JP2015082474A - Illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination device capable of achieving high spatial presentation by interlocking the uniform light irradiation as a whole and the spot light irradiation of an irradiated object with the light emission intensity and also by one illumination device.SOLUTION: Disclosed is an illumination device in which brightness is varied along with variation of dimming level. This illumination device includes: a substrate; a light source group which is installed on the substrate and different in directivity of light emitted for every group; a current supply part which is independent for every light source group and supplies a driving current to the light source; and a control part which controls the current to be supplied for every light source group in accordance with a control signal inputted from the outside and independently controls the lighting start time of a plurality of light source groups from the current supply part.

Description

  The present invention relates to a lighting device including a plurality of light sources. The present invention particularly relates to a lighting device in which a light source includes a semiconductor light emitting device.

  Conventionally, illumination devices such as downlights, universal downlights, and spotlights having a plurality of light emitting elements such as LEDs have been widely used as general illumination. Patent Documents 1 to 3 describe a method of exchanging a lens and a reflection plate as means for obtaining a light distribution characteristic suitable for a purpose in a lighting device.

JP 2010-73627 A JP 2009-9826 A JP 2005-317557 A

  On the other hand, in general illumination devices in recent years, not only illumination devices that irradiate uniform light as in the prior art, but also illumination devices that produce a space are desired. However, instead of a conventional downlight that irradiates uniform light, for example, when it is desired to irradiate an object in a spot manner in conjunction with an increase in emission intensity, a conventional downlight has been installed. However, another spotlight that can emit light of different characteristics must be installed separately. Therefore, in a normal case of irradiating uniform light, and in a case where it is desired to irradiate an object to be spotted in conjunction with an increase in emission intensity, it can be controlled with a simple and compact device with a single illumination device. There wasn't.

  The present invention has been made in view of such problems, and the object of the present invention is to link the irradiation of uniform light as a whole and the irradiation of light that illuminates the irradiated object in a spot manner to the emission intensity. Then, it is providing the illuminating device which can implement | achieve a high space effect, performing it selectively or simultaneously with one illuminating device.

In order to achieve the above object, the lighting device of the present invention is a lighting device whose brightness fluctuates with a change in the light control level,
A substrate,
A light source group installed on the substrate;
A current supply unit for supplying a drive current to the light sources independently for each light source group;
A controller that controls a current supplied to each of the light source groups according to a control signal input from the outside,
The light source group is different in the directivity of light emitted from each group,
The control unit may independently control lighting start timings of the plurality of light source groups from the current supply unit.

In the illumination device described above, the control unit may sequentially turn on the light source groups as the total amount of power supplied to the light source groups increases.
In addition, the control unit may apply a light source group that emits light with high directivity from a light source group with low directivity to sequentially turn on the light source group as the total amount of power supplied to the light source group increases. Good.

Alternatively, as the total amount of power supplied to the light source group increases, the control unit applies a light source group that emits light with low directivity from a light source group with high directivity, and sequentially turns on the light source groups. Good.
In any one of the lighting devices described above, a light source group with high directivity may be disposed in a central region on the substrate, and a light source group with low directivity may be disposed in a peripheral region on the substrate.

In any one of the illumination devices described above, the light emitting point of the light source group with high directivity is arranged at or near the focal point of the one-core type condensing optical component, and the light source group with low directivity is the focal point of the condensing optical component. It may be arranged in a region farther from the.
In any one of the illumination devices described above, the condensing optical member of the light source group with high directivity and the condensing optical member of the light source group with low directivity are configured independently, and the light source group with high directivity The light distribution angle of the light collecting optical member may be narrower than the light distribution angle of the light collecting optical member of the light source group having low directivity.

In any one of the lighting devices described above, the condensing optical member of the light source group with high directivity and the condensing optical member of the light source group with low directivity are configured independently, and the light source group with low directivity The exit surface of the condensing optical member may form a diffusion surface.
In the above case, the condensing optical member of the light source group with high directivity and the condensing optical member of the light source group with low directivity may be integrally formed.

In any one of the illumination devices described above, the light source may be an LED.
In any one of the lighting devices described above, the chromaticity of the light source groups may be the same between the light source groups.
In any one of the illumination devices described above, the chromaticity of the light source group may be different for each light source group.

