JP2015111523A - Lighting device and optical lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED lighting device ensuring high focusing power for focusing light emitted from LED, ensuring higher maximum luminous intensity on a radiated surface, and suppressing color irregularity on the radiated surface.SOLUTION: Provided is a lighting device including a semiconductor light-emitting element; and an optical lens. The optical lens has a light incident surface, a light emission surface, and a total reflection surface. The incident surface is a concave surface having an opening that is open toward the semiconductor light-emitting element. The concave incident surface is formed out of an upper light incident surface and a lateral light incident surface, an area of the light incident surface surrounded by an edge of the upper light incident surface is smaller than an area thereof surrounded by an edge of the opening, and the lateral light incident surface is a curved surface.

Description

  The present invention relates to an illumination device using an LED as a light emitting element, and an optical lens used in the illumination device.

A light-emitting diode (hereinafter referred to as “LED”) is expected to be a new light source because it has a higher efficiency and a longer life than conventional illumination light sources such as fluorescent lamps and incandescent lamps. In order to obtain an arbitrary light distribution characteristic according to the application of the lighting device, it is considered to combine such an LED light source and a lens for light distribution control.
For example, Patent Document 1 describes using a hybrid lens that combines a light-emitting surface having a convex portion and a total reflection surface as a method of increasing luminance by changing the light distribution characteristics of an LED element from a wide angle to a narrow angle. Has been. The hybrid lens has an optical path for emitting lens incident light from an LED element disposed in the center as light substantially parallel to the lens central axis (optical axis) by total reflection by a reflecting surface, and an output having a convex portion. There are two types of optical paths: light paths that are condensed and emitted as substantially parallel light to the optical axis by refraction by the surface. A lens for controlling the light emitted from the LED element by the both optical paths is described.

JP 2007-59073 A

  However, in a conventional illumination device using an optical lens, for example, when an LED having a certain size on the light emitting surface is used as a semiconductor light emitting element, or when a plurality of semiconductor light emitting elements are used to have a plurality of light emitting surfaces In, the light emitted from the semiconductor light emitting device is not properly introduced into the lens. For this reason, light that is not controlled by the convex portion of the lens exit surface and the lens total reflection surface is generated, so that the concentration of the light emitted from the LED illumination does not increase. The result is that the central intensity does not increase. Furthermore, this results in uneven color on the irradiated surface due to the uncontrolled light.

Furthermore, in the case of a compact lighting device with limited size and shape, such as MR-16 type and halogen bulb replacement, the light emitted from the semiconductor light emitting element is controlled to have a desired light distribution. It is required to do.
The present invention has been made in view of such points, and the concentration of light emitted from LED illumination is high, the central luminous intensity of the irradiated surface is higher, and the uneven color of the irradiated surface is suppressed. An object of the present invention is to provide an LED illumination device and a lens used in the illumination device.

An illumination device of the present invention is an illumination device comprising a semiconductor light emitting element and an optical lens,
The optical lens includes a light incident surface that introduces light emitted from the semiconductor light emitting element, a light emergent surface that emits light to the outside, and light introduced from a part of the light incident surface. A total reflection surface facing
The light incident surface has a concave shape with an opening directed toward the semiconductor light emitting element, and the concave shape is located at a position opposite to the light emitting surface of the semiconductor light emitting element. A side light incident surface rising toward the edge of the incident surface, and the upper incident surface introduces light emitted upward from the light emitting surface of the semiconductor light emitting element into the optical lens, and the side light The incident surface introduces light emitted laterally from the light emitting surface of the semiconductor light emitting element into the optical lens,
The total reflection surface has a curved surface having a substantially parabolic cross section whose focal point is near the periphery of the light emitting surface of the semiconductor light emitting element, and emits light introduced into the optical lens from the side light incident surface. Reflected in the direction of the surface,
The light exit surface is provided at a position facing the upper entrance surface, is located at the center of the light exit surface, and is formed of a part of a substantially rotating curved surface, and an outer periphery of the projecting portion And has a substantially flat portion that is substantially orthogonal to the optical axis of the optical lens,
The area of the surface surrounded by the edge of the upper light incident surface is smaller than the area of the surface surrounded by the edge of the opening of the light incident surface, and the side light incident surface has a curved surface. It is.

