JP2017228507A - Lighting device and illumination device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a dimming function while improving a power factor with a number of components smaller than the conventional number of components.SOLUTION: A step-up chopper circuit 12 converts an input from a rectification circuit 11 to DC voltage by turning on/off the input by a switching element Q1, and applies the DC voltage to a light source 20. A control circuit 13 comprises a first charging circuit 131 which supplies constant first charging current I1 to a capacitor C1, and a discharging circuit 132 which discharges electric charge from the capacitor C1 when the switching element Q1 is off. A second charging circuit 14 supplies second charging current I2 of a current value according to a dimming level to the capacitor C1. When the switching element Q1 is on, the capacitor C1 is charged with the composite current of the first charging current I1 and the second charging current I2. If the charging voltage of the capacitor C1 becomes higher than threshold voltage V2 when the switching element Q1 is on, the control circuit 13 turns off the switching element Q1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lighting device and a lighting device including the lighting device, and more particularly to a lighting device having a dimming function and a lighting device including the lighting device.

  Conventionally, there has been an illumination LED power supply device that includes a power factor correction circuit, a step-down chopper circuit, a control circuit, and a dimming signal processing circuit and lights an LED (Light Emitting Diode) load (see, for example, Patent Document 1). ).

  The power factor correction circuit is a step-up chopper circuit and generates a constant DC voltage obtained by boosting the input voltage. The step-down chopper circuit steps down the output voltage of the power factor correction circuit and applies it to the LED load. The dimming signal processing circuit converts a dimming signal composed of a PWM (Pulse Width Modulation) signal into a DC voltage having a voltage value corresponding to the duty of the dimming signal. The control circuit controls the duty of the switching element of the step-down chopper circuit according to the voltage value of the DC voltage output from the dimming signal processing circuit, so that the output voltage of the step-down chopper circuit depends on the duty of the dimming signal To control the voltage value. Thereby, the LED power supply for illumination turns on the LED load at a dimming level corresponding to the dimming signal.

JP 2014-32748 A

  The LED power supply for illumination of Patent Document 1 includes two converter circuits, a power factor improvement circuit (a step-up chopper circuit) and a step-down chopper circuit, in order to dimm and light the LED load while improving the power factor. Therefore, there is a problem that the number of circuit components increases.

  The objective of this invention is providing the lighting device which can implement | achieve a light control function, aiming at the improvement of a power factor with the number of parts smaller than before, and an illuminating device provided with the same.

  The lighting device of one embodiment of the present invention includes a boost chopper circuit and a control circuit. The step-up chopper circuit converts an input from a power source to a DC voltage by turning on / off the switching element, and applies the converted DC voltage to a light source including a solid state light emitting element. The control circuit controls on / off of the switching element. The control circuit includes a first charging circuit that supplies a constant first charging current to a capacitor, and a discharge circuit that discharges the capacitor when the switching element is turned off. The control circuit is configured to turn off the switching element when a charging voltage of the capacitor becomes equal to or higher than a threshold voltage when the switching element is on. The lighting device according to one aspect of the present invention further includes a second charging circuit that supplies a second charging current having a current value corresponding to the dimming level to the capacitor. The capacitor is charged with a combined current of the first charging current and the second charging current when the switching element is on.

  An illumination device of one embodiment of the present invention includes the lighting device, a light source to which a DC voltage is applied by the boost chopper circuit, and a lighting device and a fixture main body that holds the light source.

  ADVANTAGE OF THE INVENTION According to this invention, the lighting device which can implement | achieve a light control function, aiming at the improvement of a power factor with the number of parts smaller than before, and an illuminating device provided with the same can be provided.

FIG. 1 is a circuit diagram of a lighting device according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the lighting device according to the embodiment of the present invention. 3A to 3C are waveform diagrams of respective parts of the lighting device. FIG. 3A is a waveform diagram of the charging voltage of the capacitor. FIG. 3B is a waveform diagram of the gate voltage of the switching element. FIG. 3C is a waveform diagram of a current flowing through the coil. FIG. 4 is a waveform diagram of the input current flowing from the AC power supply and the current flowing to the coil of the boost chopper circuit in the half cycle of the AC power supply in the above lighting device.

