JP6155807B2 - Lighting device and lighting apparatus - Google Patents

Description

The present invention relates to a lighting device and a lighting fixture .

  Conventionally, as described in, for example, Japanese Patent Application Laid-Open No. 2012-15052, a lighting device for a low temperature environment is known. The technology according to this publication is a low temperature lighting device in which the electrolytic solution of the electrolytic capacitor freezes. After turning on the power, the light is lit by 50% for a predetermined time to dissolve the electrolytic solution of the electrolytic capacitor, and then 100% A technique for lighting (all-light lighting) is disclosed.

JP 2012-15052 A

  However, in the above conventional technique, after the power is turned on, the light is dimmed by 50% for a predetermined time regardless of whether or not the electrolytic solution of the electrolytic capacitor is actually frozen. For this reason, even in a normal environment where the electrolytic solution of the electrolytic capacitor is not frozen, there is a problem that it takes unavoidably a long time before the lamp is lit 100%.

An object of this invention is to provide the lighting device and lighting fixture which can perform lighting control appropriately according to whether the electrolyte solution of an electrolytic capacitor is actually in a frozen state.

The lighting device according to the first invention is:
A chopper circuit having an electrolytic capacitor and charging the electrolytic capacitor with an input voltage from a power source;
A lighting circuit for supplying a current generated from a charge of the electrolytic capacitor to a light emitting element;
A temperature detection circuit that emits an output corresponding to the temperature of the electrolytic capacitor;
A control circuit for adjusting a current supplied to the light emitting element;
With
The control circuit, the current to the light emitting device after starting activation was the increased current to the light emitting element to reach the target current value, from said initial value current is determined in advance to the light emitting element after the start start The start-up time, which is the time to reach the target current value, is adjusted so as to increase as the temperature of the electrolytic capacitor detected by the temperature detection circuit decreases, and the temperature of the electrolytic capacitor detected by the temperature detection circuit The lower the is, the lower the rate of increase of current to the light emitting element within the startup time .

The lighting device according to the second invention is
A chopper circuit connected to the power supply;
A lighting circuit comprising an electrolytic capacitor, and smoothing the output current of the chopper circuit with the electrolytic capacitor and supplying the light emitting element;
A temperature detection circuit that emits an output corresponding to the temperature of the electrolytic capacitor;
A control circuit for adjusting a current supplied to the light emitting element;
With
The control circuit, the current to the light emitting device after starting activation was the increased current to the light emitting element to reach the target current value from an initial value the current is predetermined to the light emitting element after the start start The start-up time, which is the time to reach the target current value, is adjusted so as to become longer as the temperature of the electrolytic capacitor detected by the temperature detection circuit is lower , and of the electrolytic capacitor detected by the temperature detection circuit The lower the temperature, the lower the rate of increase of current to the light emitting element within the startup time .

  According to the present invention, it is possible to appropriately control lighting depending on whether or not the electrolytic solution of the electrolytic capacitor is actually in a frozen state.

It is a typical side view which shows a part of structure of the lighting device concerning embodiment of this invention. It is a circuit diagram of the lighting device concerning an embodiment of the invention. It is a figure for demonstrating operation | movement of the lighting device concerning embodiment of this invention, and is an operation | movement waveform diagram in the lighting device of FIG. It is a circuit diagram which shows the lighting device concerning the modification of this Embodiment. It is a circuit diagram which shows the lighting device concerning the modification of this Embodiment. It is the table which defined the relationship between the setting voltage and starting time concerning embodiment of this invention. It is a wave form diagram which shows one Example of the output current waveform at the time of starting in the lighting device concerning embodiment of this invention. It is a wave form diagram which shows one Example of the output current waveform at the time of starting in the lighting device concerning embodiment of this invention. It is a wave form diagram which shows one Example of the output current waveform at the time of starting in the lighting device concerning embodiment of this invention. It is a circuit diagram of the lighting device concerning the modification of embodiment of this invention.