In the illumination device of the present invention, the upper light incident surface is a substantially flat surface or a convex surface.
In the illumination device of the present invention, the side light incident surface has a curved surface having a substantially parabolic cross section with a focal point near the periphery of the light emitting surface of the semiconductor light emitting element.
The illumination device of the present invention is characterized in that the semiconductor light emitting element is a single light source that emits light from only one light emitting surface.

The illumination device of the present invention satisfies the following general formula (1), where E is the maximum diameter of the light emitting surface of the light source and L is the outermost diameter of the upper light incident surface.
0.4 ≦ E / L ≦ 1.2 (1)
The illumination device of the present invention includes a height (H) of an optical lens that is a distance from an edge of the opening of the light incident surface to a vertex of the convex portion of the light output surface, and a substantially flat surface of the light output surface. The outermost diameter (W) of the portion satisfies the following general formula (2).

0.2 ≦ H / W ≦ 0.8 (2)
The illuminating device of the present invention is characterized in that an outer diameter of the light emitting surface is 10 mm or more and 100 mm or less.
The illumination device of the present invention is characterized in that an outer diameter of the convex portion of the light exit surface is 3 mm or more and 50 mm or less.

The illuminating device of the present invention is characterized in that the optical lens includes a fixing portion for fixing the optical lens to a part of the illuminating device on a side of the optical lens.
Further, the lens of the present invention includes a light incident surface for introducing light emitted from the semiconductor light emitting element, a light emission surface for emitting light to the outside, and light introduced from a part of the light incident surface. An optical lens having a total reflection surface directed toward the exit surface,

The light incident surface has a concave shape with an opening directed toward the semiconductor light emitting element, and the concave shape is located at a position opposite to the light emitting surface of the semiconductor light emitting element. A side light incident surface rising toward the edge of the incident surface, and the upper incident surface introduces light emitted upward from the light emitting surface of the semiconductor light emitting element into the optical lens, and the side light The incident surface introduces light emitted laterally from the light emitting surface of the semiconductor light emitting element into the optical lens,
The total reflection surface has a curved surface having a substantially parabolic cross section whose focal point is near the periphery of the light emitting surface of the semiconductor light emitting element, and emits light introduced into the optical lens from the side light incident surface. Reflected in the direction of the surface,

The light exit surface is provided at a position facing the upper entrance surface, is located at the center of the light exit surface, and is formed of a part of a substantially rotating curved surface, and an outer periphery of the projecting portion And has a substantially flat portion that is substantially orthogonal to the optical axis of the optical lens,
The area of the surface surrounded by the edge of the upper light incident surface is smaller than the area of the surface surrounded by the edge of the opening of the light incident surface, and the side light incident surface has a curved surface. Features.

  In the present invention, even in a compact LED lighting device such as an MR-16 type LED lamp, the concentration of light emitted from the LED is high, the central luminous intensity of the irradiated surface is high, and color unevenness and light intensity unevenness are also observed. It is possible to provide a small illumination device in which color deviation due to an irradiation angle is reduced and a lens used in the illumination device.

It is sectional drawing which shows the relationship between the LED light source and lens of the illuminating device which concerns on embodiment of this invention. It is (1) front view of the lens which comprises the illuminating device which concerns on embodiment of this invention, (2) Side view, (3) Rear view, (4) Side sectional drawing. It is a perspective view of the lens which concerns on embodiment whose light reflection side is a facet shape. It is a disassembled perspective view of the illuminating device (MR16 type lamp) 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.

<Configuration of LED light source and lens portion of illumination device>
An illumination device of the present invention is an illumination device comprising a semiconductor light emitting element and an optical lens,
The optical lens includes a light incident surface that introduces light emitted from the semiconductor light emitting element, a light emergent surface that emits light to the outside, and light introduced from a part of the light incident surface. A total reflection surface facing

The light incident surface has a concave shape with an opening directed toward the semiconductor light emitting element, and the concave shape is located at a position opposite to the light emitting surface of the semiconductor light emitting element. A side light incident surface rising toward the edge of the incident surface, and the upper incident surface introduces light emitted upward from the light emitting surface of the semiconductor light emitting element into the optical lens, and the side light The incident surface introduces light emitted laterally from the light emitting surface of the semiconductor light emitting element into the optical lens,
The total reflection surface has a curved surface having a substantially parabolic cross section whose focal point is near the periphery of the light emitting surface of the semiconductor light emitting element, and emits light introduced into the optical lens from the side light incident surface. Reflected in the direction of the surface,

