JP5620872B2 - LED light emitting device - Google Patents

Description

  The present invention relates to an LED light-emitting device that does not give a user a sense of incongruity when used as a substitute for a dimming incandescent light bulb that is widely used in general lighting applications.

  Light-emitting diodes (hereinafter referred to as “LEDs”), which have lower power consumption and longer life than conventional incandescent bulbs, are used as one of the energy-saving measures along with increasing ecological awareness of consumers. In particular, there is a growing demand to use LED light-emitting devices incorporating LEDs as an alternative to incandescent lamps.

  By the way, conventionally, “light control” is performed to gradually decrease (or gradually increase) the amount of light emitted from the incandescent lamp by decreasing the current supplied to the incandescent lamp or decreasing the applied voltage. It is applied to indoor downlights.

  Since the LED light emitting device is naturally required to have a dimming function as long as it is used as an alternative to such an incandescent lamp, an LED light emitting device having a dimming function has been developed (for example, Patent Document 1). ).

As shown in FIG. 4 , the LED light emitting device 1 of Patent Document 1 includes a DC power source 2 that can change an output voltage, a plurality of LEDs 3 a to 3 c connected in parallel to the DC power source 2, and a DC power source 2. It is composed of a plurality of voltage gates 4a to 4c connected in series, which sequentially apply voltages to the LEDs 3a to 3c in accordance with the applied voltage from the LED, and lower the output voltage from the DC power supply 2 As a result, the voltage gates 4a to 4c are sequentially turned off, and the LEDs 3a to 3c are extinguished, thereby enabling "dimming".

  In addition, since the incandescent lamp has the characteristic that the emitted light amount decreases and the color temperature of the light also decreases, the output voltage from the DC power source 2 also decreases in the LED light emitting device 1 of Patent Document 1. From the existing incandescent lamp, the emission color temperature of each of the LEDs 3a to 3c is set to be lower in the order of turning off the light so that the light emission amount from the LED light emitting device 1 is reduced and the emission color temperature is lowered at the same time. This makes it possible to further reduce the sense of incongruity when switching.

Registered Utility Model No. 3082719

  However, the LED light emitting device 1 of Patent Document 1 is still incomplete as an alternative to an incandescent lamp.

That is, as shown in FIG. 5 (FIG. 1 of Patent Document 1), a plurality of LEDs 3a to 3c are simply arranged side by side, and the number of LEDs 3a to 3c that emit light by increasing or decreasing the output voltage from the DC power supply 2 is determined. When the light emission is increased or decreased, the apparent light emission position of the LED light emitting device 1 is shifted, and the irradiation region by the LED light emitting device 1 is naturally shifted. Therefore, even if the light amount is increased or decreased, the light emission position (filament position) is changed. There was no sense of incongruity with an incandescent lamp that did not change and the irradiation area did not shift.

  Of course, if a large number of LEDs with different emission color temperatures are mixed and arranged evenly, when the LEDs with the highest emission color temperatures are gradually dimmed in order and finally turned off, there will be no concern about the deviation of the irradiation area. You can However, disposing LED groups with the same emission color temperature evenly dispersed and wiring for each LED group arranged in a discrete manner increases the manufacturing effort and the associated high cost. Actually, it is not realistic, but in reality, a “low color temperature region” in which low color temperature LEDs having a low emission color temperature are collected and a high color temperature LED having a higher emission color temperature than the low color temperature LEDs are collected. In other words, the “high color temperature region” must be divided into large parts, and the above-mentioned problem of “irradiation region shift” cannot be practically solved.

  The present invention has been developed in view of such problems of the prior art. Therefore, the main problem of the present invention is to reduce the amount of light emitted from the LED group divided into “low color temperature region” and “high color temperature region” by dimming and turning off the LEDs arranged in the high color temperature region. In this case, the emission color temperature of the entire device can be lowered, and even if the LED is dimmed and extinguished, it is difficult for the user to perceive the displacement of the irradiation area. However, an object of the present invention is to provide an LED light-emitting device that has little discomfort.

The invention described in claim 1
"A low color temperature region 26 emission color low temperature low color temperature LED20 has been collected, the high color temperature region 28 where the said at ambient low color temperature high color temperature LED22 emission color temperature is higher than LED20 was collected LED unit 12 formed on the surface thereof,
The LED unit 12 is disposed on the bottom thereof, and a bowl-shaped reflector 14 having a reflection surface 30 formed on the inner surface thereof;
And a convex lens 36 disposed in front of the LED unit 12,
Before SL convex lens 36, the low color temperature region 26 light Lb emitted from, and the outer peripheral side of the high color temperature region 28 irradiated region part Lc of predetermined light emitted from S formed inside Focused on
The reflective surface 30 of the reflector 14 reflects the remaining portion La of the light emitted from the high color temperature region 28 on the outer peripheral side and collects it in the irradiation region S ”. is there.

