as described above, the lamp supply power at the lighting start time (cumulative lighting time is 0) is set to a value lower than the rated lamp power, and the rated life time of the discharge lamp La (12000 hours in FHF32) elapses. Since the lamp supply power is linearly increased during the cumulative lighting time of 0 to 12000 hours so that the lamp supply power becomes higher than the rated lamp power (see FIG. 3A), the comparison circuit The threshold voltage to be compared with the detection voltage at 22 also needs to be changed according to the lamp supply power. For this purpose, in the present embodiment, a threshold voltage generator 23 is provided in the correction controller 6. The threshold voltage generator 23 adds the time counted by the time timer unit 14 to the cumulative lighting time stored in the memory, and as shown in FIG. The voltage is monotonously decreased linearly and output to the comparison circuit 22. Note that the initial value of the threshold voltage (threshold voltage when the cumulative lighting time is 0) is set to such a level that the detection voltage exceeds when the power supplied to the filament is about 10 W to 15 W, for example. The threshold voltage when the rated life time elapses is set to such a level that the detection voltage exceeds when the power supplied to the filament is about 5 W to 10 W, for example.

  Thus, when the emitter applied to the filament of the discharge lamp La disappears and half-wave discharge occurs, the detection voltage of the DC voltage detection circuit 21 exceeds the threshold voltage corresponding to the cumulative lighting time at that time. Since the discharge lamp La is considered to have reached the end of its life, and the stop circuit 18 stops the operation of the inverter circuit 2 by the output of the comparison circuit 22, a power larger than the rated lamp power is supplied to the discharge lamp La that has reached the end of its life. As a result, it is possible to prevent such a problem that high energy is continuously injected into the filament and heated to a high temperature at which the glass tube and the stem glass near the filament are deformed and melted. However, in the preceding preheating period and the starting period, even if the discharge lamp La is normal, a higher voltage than that at the time of lighting is supplied to the filament, so that the detection voltage may exceed the threshold voltage and be erroneously detected. Therefore, the control operation of the stop circuit 18 according to the comparison result of the comparison circuit 22 is performed after the discharge lamp La is started. Further, in the present embodiment, the inverter circuit 2 is stopped when the discharge lamp La reaches the end of its life, but it is not always necessary to stop it, and the output of the inverter circuit 2 may be suppressed.

  FIG. 4 shows the lighting apparatus of this embodiment. This lighting fixture includes a rectangular box-shaped fixture main body 100 having an open bottom surface, and a lamp provided with a discharge lamp La made of a fluorescent lamp of FHF 32 provided on each side surface of the fixture main body 100 facing each other in the longitudinal direction. A socket 101 and a triangular prism-shaped reflecting plate 102 provided between the two discharge lamps La and La mounted on each lamp socket 101 on the bottom surface of the fixture main body 100 are provided. A discharge lamp lighting device 110 is accommodated.

When the conventional discharge lamp lighting device is installed, the lamp efficiency of the FHF 32 is about 110 lm / W, so based on the concept of maintenance rate,
45W × 110lm / W × 0.7 = 3465lm
The number of luminaires is determined based on the luminous flux.

In contrast, in this embodiment,
55W × 110lm / W × 0.7 = 4235lm
The luminous flux is about 1.2 times that of the conventional example. Therefore, in the luminaire using the conventional example, ten luminaires are necessary, and eight luminaires of the present embodiment can obtain almost the same illuminance.

  Furthermore, the average power consumption from the initial use of the discharge lamp La to the rated life time is 10 units × 2 lamps × {(45 W × 0.7) +45 W} / 2 = 765 W in the conventional example. In the appliance, since 8 units × 2 lights × {(55 W × 0.7) +55 W} / 2 = 748 W, power saving equivalent to that of the conventional example is possible. In addition, since the number of installed lighting fixtures and the number of discharge lamps La used is about 80% compared to the conventional example, the amount of materials used is naturally 80% and the resources can be saved. It is.

(Embodiment 2)
FIG. 5 shows a circuit configuration diagram of Embodiment 2 of the present invention. Since the basic configuration of the present embodiment is the same as that of the first embodiment, the same components as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

  As described in the first embodiment, in the fluorescent lamp of FHF32, the luminous efficiency does not decrease even when power of about 55 W is supplied, and the decrease in luminous efficiency is minus 2% even when power of about 60 W to 65 W is supplied. To a certain extent.

