JP6245504B2 - Lighting device and lighting fixture using the same - Google Patents

Description

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

  Conventionally, a power supply assembly for supplying power to an LED module has been provided (see, for example, Patent Document 1). This power supply assembly includes a series circuit of a diode and a control switch connected between both ends of a DC power supply, and a controller that outputs a dual PWM signal to the control switch. Between the both ends of the diode, an inductor and an LED module are provided. A series circuit is connected.

  The controller has a pulse width modulator, and a current reference signal, a detection current, and a high-frequency sawtooth signal from a current source are input to the pulse width modulator. The pulse width modulator outputs a high frequency PWM signal to one input part of the AND gate, and a low frequency PWM signal is inputted to the other input part of the AND gate. The AND gate outputs a dual PWM signal obtained by combining the high-frequency PWM signal and the low-frequency PWM signal, and this dual PWM signal is input to the gate of the control switch via the amplifier.

  In this power supply assembly, the intensity of light output from the LED module can be changed by changing the low frequency component of the dual PWM signal output from the controller to the control switch.

JP 2006-511078 gazette

  In the power supply assembly shown in Patent Document 1 described above, dimming is performed so that the load current intermittently flows through the LED module, so that dimming can be easily performed to a low luminous flux by so-called burst dimming, but the load current is intermittent. There is a rest period during which no load current flows. For this reason, for example, when the LED module is viewed through a video device such as a video camera, there is a case where the frequency and interference flickering unique to the video device are visually observed.

  Further, since a pulse width modulator or the like is required as described above, there is a problem that the circuit configuration becomes complicated.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a lighting device that suppresses flicker when a light-emitting element during dimming is viewed through a video device with a simple circuit configuration, and the same It is in providing the lighting fixture using.

A lighting device of the present invention includes a DC power supply unit that converts an AC voltage from a commercial power supply into a DC voltage having a desired voltage value, and a series circuit of a light emitting element and a switch element that are connected between output terminals of the DC power supply unit. A current adjusting unit that changes the current flowing through the light emitting element stepwise by changing the voltage applied to the control terminal of the switch element stepwise according to on / off of the commercial power supply. It is characterized by that.

  The lighting fixture of this invention is equipped with said lighting device, It is characterized by the above-mentioned.

  Since the current flowing to the light emitting element is changed stepwise according to the dimming signal from the outside, there is no pause in the load current as in the conventional example, and flicker when viewing the light emitting element during dimming through video equipment There is an effect that can be suppressed. Further, since it is not necessary to use a pulse width modulator as in the conventional example, there is an effect that flicker can be suppressed by a simple circuit configuration.

2 is a circuit diagram illustrating an example of a lighting device according to Embodiment 1. FIG. (A)-(d) is a partial circuit diagram of the direct-current power supply part used for the same as the above. It is a circuit diagram which shows an example of the lighting device of Embodiment 2. It is sectional drawing which shows the construction state of the lighting fixture using the lighting device of Embodiment 1 or 2.

  Embodiments of a lighting device and a lighting fixture using the lighting device will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a circuit diagram illustrating an example of a lighting device 1 according to the present embodiment. The lighting device 1 includes a DC power supply unit 11, a current adjustment unit 12, and a dimming control unit 13, and includes a dimmer 2. The light emitting unit 3 is turned on at a dimming level corresponding to the dimming signal S1 output from the.

  The light emitting unit 3 includes a plurality (four in FIG. 1) of LEDs 31 (light emitting elements) connected in series, and is connected between the output terminals of the DC power supply unit 11 via a transistor Q2 (switching element) and a resistor R1. ing. Note that the number of the LEDs 31 constituting the light emitting unit 3 may be one, or may be two, three, or a plurality of five or more. Moreover, you may comprise the light emission part 3 by connecting several LED31 in parallel.

  The DC power supply unit 11 has a so-called diode bridge DB1 constituted by four diodes, and a smoothing capacitor C1 is connected between the output terminals of the diode bridge DB1. A series circuit of a primary winding n1 of the transformer Tr1 and a transistor Q1 is connected between the output terminals of the diode bridge DB1. A diode D1 is connected to one end of the secondary winding n2 of the transformer Tr1, and a smoothing capacitor C2 is connected between both ends of the secondary winding n2.

  Here, in this embodiment, an N-channel MOSFET is used as the transistor Q1, and the drive circuit 111 is connected to the gate of the transistor Q1. The transistor Q1 is controlled to be turned on / off by a PWM signal output from the drive circuit 111. In the DC power supply unit 11, a DC voltage generated between both ends of the smoothing capacitor C <b> 2 becomes an output voltage of the DC power supply unit 11.