  According to the LED light emitting device 10 to which the present invention is applied, the light Lb radiated from the color temperature region 26 formed inside is condensed on the predetermined irradiation region S by the lens 16, and the color temperature region The light La and Lc emitted from the color temperature region 28 formed on the outer periphery of the lens 26 is partly focused on the irradiation region S by the lens 16 toward the light receiving surface 40 of the lens 16 and the lens 16. The remaining light La deviated from the light receiving surface 40 is reflected by the reflecting surface 30 of the reflector 14 and then condensed on the irradiation region S.

  As described above, the light La, Lb, and Lc emitted from the “low color temperature region 26” and the “high color temperature region 28” are condensed toward the same irradiation region S. By gradually dimming the arranged high color temperature LED 22 and finally turning it off, the light emission amount and the color temperature of the light of the LED light emitting device 10 as a whole can be reduced, and the dimming / extinguishing is performed. It is possible to suppress the deviation of the irradiation region S before and after.

In addition, as shown in FIG. 3, the high color temperature formed on the outer periphery compared to the light Lb (inner light) condensed by the lens 16 after being emitted from the low color temperature region 26 formed on the inner side. After being emitted from the region 28, the light Lc (outside light) that has passed through the lens 16 forms an irradiation region S1 wider on the irradiation surface SP than the irradiation region S2 of the inner light Lb. A region (Sy in the figure) where the irradiation regions S1 and S2 of Lb and the outside light Lc do not overlap is irradiated with only the outside light Lc, and this region is a region where the inside light Lb and the outside light Lc overlap (in the drawing). , Sz. (Hereinafter referred to as “overlapping irradiation region”), it becomes a region that is more inconspicuous than the overlapping irradiation region Sz.

  In the present invention, by forming the “low color temperature region 26” on the inner side and the “high color temperature region 28” on the outer periphery thereof, the low color temperature light is set as the inner light Lb, and the high color temperature light is set as the outer light Lc. Therefore, when the high color temperature LED 22 arranged in the high color temperature region 28 is dimmed and extinguished, the position of the “bright and conspicuous” irradiation region before and after that is the overlapping irradiation region Sz (= before dimming and extinguishing). , And the low color temperature light irradiation region S2 (= after dimming / extinguishing).

  This makes it difficult for the user to perceive the “irradiation area shift” before and after the high color temperature LED 22 is dimmed and extinguished. Therefore, the LED light emitting device 10 that is more suitable as an alternative to the conventional dimming incandescent lamp is provided. Can be configured.

  According to the present invention, the amount of light emitted from the LED light emitting device as a whole and the color temperature of light are lowered by gradually dimming and finally turning off the high color temperature LEDs arranged in the high color temperature region. In addition, it is possible to provide an LED light-emitting device that can suppress the deviation of the irradiation region before and after the extinguishment and does not cause a sense of incongruity even when used in place of an incandescent lamp.

It is sectional drawing which shows the LED light-emitting device of 1st Example. It is sectional drawing which shows the LED light-emitting device which concerns on the modification of 1st Example. It is a figure explaining the difference of the irradiation range between inner side light and outer side light. It is a figure explaining a prior art. It is a figure explaining a prior art.

DETAILED DESCRIPTION embodiment of the present invention have use to the drawings, the lens 16, the first embodiment will be described using a typical convex lens 36.

As shown in FIG. 1, the LED light emitting device 10 according to the present embodiment is generally composed of an LED unit 12, a reflector 14, and a lens 16.

  The LED unit 12 includes a plurality of low color temperature LEDs 20 having a low emission color temperature, a plurality of high color temperature LEDs 22 having a emission color temperature higher than the low color temperature LEDs 20, and the LEDs 20 and 22 mounted (fixed, wired). And a substrate 24.