  Therefore, in this embodiment, when an FHF32 fluorescent lamp is used as the discharge lamp La, the lamp supply power starts to be supplied from a value higher than the rated power of 45 W in the initial stage of use, and after the rated life time of the discharge lamp La. The lamp power supply is adjusted by changing the dimming signal according to the cumulative lighting time so that the power is 60 W to 65 W. Specifically, as shown in FIG. 6, the lamp supply power at the start of lighting (cumulative lighting time is 0) is 46 W, and the lamp supply power at the time when the rated life time of FHF 32 (= 12000 hours) has elapsed is 65 W. During the cumulative lighting time of 0 to 12000 hours, the lamp supply power is increased linearly, and after the lamp supply power reaches 65 W, the constant power (= 65 W) is supplied. The optical signal relationship is set and stored in the correction table. Here, the lamp supply power (= 65 W) when the rated life time elapses is about 1.33 times the value of the rated power (= 45 W).

  Thus, in the present embodiment, the lamp supply power is changed from 46 W to 65 W, but as is clear from FIG. 2A, the light / power ratio from 46 W to 65 W is approximately in the FHF32 fluorescent lamp. Since it becomes constant, the amount of light can be increased without significantly impairing the luminous efficiency of the discharge lamp La.

  By the way, as the commercially available lighting fixtures, there are those that can be used by arbitrarily selecting different types (for example, FHF32, FLR40, FL40, etc.) among straight tube fluorescent lamps having a tube length of 1200 mm. ing. In the first embodiment and the present embodiment, the fluorescent lamp (discharge lamp La) of the FHF 32 is supplied with power having a value (55 W to 65 W) higher than the rated lamp power, so that the fluorescent lamps other than the FHF 32 (for example, the FLR 40 and the like) When an FL40 is installed, the impedance of the filament used differs depending on the type of fluorescent lamp, so that an excess current is supplied to the filament, so that the vicinity of the filament, that is, the end of the glass tube, There is a possibility that the stem glass is heated to a relatively high temperature, and conversely, there is a possibility that the emitter may be scattered due to a shortage of the preheating current, resulting in a shortened life.

Therefore, in this embodiment, the preheating current supplied from the preheating circuit 8 to the filament of the discharge lamp La is detected by the preheating current detection circuit 24, and the detection voltage of the preheating current detection circuit 24 (according to the magnitude of the current flowing through the filament) is detected. When the comparison circuit 22 compares the voltage level Vs) with the upper threshold voltage V _{th1 and the} lower threshold voltage V _th2 (V _th2 <V _th1 ), the mounted discharge lamp La is normal. It is determined whether or not it is a type, and when it is determined that a different type of discharge lamp is mounted, the operation of the inverter control signal generation circuit 11 and the preheating timer circuit 10 is stopped by the stop circuit 18 or the drive By stopping the drive signal output from the circuit 12, the operation of the inverter circuit 2 is stopped so that different types of discharge lamps are not misused. The occurrence of the following problems is prevented.

The comparison circuit 22 includes a window comparator that compares the detection voltage Vs of the preheating current detection circuit 24 with the upper threshold voltage V _{th1 and the} lower threshold voltage V _th2 , and the detection voltage Vs is the upper threshold voltage V _th1. Lower than the lower threshold voltage V _th2 (V _th2 <Vs <V _th1 ), an H level signal indicating that the regular discharge lamp La is mounted is output, and the detection voltage L level indicating that different types of discharge lamps are mounted when Vs is equal to or higher than the upper threshold voltage V _th1 or lower threshold voltage V _th2 (Vs ≦ V _th2 or V _th1 ≦ Vs). The signal is output. The stop circuit 18 stops the operation of the inverter control signal generation circuit 11 and the preheating timer circuit 10 when the comparison circuit 22 outputs an L level signal, or stops the drive signal output from the drive circuit 12. As a result, the operation of the inverter circuit 2 is stopped. As in the first embodiment, the threshold voltage generator 23 changes the upper threshold voltage V _{th1 and the} lower threshold voltage V _th2 as the cumulative lighting time of the discharge lamp La elapses. I do not care.

