Wall washer-type lighting device

Abstract

To provide a dotless wall washer type lighting device capable of suppressing the reflection of a light source on a floor surface, etc.SOLUTION: A wall washer type lighting device 10 comprises: a plurality of LEDs 12 arranged along a predetermined direction; a first long lens 16 that controls and emits light from the plurality of LEDs 12; and a second long lens 18 that refracts light from the first lens 16 in a predetermined direction and emits it.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a lighting device, and particularly to a wall washer type lighting device for lighting a wall surface or the like.

Background Art

[0002] Conventionally, a wall washer type lighting device designed to uniformly illuminate a wall surface or the like is known. For example, Patent Document 1 discloses a wall washer type lighting device including a plurality of LEDs and a lens that optically controls the emitted light from the plurality of LEDs.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the wall washer type lighting device having the configuration as in Patent Document 1 above, since strong light is irradiated from the lens portion near the LED, there is a problem that the light emission becomes dot-like. For example, when using marble or tiles with a mirror-like material on the floor surface, the dot-like light emission may be reflected on the floor surface, which may impair the luxurious feeling.

[0005] The present invention has been made in view of such a situation, and an object thereof is to provide a dotless wall washer type lighting device capable of suppressing the reflection of the light source on the floor surface or the like.

Means for Solving the Problems

[0006] In order to solve the above problems, a wall washer lighting device according to one embodiment of the present invention comprises a plurality of light sources arranged along a predetermined direction, a long first lens that controls and emits light from the plurality of light sources, and a long second lens that refracts the light from the first lens in a predetermined direction and emits it.

[0007] Any combination of the above components and any conversion of the present invention into an apparatus, method, system, etc. are also valid aspects of the present invention. Effect of the Invention

[0008] According to the present invention, it is possible to provide a dotless wall washer type lighting device capable of suppressing reflection of a light source on a floor surface or the like. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic perspective view of a wall washer type lighting device according to an embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view of the wall washer type lighting device shown in FIG. 1 along the line AA. [Diagram 3] 2 is a cross-sectional view of the wall washer type lighting device shown in FIG. 1 . [Figure 4] FIG. 1 is a schematic top view of a wall washer type lighting device. [Diagram 5] FIG. 13 is a schematic perspective view of a wall washer type lighting device according to a modified example. [Figure 6] FIG. 13 is a schematic perspective view of a second lens used in a wall washer-type lighting device according to a modified example. [Figure 7] FIG. 2 is a schematic cross-sectional view of an end of a wall washer type lighting device. [Figure 8] FIG. 13 is a diagram showing the results of a ray tracing simulation of an end member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] FIG. 1 is a schematic perspective view of a wall washer type lighting device 10 according to an embodiment of the present invention.

[0011] The wall washer lighting device 10 can be used mainly for wall washer lighting. Wall washer lighting is generally used as an indirect lighting method, and is a lighting method that irradiates light evenly over the entire wall surface as if washing it with water.

[0012] The wall washer lighting device 10 of this embodiment is installed on an installation surface such as a ceiling surface, and irradiates light onto a wall surface intersecting the installation surface. The wall washer lighting device 10 includes an LED 12 as a light source, a substrate 14 on which the LED 12 is mounted, a first lens 16 for controlling the light emitted from the LED 12, a second lens 18 for controlling the light emitted from the first lens 16, and a housing 20 for housing the substrate 14, the first lens 16, and the second lens. For the sake of explanation, FIG. 1 shows a state in which the substrate 14, the first lens 16, and the second lens 18 are partially pulled out from an end of the housing 20.

[0013] 1, the wall washer-type lighting device 10 of this embodiment is an elongated lighting device extending in a predetermined direction (Y-axis direction) and capable of emitting light in a line. Such an elongated wall washer-type lighting device 10 can illuminate a wide range of the wall surface in the lateral direction as well as a wide range of the wall surface in the height direction.

[0014] Fig. 2 is an AA cross-sectional view of the wall washer type lighting device 10 shown in Fig. 1. Fig. 3 is a BB cross-sectional view of the wall washer type lighting device 10 shown in Fig. 1. Fig. 2 shows a cross-section perpendicular to the longitudinal direction (Y-axis direction) of the wall washer type lighting device 10, and Fig. 3 shows a cross-section parallel to the longitudinal direction (Y-axis direction) of the wall washer type lighting device 10.

