JP7170225B2 - Lenses and lighting fixtures - Google Patents

Description

TECHNICAL FIELD The present invention relates to a lens and a lighting fixture having the same.

2. Description of the Related Art Lighting fixtures such as downlights and spotlights may use optical components that control the light distribution of light emitted from a light source. As such an optical component, for example, a lens arranged in front of the light source is used. For example, a lighting fixture uses a condensing lens that condenses light emitted from a light source.

Conventionally, as this type of lens, there is known a lens in which a plurality of concentric annular projections having a Fresnel lens function are formed on the light incident side (light source side) surface of the lens (for example, Patent Document 1).

JP 2012-204085 A

In a lighting fixture using a lens, when illumination light is applied to a light irradiation surface such as a wall surface or a floor surface, the light may not spread over the entire light irradiation surface. In addition, it is desirable to suppress a decrease in light extraction efficiency for lenses used in lighting fixtures.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and provides a lens and a lighting fixture that can increase the spread of light on a light irradiation surface while suppressing a decrease in light extraction efficiency. With the goal.

In order to achieve the above object, one aspect of the lens according to the present invention is a lens that controls the light distribution of incident light, the lens comprising: a first projecting portion annularly formed on the outer peripheral portion on the light incident side; A plurality of second protrusions formed in a concentric ring on the light emitting side and surrounding the plurality of second protrusions are arranged to control the light distribution of light incident from the inner surface of the recess formed by the first protrusions. and an annular third protrusion, the third protrusion having a stepped inner surface as a light exit surface.

Further, one aspect of a lighting fixture according to the present invention includes the lens described above, and a light source arranged to face the concave portion of the lens.

It is possible to increase the spread of light on the light irradiation surface while suppressing a decrease in light extraction efficiency.

1 is an external view of a lighting fixture according to an embodiment; FIG. 1 is a cross-sectional view of a lighting fixture according to an embodiment; FIG. It is a perspective view when the lens according to the embodiment is viewed from the light exit side. It is a perspective view when the lens which concerns on embodiment is seen from the light-incidence side. 1 is a cross-sectional view of a lens according to an embodiment; FIG. It is a top view when the lens which concerns on embodiment is seen from the light-incidence side. 2 is an enlarged cross-sectional perspective view of the lens according to the embodiment when viewed from the light incident side; FIG. It is a figure for demonstrating the optical action of the lens of a comparative example. FIG. 10 is a diagram showing the illuminance distribution of illumination light in the X-axis direction in a lighting fixture using a lens of a comparative example; FIG. 10 is an enlarged view around 1/10 illuminance in the illuminance distribution of illumination light in the X-axis direction in a lighting fixture using a lens of a comparative example. FIG. 10 is an enlarged view around 1/20 illuminance in the illuminance distribution of the illumination light in the X-axis direction in the lighting fixture using the lens of the comparative example. It is a figure for demonstrating the optical action of the lens which concerns on embodiment. It is a figure which shows the illumination intensity distribution of the X-axis direction of the illumination light in the lighting fixture using the lens which concerns on embodiment. FIG. 10 is an enlarged view around 1/10 illuminance in the illuminance distribution of the illumination light in the X-axis direction in the lighting fixture using the lens according to the embodiment. FIG. 10 is an enlarged view around 1/20 illuminance in the illuminance distribution of the illumination light in the X-axis direction in the lighting fixture using the lens according to the embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that each of the embodiments described below is a specific example of the present invention. Therefore, the numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, steps and order of steps, etc. shown in the following embodiments are examples and are not intended to limit the present invention. do not have. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in independent claims representing the highest level concept of the present invention will be described as optional constituent elements.

Each figure is a schematic diagram and is not necessarily strictly illustrated. Therefore, for example, the scales and the like do not necessarily match in each drawing. Moreover, in each figure, the same code|symbol is attached|subjected to the substantially same structure, and the overlapping description is abbreviate|omitted or simplified.

(Embodiment)
A configuration of a lighting fixture 1 according to an embodiment will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is an external view of a lighting fixture 1 according to an embodiment. FIG. 2 is a cross-sectional view of the lighting fixture 1. As shown in FIG.

A lighting fixture 1 according to the present embodiment is a downlight that emits illumination light downward (floor, ground, wall, etc.), and is installed on the ceiling of a building or the like. For example, the lighting fixture 1 is embedded in an opening of the ceiling.

As shown in FIGS. 1 and 2, the lighting fixture 1 includes a lens 100 and a light source 200. As shown in FIG. In this embodiment, lighting fixture 1 further includes fixture body 300 , tubular member 400 , frame 500 , and mounting member 600 .

The lighting fixture 1 in this embodiment is a universal downlight, and can change the irradiation direction of the illumination light. Specifically, the fixture main body 300 (lamp body section) in which the light source 200 is arranged is rotatably supported by the frame body 500 so that the posture with respect to the ceiling surface can be changed. By changing the posture of the fixture main body 300 with respect to the ceiling surface, the direction of light emitted from the lighting fixture 1 can be changed.

Each component of the lighting fixture 1 will be described in detail below. In addition, in the present embodiment, the light emitting side of the light source 200 is defined as the front side.

[lens]
The lens 100 is a translucent optical member that controls the light distribution of incident light. In this embodiment, the lens 100 is a condensing lens that condenses incident light.