  Embodiment described below is only an example of the lighting device which concerns on this invention, and an illuminating device provided with the same. The present invention is not limited to the following embodiments, and various modifications can be made in the following embodiments depending on the design or the like as long as the object of the present invention can be achieved.

(1) Overview The lighting device 10 of the present embodiment includes a boost chopper circuit 12 and a control circuit 13 as shown in FIG.

  The step-up chopper circuit 12 converts the input from the power supply (rectifier circuit 11 in FIG. 1) into a DC voltage by turning on / off the switching element Q1. The step-up chopper circuit 12 applies the converted DC voltage to the light source 20 including the solid state light emitting element (the light emitting diode 201 in FIG. 1).

  The control circuit 13 controls on / off of the switching element Q1. The control circuit 13 includes a first charging circuit 131 that supplies a constant first charging current I1 to the capacitor C1, and a discharging circuit 132 that discharges the capacitor C1 when the switching element Q1 is turned off. The control circuit 13 turns off the switching element Q1 when the charging voltage of the capacitor C1 becomes equal to or higher than the threshold voltage V2 when the switching element Q1 is on.

  The lighting device 10 further includes a second charging circuit 14. The second charging circuit 14 supplies a second charging current I2 having a current value corresponding to the dimming level to the capacitor C1. Therefore, the capacitor C1 is charged with a combined current of the first charging current I1 and the second charging current I2 when the switching element Q1 is on. Note that the current value of the combined current is a current value obtained by adding the current value of the first charging current I1 and the current value of the second charging current I2.

  As a result, the capacitor C1 is charged with a combined current of the constant first charging current I1 and the second charging current I2 having a current value corresponding to the dimming level, so that the ON time of the switching element Q1 is the dimming level. It depends on. Therefore, the dimming function can be added to the boost chopper circuit 12 simply by adding the second charging circuit 14. Therefore, it is possible to realize the dimming function while improving the power factor with a smaller number of parts than the conventional one including the step-up chopper circuit and the step-down chopper circuit. When the current value of the second charging current I2 is zero, the light output of the light source 20 is a rated output. Hereinafter, a state where the light output of the light source 20 is the rated output is defined as a state where the light control level is 100%. Further, a state where the light output of the light source 20 is minimum, for example, a state where the light source 20 is turned off is defined as a state where the light control level is 0%. Therefore, in the present embodiment, as the dimming level decreases, the on-time of the switching element Q1 is shortened, so that the current value of the second charging current I2 supplied from the second charging circuit 14 to the capacitor C1 increases.

  Moreover, the illuminating device 1 of this embodiment is the lighting device 10, the light source 20 to which a DC voltage is applied by the step-up chopper circuit 12, the lighting device 10 and the fixture main body 50 (see FIG. 2) holding the light source 20, Is provided.

(2) Details Hereinafter, the lighting device 10 and the lighting device 1 according to the embodiment will be described with reference to FIGS.

(2.1) Lighting Device (2.1.1) Configuration As illustrated in FIG. 1, the lighting device 10 according to the present embodiment includes a boost chopper circuit 12, a control circuit 13, and a second charging circuit 14. I have.

  Further, the lighting device 10 of the present embodiment further includes a rectifier circuit 11, a control power supply circuit 16, and an abnormality detection circuit 17. The rectifier circuit 11, the control power supply circuit 16, and the abnormality detection circuit 17 are not essential components for the lighting device 10, and can be omitted as appropriate.

  The rectifier circuit 11 is composed of a diode bridge circuit, for example. The rectifier circuit 11 full-wave rectifies an input current from an AC power source 2 (for example, AC 100/200 V, 50/60 Hz AC power source) such as a commercial AC power source, and outputs it to the boost chopper circuit 12.

  The step-up chopper circuit 12 includes a coil L1, a switching element Q1, a diode D1, and a smoothing capacitor C2. The switching element Q1 is, for example, an N channel type MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The drain electrode of the switching element Q1 is electrically connected to one end of the coil L1, and the other end of the coil L1 is electrically connected to the output terminal on the high potential side of the rectifier circuit 11. The source electrode of the switching element Q1 is electrically connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the circuit ground. The gate electrode of the switching element Q1 is electrically connected to the output terminal of the control circuit 13.