The light exit surface is provided at a position facing the upper entrance surface, is located at the center of the light exit surface, and is configured by a part of a substantially rotating curved surface that is substantially orthogonal to the optical axis of the optical lens. A convex portion, and a substantially flat portion located on the outer periphery of the convex portion and substantially orthogonal to the optical axis of the optical lens;
The area of the surface surrounded by the edge of the upper light incident surface is smaller than the area of the surface surrounded by the edge of the opening of the light incident surface, and the side light incident surface has a curved surface. It is.

FIG. 1 is a cross-sectional view showing a relationship between an LED light source (semiconductor light emitting element) 20 and a lens 30 when the illumination device according to the embodiment of the present invention is cut along a plane including the optical axis. The lighting device includes at least an LED light source 20 and a lens 30. As will be described later, the lens 30 has a rotating body shape with its optical axis as the center, and has a structure including a light incident surface 31, a light emitting surface 32, and a light total reflection side surface 33. In addition, the shape of the light incident surface 31 of the lens 30 is provided so as to be symmetrical with respect to the optical axis of the lens 30 and forms one concave portion. The incident surface 31 of the lens 30 includes an upper light incident surface 31a facing the LED light source 20 and a side incident surface 31b surrounding the periphery, and the upper incident surface 31a has a substantially flat or convex lens shape.

<LED light source 20>
(Configuration of LED light source 20)
As the LED light source 20, for example, an LED light emitting module can be used by mounting an LED chip on a module substrate. In this case, it is preferable to provide a one-core type semiconductor light emitting module (having a single continuous light emitting surface) in which LED chips are centrally arranged at the center of the module substrate and covered with a phosphor layer (wavelength conversion member). . By adopting such a one-core LED light source, the entire LED lighting device can be a single surface light source that is close to a point light source. In addition, by adopting such a one-core LED light source, multi-shadows can be effectively eliminated or alleviated, and a uniform and stable illumination effect with little light unevenness can be realized. Also in multi-core type semiconductor light-emitting modules, by using an optical lens with excellent light-condensing properties as in the present invention, an LED illumination device that is close to a point light source and suppresses multi-shadows is created by a simple production method. can do.

As the module substrate for mounting the LED chip, for example, a metal base substrate formed of a metal material such as aluminum having good thermal conductivity or an insulating material is preferably used.
As the LED light source 20, for example, one having a chip-on-board structure in which one or a plurality of near-ultraviolet or purple LED chips are directly mounted on a wiring provided on the mounting surface of the module substrate can be used. Alternatively, it may be configured by being potted by a translucent resin in which a blue phosphor, a green phosphor, and a red phosphor that are excited by a purple LED chip to emit light are mixed. Alternatively, the white semiconductor light emitting device in which the phosphor layer is directly formed on the chip may be directly mounted on the substrate by, for example, flip chip bonding. As the LED chip, not only a near-ultraviolet or purple LED chip but also various LED chips such as a blue LED chip can be used, and various phosphors can be selected depending on the LED chip to be used. In addition, it is preferable to use a material having a lattice constant or a coefficient of thermal expansion that is equal to or close to that of the semiconductor material constituting the light emitting layer, for example, a nitride semiconductor for the light emitting layer. It is preferable to use a nitride semiconductor, silicon carbide, or sapphire for the substrate. In particular, when the semiconductor material constituting the light emitting layer is a Ga-containing nitride semiconductor, the GaN substrate has almost the same lattice constant and thermal expansion coefficient. This is particularly preferable from the viewpoint of durability and durability. When an LED chip using such a substrate is applied, even if a large current is applied to the LED chip, thermal degradation due to heat generation is small, and long-life LED illumination with a large luminous flux can be realized.

As materials constituting these LED chips, known materials can be appropriately selected according to the purpose and application of the LED lighting device, and the LED chips can be manufactured by a known method.
The LED light source 20 can adopt a package structure instead of using the chip-on-board structure, and can be applied to various forms. The LED light source 20 can also be provided with a plurality of LED chips dispersed on a substrate.