In the above case, the color temperature of light emitted from the light source group having high directivity may be higher than the color temperature of light emitted from the light source group having low directivity.
In the above-described lighting device in which the light source is an LED, the light source group includes a first LED group with high directivity and a second LED group with low directivity,
The first LED group, the second LED group, and a detection resistor for detecting the magnitude of current supplied from an external power source to the first LED group and the second LED group are connected in series. A light emitting circuit,
A shunt circuit connected in parallel with the second LED group;
A control circuit for controlling the current passing through the shunt circuit based on the current passing through the detection resistor;
The light emitting circuit, the shunt circuit, and the control circuit may be provided on the substrate.

  In the present invention, the light distribution (directivity) of light can be changed in accordance with the light emission intensity of the lighting device, there is no need to procure new parts for replacement, and it is compact and has a single illumination. With the device, the light distribution of the light emitted by the lighting device can be continuously changed.

It is the schematic diagram which showed distribution of the irradiation area | region of the said light at the time of irradiating light using the illuminating device which concerns on embodiment. It is a side view of the illuminating device which controls the emission angle of a light source using the condensing optical member in this invention. It is a front view of the lens which concerns on embodiment. It is a disassembled perspective view of the illuminating device (MR16 type LED lamp) which concerns on embodiment. It is a block diagram which shows the outline of the LED module apparatus of this embodiment. It is an electric circuit diagram of the LED module apparatus of 1st Example. It is the schematic which shows the relationship between the electric current value applied to an illuminating device, and the illumination intensity of the irradiation area | region of the said light in the case of irradiating light using the illuminating device which concerns on embodiment.

  Hereinafter, embodiments of the present invention will be described in detail based on examples and modifications with reference to the drawings. In addition, this invention is not limited to the content demonstrated below, In the range which does not change the summary, it can change arbitrarily and can implement. In addition, the drawings used for explaining the embodiments and the modified examples both schematically show the lighting device according to the present invention, and are partially emphasized, enlarged, reduced, or omitted to deepen the understanding. In some cases, it does not accurately represent the scale or shape of each component. Furthermore, the various numerical values and quantities used in the embodiments and the modifications are only examples, and can be variously changed as necessary.

<Embodiment>
The illumination device according to the embodiment is an LED lamp provided with a semiconductor light emitting device (LED) as a light source, and its housing conforms to a standard size established by a standard such as JIS (Japanese Industrial Standard). It is configured as follows. Here, with reference to FIG. 1, the example which comprises the illuminating device 1 which concerns on this embodiment as the MR16 type | mold LED lamp 1 which can substitute for the MR16 type | mold halogen light bulb which has an outer diameter of about 50 mm is demonstrated.

  FIG. 4 is an exploded perspective view of the MR16 type LED lamp 1 according to the present embodiment. The MR16 type LED lamp 1 includes an LED module 2, a lens 16, a housing 5, and the like. In the present specification, the side on which the lens 16 is provided is defined as “front” of the lighting device 1 (MR16 type LED lamp 1A). The LED module 2 includes a first LED group (one LED in this example) 12 and a second LED group 13 (three LEDs in this example) as a light source, and a module substrate 14 on which the LEDs are mounted. The first LED 12 is arranged at the center of the module substrate 14, and the second LED 13 is arranged around the first LED. The lens is a one-core type lens (one-core type condensing optical component) 16, the first LED 12 is arranged at the focal position, and the second LED 13 is arranged at a position away from the surrounding focal point. (FIG. 2 (1)). By arranging in this way, the light emitted from the first LED 12 can be light with high directivity (narrow light distribution angle), and the light emitted from the second LED 13 has low directivity. It can be light (with a wide light distribution angle).

  As a modified example, the lens 16 may be a multi-lens in addition to the one-core lens. As shown in FIG. 2 (2), a multi-lens is used in which a narrow-angle exit lens is arranged at the center and a wide-angle exit lens is arranged around the center, and the first LED 12 is placed at the focal position of the narrow-angle exit lens. By disposing the second LED 13 at the focal position of the wide-angle exit lens, the same effect as in the above embodiment can be obtained. The lens has been described as an example in which a multi-lens connected in terms of reduction in the number of components and ease of handling is used, but a lens having a different light distribution angle can be individually mounted for each LED group.

Furthermore, as another modification described above, a multi-lens having a diffusing surface can be used. As shown in FIG. 2 (3), a narrow-angle exit lens that does not have a diffusion region on the exit surface is disposed, and a connected multi-lens in which a narrow-angle exit lens that has a diffuse region on the exit surface is disposed. The first LED 12 is disposed at the focal position of the narrow-angle exit lens having no diffusion region on the exit surface, and the second LED 13 is disposed at the focus position of the narrow-angle exit lens having the diffusion region on the exit surface. The same effect as the example can be obtained.