  The drain electrode of the switching element Q1 is electrically connected to the anode electrode of the diode D1, and the cathode electrode of the diode D1 is electrically connected to one end of the smoothing capacitor C2. The other end of the smoothing capacitor C2 is connected to the circuit ground.

  A light source 20 and a current detection resistor R2 are electrically connected in series between both ends of the smoothing capacitor C2. The light source 20 includes a plurality (for example, several tens) of light emitting diodes 201 connected in series.

  When the control circuit 13 performs PWM control of the switching element Q1, the boost chopper circuit 12 can convert the output voltage of the rectifier circuit 11 into a constant DC voltage obtained by boosting the output voltage of the boost chopper circuit 12. 20 is applied. The light source 20 has a series circuit of several tens of light emitting diodes 201, and the boost chopper circuit 12 applies a voltage higher than the sum of the forward voltages of the several tens of light emitting diodes 201 to the light source 20. By doing so, the light source 20 is turned on. In the step-up chopper circuit 12, since the input current from the AC power supply 2 always flows, the power factor of the circuit can be improved.

  The control circuit 13 includes a first charging circuit 131 and a discharging circuit 132. The control circuit 13 according to the present embodiment further includes an error amplifier 133, a comparator 134, a NOT gate 135, and a constant voltage source 136.

  The first charging circuit 131 includes a constant current source connected in series with the capacitor C1. The first charging circuit 131 supplies a constant first charging current I1 to the capacitor C1.

  The discharge circuit 132 includes a switch SW1 connected in parallel to the capacitor C1. The output terminal of the NOT gate 135 is electrically connected to the control terminal of the switch SW1. The switch SW1 is turned on or off according to the voltage level of the output voltage of the NOT gate 135. When the voltage level of the output voltage of the NOT gate 135 becomes H level, the switch SW1 is turned on, and the charge charged in the capacitor C1 is discharged via the switch SW1. When the voltage level of the output voltage of the NOT gate 135 becomes L level, the switch SW1 is turned off and the capacitor C1 is charged.

  The error amplifier 133 is realized by an operational amplifier. A voltage V1 generated between both ends of the resistor R2 is input to the negative input terminal of the error amplifier 133. A constant reference voltage Vref is input from the constant voltage source 136 to the plus side input terminal of the error amplifier 133. The error amplifier 133 generates a threshold voltage V2 having a magnitude proportional to the difference voltage between the voltage V1 and the reference voltage Vref.

  The comparator 134 is realized by an operational amplifier, and the threshold voltage V <b> 2 is input from the error amplifier 133 to the positive input terminal of the comparator 134. The charging voltage V3 of the capacitor C1 is input to the negative input terminal of the comparator 134. That is, the comparator 134 compares the threshold voltage V2 input from the error amplifier 133 with the charge voltage V3 of the capacitor C1. The output terminal of the comparator 134 is electrically connected to the gate electrode of the switching element Q1.

  The input terminal of the NOT gate 135 is electrically connected to the output terminal of the comparator 134. The output terminal of the NOT gate 135 is electrically connected to the control terminal of the switch SW1.

  The control circuit 13 of the present embodiment is for power factor improvement in which circuit components such as the first charging circuit 131, the discharging circuit 132, the error amplifier 133, the comparator 134, the NOT gate 135, and the constant voltage source 136 are integrated. It is realized by an integrated circuit.

  For example, the control power supply circuit 16 steps down the output voltage of the step-up chopper circuit 12 to generate a constant DC voltage.

  The second charging circuit 14 includes a dimming control circuit 15 and a resistor R3. One end of the resistor R3 is electrically connected to a connection point between the first charging circuit 131 and the capacitor C1. The other end of the resistor R3 is electrically connected to the output end of the dimming control circuit 15. The dimming control circuit 15 has a receiving function for receiving, for example, a dimming signal transmitted from the controller 3 as a radio signal such as infrared light or radio waves. The dimming control circuit 15 converts the voltage value of the DC voltage input from the control power supply circuit 16 into a voltage value corresponding to the dimming level represented by the dimming signal received from the controller 3, and outputs the voltage value to the resistor R3. . Accordingly, the second charging current I2 having a current value corresponding to the dimming level is supplied from the second charging circuit 14 to the capacitor C1. Therefore, a combined current obtained by adding the first charging current I1 and the second charging current I2 is supplied to the capacitor C1.

