CN209926035U

CN209926035U - Lighting apparatus

Info

Publication number: CN209926035U
Application number: CN201920951059.7U
Authority: CN
Inventors: 村上忠史; 山村泰典
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2018-06-26
Filing date: 2019-06-24
Publication date: 2020-01-10
Anticipated expiration: 2029-06-24
Also published as: JP2020004530A

Abstract

A lighting fixture (10) is provided with: a tubular light guide (16) having a light extraction structure (20) on the outer peripheral surface (16 a); a light source group (19) composed of a plurality of light sources (18) arranged in a ring shape along the upper end surface of the light guide body (16) in the axial direction; a cylindrical outer cylinder member (14) disposed around the outer side of the light guide (16); the base member (12) is provided so as to cover one axial end of the light guide (16) and the outer cylinder member (14), and is provided with a drive circuit (13) for driving the light source group (19) to emit light.

Description

Lighting apparatus

Technical Field

The present disclosure relates to lighting fixtures.

Background

In the related art, japanese patent application laid-open No. 2011-150971 describes a lighting device including: an appliance main body; an LED light emitting unit provided in the appliance main body; and a cover having a double hollow communicating portion communicating inside and outside, a tube portion provided on the inside, an insertion portion into which the garnish can be inserted being provided on the tube portion on the outside, and the insertion portion being openable and closable. In this lighting apparatus, a light guide sheet is attached to the inner surface of the inner tube portion, and light from the LED light emitting portion is surface-emitted through the light guide sheet.

SUMMERY OF THE UTILITY MODEL

In the lighting apparatus described in patent document 1, since the LED light emitting unit is disposed inside the upper end portion of the inner tubular portion, the amount of light reaching varies depending on the distance between the LED light emitting unit and each portion in the axial direction of the light guide sheet attached to the inner surface of the inner tubular portion. Therefore, the light guide sheet attached to the inner surface of the inner tube portion is bright near the LED light emitting portion, and the tip end becomes dark. Further, since the light guide sheet does not have a function of controlling the direction of the output light, there is a problem that the light distribution of the lighting fixture cannot be controlled.

An object of the present disclosure is to provide a lighting fixture capable of uniformly emitting light in an axial direction from a tubular light guide and capable of designing a shape of output light distribution according to an object.

The lighting apparatus of the present disclosure has: a cylindrical light guide having a light extraction structure on an outer peripheral surface; a light source group including a plurality of light sources arranged in a ring shape along an upper end surface of the light guide body in an axial direction; a cylindrical outer cylinder member disposed around an outer side of the light guide; and a base member that is provided so as to cover one end portion in the axial direction of the light guide and the outer cylinder member, and on which a drive circuit for driving the light source group to emit light is arranged.

Further, the inner peripheral surface of the outer tube member may be mirror-finished or light-diffused.

The light extraction structure may be formed by dot coating using a paint containing a diffusing pigment, or a concave or convex prism.

The dot coating or the prisms may have a constant coverage or may have a distribution that increases from the upper end surface to the lower end surface in the axial direction of the light guide.

When the light guide is cut on a plane including the central axis, the cross-sectional shape of the prism may be substantially triangular, and the prism may have an angle of 10 ° to 40 ° with respect to an axial line along the outer peripheral surface of the light guide.

The prism may have a substantially conical shape, or may have a groove or a projection having the same cross section and being continuous in the circumferential direction.

Further, the lower end surface of the light guide body in the axial direction may be subjected to embossing, texturing, or diffusion coating for diffusing and transmitting light that has advanced in the axial direction within the light guide body.

Further, the plurality of light sources constituting the light source group may be divided into a plurality of groups in the circumferential direction, and the lighting state may be controlled by the drive circuit.

Effect of the utility model

According to the lighting fixture of the present disclosure, the tubular light guide can be made to emit light uniformly in the axial direction, and the shape of the output light distribution can be designed according to the purpose.

Drawings

Fig. 1 is a side view showing a lighting fixture according to an embodiment of the present disclosure.

Fig. 2 is an exploded perspective view (including a partially enlarged view) of the lighting fixture shown in fig. 1.

Fig. 3 is a diagram for explaining light distribution emitted from the wall surface of the light guide.

Fig. 4 is a diagram for explaining the light distribution of the lighting fixture.

Fig. 5 is a diagram showing a state in which the light distribution changes according to the diffusion property of the dots.