As still another modification, a reflector may be used as the condensing optical member instead of the lens. By arranging the first LED 12 at the focal position of the narrow-angle outgoing reflector and arranging the second LED 13 at the focal position of the wide-angle outgoing reflector, the same effect as in the above embodiment can be obtained.
The module substrate 14 is, for example, a metal base substrate formed of a metal material such as aluminum with good heat dissipation or an insulating material.

  The first LED 12 and the second LED 13 have, for example, a chip-on-board structure in which one or a plurality of near-ultraviolet LED chips are directly mounted on a wiring provided on the mounting surface of the module substrate 14. It is configured by being potted by a translucent resin mixed with a blue phosphor, a green phosphor and a red phosphor that are excited by the light. As the LED chip, not only a near ultraviolet LED chip but also various LED chips such as a blue LED chip can be used, and various phosphors can be selected according to the LED chip to be used. Moreover, what has a GaN (gallium nitride, gallium nitride) board | substrate can be used for the LED chip in this embodiment. Thus, when an LED chip using a GaN substrate is applied, a large current can be input, and a point light source with a large luminous flux can be realized.

  The first LED 12 and the second LED 13 can adopt a package structure instead of using a chip-on-board structure, and can be applied to various forms. Moreover, the LED light emitting module 2 can also disperse | distribute and arrange | position several 1st LED12 and 2nd LED13 on the module board | substrate 14. FIG. Further, a substrate other than the GaN substrate, such as a sapphire substrate or a silicon substrate, may be applied to the LED chip.

  The lens 16 can include a one-core lens and a lens holder to which the lens 16 can be attached. The one-core lens is a lens that has only one optical axis and gives a predetermined light distribution angle to emitted light. As the one-core lens, for example, a collimator lens, a Fresnel lens, or the like can be used. The one-core lens is formed of, for example, an acrylic resin or a polycarbonate resin, and has, for example, a substantially truncated cone shape as a whole, and has an emission surface 16a that emits light emitted from the LEDs 12 and 13. Yes. In the one-core lens, when the side on which the emission surface 16a is formed is defined as the “front part”, a concave part 16c for accommodating the LED is formed in the rear part of the one-core lens.

  Next, the one-core lens 16 will be described with reference to FIG. FIG. 3- (1) is a front view of the lens 16 of the LED module 2 constituting the illumination device 1 of the present embodiment. FIG. 3- (2) is a side view of the first lens 16 of the LED module 2 that constitutes the illumination device 1 of the present embodiment. Further, FIG. 3- (3) is a cross-sectional view of the lens 16 taken along line XX of FIG. 3- (1).

As can be seen from FIG. 3, the lens 16 as a whole has a shape of a rotating body in which a substantially parabola rotates around the optical axis, and the light exit surface 16a side is a flat surface. Further, as shown in FIG. 3- (3), the lens 16 has an opening 16c on the light incident surface 16b side. The bottom surface of the opening 16c protrudes toward the light incident surface 16b so as to form a convex lens. In the LED module 2 in a state where the light emitter 14 and the optical body 18 are joined, the first LED 12 and the second LED 13 are disposed so as to face the opening 16c portion of the first lens 16. . By disposing the first LED 12 at the focal position of the parabola, it is possible to emit light at a narrow angle as compared to the second LED 13 disposed around the first LED 12.

  The light exit surface 16a of the one-core lens is, for example, a flat surface. In addition, a convex lens is provided at the bottom of the concave portion 16c in the one-core lens so as to be convex toward the rear portion, for example. The exit surface 16a is not limited to a flat surface, and various lenses such as a collimator lens and a Fresnel lens can be preferably used. Further, as shown in FIG. 3, the one-core lens is provided at a position facing the LED mounted on the module substrate 14, and the first LED 12 and the second LED 13 are accommodated in the recess 16c. Interference between the one-core lens and the first LED 12 and the second LED 13 is suppressed. The shape, size, material, and the like of the one-core lens can be changed as appropriate.

  The lens holder has a holder body having a substantially cylindrical shape capable of holding the one-core lens 16 therein. The inner diameter of the holder body is equal to the outer diameter of the one-core lens, and the lens holder can hold the one-core lens by fitting the lens 16 into the holding portion. The lens holder has translucency and is made of, for example, a transparent resin. The lens holder further includes a pair of projecting arm portions that project downward from the holder body. Further, a hook-shaped connecting claw is formed at the tip of the protruding arm portion. Details of the lens module will be described later. In the present embodiment, the protruding arm portion corresponds to the protruding portion and the connecting portion in the present invention.