  The abnormality detection circuit 17 includes a comparator 171 and resistors R4 to R7. A series circuit of resistors R4 and R5 is electrically connected between both ends of the smoothing capacitor C2. The series circuit of the resistors R6 and R7 is electrically connected between the output terminal of the control power supply circuit 16 and the circuit ground. The positive side input terminal of the comparator 171 receives the output voltage of the boost chopper circuit 12, that is, the voltage V4 obtained by dividing the voltage across the smoothing capacitor C2 by the resistors R4 and R5. A constant reference voltage V5 obtained by dividing the output voltage of the control power supply circuit 16 by resistors R6 and R7 is input to the negative input terminal of the comparator 171. The comparator 171 compares the voltage V4 with the reference voltage V5, and the output of the comparator 171 is input to the dimming control circuit 15.

  In the present embodiment, the abnormality detection circuit 17 detects that there is an abnormality when the voltage V4 is lower than the reference voltage V5, and detects that there is no abnormality when the voltage V4 is equal to or higher than the reference voltage V5.

  For example, when some of the plurality of light emitting diodes 201 constituting the light source 20 are short-circuited, the current flowing through the light source 20 increases, and the control circuit 13 decreases the output voltage of the boost chopper circuit 12 accordingly. When the voltage V4 obtained by dividing the output voltage of the boost chopper circuit 12 becomes lower than the reference voltage V5, the abnormality detection circuit 17 detects that there is an abnormality and performs an operation of suppressing the output of the boost chopper circuit 12.

(2.1.2) Operation Hereinafter, the operation of the lighting device 10 will be described.

  First, the operation of the lighting device 10 when the current value of the second charging current I2 is zero, that is, when the dimming level is 100% will be described.

  A voltage V1 proportional to the current value flowing through the light source 20 is generated between both ends of the resistor R2, and the error amplifier 133 is proportional to an error between the voltage V1 generated between both ends of the resistor R2 and the reference voltage Vref. A threshold voltage V2 is generated. Therefore, when the voltage V1 across the resistor R2 varies with respect to the reference voltage Vref, the threshold voltage V2 input from the error amplifier 133 varies accordingly. That is, when the light output of the light source 20 changes, the threshold voltage V2 input from the error amplifier 133 changes accordingly.

  When the switching element Q1 is on, the switch SW1 is turned off, and the capacitor C1 is charged by the combined current of the first charging current I1 and the second charging current I2. Therefore, the charging voltage generated across the capacitor C1 V3 gradually increases. When the charging voltage V3 of the capacitor C1 becomes larger than the threshold voltage V2, the voltage level of the output voltage V6 of the comparator 134 becomes L level, and the switching element Q1 is turned off. When the voltage level of the output voltage V6 of the comparator 134 becomes L level, the voltage level of the output voltage of the NOT gate 135 becomes H level, so that the switch SW1 is turned on and the charge charged in the capacitor C1 is switched to the switch SW1. Discharge through.

  When the charge charged in the capacitor C1 is discharged and the charging voltage V3 of the capacitor C1 becomes lower than the threshold voltage V2, the voltage level of the output voltage V6 of the comparator 134 becomes H level, and the switching element Q1 is turned on. . When the voltage level of the output voltage V6 of the comparator 134 becomes H level, the voltage level of the output voltage of the NOT gate 135 becomes L level, and the switch SW1 is turned off. At this time, the capacitor C1 is charged by the combined current of the first charging current I1 and the second charging current I2, and the charging voltage V3 of the capacitor C1 increases.

  When the charging voltage V3 of the capacitor C1 becomes larger than the threshold voltage V2 input from the error amplifier 133, the voltage level of the output voltage V6 of the comparator 134 becomes L level, and the switching element Q1 is turned off. Further, when the voltage level of the output voltage V6 of the comparator 134 becomes L level, the voltage level of the output voltage of the NOT gate 135 becomes H level and the switch SW1 is turned on, so that the charge charged in the capacitor C1 is switched to the switch SW1. It is discharged through.