  FIG. 1 is a schematic side view showing a part of the configuration of a lighting device 100 according to an embodiment of the present invention. The lighting device 100 includes a printed circuit board PWB on which the component parts are mounted. FIG. 1 shows some of the components described below among the components of the lighting device 100, and other components are omitted for convenience.

  An electrolytic capacitor C1 is mounted on the printed circuit board PWB. The electrolytic capacitor C1 has an electrolytic solution therein, and the capacitance changes according to the temperature.

  On the back side of the printed circuit board PWB, a temperature sensor SEN (thermistor Rm) is arranged at a position facing the electrolytic capacitor C1. Next to the temperature sensor SEN, a control circuit 50 (CPU), which is a microcomputer that receives an output signal of the temperature sensor SEN, is provided, and these are connected by a wiring W1. The control circuit 50 is connected to the lighting control circuit 41 of the lighting circuit 40 via the wiring W2. The control circuit 50 can adjust the control content of the lighting control circuit 41 according to the temperature detected by the temperature sensor SEN.

  FIG. 2 is a circuit diagram of the lighting device 100 according to the embodiment of the present invention. Circuit elements not shown in FIG. 1 are also shown in detail. The lighting device 100 is connected to the light source module 200 and supplies a direct current to the light source module 200. The light source module 200 includes a plurality of LEDs connected in series. In this embodiment, a case where the number of LEDs connected in series is five will be described. However, the present invention is not limited to this, and arbitrary LEDs may be connected in series, or LEDs may be connected in parallel.

  The lighting device 100 includes a diode bridge DB that rectifies an AC power supply, and a boost chopper circuit 10 connected to the diode bridge DB. The boost chopper circuit 10 is a circuit that boosts the input voltage from the diode bridge DB to a higher voltage. The step-up chopper circuit 10 is connected to a lighting circuit 40 (constant current circuit) that supplies power to the connected LED module.

  The lighting device 100 includes a control power supply circuit 60. The control power supply circuit 60 supplies the control power supply Vcc1 to the boost chopper circuit 10 and the lighting circuit 40.

  The lighting device 100 includes a temperature detection circuit 30 that detects the temperature. The temperature detection circuit 30 is a circuit built in the temperature sensor SEN described above.

  The step-up chopper circuit 10 includes resistors R1 and R2 that detect a voltage waveform of an output voltage output from the diode bridge DB. The voltage divided by the resistors R1 and R2 is input to the PFC control circuit 11. One end of the series circuit of the resistors R1 and R2 is connected to the lighting circuit 40 via a series circuit of the inductor L1 and the diode D1.

  The step-up chopper circuit 10 includes a MOS-FET (MOS field effect transistor) Q1 provided as a switching element, and a resistor R3 inserted in series between the MOS-FET Q1 and the ground. The PFC control circuit 11 can control ON / OFF of the MOS-FET Q1 by giving a control signal to the gate.

  The step-up chopper circuit 10 includes an electrolytic capacitor C1. The electrolytic capacitor C1 is inserted between the cathode of the diode D1 and the ground. The electrolytic capacitor C1 can function as a smoothing capacitor.

  The temperature detection circuit 30 is configured by connecting a resistor R4 and a thermistor Rm in series. The thermistor Rm is arranged close to the electrolytic capacitor C1, and the resistance value changes according to the temperature of the electrolytic capacitor C1. More specifically, the “temperature of the electrolytic capacitor C1” is a temperature detected via the peripheral component (printed circuit board PWB) of the electrolytic capacitor C1, and is a temperature depending on the temperature of the electrolytic capacitor C1.

  Specifically, for example, an NTC thermistor or a PTC thermistor can be used as the thermistor Rm. An NTC thermistor is a thermistor whose resistance decreases with increasing temperature. A PTC thermistor is a thermistor whose resistance increases with respect to temperature rise. In this embodiment, a case where a PTC thermistor is used will be described.