  The housing 5 is a housing (housing) of the MR16 type LED lamp 1, and houses the LED module 2, the lens module, and the like. Moreover, the housing | casing 5 has at least one part the heat sink which thermally radiates the heat | fever which the 1st LED12 and the 2nd LED13 emit. Specifically, the housing 5 supplies a heat sink 8 that dissipates heat generated by the first LED 12 and the second LED 13, and driving power to the first LED 12 and the second LED 13 in the LED module 2 from a power source. And a driver housing 9 that houses a circuit board 10 for power supply.

  As the material of the driver housing 9, various resins, inorganic materials such as ceramics, and metals such as aluminum can be applied. The driver housing 9 may be configured by using these materials in combination. In the present embodiment, PBT (polybutylene terephthalate) is used for the driver housing 9, but is not limited thereto. In addition, the material of the driver housing 9 is preferably a resin-based material having no conductivity. The driver housing 9 includes a board housing portion that houses the circuit board 6 and a conductor pressing attachment portion that is connected to the rear of the board housing portion. The substrate housing portion has a set of fixing portions to which a fastener such as a screw can be screwed.

  As shown in FIG. 4, a conductor pressing member is mounted on the conductor pressing mounting portion of the driver housing 9. The conducting wire pressing member 11 is formed of an insulating member. In addition, a set of pin insertion holes are formed in the conductor pressing member in the thickness direction. A base pin of a base provided on the circuit board 10 is inserted into the pin insertion hole. Furthermore, the conducting wire pressing member 11 has an engaging claw that is engaged with an engaging portion provided on the conducting wire retainer mounting portion side of the driver housing 9 (see FIG. 4). When the MR16 type LED lamp 1 is assembled, the circuit board 10 is housed in the board housing portion of the driver housing 9 and the base pin is inserted into the pin insertion hole of the conductor holding member 11. Then, the conductor pressing member 11 can be mounted on the driver housing 9 by hooking the locking claw of the conductor pressing member 11 on the locking portion of the conductor pressing mounting portion. In addition, the cap pin which protrudes outside through the pin insertion hole of the conducting wire pressing member 11 can be inserted and connected to a socket (not shown). Thereby, electric power can be supplied to the circuit board 10 from an external power supply.

(Configuration of LED module of this embodiment)
FIG. 5 is a block diagram showing an outline of an LED (semiconductor light emitting device) module 2 according to this embodiment. As shown in FIG. 5, the LED module 2 includes a substrate 14, a variable constant current circuit 22, a light emitting circuit 23, a control circuit 24, and a shunt circuit 25. The light emitting circuit 23, the control circuit 24 and the shunt circuit 25 are mounted on the substrate 14. For example, as shown in FIG. 6, the light emitting circuit 23 includes a second LED 13, a first LED 12, and a current detection resistor (Rse) 26 connected in series in the conduction direction.

  The variable constant current circuit 22 is provided with an external connection terminal (not shown). The external connection terminal is connected to an external power source (not shown) for supplying current to the variable constant current circuit 22. The variable constant current circuit 22 is connected to the light emitting circuit 23. The wiring is patterned on the substrate 14, and the light emitting circuit 23, the control circuit 24, and the shunt circuit 25 are connected by the patterned wiring. In this way, the LED module 2 supplies current to the variable constant current circuit 22, the light emitting circuit 23, the control circuit 24, and the shunt circuit 25.

As the substrate 14, for example, an aluminum substrate formed by sequentially laminating an aluminum material, an insulating layer, and a copper foil, or other metal substrate can be used. In particular, the aluminum substrate is excellent in thermal conductivity, heat resistance, workability, and voltage resistance, and contributes to improving the light emission characteristics and reliability of the LED module 2.
The variable constant current circuit 22 converts a current supplied from an external power supply (not shown) into a direct current having a constant current value. The variable constant current circuit 3 can continuously vary the current value supplied from the external power supply by an external operation. In this way, the LED module 1 can control the luminous flux (illuminance) emitted from the first LED 12 and the second LED 13 based on an external operation.

The voltage supplied to the LED module 2 is determined by the number of serial connections of the first LED 12 and the second LED 13. Since the near ultraviolet to blue LED is a GaN LED, the forward voltage per LED is about 3V.
The light emitting circuit 23 is connected to a variable constant current circuit 22, a control circuit 24 and a shunt circuit 25. For example, as shown in FIG. 6, the light emitting circuit 23 is configured by connecting the second LED 13, the first LED 12, and the current detection resistor 26 in series in the conduction direction. The first LED 12 and the second LED 13 emit light based on the direct current supplied from the variable constant current circuit 22.