  When the lighting device 10 repeats the above operation, the switching element Q1 is turned on / off periodically and the switching element Q1 is turned on so that the voltage V1 across the resistor R2 has a constant voltage value. The period is adjusted.

  In the above description, in the comparison between two values such as a voltage, “greater than” means that one of the two values exceeds the other. However, without being limited thereto, “greater than” may be synonymous with “more than” including both the case where one of the two values exceeds the other and the case where the two values are equal. That is, whether or not the case where the two values are equal can be arbitrarily changed depending on the setting of the reference value or the like, so there is no technical difference between “larger” and “greater than”. Similarly, “lower” may be synonymous with “below”.

  Next, the operation of the lighting device 10 when the light output of the light source 20 is dimmed by the dimming control circuit 15 will be described with reference to FIGS.

  The dimming control circuit 15 increases the voltage level of the voltage output to the resistor R3 as the dimming level represented by the dimming signal received from the controller 3 is smaller. That is, the smaller the dimming level of the dimming signal received by the dimming control circuit 15 from the controller 3, the larger the current value of the second charging current I2 supplied from the second charging circuit 14 to the capacitor C1.

  FIG. 3A is a waveform diagram of the charging voltage V3 of the capacitor C1. FIG. 3B is a waveform diagram of the gate voltage applied to the gate electrode of the switching element Q1, that is, the output voltage V6 of the comparator 134. FIG. 3C is a waveform diagram of the current IL1 flowing through the coil L1 of the boost chopper circuit 12. FIG. 4 is a waveform diagram of the input current I10 flowing from the AC power supply 2 to the lighting device 10 and the current IL1 flowing through the coil L1 of the boost chopper circuit 12 in the half cycle of the AC power supply 2.

  The waveform indicated by the solid line in FIGS. 3A, 3B, and 3C is a waveform when the current value of the second charging current I2 is zero, that is, when the dimming level is 100%. The waveform indicated by the dotted line in FIGS. 3A, 3B, and 3C is a waveform when the current value of the second charging current I2 is a current value when the dimming level is less than 100%. 3A, 3 and 3C show waveforms only during a period in which the switching element Q1 is turned on once. Further, the waveform corresponding to a half cycle of the AC power supply 2 shown on the left side of FIG. 4 is a waveform when the current value of the second charging current I2 is zero, that is, when the dimming level is 100%. The waveform corresponding to a half cycle of the AC power supply 2 shown on the right side of FIG. 4 is a waveform when the current value of the second charging current I2 is a current value when the dimming level is smaller than 100%.

  When the dimming control circuit 15 supplies the second charging current I2 having a current value corresponding to the dimming level to the capacitor C1, the charging voltage V3 of the capacitor C1 is a threshold value compared to the case where the second charging current I2 is zero. The time until the voltage V2 is reached is shortened (see FIG. 3A). As a result, as shown in FIG. 3B, since the period during which the output voltage V6 of the comparator 134 is at the H level is shortened, the period during which the switching element Q1 is turned on is shortened, and the peak value of the current IL1 flowing through the coil L1 is reduced. (See FIG. 3C). Therefore, as shown in FIG. 4, when the dimming control circuit 15 causes the second charging current I2 having a current value corresponding to the dimming level to flow through the capacitor C1, compared to when the second charging current I2 is zero. In the half cycle of the AC power supply 2, the peak value of the input current I10 decreases. Therefore, the dimming level of the light source 20 is lower than 100%, and the light output of the light source 20 is reduced.

  As described above, the second charging circuit 14 supplies the capacitor C1 with the second charging current I2 whose current value increases as the dimming level decreases, so that the switching element Q1 is turned on as the dimming level decreases. The light source 20 can be dimmed by shortening the period.

  Further, in the lighting device 10 of the present embodiment, the abnormality detection circuit 17 compares the level of the voltage V4 obtained by dividing the output voltage of the boost chopper circuit 12 with the reference voltage V5 to determine whether the output of the boost chopper circuit 12 is abnormal. Is detected.