As shown in FIG. 2, lens 100 is placed in front of light source 200 . Specifically, the lens 100 is arranged on the light emitting side of the light source 200 with a predetermined distance from the light source 200 . Therefore, the lens 100 controls the light distribution of light emitted from the light source 200 and incident on the lens 100 . It is preferable that the optical axis of the lens 100 substantially coincides with the optical axis of the light source 200 .

The lens 100 is formed in a predetermined shape so as to have a predetermined lens action. Lens 100 is formed using a translucent material. Specifically, the lens 100 is molded into a predetermined shape using a mold or the like using a transparent resin material such as acrylic or polycarbonate or a transparent material such as a glass material.

A specific shape of the lens 100 will now be described with reference to FIGS. 3 to 7. FIG. 3 is a perspective view of the lens 100 according to the embodiment when viewed from the light emitting side, FIG. 4 is a perspective view of the lens 100 when viewed from the light incident side, and FIG. 6 is a plan view of the lens 100 viewed from the light incident side, and FIG. 7 is an enlarged sectional perspective view of the lens 100 viewed from the light incident side. is. 3 to 7 show the designed shape of the lens 100. FIG.

As shown in FIGS. 3 to 5, the lens 100 includes a first projecting portion 110 (first light transmitting portion) formed on the light incident side (light source 200 side) and a light emitting side (opposite to the light source 200 side). side) and a second projecting portion 120 (second light-transmitting portion) and a third projecting portion 130 (third light-transmitting portion).

The first protrusion 110 is formed in an annular shape on the outer periphery of the lens 100 on the light incident side. Specifically, the first protrusion 110 protrudes toward the light source 200 so as to surround the light source 200 . In the present embodiment, as shown in FIG. 5, the first projecting portion 110 has a substantially triangular shape in a cross-sectional view and tapers toward the light source 200 side.

Also, by forming the first protrusion 110 on the lens 100 , a recess 140 is formed on the lens 100 . Recess 140 is formed to be recessed in a direction away from light source 200 . Specifically, the concave portion 140 has a shape that is hollowed out in a substantially cylindrical shape or a substantially truncated cone shape.

A recess 140 configured by the first protrusion 110 is formed at a position facing the light source 200 . Specifically, recess 140 is provided to cover the light emitting portion of light source 200 . Therefore, light emitted from the light source 200 enters the concave portion 140 . Specifically, light emitted from light source 200 enters inner surface 141 of recess 140 . That is, the inner surface 141 of the concave portion 140 is a light incident surface on which the light emitted from the light source 200 is incident. The inner surface 141 of the recess 140 has a side surface 141a (wall surface) as a first light incident surface and a bottom surface 141b as a second light incident surface.

The inner surface 111 of the first projecting portion 110 serves as a light incident surface that forms part of the inner surface 141 of the recess 140 . In the present embodiment, inner surface 111 of first protrusion 110 is side surface 141 a of recess 140 . On the other hand, the outer surface 112 of the first protrusion 110 is a light reflecting surface that totally reflects the light incident on the first protrusion 110 from the side surface 141a of the recess 140 (the inner surface 111 of the first protrusion 110). The tip of the first protrusion 110 forms a connecting portion (boundary portion) between the inner surface 111 of the first protrusion 110, which is the light incident surface, and the outer surface 112 of the first protrusion 110, which is the light reflecting surface. .

As shown in FIGS. 6 and 7, the tip of the first projecting portion 110 is provided with an uneven structure 150 that forms unevenness when the lens 100 is viewed from above from the light incident side. That is, the concave-convex structure 150 is formed in a plane parallel to the opening surface of the concave portion 140 at the connection portion between the inner surface 111 (light incident surface) of the first protrusion 110 and the outer surface 112 (light reflecting surface) of the first protrusion 110. It is provided so as to form unevenness.

Specifically, the concave-convex structure 150 is a structure in which a plurality of minute concave portions and minute convex portions are alternately repeated to form a ring. Concavo-convex structure 150 is formed over the entire circumference of the tip of first projecting portion 110 .

As shown in FIGS. 4, 5 and 7, in the present embodiment, the uneven structure 150 extends not only from the tip of the first protrusion 110 but also from the tip of the first protrusion 110 to the first protrusion 110. It is formed in the range up to the root.

Specifically, the uneven structure 150 is provided on the entire inner surface of the first protrusion 110 (that is, the entire side surface 141 a of the recess 140 ) so as to extend in the depth direction of the recess 140 . More specifically, the concave-convex structure 150 is a linear gutter-shaped minute concave portion extending from the opening surface of the concave portion 140 (tip of the first projecting portion 110) to the bottom surface 141b of the concave portion 140. It is a shape formed in a plurality continuously along the circumferential direction of the side surface 141 a of the recess 140 . In other words, the concave-convex structure 150 has a shape in which a plurality of fine linear protrusions are continuously formed along the circumferential direction of the concave portion 140 .

As shown in FIG. 6, regarding the uneven structure 150, when the lens 100 is viewed from the light incident side, the distance from the outer surface 112 (light reflecting surface) of the first protrusion 110 to the bottom of the minute recess is a, Assuming that the distance from the outer surface 112 (light reflecting surface) of the first protrusion 110 to the apex of the minute protrusion is b, the relationship ba>a is satisfied. In addition, it is preferable that the distance b is, for example, 0.01 mm or less. Also, a may be 0 mm.

A plurality of dimples 160 are provided on the bottom surface 141b of the recess 140. As shown in FIG. In the present embodiment, the dimples 160 are formed so as to cover the entire surface of the bottom surface 141 b of the recess 140 .