  The current adjustment unit 12 includes a DC voltage source 121 whose output voltage varies according to the control signal S2 output from the dimming control unit 13, and the positive electrode of the DC voltage source 121 is connected to the non-inverting input terminal of the operational amplifier 122. Has been. Further, the negative electrode of the DC voltage source 121 is connected to the negative electrode of the DC power supply unit 11. The connection point between the transistor Q2 and the resistor R1 is connected to the inverting input terminal of the operational amplifier 122. Furthermore, the output terminal of the operational amplifier 122 is connected to the gate (control terminal) of the transistor Q2.

  Here, in the present embodiment, an N-channel MOSFET is used as the transistor Q2, and the impedance of the transistor Q2 changes according to the magnitude of the voltage output from the operational amplifier 122. Thereby, the magnitude | size of the electric current which flows into the light emission part 3 can be adjusted.

  When the dimming signal S1 from the dimmer 2 is input, the dimming control unit 13 generates a control signal S2 corresponding to the dimming signal S1, and outputs the generated control signal S2 to the current adjustment unit 12. To do. Here, the dimming signal S1 is a signal indicating the magnitude of the load current to be passed through the light emitting unit 3, that is, the brightness of the light emitting unit 3.

  Next, the operation of the lighting device 1 will be described. The operation of the DC power supply unit 11 is well known in the art and will not be described here.

  When the dimming signal S1 from the dimmer 2 is input, the dimming control unit 13 generates a control signal S2 based on the dimming signal S1, and outputs the generated control signal S2 to the current adjustment unit 12. To do. When the control signal S2 is input, the current adjustment unit 12 changes the output voltage of the DC voltage source 121 in a stepwise manner in accordance with the control signal S2.

  As a result, the voltage output from the operational amplifier 122 also changes stepwise, so that the impedance of the transistor Q2 also changes stepwise. Then, as the impedance of the transistor Q2 changes stepwise, the current flowing through the light emitting unit 3 also changes stepwise. Thus, since the current flowing through the light emitting unit 3 changes stepwise, there is no idle period during which no load current flows as in the conventional example. Therefore, the light emitted from the light emitting unit 3 does not flicker when the light emitting unit 3 during dimming is viewed through a video device (not shown).

  As described above, the current flowing through the light emitting unit 3 is changed stepwise in accordance with the dimming signal S1 from the dimmer 2, so that the load current has no pause period as in the conventional example, and the video equipment It is possible to suppress flickering of light when viewing the light emitting unit 3 during light control. Further, since it is not necessary to use a pulse width modulator as in the conventional example, flicker can be suppressed with a simple circuit configuration.

  By the way, in this embodiment, the output voltage of the diode bridge DB1 is stepped down by the flyback converter using the transformer Tr1 and applied to the light emitting unit 3. However, instead of the flyback converter, the step-up chopper shown in FIG. The circuit 112 may be used.

  Further, instead of the flyback converter, a step-up / step-down chopper circuit 113 shown in FIG. 2B, a step-down chopper circuit 114 shown in FIG. 2C, a forward converter circuit 115 shown in FIG. Good. In any case, the same effect can be obtained by providing the current adjusting unit 12 between the light emitting unit 3.

  In the present embodiment, the case where the light emitting element is an LED has been described as an example. However, the light emitting element is not limited to the LED, and may be, for example, an organic EL element or a laser diode (LD).

  The lighting device 1 includes a DC power supply unit 11, a series circuit of an LED 31 and a transistor Q <b> 2 connected between output terminals of the DC power supply unit 11, and a current adjustment unit 12. The current adjusting unit 12 changes the current flowing through the LED 31 stepwise by changing the voltage applied to the gate of the transistor Q2 stepwise according to the external dimming signal S1.

(Embodiment 2)
Embodiment 2 of the lighting device 1 will be described with reference to FIG. In the first embodiment, the current flowing through the light emitting unit 3 is changed stepwise according to the dimming signal S 1 from the dimmer 2. The flowing current is changed step by step. In addition, about another structure, it is the same as that of Embodiment 1, the same code | symbol is attached | subjected to the same component and description is abbreviate | omitted.

  FIG. 3 is a circuit diagram illustrating an example of the lighting device 1 of the present embodiment. The lighting device 1 includes a DC power supply unit 11, a current adjustment unit 12, a dimming control unit 13, and a power supply detection unit 14. Prepare.

  The power source detection unit 14 detects whether the commercial power source 10 is turned on / off. For example, in this embodiment, the power source detecting unit 14 turns off / on the switch SW1 attached to the wall once from the “on” state. It is detected that 10 is once turned off. The power supply detection unit 14 outputs a control signal S3 when detecting that the commercial power supply 10 is once turned off, and the dimming control unit 13 is based on the control signal S3 input from the power supply detection unit 14. To generate a control signal S4.