The first LED 12 and the second LED 13 are connected such that the directions of the LEDs are the same. The number of connected LEDs is determined by the desired luminous flux and usable drive voltage. For example, when the voltage supplied to the LED module 1 is 12 to 15 V, it is preferable to connect one first LED 12 and three second LEDs 13 in series.
The first LED 12 and the second LED 13 have a near-ultraviolet or violet LED chip (semiconductor light emitting element) and a blue phosphor, a green phosphor and a red phosphor covering the near-ultraviolet or violet LED chip. Alternatively, blue, green, and red phosphors are excited by near-ultraviolet or violet light emitted from a purple LED chip to emit blue light, green light, and red light to synthesize blue light, green light, and red light. Then, white light is emitted. In the LED module 1, the color temperature of the emitted light can be adjusted by changing the combination of the types of phosphors used for the first LED 12 and the second LED 13 and the blending amount thereof.

The first LED 12 and the second LED 13 may use the same color temperature LED, but when the first LED 12 and the second LED 13 use different color temperature LEDs, the first LED 12 and the second LED 13 The color temperature of the synthesized white light can be changed by changing the luminous flux of the light emitted from each of the two LEDs 13. The second LED 13 emits white light having a color temperature of about 1900K, for example, and the first LED 12 emits white light having a color temperature of about 4000K, for example. That is, the second LED 13 emits white light having a low color temperature, and the first LED 12 emits white light having a higher color temperature than the second LED 13.

  The current detection resistor 26 detects the magnitude of the current using a voltage drop caused by the passing current. The resistance value of the current detection resistor 26 depends on the active element used for the control circuit 24. For example, when the active element is a silicon bipolar transistor, the resistance value of the current detection resistor 26 is a voltage of about 0.6 to 0.7 V, which is a forward voltage of a pn junction between the base and emitter of the active element. It is preferable to select such a resistance value.

  The control circuit 24 is connected to the light emitting circuit 23 and the shunt circuit 25. The control circuit 24 detects a change in current by the voltage across the current detection resistor 26, generates a control signal for controlling the current passing through the shunt circuit 25, transmits the control signal to the shunt circuit 25, and shunts the current. It is a circuit that controls the amount of current that is shunted to the circuit 25. That is, the control circuit 24 controls the current passing through the shunt circuit 25 based on the current passing through the current detection resistor 26. The control circuit 24 is composed of active elements such as bipolar transistors, junction FETs, MOSFETs, and operational amplifiers (OP amplifiers).

The shunt circuit 25 is connected to the light emitting circuit 23 in parallel. In particular, the shunt circuit 25 is connected in parallel to the first LED 12, and shunts (bypasses) part or substantially all of the current that should flow through the second LED 13 to the first LED 12. The amount of current to be bypassed is increased or decreased based on a control signal transmitted from the control circuit 24. The shunt circuit 25 is configured by an active element such as a bipolar transistor, a junction FET, or a MOSFET, for example. The active element of the shunt circuit 25 is preferably one that handles a current of about 0.5 to 1A.
The outline of the LED module used in the present invention has been described based on FIG. The configuration of the electric circuit diagram of the LED module device of the first embodiment will be described in detail below with reference to FIG.

(Electric circuit diagram of the LED module device of the first embodiment)
FIG. 6 is an electric circuit diagram showing an outline of the LED module 2 of the first embodiment. As shown in FIG. 6, the LED module 2 of the first embodiment includes an npn bipolar transistor as a control circuit 2.
4 and the shunt circuit 25.

  The light emitting circuit 23 is configured by connecting the second LED 13, the first LED 12, and the current detection resistor 26 in series in the conduction direction from the positive terminal of the variable constant current circuit 22 to the negative terminal. . Specifically, in the light emitting circuit 23, the positive terminal of the variable constant current circuit 22 and the anode terminal of the second LED 13 are connected, and the cathode terminal of the second LED 13 and the anode side of the first LED 12 are connected. And the cathode side terminal of the first LED 12 and one end side of the current detection resistor 26 are connected to each other. The other end side of the current detection resistor 26 and the negative electrode side terminal of the variable constant current circuit 22 are connected to each other. Is connected.

  In the example of FIG. 6, the light-emitting circuit 23 includes one first LED 11 and three second LEDs 12 connected in series. The voltage supplied to the LED module 2 is preferably 12 to 15V. The resistance value of the current detection resistor 26 is preferably about 7Ω in consideration of obtaining a voltage drop of about 0.7 V at 0.1 A.