Therefore, when the detection voltage Vs of the preheating current detection circuit 24 is out of a predetermined range (Vs ≦ V _th2 or V _th1 ≦ Vs), it is considered that a discharge lamp of a different type from the normal discharge lamp La is mounted, and the comparison is made. Since the stop circuit 18 stops the operation of the inverter circuit 2 by the output of the circuit 22, different types of discharge lamps are not misused, and as a result, excessive current is supplied to the filament, so that the vicinity of the filament, That is, it is possible to prevent the occurrence of a problem such that the end of the glass tube or the stem glass is heated to a relatively high temperature, or conversely, the emitter is scattered due to a lack of preceding preheating current, leading to a shortened life. . However, since a higher power is supplied to the filament in the preceding preheating period and the starting period than in the lighting, the detection voltage Vs may be out of the predetermined range even in the case of a regular discharge lamp La. The control operation of the stop circuit 18 according to the comparison result of the circuit 22 is performed after the discharge lamp La is started. In this embodiment, the inverter circuit 2 is stopped when different types of discharge lamps are mounted. However, the inverter circuit 2 is not necessarily stopped, and the output of the inverter circuit 2 may be suppressed. In the preheating current detection circuit 24, the preheating current is indirectly detected by the voltage generated in the filament. However, the preheating current may be directly detected using a current transformer. In the present embodiment as well, as in the first embodiment, if the dimming control circuit 4 is provided with a configuration that detects the half-wave discharge of the discharge lamp La and stops the inverter circuit 2, the safety can be further improved. .

(Embodiment 3)
FIG. 7 shows a circuit configuration diagram of Embodiment 3 of the present invention. This embodiment is characterized by the configuration of the preheating circuit 8 ′, and the configuration other than the preheating circuit 8 ′ is common to the second embodiment. Therefore, the same code | symbol is attached | subjected to the same component as Embodiment 2, and description is abbreviate | omitted.

  In the preheating circuit 8 ′ in this embodiment, a DC cut capacitor C2 and a primary winding of a preheating transformer T1 are connected between output terminals of the inverter circuit 2 via a switching element Q3, and a pair of the preheating transformer T1. The secondary winding is connected to each filament of the discharge lamp La. This switching element Q3 is composed of a normally-off type MOSFET and is controlled to be turned on and off by the preheating timer circuit 10 and is turned on during the preceding preheating period and the starting period, and is turned off after the discharge lamp La is lit. The

  Thus, during the preceding preheating period and the starting period, the switching element Q3 is turned on by the preheating timer circuit 10 and a preheating current is supplied from the preheating circuit 8 'to the filament of the discharge lamp La. Since the switching element Q3 is turned off, no current is supplied from the preheating circuit 8 ′ to the filament of the discharge lamp La, and as a result, the current supplied from the preheating circuit 8 ′ to the filament of the discharge lamp La at the time of lighting is almost zero. As a result, an increase in the filament temperature can be suppressed, and the lifetime of the emitter can be prevented from being shortened by suppressing the consumption of the emitter. However, since the switching element Q3 is turned off at the time of lighting, the control operation of the stop circuit 18 according to the comparison result of the comparison circuit 22 needs to be performed between the preceding preheating period and the starting period of the discharge lamp La. In this embodiment, the inverter circuit 2 is stopped when different types of discharge lamps are mounted. However, the inverter circuit 2 is not necessarily stopped, and the output of the inverter circuit 2 may be suppressed. In the present embodiment as well, as in the first embodiment, if the dimming control circuit 4 is provided with a configuration that detects the half-wave discharge of the discharge lamp La and stops the inverter circuit 2, the safety can be further improved. .

  Here, since the preheating circuit 8 ′ of the present embodiment includes the preheating transformer T1, the preheating circuit 8 ′ is always compared with the preheating circuit 8 of the second embodiment regardless of the operation state of the inverter circuit 2 and the lighting state of the discharge lamp La. A stable current can be supplied to the filament. Therefore, there is an advantage that it is easy to determine the type of the discharge lamp La based on the difference in the impedance of the filament.