As shown in FIGS. 3 and 5 , the second protrusions 120 protrude in the opposite direction to the first protrusions 110 and are formed in a concentric annular shape on the light exit side of the lens 100 . The plurality of second protrusions 120 are formed at positions facing the recesses 140 . The plurality of second protrusions 120 controls the light distribution of light incident from the inner surface 141 of the recess 140 formed by the first protrusions 110 . Specifically, the plurality of second protrusions 120 controls the light distribution of light incident on the side surface 141 a and the bottom surface 141 b of the recess 140 .

In the present embodiment, the plurality of second protrusions 120 constitute ring zones of the Fresnel lens. Thereby, the lens 100 can be thinned. Specifically, the plurality of second protrusions 120 are configured by a central protrusion 121 and a plurality of annular protrusions 122 concentrically surrounding the central protrusion 121 .

The center protrusion 121 is a lens forming the center of the Fresnel lens, and is a convex lens formed to protrude in a direction away from the light source 200 . The central axis of the central protruding portion 121 is the optical axis J (central axis) of the lens 100 and preferably substantially coincides with the optical axis of the light source 200 .

In the present embodiment, the central projecting portion 121 has a flat surface 121a and a curved surface 121b as light exit surfaces. The flat surface 121 a is formed in the central portion of the central protruding portion 121 . In the present embodiment, flat surface 121a is circular in top view. The curved surface 121b is formed on the periphery of the central projecting portion 121 so as to surround the flat surface 121a. The surface shape of the curved surface 121b constitutes, for example, a part of a spherical surface. That is, the cross-sectional shape of the curved surface 121b is an arc. Note that the surface shape of the curved surface 121b is not limited to this.

The plurality of annular protrusions 122 are portions of the Fresnel lens that form a sawtooth cross section. Each annular projecting portion 122 has a substantially triangular shape in a cross-sectional view, and tapers away from the light source 200 . It is preferable that the center axis of each annular projecting portion 122 substantially coincides with the optical axis of the light source 200 .

Each of the plurality of annular protrusions 122 preferably has an aspect ratio of 1.0 or less, preferably 0.82 or less. In particular, the outermost annular protrusion 122 among the plurality of annular protrusions 122 (that is, the outermost second protrusion 120 among the plurality of second protrusions 120) has an aspect ratio of 0.5. It is good in it being 82 or less. In other words, it is preferable that the outermost annular projection 122 satisfies H/W≦0.82, where W is the width of the bottom portion and H is the height.

In this embodiment, two annular protrusions 122 are formed. In this case, assuming that the width of the bottom portion of the outer annular protrusion 122 is W1 and the height thereof is H1, W1=6.188 mm and H1=4.948 mm. Therefore, the aspect ratio (H1/W1) of the outer annular protrusion 122 is 0.7996. Assuming that the width of the bottom portion of the inner annular protrusion 122 is W2 and the height thereof is H2, W2=6.236 mm and H2=4.643 mm. Therefore, the aspect ratio (H2/W2) of the inner annular protrusion 122 is 0.7445.

As shown in FIG. 5 , the third protrusion 130 protrudes on the side opposite to the first protrusion 110 , similarly to the second protrusion 120 . The third projecting portion 130 is formed in an annular shape so as to surround the second projecting portion 120 . The third projecting portion 130 is tapered as it goes away from the light source 200 .

The third projecting portion 130 has a stepped inner surface 131 as a light exit surface. That is, the inner surface 131 of the third protruding portion 130 is configured by a plurality of steps. Specifically, the inner surface 131 of the third protrusion 130 has a step surface 131a and a side surface 131b at each step. A stepped surface 131 a at each step forming the inner surface 131 of the third projecting portion 130 has an annular shape in a plan view, and the inner diameter decreases toward the light source 200 . Thus, the inner surface 131 of the third projecting portion 130 is formed with a concentric ring-shaped stepped portion.

In the present embodiment, the intersection of the side surface 141a and the bottom surface 141b of the recessed portion 140 is defined as the first point P1, and the outermost portion of the plurality of steps forming the stepped inner surface 131 of the third projecting portion 130 is the first point P1. Assuming that the intersection of the step surface 131a and the side surface 131b of the step is a second point P2, the straight line connecting the first point P1 and the second point P2 is the stepped inner surface 131 of the third projecting portion 130. do not intersect with the stepped surfaces 131a of the plurality of steps forming the .

As shown in FIG. 5 , the outer surface 132 of the third protrusion 130 is continuous with the outer surface 112 of the first protrusion 110 . In other words, like the outer surface 112 of the first protrusion 110, the outer surface 132 of the third protrusion 130 is a light reflecting surface that totally reflects the light incident on the third protrusion 130 from the inner surface 141 (light incident surface) of the recess 140. It is the surface.

The lens 100 configured in this manner is fixed to the instrument body 300 as shown in FIG. In this embodiment, the lens 100 is fixed to the instrument body 300 via a frame-shaped mounting member 600 fixed to the instrument body 300 . Specifically, the mounting member 600 is fixed so as to be fitted into the inner surface of the shade portion 320 of the instrument body 300, and the lens 100 is a claw portion provided at the front open end of the mounting member 600. 610 is locked. As shown in FIGS. 3 to 5, a recessed portion 170 having a stepped shape to which the claw portion 610 of the mounting member 600 engages is formed in the periphery of the lens 100 on the light exit side. As shown in FIG. 2, the lens 100 can be fixed to the mounting member 600 by snap-in engaging the claw portion 610 of the mounting member 600 with the recess portion 170 of the lens 100 . Although the mounting member 600 is made of resin, for example, it may be made of metal.