[0015] A substrate 14 is disposed on the bottom surface 20a inside the housing 20. The substrate 14 is an elongated substrate extending in the Y-axis direction. The main surface of the substrate 14 is parallel to the XY plane. As shown in FIG. 3, a plurality of LEDs 12 are disposed on the substrate 14 at predetermined intervals along the Y-axis direction. Each LED 12 is disposed so that its optical axis Ax faces the Z-axis direction perpendicular to the XY plane.

[0016] The LED 12 may emit, for example, white light. The LED 12 may include a blue LED chip and a yellow light emitter. By using the blue light emitted from the blue LED chip to excite a yellow phosphor with a part of the light, white light can be produced by mixing the blue light and the yellow light.

[0017] The first lens 16 is disposed in front (in the direction of illumination) of the multiple LEDs 12. The first lens 16 controls the light from each LED 12 to form a light distribution suitable for wall washer lighting. The first lens 16 may be formed of a transparent material such as glass, acrylic, polycarbonate, or the like, or may be formed of a material containing a diffusing agent.

[0018] The first lens 16 is an elongated lens extending in the Y-axis direction. An incident surface for allowing light from the LED 12 to enter the first lens 16 is provided on the surface of the first lens 16 facing the LED 12. The incident portion is made up of a first incident surface 16a and a second incident surface 16b. Meanwhile, the surface of the first lens 16 opposite to the surface facing the LED 12 is made into an exit surface 16c. The exit surface 16c is formed into a flat surface.

[0019] The first incident surface 16a is located on the optical axis Ax of the LED 12. Light emitted from the LED 12 and having a relatively small emission angle enters the first incident surface 16a. The first incident surface 16a has a cross-sectional shape perpendicular to the longitudinal direction of the first lens formed into a convex curve, and the curvature is set to a size such that the light incident on the first incident surface 16a from the LED 12 becomes parallel light parallel to the optical axis Ax. FIG. 2 illustrates how a part of the light L1 emitted from the LED 12 is converted into parallel light by the first incident surface 16a and is emitted from the emission surface 16c.

[0020] The second incident surface 16b is located on the side of the first incident surface 16a (outside the first incident surface 16a). Light emitted from the LED 12 and having a relatively large emission angle is incident on the second incident surface 16b. A reflecting surface 16d is formed on the side of the second incident surface 16b (outside the second incident surface 16b) on the surface of the first lens 16 facing the LED 12, which reflects (internal reflection) the light incident from the second incident surface 16b into the first lens 16 toward the emission surface 16c. The reflecting surface 16d is configured to reflect the light from the second incident surface 16b as parallel light parallel to the optical axis Ax. FIG. 2 illustrates how a part of the light L2 emitted from the LED 12 enters from the second incident surface 16b, is totally reflected by the reflecting surface 16d, and is emitted to the emission surface 16c as parallel light.

[0021] In this manner, the first lens 16 according to the present embodiment is configured as a collimator lens that converts the light from each LED 12 into parallel light and emits it. The term "parallel light" here means parallel light in a cross section perpendicular to the longitudinal direction (Y-axis direction) of the first lens 16 as shown in FIG. 2. The configuration of the collimator lens that converts the light from each LED 12 into parallel light may be a configuration other than that of the present embodiment. In addition, the first lens 16 is not limited to a collimator lens that converts the light from the LED 12 into parallel light and emits it, and may be any lens that controls the light from each LED 12 in a cross section perpendicular to the longitudinal direction (Y-axis direction) of the first lens 16 according to the light distribution characteristics required for the wall washer type lighting device 10.

[0022] The second lens 18 is disposed above the first lens 16. That is, the second lens 18 is disposed so as to face the exit surface 16c of the first lens 16. In this embodiment, the second lens 18 is separate from the first lens 16. By making the first lens 16 and the second lens 18 separate, it becomes easy to configure the first lens 16 and the second lens 18 from different materials. For example, by configuring the first lens 16 and the second lens 18 from materials with different refractive indices, the degree of freedom of light distribution design can be increased. In addition, by making the first lens 16 and the second lens 18 separate, the lens shapes are simplified, making it easier to manufacture the lenses.