(About the maximum diameter E of the light emitting surface of the LED light source)
In the present invention, the maximum diameter E of the light emitting surface of the LED light source means the maximum diameter E of the light emitting surface when the LED light source of the present invention is regarded as a single light source. That is, for example, in the case of an LED light source that is a one-core (one grain) type LED light emitting module, the maximum distance E is the maximum distance among the distances from the end of the light emitting surface of the one-core LED light source. . Further, when a plurality of LED light emitting modules are simply provided on the substrate, the maximum diameter E is the distance from the outer end to the end of the light emitting surface of the LED light emitting module that is farthest away.
E is usually 300 μm to 10 mm, preferably 500 μm or more, more preferably 1 mm or more, and further preferably 3 mm or more. E is preferably 9 mm or less, more preferably 8 mm or less, and even more preferably 7 mm or less.

<Lens 30>
(Configuration of lens 30)
In the present invention, the lens includes a light incident surface for introducing light emitted from the semiconductor light emitting element, a light emission surface for emitting light to the outside, and light emitted from a part of the light incident surface. An optical lens having a total reflection surface facing the surface,
The light incident surface has a concave shape with an opening directed toward the semiconductor light emitting element, and the concave shape is located at a position opposite to the light emitting surface of the semiconductor light emitting element. A side light incident surface rising toward the edge of the incident surface, and the upper incident surface introduces light emitted upward from the light emitting surface of the semiconductor light emitting element into the optical lens, and the side light The incident surface introduces light emitted laterally from the light emitting surface of the semiconductor light emitting element into the optical lens,

The total reflection surface has a curved surface having a substantially parabolic cross section whose focal point is near the periphery of the light emitting surface of the semiconductor light emitting element, and emits light introduced into the optical lens from the side light incident surface. Reflected in the direction of the surface,
The light exit surface is provided at a position facing the upper entrance surface, is located at the center of the light exit surface, and is a convex portion that is formed by a part of a substantially rotating curved surface that is substantially orthogonal to the optical axis. And a substantially flat portion that is located on the outer periphery of the convex portion and is substantially orthogonal to the optical axis,
The area of the surface surrounded by the edge of the upper light incident surface is smaller than the area of the surface surrounded by the edge of the opening of the light incident surface, and the side light incident surface has a curved surface. Features.

FIG. 1 is a cross-sectional view schematically showing an illumination apparatus according to an embodiment of the present invention. FIG. 1 shows a cross-sectional view when a lens 30 is cut along a plane including an optical axis. 2 to 4 are a side view, a front view, and a perspective view of a lens constituting the illumination device according to the embodiment of the present invention.
The lens 30 has a rotating body shape centered on the optical axis, and has a structure including an incident surface 31, an output surface 32, and a reflective side surface 33. The above-mentioned rotator shape means that the entire lens is a substantially symmetric rotator shape, and even if a member is added or processed and deformed so as not to affect the light collecting function, the present invention It shall be included in the shape of the rotating body.

The shape of the incident surface 31 of the lens 30 is provided so as to be symmetrical with respect to the optical axis of the lens 30 and forms one concave portion (see FIGS. 1 and 4). The incident surface 31 of the lens 30 includes an upper incident surface 31a that faces the LED light source 20 and a side incident surface 31b that surrounds the upper incident surface 31a. The upper incident surface 31a forms a convex lens.
In the embodiment of the present invention, the light emitted from the LED light source 20 is refracted by the upper incident surface 31a of the lens 30 having a convex shape, is condensed in the optical axis direction, and is emitted from the emission surface 32 of the lens 30 to the outside. Is emitted. Further, a part of the light incident from the upper incident surface 31 a or the side incident surface 31 b of the lens 30 is totally reflected by the reflection side surface 33 inside the lens 30, condensed in the optical axis direction, and collected by the lens 30. The light is emitted from the emission surface 32 to the outside.