Fig. 6 is a partially enlarged perspective view of a light guide showing an example of a prism constituting the light extraction structure.

Fig. 7A and 7B are diagrams showing angles of prisms.

Fig. 8A to 8C are diagrams showing changes in light distribution according to the angle of the prism, and fig. 8D is a diagram showing a case where light is emitted toward the opposing wall surface inside the tubular light guide.

Description of the symbols

2-a ceiling; 4-a through hole; 10-a lighting fixture; 12-a base part; 12 a-a floor portion; 12 b-a sidewall portion; 13-a drive circuit; 14-an outer barrel component; 16-a light guide; 16 a-peripheral surface; 16 b-inner peripheral surface; 18-a light source; 19-a light source group; 20. 20a, 20 b-light extraction structures; 22-point; 24 a-prisms or grooves; 24 b-a prism; a-a central axis; la, Lb, Lc, La, b-light distribution; lg-synthesized light distribution; theta-angle or prism angle.

Detailed Description

Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. In this description, specific shapes, materials, numerical values, directions, and the like are examples for easy understanding of the present disclosure, and can be appropriately changed according to the application, purpose, specification, and the like. In addition, when a plurality of embodiments, modifications, and the like are included below, it is assumed from the beginning that the features of these embodiments are appropriately combined and used.

Fig. 1 is a side view showing a lighting fixture 10 according to an embodiment of the present disclosure. Fig. 2 is an exploded perspective view (including a partial enlarged view) of the illuminator 10 shown in fig. 1. As shown in fig. 1 and 2, the lighting apparatus 10 includes a base member 12, an outer tube member 14, a light guide 16, and a light source group 19. As shown in fig. 1, the lighting fixture 10 is provided as a down lamp in a through hole 4 formed in the ceiling 2, for example.

The base member 12 of the illuminator 10 is made of, for example, a metal member. The base member 12 functions as a cover member that covers the upper end portion of the lighting fixture 10. The base member 12 has a circular bottom plate portion 12a and a side wall portion 12b erected on the outer peripheral edge of the bottom plate portion 12 a. A drive circuit 13 is disposed inside the lighting apparatus 10 and on the bottom plate portion 12a of the base member 12. The drive circuit 13 controls the supply of electric power to the light source group 19, and controls the light emission state (i.e., on, off, blinking, dimming, etc.) of the light sources 18 such as LEDs constituting the light source group 19. In addition, it is preferable to provide an opaque cover member inside the side wall portion 12b of the base member 12 so that the drive circuit 13 is not visible from below, in order to improve the appearance of the lighting fixture 10.

The outer tube member 14 is a profile member forming the outer peripheral side surface of the lighting fixture 10. The outer cylinder member 14 is formed of, for example, synthetic resin or a metal plate. The outer tube member 14 is formed in a cylindrical shape, for example. In the present embodiment, the outer cylindrical member 14 is formed to have the same size as the base member 12 in diameter. The outer cylindrical member 14 has a function of reflecting light leaking from the light guide 16 to the outside, and the inner peripheral surface thereof is subjected to mirror processing or light diffusion processing. The light diffusion treatment can be performed by, for example, embossing, texturing, or diffusion coating.

Fig. 1 and 2 show an example in which the outer tube member 14 is formed in a cylindrical shape having a constant diameter from the upper end surface to the lower end surface, but the present invention is not limited to this. The outer tube member 14 may be formed in a truncated cone shape having a larger inner diameter at its lower end side than at its upper end side. Alternatively, the outer tubular member 14 may be extended downward in a trumpet-like curved surface.

The light guide 16 is formed in a cylindrical shape. Fig. 2 (and fig. 6 as well) shows a central axis a of the light guide 16 by a dashed-dotted line. The light guide 16 has a function of guiding light introduced from an upper end surface in the axial direction of the central axis a toward a lower end side. The light guide 16 is preferably formed of, for example, a transparent resin material (e.g., acryl resin) or a glass material.

The light guide 16 has a light extraction structure 20 on its outer peripheral surface. As shown in a partially enlarged view in fig. 2, the light extraction structure 20 is preferably formed by dot coating. In the present embodiment, an example is shown in which circular dots 22 are formed in a staggered manner. The dots 22 may be formed in a matrix shape in the expanded state. The dots 22 are formed by printing or painting a paint containing a diffusion pigment.