The control circuit 24 uses the npn bipolar transistor 27 as an active element. The control circuit 24 is configured to be connected in parallel with the light emitting circuit 23. The control circuit 24 is configured by connecting an npn bipolar transistor 27, an emitter resistor 28, and a first load resistor 29. Specifically, in the control circuit 24, the emitter terminal of the npn bipolar transistor 27 is connected to the other end side of the current detection resistor 26 via the emitter resistor 28, and the base terminal of the npn bipolar transistor 27 is connected to the first LED 12. The collector terminal of the npn bipolar transistor 27 is connected to the anode terminal of the second LED 13 via the first load resistor 29.

The npn bipolar transistor 27 is a control transistor. As the npn bipolar transistor 27, for example, 2SC1815 is suitable in consideration of collector loss. The emitter resistor 28 is a resistance on the emitter side of the npn bipolar transistor 27,
About 500Ω is preferable. The first load resistor 29 is a load resistor of the collector of the npn bipolar transistor 27, and the resistance value is preferably about 1 to 5 kΩ.

Similar to the control circuit 24, the shunt circuit 25 uses an npn bipolar transistor 27 as an active element. The shunt circuit 25 is configured to be connected in parallel with the first LED 12 of the light emitting circuit 23. Specifically, in the shunt circuit 25, the emitter terminal of the npn bipolar transistor 27 is connected to the current detection resistor 26, the base terminal of the npn bipolar transistor 27 is connected to the collector terminal of the npn bipolar transistor 27, and the npn bipolar transistor. The collector terminal of the transistor 27 is connected to the anode side terminal of the first LED 12.

The npn bipolar transistor 27 is a shunting transistor. As the npn bipolar transistor 27, for example, 2SC1815, 2SC1858, 2SC3325, or an equivalent thereof can be used. The current detection resistor 26 also serves as a resistance on the emitter side of the npn bipolar transistor 27.

Next, operation | movement of the LED module 2 of an Example is demonstrated. First, when the variable constant current device 3 is operated from the outside to increase the current value (increase the illuminance) when the current value is 0, the LED module 2 causes a small amount of current to flow through the first load resistor 16. Flows, and the npn bipolar transistor 27 is turned on. Subsequently, in the LED module 2, a current flows in the order of the second LED 13, the npn bipolar transistor 27 and the second bias resistor 28 and the current detection resistor 26 as the collector current of the npn bipolar transistor 27. Thereby, light emission of the 2nd LED13 starts. At this time, almost no current flows through the first LED 12, and the first LED 12 does not emit light to a degree that is substantially meaningful as a lighting device.

Subsequently, when the LED module 2 is further operated to increase the current value from the outside, the current flowing through the second LED 13 increases, and the second LED 13 emits light more strongly. Subsequently, when the LED module 2 is further operated to increase the current value from the outside, in addition to the second LED 13 and the npn bipolar transistor 27, a current flows through the first LED 12, and the first LED 12 emits light. Start. Thereby, the synthetic white light of the first LED 12 and the second LED 13 is emitted.

That is, the control circuit 24 causes the current to flow through the shunt circuit 25 and does not substantially cause the current to flow through the first LED 12 until the current value of the current supplied to the light emitting circuit 23 changes from 0 to a predetermined current value. Further, the control circuit 24 causes a current to flow through both the shunt circuit 25 and the first LED 12 when the current value of the current supplied to the light emitting circuit 23 becomes equal to or greater than a predetermined current value.
Subsequently, the LED module 2 is further operated to increase the current value from the outside, and when a current of 100 mA flows through the current detection resistor 26 (the resistance value of the current detection resistor 26 is 7Ω), the base of the npn bipolar transistor 37 The emitter-to-emitter voltage V _BE is about 0.7 V, and the npn bipolar transistor 37 is turned on. Subsequently, in the LED module 2, current starts to flow in the order of the first load resistor 29, the npn bipolar transistor 37, and the emitter resistor 28 as the collector current of the npn bipolar transistor 37.

Subsequently, when the LED module 2 is further operated to increase the current value from the outside, the voltage drop of the current detection resistor 26 increases, and as a result, the base-emitter voltage V _{BE of the} npn bipolar transistor 37 increases. The collector current of the npn bipolar transistor 37 increases. As a result, the LED module 2 has a large voltage drop across the first load resistor 16, and as a result, the base-emitter voltage V _{BE of the} npn bipolar transistor 27.
Decreases, and the collector current flowing in the npn bipolar transistor 27 decreases. That is, the current flowing through the first LED 12 increases, and the first LED 12 emits light more intensely.