[0023] The second lens 18 is configured to refract and emit the light from the first lens 16 in a predetermined direction (Y-axis direction) with respect to the optical axis Ax. The "predetermined direction" is the longitudinal direction of the wall washer lighting device 10, which is the arrangement direction of the multiple LEDs 12. The second lens 18 may be formed of a transparent material such as glass, acrylic, or polycarbonate.

[0024] The second lens 18 is an elongated lens extending in the Y-axis direction, and includes an incident surface 18a that receives light from the first lens 16 and an exit surface 18b that emits the light forward. The incident surface 18a is formed in a flat shape. The second lens 18 is disposed such that the incident surface 18a faces the exit surface 16c of the first lens 16.

[0025] The exit surface 18b of the second lens 18 has an uneven structure 18e in which concave portions 18c and convex portions 18d extending in a direction (X-axis direction) perpendicular to a predetermined direction (Y-axis direction) are alternately arranged along the predetermined direction (Y-axis direction). Due to this uneven structure 18e, the light emitted from the exit surface 18b of the second lens 18 is refracted in the Y-axis direction with respect to the optical axis Ax in a cross section parallel to the Y-axis direction. Fig. 3 illustrates how the light L3 emitted from the exit surface 18b is refracted in the Y-axis direction, and illustrates how the light emitted from the exit surface 18b has a lens effect similar to that of parallel light parallel to the optical axis Ax, similar to that of the exit surface 16c of the first lens.

[0026] FIG. 4 is a schematic top view of the wall washer type lighting device 10. The right half of FIG. 4 shows a state with the second lens 18, and the left half of FIG. 4 shows a state without the second lens 18. In the wall washer type lighting device 10 according to the present embodiment, as described above, the second lens 18 emits light from the first lens 16 in a predetermined direction (Y-axis direction) from the emission surface 18b with respect to the optical axis Ax, so that the images 25 of the multiple LEDs 12 overlap in the predetermined direction (Y-axis direction), thereby realizing soft, smooth, linear emission in which dot-like emission is not visible (dotless). FIG. 4 illustrates the overlapping of the images 25 seen from the emission surface 18b of the second lens. The pitch of the recesses 18c and the protrusions 18d and the height difference between the recesses 18c and the protrusions 18d can be appropriately set according to the arrangement pitch of the LEDs 12, the thickness of the first lens, and the like. For example, if the arrangement pitch of the LEDs 12 is 7 mm, the pitch between the recesses 18c and the protrusions 18d may be about 1 mm, and the height difference between the recesses 18c and the protrusions 18d may be about 0.25 mm.

[0027] In this way, according to the wall washer lighting device 10 of this embodiment, the first lens 16 satisfies the light distribution characteristics required for extended wall washer lighting, while the second lens 18 emits the emitted light in a predetermined direction (Y-axis direction) from the emission surface 18b, so that the images 25 of the multiple LEDs 12 overlap in the predetermined direction (Y-axis direction), thereby suppressing the reflection of dot-like emitted light on the floor surface.

[0028] The wall washer lighting device 10 according to this embodiment has an air layer 22 between the exit surface 16c of the first lens 16 and the entrance surface 18a of the second lens 18. In order to form such an air layer 22, the second lens 18 has a support portion 18f for supporting the second lens 18 with respect to the first lens 16. By providing the air layer 22, light is emitted from the exit surface 18b of the second lens 18 after being partially totally reflected between the exit surface 16c of the first lens 16 and the entrance surface 18a of the second lens 18, thereby enhancing the dotless light emission effect. In this embodiment, the first lens 16 and the second lens 18 are configured as separate bodies, so that it is easy to provide such an air layer 22.

[0029] Fig. 5 is a schematic perspective view of a wall washer-type lighting device 40 according to a modified example. Fig. 6 is a schematic perspective view of a second lens 18 used in the wall washer-type lighting device 40 according to the modified example.