In the case where the light extraction structure 20 is constituted by dot coating in this manner, the coverage or arrangement density of the dots 22 may be constant from the upper end surface to the lower end surface in the axial direction of the light guide 16. With this configuration, the amount of light extracted to the inner peripheral surface of the light guide 16 is large on the upper end surface side and small on the lower end surface side. Therefore, the surface of the inner peripheral surface of the light guide 16 can be shaded.

In contrast, the coverage or arrangement density of the dots 22 constituting the dot coating may be increased from the upper end surface to the lower end surface of the light guide 16 in the axial direction. With this configuration, the amount of light extracted to the inner peripheral surface of the light guide body 16 is constant from the upper end surface to the lower end surface. Therefore, the inner peripheral surface of the light guide 16 can be uniformly surface-illuminated in the axial direction.

The light extraction structure provided on the outer peripheral surface of the light guide 16 is not limited to dot coating, and may be configured by fine prisms, grooves, and the like formed on the outer peripheral surface of the light guide 16. The shape of the prism and the like will be described later.

In the present embodiment, the light guide 16 is formed in a cylindrical shape having a constant diameter from the upper end surface to the lower end surface, but the present invention is not limited thereto. Similarly to the outer cylindrical member 14, the light guide 16 may be formed so that the inner diameter thereof is expanded from the upper end surface toward the lower end surface in a truncated cone shape or a trumpet shape.

The lower end surface of the light guide 16 in the axial direction is preferably subjected to embossing, texturing, or diffusion coating. With this configuration, light introduced from the upper end surface of the light guide 16 and traveling in the axial direction in the light guide 16 can be diffused, transmitted, and emitted by processing the lower end surface with irregularities or the like. Therefore, the light emission state at the lower end surface of the annular light guide 16 can be made uniform in the circumferential direction. In other words, it is possible to suppress a state in which each light source 18 appears to emit light in granular form when the illuminator 10 is viewed from below.

As shown in fig. 1 and 2, the light source group 19 includes a plurality of light sources 18 arranged in a ring shape along the upper end surface of the light guide 16 in the axial direction. The light source 18 is preferably constituted by an LED, for example. The plurality of light sources 18 are preferably arranged at equal intervals in the circumferential direction. With this configuration, the surface light emission state of the inner circumferential surface of the light guide 16 can be made uniform in the circumferential direction. However, the arrangement pitch of the plurality of light sources 18 is not limited to this, and the surface light emission state of the inner circumferential surface of the light guide 16 may be made to be shaded in the circumferential direction.

The plurality of light sources 18 constituting the light source group 19 may be provided on the lower surface of the side wall portion 12b of the base member 12. In this case, the light source 18 may be provided so as to be exposed to the lower surface of the side wall portion 12b, or may be embedded in the vicinity of the lower surface of the side wall portion 12 b. The light sources 18 are electrically connected to the drive circuit 13 via wires, not shown. Thereby, each light source 18 can emit light by receiving power supply from the drive circuit 13. The light source group 19 including the plurality of light sources 18 may be fixedly disposed on the upper end surface of the light guide 16, or may be disposed as another member sandwiched between the base member 12 and the light guide 16.

The plurality of light sources 18 constituting the light source group 19 are preferably arranged so as to face each other in contact with or in proximity to the upper end surface of the cylindrical light guide 16. This enables light emitted from the light source 18 to be efficiently introduced into the light guide 16, and as a result, the inner peripheral surface of the light guide 16 and the like can be made uniform in the axial direction and can be made brighter to perform surface light emission.

Fig. 3 is a diagram for explaining light distribution emitted from the wall surface of the light guide 16. As shown in fig. 3, a light extraction structure 20 is provided on the outer peripheral surface 16a of the light guide 16, and a light distribution La is generated on the inner peripheral side (left side in fig. 3) of the light guide 16. On the outer peripheral side (right side in fig. 3) of the light guide 16, a light distribution Lb that leaks from between spot coatings constituting the light extraction structure 20 is generated. Further, the light distribution Lc passes through the inside of the light guide 16 in the axial direction and is emitted from the lower end surface in the axial direction.

Fig. 4 is a diagram for explaining the light distribution of the lighting fixture 10. As shown in fig. 4, on the inner peripheral surface 16b side of the light guide 16, a light distribution La extracted by the light extraction structure 20 and a light distribution Lb leaking on the outer peripheral side of the light guide 16 and reflected or diffused by the inner peripheral surface of the outer tube member 14 are generated. Further, as described above, the light distribution Lc is generated which passes through the inside of the light guide 16 in the axial direction and is emitted from the lower end surface in the axial direction. By combining these light distributions La, Lb, and Lc, a combined light distribution Lg as illumination light of the illuminator 10 is generated and irradiated below the illuminator 10.