  The temperature detection circuit 30 outputs a voltage at an intermediate point between the resistor R4 and the thermistor Rm to the control circuit 50. That is, the temperature detection circuit 30 detects the divided voltage divided by the resistor R4 and the thermistor Rm. In the temperature detection circuit 30, the voltage dividing ratio between the resistor R4 and the thermistor Rm changes as the resistance value of the thermistor Rm changes. Therefore, the detection voltage output from the temperature detection circuit 30 changes in proportion to the temperature change of the electrolytic capacitor C1.

  The lighting circuit 40 includes a MOS-FET (MOS field effect transistor) Q2 and a lighting control circuit 41 that controls on / off of the MOS-FET Q2. The lighting circuit 40 is a converter circuit using the MOS-FET Q2 as a switching element. The capacitor C2 has one end connected to the output of the MOS-FET Q2 and the other end connected to the ground, and functions as a smoothing capacitor.

  The cathode of the diode D2 is connected to the anode side of the light source module 200, and the anode of the diode D2 is connected to the cathode side of the light source module 200. One end of the resistor R5 is connected to the cathode of the light source module 200, the anode of the diode D2, and the lighting control circuit 41, and the other end of the resistor R5 is connected to the ground.

  The control circuit 50 is specifically a microcomputer. The control circuit 50 stores a table in which the set voltage and the activation time T are associated with each other. The startup time T is the time from when the power is turned on until the target current value is reached. In the present embodiment, the startup time T is the time from when the AC power is turned on until the LED reaches maximum lighting (100% lighting) by gradually increasing the output current.

  The control circuit 50 compares the detection voltage output from the temperature detection circuit 30 with a set voltage set inside. As a result of the comparison, one set voltage closest to the detected voltage is determined, and the activation time T corresponding to the closest set voltage is read from the table. By such processing, the activation time T for activating the lighting circuit 40 can be determined.

  In this embodiment, the set voltage is set in five stages as shown in the table shown in FIG. However, the present invention is not limited to this, and the set voltage is not limited to five stages, and may be set by being divided into arbitrary stages. The set voltage is continuously associated with the start-up time T in the form of a mathematical expression. May be.

  The control power supply circuit 60 generates the control power supply Vcc1 and supplies it to the lighting control circuit 41 of the lighting circuit 40, the PFC control circuit 11 of the boost chopper circuit 10, and the control circuit 50, respectively.

  Next, the operation of the lighting device 100 according to the embodiment of the present invention will be described with reference to FIG. FIG. 3 is a diagram for explaining the operation of the lighting device 100 according to the embodiment of the present invention. In FIG. 3, the hatched areas have the following meanings. A graph VQ1 shows the source-drain voltage VDS of the MOS-FET Q1 of the boost chopper circuit 10. A graph Io shows an output current waveform of the lighting circuit 40. A graph VD2 shows the waveform of the voltage across the diode D2 in the lighting circuit 40 (back converter circuit).

  FIG. 3A is a diagram for explaining a problem at a low temperature (when the electrolytic solution of the electrolytic capacitor C1 is frozen) when the control according to the present embodiment is not performed. FIG. 3B shows a voltage waveform when the start-up sequence of the present embodiment is performed at the start-up time T1 when the temperature of the electrolytic capacitor C1 is tc1. FIG. 3C shows a voltage waveform when the start-up sequence of the present embodiment is performed at the start-up time T2 when the temperature of the electrolytic capacitor C1 is tc2 (where tc1> tc2). However, T1 <T2.

  In the present embodiment, the control circuit 50 executes a different startup sequence depending on the temperature of the electrolytic capacitor C1. Specifically, as shown in FIGS. 3B and 3C, the startup time T is set longer as the temperature of the electrolytic capacitor C1 is lower.

  Next, specific control contents executed in the lighting device 100 according to the embodiment will be described. First, when an AC power supply is turned on to the lighting device 100, the control power supply circuit 60 is activated to generate the control power supply Vcc1, and the PFC control circuit 11, the lighting control circuit 41, and the control circuit 50 receive the control power supply Vcc1. to start.