Note that a small part of the light incident on the lens 30 may leak from a portion other than the emission surface 32 (for example, the reflective side surface 33 or the flange portion 35).
In the present invention, the shape of the side incident surface 31b of the lens 30 is preferably a shape having a curved surface in a cross section when the lens 30 is cut by a plane including the optical axis, that is, in the cross sectional view of FIG. . Further, the shape of the side incident surface 31b is more preferably a part of a spherical shape, and particularly preferably a part of a hemispherical shape. By making the side incident surface 31b into the above-mentioned shape, the radiation angle (beam angle) of the emitted light from the lens 30 can be made sufficiently small, and the light is emitted directly above the emitting surface 32 of the lens 30. The design margin of the maximum diameter (convex lens diameter) of the upper incident surface 31a to ensure a sufficient amount of light (to increase light extraction efficiency) can be widened, and the yield when mass producing lenses and the like is improved. Can do. Further, by forming the side incident surface 31b as described above, it is possible to realize a uniform and stable illumination effect with little light unevenness.

  In the present invention, the height (H) of the optical lens, which is the distance from the edge of the opening of the light incident surface of the lens to the apex of the convex portion of the light exit surface, and the substantially flat portion of the light exit surface The outermost diameter (W) preferably satisfies the following general formula (2) (see FIG. 1). By adopting such a lens, it is possible to realize a compact illumination device that complies with the standards of illumination devices such as MR-11, MR-16, and the like.

0.2 ≦ H / W ≦ 0.8 (2)
The outer diameter of the light exit surface of the lens is preferably 10 mm or more and 100 mm or less. Furthermore, the outer diameter of the convex portion of the light exit surface of the lens is preferably 3 mm or more and 50 mm or less, and more preferably 13 mm or less.
The material of the lens 30 is not particularly limited as long as the object of the present invention can be achieved, but plastic can be suitably used. Specifically, thermoplastics such as acrylic, cyclic polyolefin, and polycarbonate, photocurable plastics, UV curable plastics, and the like can be used. Among these, from the viewpoint of reducing production costs, thermoplastic plastics such as acrylic, cyclic polyolefin, and polycarbonate that can be produced by injection molding can be suitably used, and among these, polycarbonate is particularly preferred.

(About the maximum diameter L of the upper incident surface)
In the present invention, the maximum diameter L of the upper incident surface is a part of the lens 30 that faces the light emitting surface when the LED light source of the present invention is regarded as a single light source, and constitutes a convex lens. It means the maximum diameter L of the upper incident surface 31a.
L is usually 300 μm to 12 mm, preferably 500 μm or more, more preferably 1 mm or more, and further preferably 3 mm or more. L is preferably 10 mm or less, more preferably 8 mm or less, and even more preferably 7 mm or less.

(About the ratio (E / L) between the maximum diameter E of the light emitting surface of the LED light source and the maximum diameter L of the upper incident surface)
In the present invention, E / L is preferably 0.4 or more, more preferably 0.6 or more, still more preferably 0.8 or more, and more preferably 0.85 or more. More preferably, it is 0.90 or more. Further, E / L is preferably 1.2 or less, more preferably 1.15 or less, and further preferably 1.10 or less. By controlling the E / L within a specific range in this way, the emission angle (beam angle) of the light emitted from the lens 30 can be made sufficiently small, and the light is emitted directly above the emission surface 32 of the lens 30. It is possible to secure a sufficient amount of light (to increase the light extraction efficiency).

<Overall configuration of lighting device>
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. 4, 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 has an LED as a light source and a module substrate 14 on which the LED is mounted, and the LED 12 is arranged at the center of the module substrate 14. The lens is a one-core type lens (one-core type condensing optical component) 16, and the LED 12 is disposed at the focal position. By arranging in this way, the light emitted from the LED 12 can be light with high directivity (narrow light distribution angle).

  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. 2- (4), 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 16 are joined, the LED 12 is disposed so as to face the opening 16 c portion of the lens 16. By arranging the LED 12 at the focal position of the parabola, narrow-angle light can be emitted.

  The light emitting surface 16a of the lens 16 is provided at a position facing the upper incident surface, is located at the center of the light emitting surface, and is configured by a part of a substantially rotating curved surface that is substantially orthogonal to the optical axis. A convex portion and a substantially flat portion that is positioned on the outer periphery of the convex portion and is substantially orthogonal to the optical axis. In addition, when there are a plurality of LEDs mounted on the module substrate 14, they are provided at positions facing the LEDs, and the plurality of LEDs 12 groups are accommodated in the recesses 16c, so that the lens, the plurality of LEDs 12 groups, Suppresses interference. The shape, size, material, etc. of the lens can be changed as appropriate.