Fig. 5 is a diagram showing a state in which the light distribution changes according to the diffusibility of the point 22. Here, the diffusibility of the dots 22 can be adjusted by the pigment concentration contained in the dots 22. Specifically, when the pigment concentration is decreased and the diffusibility is decreased, the light distribution La and Lb change as shown in fig. 5 (a) from the state shown in fig. 5 (b), and conversely, when the pigment concentration is increased and the diffusibility is increased, the light distribution La and Lb change as shown in fig. 5 (c) from the state shown in fig. 5 (b). By adjusting the diffusibility in this way, the lighting fixture 10 having desired light distributions La and Lb can be designed according to the purpose.

Next, a modified example of the optical pickup structure will be described with reference to fig. 6 and 7. Fig. 6 is a partially enlarged perspective view of the light guide 16 illustrating an example of the

prisms

24a, 24b constituting the

light extraction structures

20a, 20 b. In the above, the example in which the light extraction structure 20 provided on the outer peripheral surface 16a of the light guide 16 is formed by dot coating has been described, but the present invention is not limited thereto. As shown in fig. 6, the light extraction structure 20 may be formed by arranging concave grooves 24a having the same cross section and continuous in the circumferential direction in the axial direction, or the light extraction structure 20b may be formed by forming a plurality of fine prisms 24b each including a substantially conical concave portion. In this case, instead of the groove 24a, a convex portion having the same cross section and continuing in the circumferential direction may be used, or instead of the prism 24b formed of a substantially conical concave portion, a convex fine prism protruding in a substantially conical shape may be used.

In the case where the

light extraction structures

20a and 20b are formed by the grooves 24a and the prisms 24b, the coverage of the outer peripheral surface 16a of the light guide 16 may be constant in the axial direction, or may be gradually increased from the upper end surface toward the lower end surface, as in the case of the dot coating.

Fig. 7A and 7B are diagrams showing angles of prisms. Preferably, as shown in fig. 7A, when the light guide 16 is cut on a plane including the central axis a, the cross-sectional shapes of the

prisms

24a, 24b are substantially triangular, and have an angle θ of 10 ° to 40 ° with respect to an axial line along the outer peripheral surface 16a of the light guide 16. By setting the angle range as described above, the light extracted on the inner peripheral side of the light guide 16 can be efficiently emitted from the lighting fixture 10 by the

light extraction structures

20a and 20b including the

prisms

24a and 24 b. As shown in fig. 7B, the hem portions and the apex portions of the prisms 24a and 24B having a substantially triangular shape may be formed in an R shape.

Fig. 8A to 8C are diagrams showing changes in the light distribution La according to the angle θ of the

prisms

24a and 24b, and fig. 8D is a diagram showing a case where light is emitted toward the opposing wall surfaces in the interior of the cylindrical light guide. Fig. 8A shows a case where the prism angle θ is 30 °, fig. 8B shows a case where the prism angle θ is 42 °, and fig. 8C shows a case where the prism angle θ is 54 °. In fig. 8A, when the prism angle θ is as large as 42 ° and 54 ° as compared with fig. 8B and 8C, the light distribution La on the inner peripheral side of the light guide body 16 approaches a direction parallel to the radial direction of the light guide body 16 (corresponding to a direction directly below in fig. 8A to 8C). As shown in fig. 8D, the light distribution La, b of the combined light, which is the light distribution La, Lb emitted from the inner peripheral surface 16b on one side in the radial direction of the light guide 16, is incident on the inner peripheral surface 16b on the other side in the radial direction, and is less likely to be emitted from the lighting fixture 10, resulting in a reduction in the luminous efficiency as a lighting fixture. Therefore, in order to suppress such a decrease in light irradiation, the prism angle θ is preferably 40 ° or less. On the other hand, when the prism angle θ is less than 10 °, the amount of light extracted by the

prisms

24a and 24b is reduced, and the amount of light emitted from the inner peripheral surface 16b of the light guide 16 is insufficient, which is not preferable.