[light source]
As shown in FIG. 2, the light source 200 is arranged on the instrument body 300 . Specifically, it is fixed to the fixing portion 310 of the instrument main body 300 . For example, the light source 200 is placed on the mounting surface of the fixed portion 310 and attached to the fixed portion 310 by an attachment member such as a holder.

The light source 200 is an LED light source (LED module) having LEDs. The light source 200 is, for example, a white LED light source that emits white light. As an example, the light source 200 has a COB (Chip On Board) structure, and includes a substrate, an LED mounted on the substrate, and a sealing member that seals the LED.

The substrate is a mounting substrate for mounting the LED, and is, for example, a ceramics substrate, a resin substrate, or a metal base substrate. The substrate is provided with a pair of electrode terminals for externally receiving DC power for causing the LED to emit light, and metal wiring for supplying DC power to the LED. The electrode terminals are electrically connected to the power supply circuit by wires. The power supply circuit is built in, for example, a power supply box arranged outside the instrument main body 300 .

An LED is an example of a light-emitting element, and is a bare chip that emits monochromatic visible light, for example. Specifically, the LED is a blue LED chip that emits blue light when energized. A plurality of LEDs are arranged, for example, in a matrix on a substrate, and are electrically connected to each other by metal wirings formed on the substrate. At least one LED should be arranged.

The sealing member is, for example, translucent resin. The sealing member in this embodiment contains a phosphor as a wavelength conversion material that converts the wavelength of light emitted from the LED. The sealing member is, for example, phosphor-containing resin in which phosphor is dispersed in silicone resin. As the phosphor particles, when the LED is a blue LED chip, for example, a YAG-based yellow phosphor can be used in order to obtain white light. In this embodiment, the sealing member is formed in a circular shape so as to collectively seal all the LEDs. may be individually sealed one by one.

Thus, the light source 200 in this embodiment is a white LED light source composed of a blue LED chip and a yellow phosphor. The yellow phosphor is excited by absorbing part of the blue light emitted by the blue LED chip and emits yellow light. Then, this yellow light and the blue light not absorbed by the yellow phosphor are mixed to form white light, which is emitted from the sealing member (light emitting portion).

[Equipment body]
As shown in FIG. 2, the instrument body 300 is a base on which the light source 200 is attached. The fixture body 300 also functions as a heat sink that dissipates heat generated by the light source 200 . Therefore, the device main body 300 is preferably made of a metal material such as aluminum or a material with high thermal conductivity such as high thermal conductive resin. As an example, the instrument main body 300 is an integral body as a whole, and is made of die-cast aluminum, for example.

In this embodiment, fixture body 300 includes fixing portion 310 , shade portion 320 , and heat dissipation portion 330 .

The fixing part 310 is a platform-like part to which the light source 200 is fixed. The fixed part 310 has a mounting surface on which the light source 200 is mounted. This placement surface is the surface on the front side of the fixed portion 310 . Moreover, a reflector formed to surround the light source 200 may be attached to the fixing portion 310 . Thereby, the light emitted sideways from the light source 200 can be reflected by the reflector and made incident on the lens 100 .

The shade portion 320 is a tubular portion provided on the front side of the fixed portion 310 . The shade portion 320 is provided on the peripheral edge of the fixed portion 310 . The emitted light of the lighting device 1 is emitted from the opening end portion on the front side of the shade portion 320 .

The heat dissipation part 330 is a part that dissipates heat generated by the light source 200 . Specifically, the heat radiating portion 330 is a heat radiating fin, and is a plurality of plate-like bodies provided on the rear side of the fixing portion 310 . A plurality of radiating fins are erected on the rear surface of the fixed portion 310 so as to be parallel to each other. By providing the heat dissipation portion 330 in the fixed portion 310 in this manner, the heat generated by the light source 200 can be efficiently dissipated.

The fixture main body 300 configured in this way is supported by the frame body 500 so as to be rotatable (swingable) in order to change the irradiation direction of the light of the lighting fixture 1 . Specifically, the fixture main body 300 is configured to change its relative angle with respect to the frame 500 fixed to the opening of the ceiling. In the present embodiment, instrument main body 300 is rotatable about a direction parallel to the opening surface of frame portion 510 of frame 500 (horizontal direction in the present embodiment) as a rotation axis.

Specifically, the screw 700 screwed into the protrusion 340 provided on the side surface of the instrument main body 300 moves along the slit of the support portion 520 of the frame 500, thereby rotating the instrument main body 300. As shown in FIG.

[Cylindrical member]
As shown in FIGS. 1 and 2 , the tubular member 400 is a tubular member arranged on the front inner surface of the shade portion 320 of the instrument body 300 . The tubular member 400 is arranged on the front side of the lens 100 . The cylindrical member 400 can be formed using a resin material such as polycarbonate or PBT, for example.

The tubular member 400 functions as a baffle that suppresses glare. The inner surface of the tubular member 400 is, for example, a black surface that serves as a glare suppressing surface. A black glare-suppressing surface can be realized, for example, by matting a black painted surface. The black glare suppressing surface can also be realized by applying texturing to a black painted surface or a surface made of a black member.

Furthermore, in the present embodiment, a stepped portion is provided on the inner surface of tubular member 400 in order to further suppress glare on the inner surface of tubular member 400 .