  When the supply of current is started to the second LED 13 from the configuration of the MR16 type LED lamp 1 as described above and the current is not yet supplied to the first LED 12, as shown in FIG. The light distribution from the lens 16 has a wide angle, and even if the total amount of power supplied to the light source group increases, the luminous flux emitted from the illumination device remains until the first LED is turned on. Although increased, the light distribution angle of the emitted light remains the same.

  Next, when the total amount of power supplied to the light source group further increases and the lighting of the first LED 12 is started, it is installed at the focal position of the one-core type lens as shown in FIG. The light distribution of the light emitted from the first LED 12 is controlled at a narrow angle by the one-core lens. Thus, as the total amount of current supplied to the light source group increases, the luminous flux emitted from the illumination device increases and the light distribution angle of the emitted light gradually changes to a narrow angle.

  That is, when the amount of power supplied to the LED group is small, the first LED group 12 is not lit, only the second LED group 13 is lit, and the total luminous flux is small, A wider range can be illuminated with uniform light as a whole. Next, in the case where the amount of power supplied to the LED group is increased, the first LED group 12 is turned on, the combined light with the second LED group 13 is emitted, and the total luminous flux is increased. Although it does not spread in the width direction of the device, it extends to a far region in the optical axis direction of the illumination device. That is, by increasing the amount of electric power supplied to the first LED 12, it becomes possible to clearly illuminate the irradiated object provided far away from the illumination device.

  In the above embodiment, the lighting device 1 has been described as an example in which lighting is started from the second LED group 13 having low directivity, and then lighting of the first LED group 12 having high directivity is started. However, as a modification, it is also possible to use an illumination device that starts lighting from the first LED group having high directivity and then starts lighting the second LED group having low directivity. By using such an illuminating device, when the luminous flux of the illuminating device is small, only the periphery of the irradiated object in the optical axis direction is clearly illuminated, and as the luminous flux increases, a wider range around the illuminating device is obtained. It can irradiate with uniform light as a whole.

<Evaluation of lighting device>
Next, changes in the characteristics of the synthetic white light emitted from the lighting device 1 when the lighting device 1 according to the present embodiment is actually attached to the ceiling will be described with reference to FIG. As a specific evaluation method, when the total amount of actual driving current (applied current) supplied to the first LED group 12 and the second LED group 13 is changed, the synthetic white light emitted from the lighting device 1 is changed. The illuminance (lx) at a position 1 m apart in the optical axis direction was measured. The horizontal axis of FIG. 7 is the total amount of actual drive current (applied current) supplied to the first LED group 12 and the second LED group 13, and the vertical axis is the optical axis of the synthetic white light emitted from the lighting device 1. Illuminance (lx) at a position 1 m away in the direction (that is, immediately below 1 m from the illumination device 1).

As shown in FIG. 7, when the total amount of applied current to the second LED group 13 is increased, the illuminance immediately below 1 m of the synthetic white light emitted from the lighting device 1 is gradually proportional to the increase in applied current. Increase.
When the total amount of applied current to the second LED group 13 reaches 200 mA, the lighting of the first LED group 12 starts and emission of light with high directivity is started. Since the emitted light from the first LED group 12 has a narrow angle, the area immediately below 1 m of the synthetic white light emitted from the illumination device 1 can be illuminated clearly with higher illuminance than the surrounding area.

  As more specific numerical data, when the total amount of applied current to the first LED group 12 and the second LED group 13 is 200 mA, the illuminance immediately below 1 m of the synthetic white light emitted from the lighting device 1 is 320 lx. On the other hand, when the total amount of current applied to the first LED group 12 and the second LED group 13 is 400 mA, the illuminance immediately below 1 m of the synthetic white light emitted from the illumination device 1 jumps to 930 lx. The price is rising.

  In the above-described embodiment, it is assumed that the first LED group 12 and the second LED group 13 have the same color temperature (for example, 4000 K). The color temperature of the group 12 and the second LED group 13 can be changed, and the increase in the luminous flux of light emitted from the lighting device, the change in directivity, and the change in color temperature can be changed in conjunction with each other. As an example of a modification, the first LED group is an LED that emits white light of 5000K, and the second LED group is an LED that emits white light of 2700K, so that the amount of power supplied to the LED group is reduced. In the case where the first LED group is not lit, only the second LED group is lit, and the total luminous flux is small, a wider range around the lighting device is reduced to a light bulb color with a low color temperature. It can irradiate with uniform light as a whole. Next, in the case where the amount of power supplied to the LED group increases, the first LED group starts to light, the combined light with the second LED group is emitted, and the total luminous flux increases, Although it does not spread in the width direction, it can be irradiated with daylight color light having a relatively high color temperature and extending to a distant region in the optical axis direction of the lighting device. That is, by increasing the amount of power supplied to the first LED, it becomes possible to illuminate an object to be irradiated far away from the lighting device with a clearer daylight color.