As described above, the lighting fixture 10 of the present embodiment includes: a cylindrical light guide 16 having a light extraction structure 20 on an outer peripheral surface 16 a; a light source group 19 including a plurality of light sources 18 arranged in a ring shape along an upper end surface in the axial direction of the light guide 16; a cylindrical outer cylinder member 14 disposed around the outer side of the light guide 16; a base member 12 provided to cover one end portion in the axial direction of the light guide 16 and the outer cylinder member 14, and provided with a drive circuit 13 for driving the light source group 19 to emit light.

According to this configuration, as compared with the case where the light source is provided at a position facing the internal space of the cylindrical light guide, the cylindrical light guide 16 can be made to emit light uniformly in the axial direction, and the shape of the output light distribution can be designed according to the purpose. Thus, a novel down lamp which has not been provided so far, in which the inner peripheral surface 16b of the cylindrical light guide 16 performs surface light emission, can be provided, and the product line and the product value can be enhanced.

In the lighting fixture 10 of the present embodiment, the inner peripheral surface of the outer tube member 14 is mirror-finished or light-diffused. This can guide the light distribution leaking from the outer peripheral surface 16a provided with the light extraction structure 20 to the inner peripheral side of the light guide 16, and can make the surface light emission state of the inner peripheral surface 16b of the light guide 16 brighter.

In the lighting apparatus 10 of the present embodiment, the

light extraction structures

20, 20a, and 20b may be dot-coated with paint containing a diffusing pigment, or may be formed of concave or convex prisms.

In this case, the dot coating or the prism may have a constant coverage or a distribution that increases from the upper end surface toward the lower end surface in the axial direction of the light guide 16.

In the lighting fixture 10 of the present embodiment, when the light guide 16 is cut on a plane including the central axis a, the cross-sectional shapes of the

prisms

24a and 24b are preferably substantially triangular, and the prisms have an angle θ of 10 ° to 40 ° with respect to an axial line along the outer peripheral surface 16a of the light guide 16.

In this case, the

prisms

24a and 24b may be substantially conical or may be grooves or protrusions having the same cross section and being continuous in the circumferential direction.

In the lighting fixture 10 of the present embodiment, the lower end surface in the axial direction of the light guide 16 is preferably subjected to embossing, texturing, or diffusion coating for diffusing and transmitting light that has advanced in the axial direction in the light guide 16. This makes it possible to make the light emission state uniform in the circumferential direction at the lower end surface of the annular light guide 16.

The lighting fixture of the present disclosure is not limited to the above-described embodiment and the modifications thereof, and various changes and modifications can be made within the scope of the features described in the claims of the present application.

For example, the plurality of light sources 18 constituting the light source group 19 may be divided into a plurality of groups in the circumferential direction, and the lighting state may be controlled by the drive circuit 13. By performing such control, unprecedented new illumination light expression can be performed in the lighting fixture 10 including the cylindrical light guide 16, and the product value can be improved.

Claims

1. A lighting device, comprising:

a cylindrical light guide having a light extraction structure on an outer peripheral surface;

a light source group including a plurality of light sources arranged in a ring shape along an upper end surface of the light guide body in an axial direction;

a cylindrical outer cylinder member disposed around an outer side of the light guide; and

and a base member that is provided so as to cover one end portion in the axial direction of the light guide and the outer cylinder member, and on which a drive circuit for driving the light source group to emit light is arranged.

2. The lighting apparatus of claim 1,

the inner peripheral surface of the outer tube member is mirror-finished or light-diffused.

3. The lighting apparatus of claim 1,

the light extraction structure is formed by dot coating formed by paint containing a diffusion pigment, or concave or convex prisms.

4. The lighting apparatus of claim 3,

the dot coating or the prism has a certain coverage, or has a distribution that increases from the upper end surface toward the lower end surface in the axial direction of the light guide.

5. The lighting apparatus of claim 3,

when the light guide is cut on a plane including the central axis, the cross-sectional shape of the prism is substantially triangular, and the prism has an angle of 10 DEG to 40 DEG with respect to an axial line along the outer peripheral surface of the light guide.

6. The lighting apparatus of claim 3,

the prism has a substantially conical shape, or a groove or a projection having the same cross section and being continuous in the circumferential direction.

7. The lighting apparatus of claim 1,

the lower end surface of the light guide body in the axial direction is subjected to embossing, texturing, or diffusion coating for diffusing and transmitting light that has advanced in the axial direction within the light guide body.

8. The lighting device according to any one of claims 1 to 7,

the plurality of light sources constituting the light source group are divided into a plurality of groups in the circumferential direction, and the lighting state can be controlled by the drive circuit.