  In the LED unit 12, a “low color temperature region 26” in which a plurality of low color temperature LEDs 20 are collected and mounted in a substantially circular shape is formed on one surface of the substrate 24. A “high color temperature region 28” in which a plurality of high color temperature LEDs 22 are collected and mounted is formed on the outer periphery of the LED. Specifically, the LEDs 23 of the same type are mounted side by side on one surface of the substrate 24 (so that the optical axes of the LEDs 23 are aligned in the same direction), and a “weir 29” surrounding the LEDs 23 is provided (this weir) 29 is a boundary between the color temperature regions 26 and 28 and a boundary between the high color temperature region 28 and the outside), and thereafter, the fluorescence having a low emission color temperature is formed on the surface of the substrate 24 surrounded by the weir 29. In addition to filling the body, the outer periphery thereof is filled with a phosphor having a high emission color temperature. Accordingly, the LED 23 in the region filled with the phosphor having a low color temperature becomes the low color temperature LED 20, and the LED 23 in the region filled with the phosphor having the high color temperature becomes the high color temperature LED 22.

  Of course, the LEDs 20 and 22 having different emission color temperatures may be mounted on the substrate 24 so as to form the color temperature regions 26 and 28, respectively, or after all the LEDs 20 and 22 are mounted, Different filters (one having a low color temperature and one having a higher color temperature) may be attached to the light output side of the corresponding LEDs 20 and 22.

  In contrast to the present embodiment, the low color temperature region 26 may be formed on the outer periphery of the high color temperature region 28. However, as will be described later, the embodiment of the present embodiment (that is, the low color temperature region 26) The aspect in which the high color temperature region 28 is formed on the outer periphery is preferable in that it is more difficult for the user to perceive the “irradiation region shift” before and after the high color temperature LED 22 is turned off.

  The reflector 14 is a bowl-shaped member having a reflective surface 30 on its inner side. As the material of the reflector 14, glass, aluminum, resin, or the like is used. In the case of aluminum, metal deposition is performed on the reflective surface 30. (Alternatively, alumite treatment may be applied instead of metal deposition). In the case of glass, in addition to a metal film such as aluminum, a visible light reflecting film by multilayer coating can also be used.

  The reflection surface 30 is formed on the inner surface of the reflector 14 as described above, and the central axis CL (the central axis CL is the optical axis X of the LED light-emitting device 10 [the optical axis of each LED 20, 22 provided in the LED unit 12). In this example, the focal point F of the spheroidal surface is the optical axis X of the LED unit 12 and the optical axis X of the LED unit 12. It is set so as to coincide with the point where the surface of the LED unit 12 intersects, and the light La emitted from the high color temperature region 28 and reflected from the lens 16 is reflected into the irradiation region S in front of the reflector 14. (As will be described later, of the light emitted from the high color temperature region 28, a part of the light Lc toward the lens 16 is collected by the lens 16, and It was the remainder of the light La is converged by the reflector 14.). Note that the shape of the reflecting surface 30 is not limited to the spheroid, as long as the light La deviated from the lens 16 can be condensed in the irradiation region S.

  A transparent cover 32 that covers the opening 14 a is attached to the opening 14 a of the reflector 14 as necessary, and the optical axis X of the LED unit 12 and the central axis of the reflector 14 are attached to the bottom opening 14 b of the reflector 14. An LED unit holding plate 34 for holding the LED unit 12 at a position where CL matches is attached so as to cover the bottom opening 14b.

  The transparent cover 32 is a plate-like material made of polycarbonate (of course, the material is not limited to this, and other resins and quartz glass may be used). They are formed integrally (of course, they may be formed separately).

  The lens 16 is a solid transparent convex lens 36 disposed in front of the LED unit 12 (of course, the material is not limited to this, and other resins and quartz glass may be used). The light Lb emitted from the low color temperature region 26 and the light Lc emitted from the high color temperature region 28 formed on the outer periphery of the low color temperature region 26 toward the convex lens 36 are condensed on the irradiation region S. It is a member.

  The center of the convex lens 36 is located on the optical axis X of the LED unit 12, so that the light Lb emission angle and the LED unit 12 can cover all the light Lb emitted from the low color temperature region 26. The diameter is determined according to the distance. It is necessary to increase the diameter of the convex lens 36 as the radiation angle of the light Lb increases and as the distance from the LED unit 12 increases. For this reason, when there is almost no gap between the LED unit 12 and the convex lens 36, “the diameter of the low color temperature region 26 ≈ the diameter of the convex lens 36”.

  The shape of the convex lens 36 may be a “plano-convex lens” whose one surface is flat as shown in FIG. 1 or a “biconvex lens” whose both surfaces are spherical as shown in FIG. It may be.