  That is, when the output voltage of the boost chopper circuit 12 falls below the abnormality determination level due to a short circuit failure in some of the plurality of light emitting diodes 201 and the voltage V4 becomes lower than the reference voltage V5, the output voltage of the comparator 171 The level becomes L level. That is, the abnormality detection circuit 17 detects that there is an abnormality.

  The dimming control circuit 15 monitors the output of the comparator 171. When the voltage level of the output of the comparator 171 becomes L level, the current value of the second charging current I2 is maximized. As a result, the ON period of the switching element Q1 is minimized and the output voltage of the boost chopper circuit 12 is minimized, so that it is possible to suppress the overcurrent from continuing to flow through the light source 20.

  Thus, when the abnormality detection circuit 17 detects that there is an abnormality, the second charging circuit 14 increases the second charging current I2 as compared with the case where the abnormality detection circuit 17 detects that there is no abnormality. The output voltage of the boost chopper circuit 12 is reduced. Therefore, the light source 20 can be protected when the output of the boost chopper circuit 12 becomes abnormal.

(2.2) Illuminating device Next, the illuminating device 1 of this embodiment is demonstrated with reference to FIG.1 and FIG.2. In the following description, each direction is defined as indicated by arrows “up” and “down” in FIG. However, these directions are not intended to define the installation direction of the lighting device 1. The arrows indicating the respective directions in FIG. 2 are merely shown for the sake of explanation, and are not accompanied by an entity.

  As illustrated in FIG. 1, the lighting device 1 of the present embodiment includes the lighting device 10 described above, a light source 20 to which a current is supplied from the lighting device 10, and a fixture body 50 (see FIG. 2).

  The lighting device 1 of the present embodiment is a lighting fixture (so-called ceiling light) in a form that is directly attached to a construction material (for example, a ceiling finishing material).

  As shown in FIG. 2, the instrument body 50 includes a base member 51, an inner cover 53, an outer cover 54, and an outer frame 55.

  The base member 51 is formed in a substantially disc shape by a metal plate such as a steel plate. The base member 51 is attached to the cylindrical hook ceiling adapter 56 in a detachable state. The hook ceiling adapter 56 is attached to a hook ceiling closet arranged on a ceiling finishing material of a house. Therefore, the base member 51 is attached to the ceiling finishing material via the hook ceiling adapter 56 and the hook ceiling rosette.

  A plurality (four in the illustrated example) of light source modules 52 are attached to the base member 51. Each of the four light source modules 52 includes a substrate 521 having a shape in which a ring-shaped plate material in plan view is divided into four in the circumferential direction. The four light source modules 52 are attached to the lower surface of the base member 51 so as to be arranged in the circumferential direction. A plurality of light emitting diodes 201 are mounted on the lower surface of the substrate 521 of each light source module 52. The plurality of light emitting diodes 201 respectively mounted on the four light source modules 52 are connected in series or in parallel, and the light source 20 is configured by the plurality of light emitting diodes 201 respectively mounted on the four light source modules 52.

  At the center of the base member 51, a cylindrical protrusion 511 that protrudes downward as compared with the outer peripheral portion is provided. The lighting device 10 is attached to the upper surface of the protruding portion 511, and current is supplied from the lighting device 10 to the plurality of light emitting diodes 201 mounted on each light source module 52. In addition, since the protrusion part 511 protrudes below compared with the outer peripheral part of the base member 51, even if the base member 51 is attached to the ceiling finishing material, the lighting device 10 does not interfere with the ceiling finishing material.

  The inner cover 53 is formed in an annular shape from a light-transmitting synthetic resin such as an acrylic resin or a polycarbonate resin. The inner cover 53 is formed such that the cross-sectional shape in the radial direction has a trapezoidal shape protruding downward, and the inner cover 53 is attached to the base member 51 so as to cover the four light source modules 52 from below. It has been. The inner cover 53 sandwiches the four light source modules 52 with the base member 51, whereby the four light source modules 52 are fixed to the base member 51.