  At this time, the control circuit 50 reads the detection voltage output from the temperature detection circuit 30. The control circuit 50 compares the read detection voltage with the set voltage in the table shown in FIG. 6 and reads the activation time T associated with the set voltage closest to the detection voltage.

  Next, the control circuit 50 outputs a control signal to the lighting control circuit 41 so as to gradually increase the output current toward the target current value based on the read activation time T. The target current value is a magnitude of a current necessary for lighting the LED of the light source module 200 with a target brightness (for example, maximum brightness). The increase in the output current is performed so that the output current of the lighting circuit 40 becomes maximum (100%) when the activation time T is reached. However, the present invention is not limited to this, and the target current value may be set to an output current less than the maximum.

  Control information for causing the lighting circuit 40 to output the target current value (for example, the ratio of the on-time of the MOS-FETs Q1 and Q2 that are switch elements) is stored and set in advance in a storage circuit provided in the control circuit 50.

  By doing in this way, the control circuit 50 can change the starting time T according to the temperature of the electrolytic capacitor C1.

  When the electrolytic solution of the electrolytic capacitor C1 is frozen, the amplitude width (vibration) of the voltage applied to the electrolytic capacitor C1 can be suppressed during the activation time T. As a result, there is no possibility that the voltage applied to the electrolytic capacitor C1 exceeds the rated voltage of the electronic components constituting the lighting device.

  Here, the problem at a low temperature (when the electrolytic solution of the electrolytic capacitor C1 is frozen) will be described in more detail.

  When the electrolytic solution of the electrolytic capacitor C1 is frozen, the capacitance of the electrolytic capacitor C1 is lower than normal (when the electrolytic solution is not frozen), and the value of ESR (equivalent series resistance) is high. Become. Therefore, when the boost chopper circuit 10 operates, the amount of charge charged in the electrolytic capacitor C1 is reduced. When the charge amount decreases, when the lighting circuit 40 supplies the maximum current to the LED, the charge of the electrolytic capacitor C1 decreases immediately and the voltage decreases. To compensate for this, the boost chopper circuit 10 increases the output voltage. And

  Therefore, as shown in FIG. 3A, after the AC power is turned on, the voltage of the electrolytic capacitor C1 vibrates violently (the amplitude is large), and the voltage is boosted as shown by the circle indicated by the symbol X. The voltage may overshoot. As a result, there is a risk that the rated voltage of the electronic components constituting the lighting device may be exceeded. In addition, the lighting circuit 40 cannot cause the LED to light stably, and causes the LED to flicker or blink.

  In this regard, according to the lighting device 100 according to the present embodiment, the starting time T of the lighting circuit 40 can be changed according to the temperature of the electrolytic capacitor C1. For this reason, when the electrolytic solution of the electrolytic capacitor C1 is frozen, the lighting circuit 40 suddenly increases the output current without supplying the maximum current (100% lighting) to the LED. Therefore, the voltage applied to the electrolytic capacitor C1 does not exceed the rated voltage of the electronic component, and the possibility that the LED flickers or blinks can be reduced.

  Moreover, since the starting time T is set according to the temperature of the electrolytic capacitor C1, the starting time T can be shortened in a temperature environment in which the electrolytic solution of the electrolytic capacitor C1 does not freeze. Therefore, it is possible to suppress useless start-up time in an environment where the electrolytic capacitor C1 is not frozen.

  As described above, according to the present embodiment, when the electrolytic solution of the electrolytic capacitor C1 is frozen, the time for gradually increasing the output current of the lighting circuit is set to be long, and the dimming lighting is completely started. Light lighting (100% lighting) can be performed. For this reason, the voltage fluctuation applied to the electrolytic capacitor of the step-up chopper circuit can be suppressed.

  Further, according to the present embodiment, when the electrolytic solution is liquefied, all-light lighting (100% lighting) can be instantaneously performed when the power is turned on. For this reason, it becomes possible to light up instantaneously under a normal environment.