  The lens holder has a holder body having a substantially cylindrical shape capable of holding the lens 16 therein. The inner diameter of the holder body is equal to the outer diameter of the lens, and the lens holder can hold the 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.

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 LED12 emits. Specifically, the housing 5 includes a heat sink 8 that dissipates heat generated by the LEDs 12, and a driver housing 9 that houses a circuit board 10 for power supply that supplies driving power to the LEDs 12 in the LED module 2 from a power source. Have.

  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.

<Simulation of light emitted from lighting device>
In the illuminating device including the LED light source (semiconductor light emitting element) and the lens shown in FIGS. 1 and 2, Lambda Research Co., Ltd. is used to analyze the emission angle (beam angle) of the emitted light and the central luminous intensity on the optical axis. TracePro ver. The simulation was calculated using 7.2.7. The simulation was performed with the wavelength of light set at 550 nm.

(conditions)
The LED light source was regarded as a cylindrical object having a diameter of 5 mm, and light was uniformly emitted from the entire disk surface in a Lambertian manner. In addition, the calculation was made assuming that the total luminous flux of the emitted light is 400 lm and 1 million light beams are emitted. In addition, about the material which comprises an LED light source, and the parameter regarding the surface, it calculated as what shows a behavior equivalent to air optically without performing calculation definition.
Table 1 shows the configuration of lenses used in the lighting device to be simulated.

  The size of the lens was calculated assuming that the height was 10 mm (optical axis direction, dimension without the convex lens on the light exit surface) and the maximum diameter was 20 mm (perpendicular to the optical axis), and the material constituting the lens was regarded as polycarbonate. The refractive index n for light of 546 nm was calculated as 1.591).

  The concave shape of the lens was such that when the side incident surface was a hemispherical surface, the diameter was 6.1 mm and the side incident surface was a hemispherical surface of R3.05 mm. In this case, the LED light source was arranged so that the center of the light emitting surface of the LED light source coincided with the center of the hemisphere. In addition, the calculation was performed with the diameter of the upper incident surface being 4.6 mm. In the case where the side incident surface is a truncated cone surface, the calculation was performed assuming that the diameter on the light emitting element side is 6.1 mm, the diameter on the upper incident surface side is 5.8 mm, and the height is 2.6 mm.

The convex lens on the light exit surface is a partial sphere having a radius of 8 mm and a height of about 0.81 mm so that the optical axis is centered.
Under the above-mentioned conditions, the value of E / L is 1.09 for both the example and the comparative examples 1 and 2. The value of H / W is 0.54 in Example and Comparative Example 2, and is 0.50 in Comparative Example 1.
(Evaluation results)
As a result of the measurement, the central luminous intensity and the angle (full angle) at which the luminous intensity becomes half with respect to the central luminous intensity were evaluated as a 1/2 beam angle.

  In the example (having a convex lens on the light exit surface and the hemispherical side entrance surface), the central luminous intensity is as high as 1552 cd, whereas the 1/2 beam angle is as narrow as the example. In the case of 1 (no convex lens on the light exit surface and the side entrance surface is a hemispherical surface), the central luminous intensity is 1417 cd, which is 135 cd, which is lower than that of the example. This indicates that, in the embodiment, the convex lens installed on the light exit surface condenses the light incident via the upper light incident surface in the optical axis direction. On the other hand, in Comparative Example 1 in which no convex lens was installed on the light exit surface, the light exiting the light exit surface via the upper light entrance surface is radiated with a wide light distribution angle while being Lambertian. Became a low value.

Further, in Comparative Example 2 (the light exit surface has a convex lens and the side incident surface is a truncated cone surface), the light collection efficiency of the light collected by the total reflection surface via the side incident surface is Since the incident surface is worse than the hemispherical embodiment, the 1/2 beam angle is increased and the central luminous intensity is decreased.
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 can be applied to various general illuminating devices, such as a spotlight, a halogen bulb, and an incandescent bulb.