[Frame body]
As shown in FIGS. 1 and 2, the frame 500 supports the instrument body 300 so that the instrument body 300 can rotate.

In this embodiment, the frame 500 has a plate-like frame portion 510 surrounding the shade portion 320 of the instrument body 300 and a support portion 520 that rotatably supports the instrument body 300 . The support portion 520 is a support arm formed to stand from a portion of the frame portion 510 . The support portion 520 is formed with a slit formed along the rotation direction of the instrument main body 300 . By screwing the screw 700 into the protrusion 340 of the instrument body 300 through the slit of the support part 520, the instrument body 300 is fixed to the support part 520 in a state in which the instrument body 300 can rotate with respect to the support part 520. can be done. The frame 500 is made of, for example, a metal plate.

When installing the luminaire 1 in the ceiling opening, the frame 500 is attached to a cylindrical metal fixing member (not shown), and the fixing member to which the frame 500 is attached is fixed to the ceiling opening. Thus, the lighting fixture 1 can be fixed to the opening of the ceiling. In this case, the fixing member can be fixed to the opening of the ceiling by a plurality of mounting springs provided on the outer peripheral surface of the fixing member.

Note that this fixing member may also be a part of the lighting fixture 1 . Alternatively, the lighting fixture 1 may be fixed to the opening of the ceiling by directly fixing the frame 500 to the opening of the ceiling without using a fixing member.

[Optical action of lens]
Next, the optical action of lens 100 according to the present embodiment will be described in comparison with lens 100A of a comparative example. Note that the lens 100A of the comparative example is also included in the present invention.

First, the optical action of the lens 100A of the comparative example will be described with reference to FIG. FIG. 8 is a diagram for explaining the optical action of the lens 100A of the comparative example. In FIG. 8 , the thick solid line indicates the trajectory of light emitted from the light source 200 .

A lens 100A of the comparative example shown in FIG. 8 has a first projecting portion 110, a second projecting portion 120A, and a third projecting portion 130A, similarly to the lens 100 according to the present embodiment. In this case, the central protruding portion 121A of the second protruding portion 120A does not have a flat surface, and the entire central protruding portion 121A has a spherically curved surface. Aspect ratio is high. Specifically, in the lens 100A of the comparative example, the width W1 and the height H1 of the bottom of the outer annular protrusion 122A are W1=5.255 mm, H1=6.002 mm, and the inner annular protrusion The width W2 and the height H2 of the bottom of the portion 122A are W2=6.243 mm and H2=5.860 mm. Therefore, the aspect ratio (H1/W1) of the outer annular protrusion 122A is 1.149. Also, the aspect ratio (H2/W2) of the inner annular protrusion 122A is 0.939.

In addition, in the third projecting portion 130A of the lens 100A of the comparative example, the intersection of the side surface 141a and the bottom surface 141b of the recessed portion 140 is defined as the first point P1, and a plurality of points forming the stepped inner surface 131 of the third projecting portion 130A. Assuming that the intersection of the step surface 131a and the side surface 131b in the outermost step of the steps is the second point P2, the straight line connecting the first point P1 and the second point P2 is the third projecting portion. It intersects with the step surface 131a of each of the plurality of steps forming the stepped inner surface 131 of 130A .

In the lens 100A of the comparative example thus configured, light emitted from the light source 200 enters the inner surface 141 of the concave portion 140, as shown in FIG. Specifically, the light emitted from the light source 200 enters the side surface 141 a and the bottom surface 141 b of the recess 140 .

At this time, the light incident on the side surface 141a (that is, the inner surface 111 of the first protrusion 110) of the inner surface 141 of the recess 140 is emitted to the outside of the lens 100 through the first protrusion 110 and the third protrusion 130A. do.

Specifically, the light incident on the first protrusion 110 travels straight through the first protrusion 110 and is totally reflected by the outer surface 112 of the first protrusion 110 or the outer surface 132 of the third protrusion 130A. The light goes straight through the first protrusion 110 and/or the third protrusion 130A and is emitted to the outside of the lens 100 from the stepped inner surface 131 of the third protrusion 130A.

On the other hand, the light incident on the bottom surface 141b of the inner surface 141 of the recess 140 passes through the second projection 120A and exits the lens 100A. Specifically, the light incident on the bottom surface 141b of the concave portion 140 is emitted to the outside of the lens 100A through the central protrusion 121A or the plurality of annular protrusions 122A of the second protrusion 120A.

In this case, the light passing through the central protrusion 121A of the second protrusion 120A is refracted by the outer surface of the central protrusion 121A, condensed, and emitted to the outside of the lens 100A. Also, the light passing through the annular protrusion 122A of the second protrusion 120A is also condensed by being refracted by the outer surface of the annular protrusion 122A, similarly to the central protrusion 121A. At this time, as shown in FIG. 8, the light passing through the annular projecting portion 122A includes the light having a negative refraction angle with respect to the optical axis J of the lens 100A and exiting the lens 100A. be

When the lens 100A of the comparative example configured in this manner is used in a lighting fixture, the illuminance distribution of the illumination light emitted from the lighting fixture on the light irradiation surface is as shown in FIGS. 9, 10A, and 10B. FIG. 9 is a diagram showing the illuminance distribution of illumination light in the X-axis direction in a lighting fixture using the lens 100A of the comparative example. 10A is an enlarged view around 1/10 illuminance in the illuminance distribution shown in FIG. 9, and FIG. 10B is an enlarged view around 1/20 illuminance in the illuminance distribution shown in FIG. 9, 10A, and 10B show incoherent illuminance.