  In the lighting device 100 shown in FIG. 1, the case where the capacitor C2 of the lighting circuit 40 does not include an electrolytic solution such as a film capacitor has been described, but an electrolytic capacitor may be used for the capacitor C2. In that case, the temperature environment in which the capacitor C2 is placed is almost equal to the temperature environment in which the electrolytic capacitor C1 is placed. Therefore, the control circuit 50 may control the lighting circuit 40 by assuming that the temperature of the electrolytic capacitor C1 is substantially the same as the temperature of the capacitor C2.

  As shown in FIG. 4, the temperature detection circuit 30a may be provided in the vicinity of the electrolytic capacitor C2a without providing the temperature detection circuit 30 for the electrolytic capacitor C1.

  Further, as shown in FIG. 5, the temperature detection circuits 30 and 30a may be provided in the electrolytic capacitor C1 and the electrolytic capacitor C2a, respectively. Thereby, the temperature detection of each of the electrolytic capacitors C1 and C2a can be accurately performed.

  Although various ways of increasing the output current can be considered, for example, the output current may be as shown in FIGS. 7 to 9, T1, T2, and T3 indicate different activation times T read by the control circuit 50 in accordance with the detected voltage, and have a relationship of T1 <T2 <T3.

  FIG. 7 shows that the output current is simply increased at a constant rate of increase within each start time T1, T2, T3 from the start time T0 toward the target current value (current value in which 100% all light is turned on in this embodiment). To increase. The slope (current increase rate) is different for each of the startup times T1, T2, and T3.

  FIG. 8 shows the case where the output current reaches the target current value within each of the activation times T1, T2, and T3 in three stages from 50% dimming lighting at the time of activation. For example, in the case of the activation time T1, the first stage increase is performed at time t11, and the second stage increase is performed at time t12. In the case of the activation time T2, the first stage increase is performed at time t21, and the second stage increase is performed at time t22. In the case of the activation time T3, the first stage increase is performed at time t31, and the second stage increase is performed at time t32. In each case, the current is increased every time the startup time is divided equally by the increased number of stages (three stages).

  FIG. 9 simply increases the output current at a constant rate of increase within each startup time T1, T2, T3 from the 50% dimming lighting to the target current value during startup. The starting times T1, T2, T3, and the slope (current increase rate) are different.

  Moreover, in this Embodiment, the control circuit 50 controlled the lighting circuit 40, and demonstrated the case where the voltage oscillation of the electrolytic capacitor C1 was suppressed. However, the present invention is not limited to this.

  FIG. 10 is a circuit diagram of a lighting device 300 according to a modification of the embodiment of the present invention. As shown in FIG. 10, the control circuit 50 may be connected to the PFC control circuit 11 of the boost chopper circuit 10. In such a circuit, the control circuit 50 controls the step-up chopper circuit 10 (specifically, the MOS-FET Q1) to adjust the start-up time T, thereby suppressing the voltage oscillation of the electrolytic capacitor C1. Good. Alternatively, the startup time T may be adjusted by the control circuit 50 controlling both the lighting circuit 40 and the step-up chopper circuit 10.

  In the present embodiment, the case where the control circuit 50 directly detects the detection voltage detected by the temperature detection circuit 30 to detect the temperature of the electrolytic capacitor C1 has been described. However, the present invention is not limited to this. An amplifier may be provided between the temperature detection circuit 30 and the control circuit 50, and the voltage value of the detection voltage of the temperature detection circuit 30 may be amplified by the amplifier. Further, the detection voltage of the temperature detection circuit 30 may be compared with a reference voltage, and the comparison result may be output to an amplifier.