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, 20 LED light source (semiconductor light emitting element)
14 Substrate (module substrate)
16, 30 Lens 17 Thermal conduction sheet 31 Light incident surface 31a Upper light incident surface 31b Side light incident surface 32 Light exit surface 32a Light exit surface convex portion 32b Light exit surface flat portion 33 Light total reflection side surface 35 Collar portion 36 Fixed Part

Claims (10)

An illumination device comprising a semiconductor light emitting element and an optical lens,
The optical lens includes a light incident surface that introduces light emitted from the semiconductor light emitting element, a light emergent surface that emits light to the outside, and light introduced from a part of the light incident surface. A total reflection surface facing
The light incident surface has a concave shape with an opening directed toward the semiconductor light emitting element, and the concave shape is located at a position opposite to the light emitting surface of the semiconductor light emitting element. A side light incident surface rising toward the edge of the incident surface, and the upper incident surface introduces light emitted upward from the light emitting surface of the semiconductor light emitting element into the optical lens, and the side light The incident surface introduces light emitted laterally from the light emitting surface of the semiconductor light emitting element into the optical lens,
The total reflection surface has a curved surface having a substantially parabolic cross section whose focal point is near the periphery of the light emitting surface of the semiconductor light emitting element, and emits light introduced into the optical lens from the side light incident surface. Reflected in the direction of the surface,
The light exit surface is provided at a position facing the upper entrance surface, is located at the center of the light exit surface, and is formed of a part of a substantially rotating curved surface, and an outer periphery of the projecting portion And has a substantially flat portion that is substantially orthogonal to the optical axis of the optical lens,
The area of the surface surrounded by the edge of the upper light incident surface is smaller than the area of the surface surrounded by the edge of the opening of the light incident surface, and the side light incident surface has a curved surface. .   The lighting device according to claim 1, wherein the upper light incident surface is a substantially flat surface or a convex surface.   The lighting device according to claim 1, wherein the side light incident surface has a curved surface having a substantially parabolic cross section with a focus on the vicinity of the periphery of the light emitting surface of the semiconductor light emitting element.   The lighting device according to claim 1, wherein the semiconductor light emitting element is a single light source that emits light from only one light emitting surface. The illumination according to any one of claims 1 to 4, wherein when the maximum diameter of the light emitting surface of the light source is E and the outermost diameter of the upper light incident surface is L, the following general formula (1) is satisfied. apparatus.
0.4 ≦ E / L ≦ 1.2 (1) The height (H) of the optical lens as the distance from the edge of the opening of the light incident surface to the apex of the convex portion of the light output surface, and the outermost diameter (W) of the substantially flat portion of the light output surface ) Satisfy | fills following General formula (2), The illuminating device of any one of Claims 1-5.
0.2 ≦ H / W ≦ 0.8 (2)   The illuminating device according to any one of claims 1 to 6, wherein an outer diameter of the light emitting surface is 10 mm or more and 100 mm or less.   The illuminating device according to any one of claims 1 to 7, wherein an outer diameter of the convex portion of the light emitting surface is 3 mm or more and 50 mm or less.   The illuminating device according to claim 1, wherein the optical lens has a fixing portion for fixing to a part of the illuminating device on a side of the optical lens. A light incident surface for introducing light emitted from the semiconductor light emitting element, a light emission surface for emitting light to the outside, and a total reflection surface for directing light introduced from a part of the light incident surface toward the light emission surface An optical lens having
The light incident surface has a concave shape with an opening directed toward the semiconductor light emitting element, and the concave shape is located at a position opposite to the light emitting surface of the semiconductor light emitting element. A side light incident surface rising toward the edge of the incident surface, and the upper incident surface introduces light emitted upward from the light emitting surface of the semiconductor light emitting element into the optical lens, and the side light The incident surface introduces light emitted laterally from the light emitting surface of the semiconductor light emitting element into the optical lens,
The total reflection surface has a curved surface having a substantially parabolic cross section whose focal point is near the periphery of the light emitting surface of the semiconductor light emitting element, and emits light introduced into the optical lens from the side light incident surface. Reflected in the direction of the surface,
The light exit surface is provided at a position facing the upper entrance surface, is located at the center of the light exit surface, and is formed of a part of a substantially rotating curved surface, and an outer periphery of the projecting portion And has a substantially flat portion that is substantially orthogonal to the optical axis of the optical lens,
The area of the surface surrounded by the edge of the upper light incident surface is smaller than the area of the surface surrounded by the edge of the opening of the light incident surface, and the side light incident surface has a curved surface. .

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