In the lighting fixture using the lens 100A of the comparative example, an annular third protrusion 130A surrounding the plurality of second protrusions 120A has a stepped inner surface 131 as a light exit surface. Therefore, as shown in FIG. 9, in the lighting fixture using the lens 100A of the comparative example, it is possible to increase the spread of light on the light irradiation surface while suppressing a decrease in the light extraction efficiency. In addition, in FIG. 9, the maximum illuminance is 5324.4 [lx]. In this case, as shown in FIGS. 10A and 10B, the position of 1/10 illuminance corresponding to 532.44 [lx], which is 1/10 of the maximum illuminance, is 308.6 [mm]. The position of 1/20 illuminance corresponding to 266.22 [lx] which is 1/20 is 347.8 [mm]. Therefore, in the lighting fixture using the lens 100A of the comparative example, the light distribution angle (1/10 illuminance angle) corresponding to the position of 1/10 illuminance to the light distribution angle (1/20 illuminance angle) corresponding to the position of 1/20 illuminance (1/20 The distance at which the illuminance attenuates up to the illuminance angle) is 347.8 [mm]-308.6 [mm]=39.2 [mm].

Lenses used in lighting fixtures are sometimes desired to further increase the spread of light on the light irradiation surface. In this case, it is desired to increase the spread of light on the light irradiation surface without lowering the light extraction efficiency.

Therefore, the inventor of the present application has studied how to increase the spread of light on the light irradiation surface without lowering the light extraction efficiency by further devising the shape of the lens. As a result, the inventor of the present application found the lens 100 shown in FIGS.

Features of the lens 100 according to the present embodiment will be described below with reference to FIG. 11 . FIG. 11 is a diagram for explaining the optical action of lens 100 according to the embodiment. In addition, in FIG. 11 , the thick solid line indicates the trajectory of light emitted from the light source 200 .

As shown in FIG. 11 , light emitted from the light source 200 also enters the inner surface 141 of the concave portion 140 in the lens 100 (Example) according to the present embodiment. Specifically, the light emitted from the light source 200 enters the side surface 141 a and the bottom surface 141 b of the recess 140 .

At this time, the light incident on the side surface 141a of the inner surface 141 of the recess 140 (that is, the inner surface 111 of the first protrusion 110) is emitted to the outside of the lens 100 through the first protrusion 110 and the third protrusion 130. do.

Specifically, the light that has entered the first protrusion 110 travels straight through the first protrusion 110 and is totally reflected by the outer surface 112 of the first protrusion 110 or the outer surface 132 of the third protrusion 130 . The light goes straight through the first protrusion 110 and/or the third protrusion 130 and exits the lens 100 from the stepped inner surface 131 of the annular third protrusion 130 surrounding the plurality of second protrusions 120 . With this configuration, it is possible to increase the spread of light on the light irradiation surface while suppressing a decrease in light extraction efficiency.

In addition, in the lens of the present embodiment, the first point P1, which is the intersection of the side surface 141a and the bottom surface 141b of the concave portion 140, The straight line connecting the second point P2, which is the intersection point between the stepped surface 131a of the outermost step and the side surface 131b, does not cross the stepped surface 131a of each of the plurality of steps of the third projecting portion . As a result, the proportion of light that enters from the side surface 141a of the concave portion 140 and exits from the step surface 131a can be reduced, and the proportion of light that travels outside the lens 100 can be increased. As a result, the spread of light on the light irradiation surface can be further increased.

On the other hand, light incident on the bottom surface 141 b of the inner surface 141 of the recess 140 passes through the second protrusion 120 and exits the lens 100 . Specifically, the light incident on the bottom surface 141 b of the concave portion 140 passes through the central protrusion 121 or the plurality of annular protrusions 122 of the second protrusion 120 and exits the lens 100 .

In this case, the outermost annular protrusion 122 among the plurality of annular protrusions 122 has an aspect ratio (H1/W1) of 1.0 or less. As a result, the spread of light on the light irradiation surface can be further increased without lowering the light extraction efficiency. This point will be described in comparison with the lens 100A of the comparative example shown in FIG.

As in the lens 100A of the comparative example, when the aspect ratio (H1/W1) of the outermost annular protrusion 122A among the plurality of annular protrusions 122A is greater than 1.0, the surface of the annular protrusion 122A ( The angle of refraction of the light emitted from the annular protrusion 122A with respect to the optical axis J becomes small, and the light is totally reflected without being refracted at the interface between the annular protrusion 122A and the air layer. In this case, the refraction angle of the light emitted from the annular projecting portion 122A is a negative value with respect to the optical axis J.

Moreover, when the aspect ratio (H1/W1) of the outermost annular protrusion 122A is greater than 1.0, as in the lens 100A of the comparative example, the outermost annular protrusion 122A is positioned inside the outermost annular protrusion 122A. The light emitted from the annular projecting portion 122A located on the outermost side enters the annular projecting portion 122A located at the outermost position, and the light extraction efficiency is lowered.

On the other hand, in the lens 100 according to the present embodiment, the aspect ratio (H1/W1) of the outermost annular protrusion 122 among the plurality of annular protrusions 122 is 1.0 or less. With this configuration, the inclination of the surface (light control surface) of the annular protrusion 122 can be moderated, so that the angle of refraction of the light emitted from the annular protrusion 122 with respect to the optical axis J can be increased. As a result, it is possible to prevent the light passing through the annular projection 122 from being totally reflected at the interface between the annular projection 122 and the air layer, so that the refraction angle of the light emitted from the annular projection 122 is positive with respect to the optical axis J. can be the value of As a result, as shown in FIG. 11, it is possible to increase the ratio of the light that is emitted from the annular projection 122 and travels outward. can be increased.