It is a circuit block diagram which shows Embodiment 1 of the discharge lamp lighting device which concerns on this invention. (A) and (b) are operation | movement explanatory drawings same as the above. (A) and (b) are operation | movement explanatory drawings same as the above. Embodiment 1 of the lighting fixture which concerns on this invention is shown, (a) is the perspective view seen from the downward | lower direction, (b) is sectional drawing. It is a circuit block diagram which shows Embodiment 2 of the discharge lamp lighting device which concerns on this invention. It is operation | movement explanatory drawing same as the above. It is a circuit block diagram which shows Embodiment 3 of the discharge lamp lighting device which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Inverter circuit 3 Resonant circuit 4 Dimming control circuit 5 Inverter control part 6 Correction control part 7 Non-volatile memory 14 Timekeeping timer part 15 Signal generation part 21 DC voltage detection circuit 22 Comparison circuit 23 Threshold voltage generation part Q1, Q2 switching Element La discharge lamp

Claims (4)

An inverter circuit that includes one or more switching elements and converts the DC input to a high-frequency AC output by switching the switching elements at a high frequency, and forms a resonance circuit together with the discharge lamp and is connected between the output terminals of the inverter circuit. One or a plurality of resonance inductors and resonance capacitors, and a dimming control circuit for adjusting high-frequency power supplied from the inverter circuit to the discharge lamp via the resonance circuit by controlling switching of the switching element. In the discharge lamp lighting device,
The dimming control circuit is configured so that the high-frequency power of the inverter circuit gradually increases as the usage time elapses during a period from the start of use of the discharge lamp to a predetermined time after reaching the rated life of the discharge lamp. A power correcting means for controlling, a power suppressing means for controlling the high frequency power of the inverter circuit to be a predetermined value or less after the predetermined time, a life detecting means for detecting that the discharge lamp has reached the end of its life, Control means for controlling the supply of electric power from the inverter circuit to the discharge lamp when the life detection means detects the life of the discharge lamp, and the life detection means is superimposed on the lamp current. that detects the voltage level corresponding to the DC voltage regarded as the detection voltage discharge lamp if beyond a predetermined threshold voltage has reached its life, the discharge lamp is about 1200m Tube length, when a straight tube fluorescent lamp having a tube diameter of approximately 25.5 mm, the predetermined value, the discharge lamp lighting device characterized in that it is set to large and 65W less than 55W. An inverter circuit that includes one or more switching elements and converts the DC input to a high-frequency AC output by switching the switching elements at a high frequency, and forms a resonance circuit together with the discharge lamp and is connected between the output terminals of the inverter circuit. One or a plurality of resonance inductors and resonance capacitors, a dimming control circuit for adjusting high-frequency power supplied from the inverter circuit to the discharge lamp via the resonance circuit by controlling switching of the switching element, In a discharge lamp lighting device comprising a preheating circuit for supplying a preheating current to a filament of an electric lamp,
The dimming control circuit is configured so that the high-frequency power of the inverter circuit gradually increases as the usage time elapses during a period from the start of use of the discharge lamp to a predetermined time after reaching the rated life of the discharge lamp. Power correcting means for controlling, power suppressing means for controlling the high frequency power of the inverter circuit to be a predetermined value or less after the predetermined time, preheating current detecting means for detecting the preheating current, and the preheating current detecting means And a control means for controlling to stop or suppress the power supply from the inverter circuit to the discharge lamp when the preheating current detected by the detector is out of a predetermined range, the discharge lamp having a tube length of about 1200 mm, In the case of a straight tube fluorescent lamp having a tube diameter of 25.5 mm, the predetermined value is set to a value greater than 55 W and not greater than 65 W. Light equipment.   The control means determines whether or not the preheating current detected by the preheating current detecting means is out of a predetermined range during a period from when the supply of high frequency power from the inverter circuit is started to when the discharge lamp is started. The discharge lamp lighting device according to claim 2.   The discharge lamp lighting device according to any one of claims 1 to 3, a fixture main body to which the discharge lamp lighting device is attached, a discharge lamp provided in the fixture main body is detachably mounted, and the discharge lamp lighting device and the discharge lamp are mounted. A lighting apparatus comprising a socket for electrically connecting an electric lamp.

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