  Thereafter, the dimming control unit 13 outputs the generated control signal S4 to the current adjusting unit 12, and the current adjusting unit 12 changes the current flowing through the light emitting unit 3 stepwise according to the control signal S4. Dimming in steps. The specific operation is the same as that of the lighting device 1 described in the first embodiment, and thus the description thereof is omitted here.

  This lighting device 1 is very effective when adding a dimming function in, for example, a light bulb-shaped LED lamp.

  As described above, the current flowing through the light-emitting unit 3 is changed stepwise in accordance with the on / off state of the commercial power supply 10, so that the load current does not have a pause period as in the conventional example, and is passed through the video equipment. Flickering when viewing the light emitting unit 3 during dimming can be suppressed. Further, since it is not necessary to use a pulse width modulator as in the conventional example, flicker can be suppressed with a simple circuit configuration.

  Also in this embodiment, instead of the flyback converter using the transformer Tr1, the one shown in FIG. 2A to FIG. 2D may be used. The same effect can be obtained by providing the current adjusting unit 12 in the circuit. Also in the present embodiment, the light emitting element is not limited to the LED, and may be, for example, an organic EL element or a laser diode (LD).

  The lighting device 1 includes a DC power supply unit 11, a series circuit of an LED 31 and a transistor Q <b> 2 connected between output terminals of the DC power supply unit 11, and a current adjustment unit 12. The DC power supply unit 11 converts the AC voltage from the commercial power supply 10 into a DC voltage having a desired voltage value. The current adjustment unit 12 changes the current flowing through the LED 31 in a stepwise manner by changing the voltage applied to the gate of the transistor Q2 in a stepwise manner according to the on / off state of the commercial power supply 10.

(Embodiment 3)
An embodiment of the lighting fixture A will be described with reference to FIG. FIG. 4 is a cross-sectional view showing a construction state of the lighting fixture A of the present embodiment. The lighting fixture A includes the lighting device 1 described in the first embodiment, the light emitting unit 3, and the fixture main body 4. . In the present embodiment, the wireless dimmer 2 is used, and the lighting device 1 lights the light emitting unit 3 at the dimming level of the dimming signal S1 output from the dimmer 2.

  The instrument body 4 is, for example, an aluminum die-cast product, and is formed in a bottomed cylindrical shape with one surface (the lower surface in FIG. 4) opened, and is embedded in the ceiling through an embedding hole 100a provided in the ceiling material 100. Established. A substrate 32 on which a plurality of (three in FIG. 4) LEDs 31 are mounted is accommodated in the cylinder of the instrument body 4, and light that diffuses light from the LEDs 31 is formed at the opening edge of the instrument body 4. A diffusion plate 33 is attached. Here, in the present embodiment, the light emitting unit 3 is configured by the substrate 32 on which the LEDs 31 are mounted and the light diffusion plate 33.

  In the lighting fixture A of the present embodiment, as shown in FIG. 4, the fixture body 4 that houses the light emitting unit 3 and the lighting device 1 are arranged with a space therebetween, and the space between the light emitting unit 3 and the lighting device 1 is between. The power line 5 is electrically connected via the connector 6. As described above, when the lighting device 1 is separated from the fixture body 4, it is only necessary to store the light emitting unit 3 inside the fixture body 4, so that the height dimension of the fixture body 4 can be reduced. In addition, there is an advantage that the degree of freedom of installation of the lighting device 1 is improved.

  As described above, by using the lighting device 1 described in the first embodiment, it is possible to realize the lighting fixture A with a simple configuration that suppresses flickering when the light-emitting unit 3 during dimming is viewed through the video equipment. it can.

  In the present embodiment, the lighting device 1 is provided separately from the fixture body 4, but the lighting device 1 may be provided integrally with the fixture body 4. Further, the lighting device 1 described in the second embodiment may be used, and in this case also, the lighting fixture A that suppresses flicker when the light emitting unit 3 at the time of dimming is viewed through the video equipment is realized with a simple configuration. be able to. Furthermore, the dimmer 2 is not limited to a wireless type, and may be a wired type.

  The lighting fixture A includes a lighting device 1.

DESCRIPTION OF SYMBOLS 1 Lighting device 2 Dimmer 11 DC power supply part 12 Current adjustment part 31 LED (light emitting element)
Q2 transistor (switch element)
S1 Dimming signal

Claims (2)

A DC power supply unit that converts an AC voltage from a commercial power source into a DC voltage of a desired voltage value;
A series circuit of a light emitting element and a switch element connected between the output ends of the DC power supply unit;
A current adjusting unit that changes the current flowing in the light emitting element in a stepwise manner by changing the voltage applied to the control terminal of the switch element in a stepwise manner in accordance with on / off of the commercial power supply. A lighting device characterized by. A lighting apparatus comprising the lighting device according to claim 1.

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