  When electric power is supplied to the LEDs 20 and 22 of the LED unit 12 in the LED light emitting device 10 of this embodiment via a power feeding circuit (not shown), light of a predetermined color temperature (from the low color temperature LED 20) is supplied from the LEDs 20 and 22. Is a low color temperature light Lb, and high color temperature light La, Lc.

  The light Lb radiated from the low color temperature region 26 is refracted by the convex lens 36 disposed in front of the optical axis, and is then applied to the irradiation region S of the irradiation surface SP set in front of the LED light emitting device 10. Focused.

  Of the light La and Lc emitted from the high color temperature region 28 formed on the outer periphery of the low color temperature region 26, the light Lc toward the light receiving surface 40 of the convex lens 36 is the light Lb from the low color temperature region 26 described above. In the same manner as described above, the light is refracted by the convex lens 36 and then condensed on the irradiation region S. In addition, the light La deviated from the light receiving surface 40 of the convex lens 36 is reflected by the reflecting surface 30 of the reflector 14 and then condensed on the irradiation region S like the other lights Lb and Lc.

  In the LED light emitting device 10 of the present embodiment, the light La, Lb, and Lc emitted from the low color temperature region 26 and the high color temperature region 28 on the LED unit 12 are thus condensed on the irradiation region S. Therefore, the light emission amount of the LED light emitting device 10 as a whole is obtained by gradually dimming the high color temperature LED 22 arranged in the high color temperature region 28 and finally turning it off, and continuing to emit light only to the low color temperature LED 20. In addition, the color temperature of the light can be lowered, and the irradiation region S can be prevented from shifting before and after the dimming / extinguishing.

  By the way, as shown in FIG. 3, the high color temperature formed on the outer periphery compared to the light Lb (inner light) emitted from the low color temperature region 26 formed on the inner side and then collected by the convex lens 36. After being emitted from the region 28, the light Lc (outside light) passing through the convex lens 36 forms an irradiation region S1 wider on the irradiation surface SP than the irradiation region S2 of the inner light Lb. A region (Sy in the drawing) where the irradiation regions S1 and S2 of the Lb and the outer light Lc do not overlap is irradiated with only the outer light Lc, and the region is an overlapping irradiation region where the inner light Lb and the outer light Lc overlap ( In the figure, compared to Sz), the area is more blurred and less conspicuous than the overlapping irradiation area Sz.

  In the LED light emitting device 10 of the present embodiment, as described above, the “low color temperature region 26” is formed on the inner side and the “high color temperature region 28” is formed on the outer periphery thereof, whereby the low color temperature light is transmitted to the inner light Lb. Since the high color temperature light is the outside light Lc, when the high color temperature LED 22 arranged in the high color temperature region 28 is dimmed and extinguished, the positions of the “bright and conspicuous” irradiation regions overlap before and after that. There is no change in the irradiation region Sz (= before dimming / extinguishing) and the low color temperature light irradiation region S2 (= after dimming / extinguishing).

  For this reason, since it becomes more difficult for the user to perceive “shift of the irradiation area” before and after the dimming / extinguishing of the high color temperature LED 22, the LED light emitting device 10 that is more suitable as an alternative to the conventional dimming incandescent lamp is provided. Can be configured.

DESCRIPTION OF SYMBOLS 10 ... LED light-emitting device 12 ... LED unit 14 ... Reflector 14a ... Opening part 14b ... Bottom part opening 16 ... Lens 20 ... Low color temperature LED
22 ... High color temperature LED
23 ... LED
24 ... substrate 26 ... low color temperature region 28 ... high color temperature region 29 ... weir 30 ... reflecting surface 32 ... transparent cover 34 ... LED unit holding plate 36 ... convex lens

Claims (1)

A low color temperature region with low light emission color temperature low color temperature LED has been collected, and the high color temperature region high color temperature LED emission color temperature is high is collected than the low color temperature LED at its periphery its An LED unit formed on the surface;
A bowl-shaped reflector in which the LED unit is disposed at the bottom and a reflecting surface is formed on the inner surface thereof;
And a convex lens disposed in front of the LED unit,
Before SL convex lens condenses light emitted from the low color temperature region formed on the inner side, and a part of light emitted from the high color temperature region of the outer peripheral side in a predetermined irradiation region,
The LED light-emitting device according to claim 1, wherein the reflecting surface of the reflector reflects the remaining light emitted from the high color temperature region on the outer peripheral side and collects the light in the irradiation region.

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