  The outer cover 54 is formed of a molded body in which a diffusing material is mixed in a synthetic resin having translucency such as an acrylic resin. The outer cover 54 is attached to the base member 51 so as to cover the inner cover 53 from below.

  The outer frame 55 is formed of a synthetic resin such as a styrene resin. The outer frame 55 includes a cylindrical frame main body 551 and an annular flange 552 that protrudes outward from the lower end of the frame main body 551 in the radial direction. The outer frame 55 is fixed to the base member 51 in a state where the base member 51 is accommodated inside the frame main body 551. In addition, in a state where the outer cover 54 is attached to the lower side of the base member 51, the outer cover 54 is also disposed inside the frame body 551.

  As described above, in the lighting device 1 of the present embodiment, the lighting device 10 and the light source 20 including the plurality of light source modules 52 are held in the fixture body 50. Here, when a current is supplied from the lighting device 10 to the plurality of light emitting diodes 201 mounted on each light source module 52, the plurality of light emitting diodes 201 emit light, and the light emitted from the plurality of light emitting diodes 201 is reflected on the inner cover. 53 and the outer cover 54 are transmitted to the outside.

(3) Modified Examples Below, lighting devices and lighting devices according to modified examples of the above embodiment are listed. In addition, each structure of the modified example demonstrated below is applicable in combination with each structure demonstrated in the said embodiment suitably.

  In the present embodiment, the light source 20 includes a plurality of light emitting diodes 201 connected in series. However, the number of the light emitting diodes 201 may be one, and the number of the light emitting diodes 201 depends on the specifications of the lighting device 10 and the like. Changes can be made as appropriate. The light source 20 includes a plurality of light source modules 52 in which a plurality of light emitting diodes 201 are connected in series, but the plurality of light source modules 52 may be connected in series or in parallel. Further, although the light source 20 includes the light emitting diode 201 as a solid light emitting element, the solid light emitting element is not limited to the light emitting diode, and may be an organic EL (Electro Luminescence) element.

  Further, although the boost chopper circuit 12 includes the switching element Q1 made of a MOSFET, the switching element Q1 is not limited to the MOSFET but may be a bipolar transistor.

  Further, the abnormality detection circuit 17 detects the presence or absence of abnormality based on the output voltage of the boost chopper circuit 12, but detects that there is an abnormality when the current flowing from the boost chopper circuit 12 to the light source 20 exceeds the reference current. Also good. Further, the abnormality detection circuit 17 detects that there is an abnormality when the temperature of a circuit component (for example, the switching element Q1) constituting the lighting device 10 or the temperature of the light emitting diode 201 constituting the light source 20 exceeds the reference temperature. Also good.

  The instrument body 50 includes a base member 51, an inner cover 53, an outer cover 54, and an outer frame 55, but the form of the instrument body 50 can be changed as appropriate according to the design and the like.

(4) Effect As described above, the lighting device 10 according to the first aspect includes the step-up chopper circuit 12 and the control circuit 13. The step-up chopper circuit 12 converts an input from a power source (for example, AC power source 2) into a DC voltage by turning on / off the switching element Q1, and converts the input to a light source 20 including a solid state light emitting element (for example, a light emitting diode 201). Apply DC voltage. The control circuit 13 controls on / off of the switching element Q1. The control circuit 13 includes a first charging circuit 131 that supplies a constant first charging current I1 to the capacitor C1, and a discharging circuit 132 that discharges the capacitor C1 when the switching element Q1 is turned off. The control circuit 13 is configured to turn off the switching element Q1 when the charging voltage V3 of the capacitor C1 becomes equal to or higher than the threshold voltage V2 when the switching element Q1 is on. Moreover, the lighting device 10 of the first aspect further includes a second charging circuit 14. The second charging circuit 14 supplies a second charging current I2 having a current value corresponding to the dimming level to the capacitor C1. Capacitor C1 is charged with a combined current of first charging current I1 and second charging current I2 when switching element Q1 is on.

  As a result, the capacitor C1 is charged with a combined current of the constant first charging current I1 and the second charging current I2 having a current value corresponding to the dimming level, so that the ON time of the switching element Q1 is the dimming level. It depends on. Therefore, the dimming function can be added to the boost chopper circuit 12 simply by adding the second charging circuit 14 that supplies the second charging current I2 having a current value corresponding to the dimming level to the capacitor C1. Therefore, compared with the case where a step-up chopper circuit and a step-down chopper circuit are provided, the number of circuit components having a dimming function with improved power factor can be reduced.