DESCRIPTION OF SYMBOLS 10 Boost chopper circuit, 11 PFC control circuit, 30 Temperature detection circuit, 30a Temperature detection circuit, 40 Lighting circuit, 41 Lighting control circuit, 50 Control circuit, 60 Control power supply circuit, 100, 300 Lighting device, 200 Light source module, C1, C2a Electrolytic Capacitor, C2 Capacitor, D1, D2 Diode, DB Diode Bridge, L1 Inductor, PWB Printed Circuit Board, Q1, Q2 MOS-FET, R1, R2, R3, R4, R5 Resistor, Rm Thermistor, SEN Temperature Sensor, To Start Time, T, T1, T2, T3 start-up time, Vcc1 control power supply

Claims (6)

A chopper circuit having an electrolytic capacitor and charging the electrolytic capacitor with an input voltage from a power source;
A lighting circuit for supplying a current generated from a charge of the electrolytic capacitor to a light emitting element;
A temperature detection circuit that emits an output corresponding to the temperature of the electrolytic capacitor;
A control circuit for adjusting a current supplied to the light emitting element;
With
The control circuit, the current to the light emitting device after starting activation was the increased current to the light emitting element to reach the target current value, from said initial value current is determined in advance to the light emitting element after the start start The start-up time, which is the time to reach the target current value, is adjusted so as to increase as the temperature of the electrolytic capacitor detected by the temperature detection circuit decreases, and the temperature of the electrolytic capacitor detected by the temperature detection circuit The lighting device is characterized in that the lower the value, the lower the rate of increase of current to the light emitting element within the startup time . A chopper circuit connected to the power supply;
A lighting circuit comprising an electrolytic capacitor, and smoothing the output current of the chopper circuit with the electrolytic capacitor and supplying the light emitting element;
A temperature detection circuit that emits an output corresponding to the temperature of the electrolytic capacitor;
A control circuit for adjusting a current supplied to the light emitting element;
With
The control circuit, the current to the light emitting device after starting activation was the increased current to the light emitting element to reach the target current value from an initial value the current is predetermined to the light emitting element after the start start The start-up time, which is the time to reach the target current value, is adjusted so as to become longer as the temperature of the electrolytic capacitor detected by the temperature detection circuit is lower , and of the electrolytic capacitor detected by the temperature detection circuit The lighting device characterized by lowering the rate of increase of current to the light emitting element within the startup time as the temperature is lower . By adjusting the control signal to the switching element of the lighting circuit or by adjusting the control signal to the switching element of the chopper circuit, the start-up time is increased or decreased according to the output of the temperature detection circuit. The lighting device according to claim 1 or 2.   A chopper circuit having an electrolytic capacitor and charging the electrolytic capacitor with an input voltage from a power source;
  A lighting circuit for supplying a current generated from a charge of the electrolytic capacitor to a light emitting element;
  A temperature detection circuit that emits an output corresponding to the temperature of the electrolytic capacitor;
  A control circuit for adjusting a current supplied to the light emitting element;
  With
  The control circuit increases the current to the light emitting element stepwise in a plurality of stages so that the current to the light emitting element reaches a target current value after the start of startup. The start-up time, which is the time from the determined initial value to the target current value, is adjusted to be longer as the temperature of the electrolytic capacitor detected by the temperature detection circuit is lower, and the start-up time is equal to the number of stages. After the start of startup, the current to the light emitting element is increased by a predetermined amount, and the interval is increased as the temperature of the electrolytic capacitor detected by the temperature detection circuit is lower. The lighting device characterized by doing.   A chopper circuit connected to the power supply;
  A lighting circuit comprising an electrolytic capacitor, and smoothing the output current of the chopper circuit with the electrolytic capacitor and supplying the light emitting element;
  A temperature detection circuit that emits an output corresponding to the temperature of the electrolytic capacitor;
  A control circuit for adjusting a current supplied to the light emitting element;
  With
  The control circuit increases the current to the light emitting element stepwise in a plurality of stages so that the current to the light emitting element reaches a target current value after the start of startup. The start-up time, which is the time from the determined initial value to the target current value, is adjusted to be longer as the temperature of the electrolytic capacitor detected by the temperature detection circuit is lower, and the start-up time is equal to the number of stages. After the start of startup, the current to the light emitting element is increased by a predetermined amount, and the interval is increased as the temperature of the electrolytic capacitor detected by the temperature detection circuit is lower. The lighting device characterized by doing.   The lighting device according to any one of claims 1 to 5,
  A light emitting element that is turned on by the lighting device;
  A lighting apparatus comprising:

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