From the above, the lighting device according to the present embodiment can be used as a substitute for a halogen bulb with a simple configuration.
And since the illuminating device 1 which concerns on a present Example can have the effect mentioned above, it applies to various general illuminating devices, such as a downlight, a spotlight, a universal downlight, a halogen bulb, and an incandescent bulb. be able to.

1 Lighting device (MR16 type LED lamp)
2 LED module 5 Housing 6 Outer frame 7 Fixing member 8 Heat sink 9 Driver housing 10 Driver (circuit board)
11 Conductor holding member 12 1st LED
13 Second LED
14 Substrate (module substrate)
15 Lens holder 16 Lens (Condensing optical member)
16a Light exit surface 16b Light incident surface 16c Opening (concave portion)
DESCRIPTION OF SYMBOLS 17 Thermal conductive sheet 18 Optical part 22 Variable constant current circuit 23 Light emission circuit 24 Control circuit 25 Current shunt circuit 26 Current detection circuit 27, 37 npn bipolar transistor 28 Emitter resistance 29 1st load resistance 43 First to-be-irradiated object

Claims (14)

A lighting device in which the brightness varies with the variation of the light control level,
A substrate,
A light source group installed on the substrate;
A current supply unit for supplying a drive current to the light sources independently for each light source group;
A controller that controls a current supplied to each of the light source groups according to a control signal input from the outside,
The light source group is different in the directivity of light emitted from each group,
The said control part controls the lighting start time of these light source groups independently from the said electric current supply part, The illuminating device characterized by the above-mentioned.   The lighting device according to claim 1, wherein the control unit sequentially turns on the light source groups as the total amount of power supplied to the light source groups increases.   The control unit applies a light source group that emits light with high directivity from a light source group with low directivity as the total amount of power supplied to the light source group increases, and sequentially turns on the light source groups. The lighting device according to claim 2.   The control unit applies a light source group that emits light with low directivity from a light source group with high directivity as the total amount of power supplied to the light source group increases, and sequentially turns on the light source groups. The lighting device according to claim 2.   5. The light source group having high directivity is arranged in a central region on the substrate, and the light source group having low directivity is arranged in a peripheral region on the substrate. Lighting equipment.   The light emitting point of the light source group with high directivity is arranged at the focal point of the one-core type condensing optical component or an area near the focal point, and the light source group with low directivity is arranged in an area farther from the focal point of the condensing optical component. The lighting device according to any one of claims 1 to 5, wherein   The condensing optical member of the light source group with high directivity and the condensing optical member of the light source group with low directivity are configured independently, and the outgoing light distribution of the condensing optical member of the light source group with high directivity The lighting device according to claim 1, wherein the angle is narrower than the outgoing light distribution angle of the condensing optical member of the light source group having low directivity.   The condensing optical member of the light source group with high directivity and the condensing optical member of the light source group with low directivity are configured independently, and the exit surface of the condensing optical member of the light source group with low directivity is The illuminating device according to claim 1, wherein a diffusing surface is formed.   The illumination device according to claim 7, wherein the condensing optical member of the light source group with high directivity and the condensing optical member of the light source group with low directivity are integrally formed.   The lighting device according to claim 1, wherein the light source is an LED.   The illuminating device according to claim 1, wherein chromaticity of the light source groups is the same between the light source groups. The illuminating device according to claim 1, wherein chromaticity of the light source group is different for each light source group.   6. The color temperature of light emitted from the light source group having high directivity is higher than the color temperature of light emitted from the light source group having low directivity. 6. Lighting equipment. The light source group includes a first LED group with high directivity and a second LED group with low directivity,
The first LED group, the second LED group, and a detection resistor for detecting the magnitude of current supplied from an external power source to the first LED group and the second LED group are connected in series. A light emitting circuit,
A shunt circuit connected in parallel with the second LED group;
A control circuit for controlling the current passing through the shunt circuit based on the current passing through the detection resistor;
The lighting device according to claim 10, wherein the light emitting circuit, the shunt circuit, and the control circuit are provided on the substrate.