Moreover, by setting the aspect ratio (H1/W1) of the outermost annular projection 122 to 1.0 or less, the light is emitted from the annular projection 122 located inside the outermost annular projection 122. Light can be prevented from entering the outermost annular protrusion 122 . Thereby, it can also suppress that light extraction efficiency falls.

Further, the aspect ratio (H1/W1) of the outermost annular projecting portion 122 is preferably 0.82 or less. As a result, it is possible to further increase the spread of light on the light irradiation surface and to further suppress a decrease in light extraction efficiency. In addition, in the present embodiment, the aspect ratio of all annular projections 122 is 0.82 or less. As a result, the refraction angles of the light emitted from all the annular protrusions 122 can be made positive with respect to the optical axis J. FIG. Therefore, the spread of light on the light irradiation surface can be further increased.

Further, in the lens 100 according to the present embodiment, the central projecting portion 121 is formed with a flat surface 121a. As a result, the central protrusion 121 in the lens 100 of the present embodiment has a weaker focusing action than the central protrusion 121A of the lens 100A of the comparative example, so that the light passing through the central protrusion 121 is loosely condensed. be able to. As a result, even if the proportion of light traveling outward is increased by the annular projection 122, the difference in illuminance at the boundary between the light that has passed through the central projection 121 and the light that has passed through the annular projection 122 can be eliminated. Therefore, the illuminance distribution on the light irradiation surface can be smoothed.

12, 13A and 13B show the illuminance distribution of the illumination light from the lighting fixture 1 using this lens 100 on the light irradiation surface. FIG. 12 is a diagram showing the illuminance distribution of the illumination light in the X-axis direction in the lighting fixture 1 using the lens 100 according to the embodiment. 13A is an enlarged view around 1/10 illuminance in the illuminance distribution shown in FIG. 12, and FIG. 13B is an enlarged view around 1/20 illuminance in the illuminance distribution shown in FIG. 12, 13A, and 13B show incoherent illuminance.

As shown in FIGS. 12, 13A, and 13B, the lens 100 according to the present embodiment has a light irradiation surface that is larger than the lens 100A of the comparative example having the illuminance distribution shown in FIGS. 9, 10A, and 10B. can further increase the spread of light.

Specifically, in FIG. 12, the maximum illuminance is 3391.6 [lx]. In this case, as shown in FIGS. 13A and 13B, the position of 1/10 illuminance corresponding to 339.16 [lx], which is 1/10 of the maximum illuminance, is 377.2 [mm]. The position of 1/20 illuminance corresponding to 169.58 [lx] which is 1/20 is 426.7 [mm]. Therefore, in the lighting fixture 1 using the lens 100 in the present embodiment, the light distribution angle (1/10 illumination angle) corresponding to the position of 1/10 illumination to the light distribution angle corresponding to the position of 1/20 illumination ( The distance at which the illuminance attenuates up to 1/20 illuminance angle is 426.7 [mm]-377.2 [mm]=49.5 [mm].

On the other hand, as described above, in the lighting fixture using the lens 100A of the comparative example, the distance at which the illuminance attenuates from 1/10 illuminance angle to 1/20 illuminance angle was 39.2 [mm].

Therefore, when the lens 100 of the present embodiment is used, the illuminance of the illumination light attenuates at a gentler slope than the lens 100A of the comparative example, and the light can be spread over the entire light irradiation surface. ing.

As described above, according to the lens 100 of the present embodiment, it is possible to increase the spread of light on the light irradiation surface while suppressing a decrease in light extraction efficiency.

Further, in the lens 100 according to the present embodiment, the concave-convex structure 150 is provided at the tip of the first projecting portion 110 .

As a result, even if the tip of the first projection 110 is rounded when the lens 100 is manufactured, the concavo-convex structure 150 weakens the condensing effect of the light incident on the tip of the first projection 110. be able to. As a result, even in a structure in which the annular first protrusion 110 is formed on the light incident side, it is possible to suppress the occurrence of bright lines due to the first protrusion 110 .

Moreover, in the lens 100 according to the present embodiment, the plurality of concentric ring-shaped second protrusions 120 are not on the side (light incident side) where the first protrusions 110 are formed, but the first protrusions 110 are formed. side (light emitting side). Thereby, the occurrence of glare can be suppressed as compared with the case where the plurality of annular second protrusions 120 are formed on the light incident side.

Further, in the lens 100 according to the present embodiment, the inner surface 111 of the first protrusion 110 is a light incident surface that constitutes a part of the inner surface 141 of the recess 140, and the outer surface 112 of the first protrusion 110 is It is a light reflecting surface that totally reflects the light incident on the first projecting portion 110 . The tip portion of the first projecting portion 110 constitutes a connecting portion between the light incident surface and the light reflecting surface, and the concave-convex structure 150 is provided at this connecting portion.

The first protruding portion 110 having the outer surface 112 serving as a total reflection surface is important in controlling the light distribution of the light incident on the lens 100 . is intentionally injected. For this reason, bright lines tend to stand out unless the uneven structure 150 is formed at the tip of the first projecting portion 110 having a total reflection surface. Since 150 is formed, it is possible to effectively suppress the generation of bright lines.