  In the lighting device 10 of the present embodiment, the control circuit is an integrated circuit in which circuit components such as the first charging circuit 131, the discharging circuit 132, the error amplifier 133, the comparator 134, the NOT gate 135, and the constant voltage source 136 are integrated. 13 is realized. Therefore, it is only necessary to add the second charging circuit 14 to the power factor improving integrated circuit (control circuit 13) originally provided in the lighting device 10 to control the step-up chopper circuit 12 and the external capacitor C1. In addition, a dimming function can be added to the lighting device 10. Thereby, compared with the case where a step-up chopper circuit and a step-down chopper circuit are provided, the number of parts of a circuit having a dimming function with improved power factor can be reduced.

  Moreover, the lighting device 10 of the second aspect may further include an abnormality detection circuit 17 that detects an abnormality of the output of the boost chopper circuit 12 in the first aspect. When the abnormality detection circuit 17 detects that there is an abnormality, the second charging circuit 14 may be configured to increase the second charging current I2 compared to when the abnormality detection circuit 17 detects that there is no abnormality.

  As a result, when the abnormality detection circuit 17 detects that there is an abnormality, the second charging circuit 14 increases the second charging current I2 to shorten the on-time of the switching element Q1, so that the output voltage of the boost chopper circuit 12 The light source 20 can be protected.

  In the lighting device 10 of the present embodiment, the control circuit is an integrated circuit in which circuit components such as the first charging circuit 131, the discharging circuit 132, the error amplifier 133, the comparator 134, the NOT gate 135, and the constant voltage source 136 are integrated. 13 is realized. Therefore, the lighting device 10 has a function of protecting the light source 20 when an abnormality occurs without changing the power factor improving integrated circuit (control circuit 13) originally provided in the lighting device 10 to control the boost chopper circuit 12. Can be added to.

  The lighting device 1 according to the third aspect includes the lighting device 10 according to the first or second aspect, the light source 20 to which a DC voltage is applied by the step-up chopper circuit 12, and the lighting device 10 and the fixture that holds the light source 20. And a main body 50.

  According to the lighting device 1, the number of components of a circuit having a dimming function with an improved power factor can be reduced as compared with a case where a step-up chopper circuit and a step-down chopper circuit are provided.

1 Lighting device 2 AC power supply
DESCRIPTION OF SYMBOLS 10 Lighting device 12 Boost chopper circuit 13 Control circuit 131 1st charging circuit 132 Discharging circuit 14 2nd charging circuit 17 Abnormality detection circuit 20 Light source 201 Light emitting diode (solid light emitting element)
50 Instrument body C1 Capacitor I1 First charging current I2 Second charging current V2 Threshold voltage Q1 Switching element

Claims (3)

A step-up chopper circuit that converts the input from the power source to a DC voltage by turning on / off the switching element, and applies the converted DC voltage to a light source including a solid state light emitting element;
A control circuit for controlling on / off of the switching element,
The control circuit includes a first charging circuit that supplies a constant first charging current to a capacitor, and a discharge circuit that discharges the capacitor when the switching element is turned off.
The control circuit is configured to turn off the switching element when a charging voltage of the capacitor is equal to or higher than a threshold voltage when the switching element is on,
A second charging circuit for supplying a second charging current having a current value corresponding to the dimming level to the capacitor;
The capacitor is charged with a combined current of the first charging current and the second charging current when the switching element is on.
A lighting device characterized by that. An abnormality detection circuit for detecting an abnormality in the output of the boost chopper circuit is further provided,
When the abnormality detection circuit detects that there is an abnormality, the second charging circuit is configured to increase the second charging current compared to when the abnormality detection circuit detects that there is no abnormality,
The lighting device according to claim 1. The lighting device according to claim 1, a light source to which a DC voltage is applied by the step-up chopper circuit, and an appliance main body that holds the lighting device and the light source.
A lighting device characterized by that.

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