[0030] Wall-washer-type lighting device 40 according to the modified example differs from the above-described wall-washer-type lighting device 10 in that an uneven structure 18e is provided on incident surface 18a of second lens 18. Exit surface 18b of second lens 18 is formed in a flat shape.

[0031] Even when the uneven structure 18e is provided on the incident surface 18a of the second lens 18 in this manner, as in the wall washer type lighting device 10 described above, in a cross section parallel to a predetermined direction (Y-axis direction), light emitted from the second lens 18 is emitted in a predetermined direction (Y-axis direction) from the exit surface 18b, so that images 25 of multiple LEDs 12 overlap in the predetermined direction (Y-axis direction), thereby achieving dotless, soft, and smooth line-like light emission.

[0032] In the wall washer lighting device 40 according to this modification, the uneven structure 18e of the second lens 18 is not exposed to the outside. This makes it difficult for water droplets to adhere to the uneven structure 18e, thereby preventing a decrease in the lens effect of the uneven structure 18e. Therefore, it can be said that the wall washer lighting device 40 is suitable for use in an outdoor environment.

[0033] 7 is a schematic cross-sectional view of an end of wall washer type lighting device 10. Wall washer type lighting device 10 has end members 24 at both longitudinal ends of first lens 16 and second lens 18. End member 24 has incident portion 24a into which light from LED 12 is incident, light guiding portion 24b that guides the light incident from incident portion 24a, and exit portion 24c that exits the light traveling inside light guiding portion 24b.

[0034] Incident portion 24a is disposed so as to receive light from LED 12 located at the edge among the plurality of LEDs 12. Light guide portion 24b is configured to guide the light incident from incident portion 24a to exit portion 24c. Exit portion 24c is formed so as to be continuous with exit surface 18b of second lens 18. Exit portion 24c has an uneven structure similar to uneven structure 18e of second lens 18.

[0035] Fig. 8 shows the results of a ray tracing simulation of end member 24. From the results of the ray tracing simulation in Fig. 7, it can be seen that light incident from incident portion 24a travels through light guiding portion 24b and is emitted from exit portion 24c. In this way, by disposing end member 24 at the end of wall washer type lighting device 10, it is possible to cause light to be emitted in the same way as exit surface 18b of second lens 18.

[0036] By providing end members 24 at the ends of the wall washer type lighting device 10, when a plurality of wall washer type lighting devices 10 are connected, seamless linear illumination can be achieved without darkening the connected portions.

[0037] The present invention has been described above based on the embodiment. The embodiment is merely an example, and it will be understood by those skilled in the art that various modifications are possible in the combination of the respective components, and that such modifications are also within the scope of the present invention. [Explanation of symbols]

[0038] 10, 40 wall washer type lighting device, 12 LED, 14 substrate, 16 first lens, 18 second lens, 20 housing, 22 air space, 24 end member.

Claims

1. A plurality of light sources arranged along a predetermined direction; a first lens having an elongated shape that controls and emits light from the plurality of light sources; a second lens having an elongated shape that refracts the light from the first lens in the predetermined direction and emits the light; A wall washer type lighting device comprising:

2. 2. The wall washer type lighting device according to claim 1, wherein the first lens is configured to convert the light from the light source into parallel light and emit the parallel light.

3. 2. The wall washer type lighting device according to claim 1, wherein the entrance surface or exit surface of the second lens has an uneven structure in which concave and convex portions extending in a direction perpendicular to the predetermined direction are alternately arranged along the predetermined direction.

4. 2. The wall washer type lighting device according to claim 1, wherein the first lens and the second lens are configured as separate bodies.

5. 5. The wall washer type lighting device according to claim 4, wherein the first lens and the second lens are made of different materials.

6. 5. The wall washer lighting device according to claim 4, further comprising an air gap between the light exit surface of the first lens and the light entrance surface of the second lens.

7. The lens unit further includes end members provided at longitudinal ends of the first lens and the second lens, The end member is an incident portion to which light from the light source is incident; a light guide portion that guides the light incident from the incident portion; an emission section that emits light traveling through the light guiding section; 7. A wall washer type lighting device according to claim 1, further comprising:

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