Further, in the lens 100 according to the present embodiment, the distance from the outer surface 112 (light reflecting surface) of the first protrusion 110 to the bottom of the minute concave portion is a, and the distance from the outer surface 112 (light reflecting surface) of the first protrusion 110 is a Assuming that the distance to the apex of the minute projection is b, the relationship ba>a is satisfied. That is, it satisfies the relationship of b>2a.

Accordingly, it is possible to more effectively suppress the occurrence of bright lines in the first projecting portion 110 .

Further, in the lens 100 according to the present embodiment, a plurality of dimples 160 are provided on the bottom surface 141b of the concave portion 140. As shown in FIG.

As a result, the dimples 160 can diffuse the light incident on the bottom surface 141b of the concave portion 140, thereby suppressing uneven illuminance and color unevenness of the light emitted from the lens 100. FIG.

(Modification)
Although the lens and lighting equipment according to the present invention have been described above based on the embodiments, the present invention is not limited to the above embodiments.

For example, in the above embodiment, the light source 200 is configured to emit white light using a blue LED chip and a yellow phosphor, but the configuration is not limited to this. For example, a phosphor-containing resin containing a red phosphor and a green phosphor may be used, and white light may be emitted by combining this phosphor-containing resin with a blue LED chip.

Also, in the above embodiments, blue LED chips are used as LEDs, but the present invention is not limited to this. For example, an LED chip that emits light in a color other than blue may be used as the LED. In this case, when using an ultraviolet LED chip that emits ultraviolet light having a shorter wavelength than a blue LED chip, a combination of phosphors that emit three primary colors (red, green, and blue) that are excited mainly by ultraviolet light can be used. In addition, although the phosphor is used as the wavelength conversion material for converting the wavelength of the light of the LED, it is not limited to this. For example, as wavelength conversion materials other than phosphors, materials containing substances that absorb light of a certain wavelength and emit light of a different wavelength from the absorbed light, such as semiconductors, metal complexes, organic dyes, and pigments, are used. be able to.

In the above embodiment, the light source 200 is an LED module having a COB structure in which an LED chip is directly mounted on a substrate, but the present invention is not limited to this. For example, instead of the COB structure LED module, an SMD (Surface Mount Device) structure LED module may be used. An LED module with an SMD structure is a package type LED element (SMD type LED element), and one or more of these are mounted on a substrate.

Moreover, in the above embodiment, an LED is used as the light source 200, but the present invention is not limited to this. For example, the light source 200 may be a semiconductor light-emitting element such as a semiconductor laser, or a solid-state light-emitting element other than an LED such as an organic EL (Electro Luminescence) or an inorganic EL. A lamp may be used.

In addition, it can be realized by applying various modifications to the above-described embodiment that a person skilled in the art can think of, or by arbitrarily combining the constituent elements and functions of the above-described embodiment without departing from the scope of the present invention. Forms are also included in the present invention.

1 lighting fixture 100, 100A lens 110 first protrusion 120, 120A second protrusion 121, 121A central protrusion 121a flat surface 122, 122A annular protrusion 130, 130A third protrusion 131 inner surface 131a step surface 131b side surface 140 concave portion 150 uneven structure 200 light source

Claims (9)

A lens that controls the light distribution of incident light,
a first protrusion annularly formed on the outer periphery on the light incident side;
a plurality of second projections formed concentrically on the light exit side to control the light distribution of light incident from the inner surface of the recess formed by the first projections;
and an annular third protrusion surrounding the plurality of second protrusions,
the third projecting portion has a stepped inner surface as a light exit surface,
The plurality of second protrusions have a central protrusion and a plurality of annular protrusions concentrically surrounding the central protrusion,
For the plurality of annular protrusions , where W is the width of the bottom portion and H is the height, all of the plurality of annular protrusions satisfy H / W ≤ 1.0.
lens. The first point is the intersection of the side surface and the bottom surface of the recess,
Letting the second point be the intersection of the stepped surface and the side surface of the outermost step among the plurality of steps forming the stepped inner surface of the third projecting portion,
a straight line connecting the first point and the second point does not intersect the step surface of each of the plurality of steps;
A lens according to claim 1 . The plurality of second protrusions constitute ring zones of a Fresnel lens,
3. A lens according to claim 1 or 2. The central protrusion has a flat surface as a light exit surface,
A lens according to claim 3 . The plurality of second protrusions are configured so that the light emitted from the plurality of second protrusions does not cross the optical axis of the lens.
A lens according to any one of claims 1 to 4. The tip of the first protrusion is provided with an uneven structure that forms unevenness when the lens is viewed from the light incident side in plan,
A lens according to any one of claims 1 to 5. The uneven structure is a structure in which a plurality of fine concave portions and fine convex portions are alternately formed repeatedly,
When a is the distance from the outer surface of the first protrusion to the bottom of the minute recess, and b is the distance from the outer surface of the first protrusion to the top of the minute protrusion, the relationship b>2a is satisfied. there is
A lens according to claim 6 . the inner surface of the first protrusion is a light incident surface forming part of the inner surface of the recess;
an outer surface of the first protrusion is a light reflecting surface that totally reflects light incident on the first protrusion from the light incident surface;
a tip portion of the first projecting portion is a connection portion between the light incident surface and the light reflecting surface;
The uneven structure is provided at the connecting portion,
A lens according to claim 6 or 7 . A lens according to any one of claims 1 to 8;
a light source disposed facing the recess of the lens;
lighting equipment.

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