The present disclosure relates to a panel light, especially a frameless panel light and a lamp assembly with a plurality of frameless panel lights.
Typical light emitting diode panel light has a lamp cover and a frame. The frame engages around the edge of the lamp cover and is configured to maintain structural strength of the existing light emitting diode panel light.
However, the frame which engages around the lamp cover not only decreases aesthetic quality but also results in apparent peripheral dark area because the frame covers around the edge of the lamp cover, and therefore, a light uniformity of the whole lamp cover and the illuminating area of the panel light are decreased.
A purpose of the present disclosure is to provide a lamp assembly and a frameless panel light to solve the problem which the prior art encounters. That is, the peripheral dark area is effectively decreased, an improved optical grade is achieved, and therefore, a light uniformity of the whole lamp cover and the illuminating area of the panel light are increased.
In some embodiments, a frameless panel light includes a lamp cover and a light source module. The lamp cover includes a front portion and a plurality of side portions. The side portions surround and adjoin the front portion. The front portion and the side portions define an accommodating space. The light source module is disposed in the accommodating space. The light source module includes a light source and a light guide plate optically coupled to the light source. The light guide plate includes a light-transmissive substrate and a microstructure. The light-transmissive substrate includes first and second major surfaces and a side surface connecting the first and second major surfaces. The microstructure is formed on the first major surface. The microstructure includes a recess and an annular groove around the recess. The annular groove has a depth greater than a depth of the recess. A bottom of the recess is at higher elevation than the first major surface from the second major surface. The annular groove has a protruding portion protruding from a bottom of the annular groove.
In some embodiments, the frameless panel light further includes at least a frame bar disposed in the accommodating space and fixed to the light source module and one of the side portions. The front portion and the light source module are separated by a light traveling space. The light traveling space exposes the front portion, each of the side portions and each joint between the side portions and the front portion, so that light of the light source module can reach the front portion, each of the side portions and the joint between the side portions and the front portion.
In some embodiments, the frame bar includes a base configured to support the light source, a supporting portion connected to a side of the base and supporting the light guide plate and the lamp cover, a positioning member disposed on one side of the supporting portion opposite to the light guide plate, and an engaging portion connected to another side of the base. The light guide plate is fixed between the engaging portion and the supporting portion. The light traveling space is between the engaging portion and the front portion.
In some embodiments, the bottom of the recess is at higher elevation than the bottom of the annular groove.
In some embodiments, a distribution density of a plurality of the microstructures increases as a distance increases from the side surface.
In some embodiments, the front portion of the lamp cover includes an anti-glare optical microstructure pattern.
In some embodiments, the lamp cover is a diffuser sheet.
In some embodiments, the bottom of the annular groove is at lower elevation than the first major surface from the second major surface.
In some embodiments, the bottom of the recess is at higher elevation than the bottom of the annular groove.
In some embodiments, the microstructure further comprises a convex surface protruding in a direction away from the second major surface, and the convex surface is at higher elevation than the first major surface from the second major surface.
In some embodiments, the convex surface connects a sidewall of the recess and a sidewall of the annular groove.
In some embodiments, a lamp assembly includes at least one connecting component; and a plurality of frameless panel lights. Any adjacent two of the frameless panel lights are arranged in a side-by-side manner and assembled together to provide a single planar light source. Each of the frameless panel lights includes a lamp cover and a light source module. The lamp cover includes a front portion and a plurality of side portions. The side portions surround and adjoin the front portion. The front portion and the side portions define an accommodating space. The light source module is disposed in the accommodating space. The light source module includes a light source and a light guide plate optically coupled to the light source. The light guide plate includes a light-transmissive substrate including first and second major surfaces and a side surface connecting the first and second major surfaces and a microstructure formed on the first major surface. The microstructure includes a recess and an annular groove around the recess. The annular groove has a depth greater than a depth of the recess. A bottom of the recess is at higher elevation than the first major surface from the second major surface. The annular groove has a protruding portion protruding from a bottom of the annular groove.
In some embodiments, the lamp assembly further includes at least a frame bar disposed in the accommodating space and fixed to the light source module and one of the side portions. The front portion and the light source module define a light traveling space therebetween. The light traveling space exposes the front portion, each of the side portions and each joint of the side portions and the front portion, so that light of the light source module can reach the front portion, each of the side portions and each joint of the side portions and the front portion unobstructedly.
In some embodiments, the frame bar includes a base configured to support the light source, a supporting portion connected to one side of the base and supporting the light guide plate and the lamp cover, a positioning member disposed on another side of the supporting portion opposite to the light guide plate, and an engaging portion connected to another side of the base. The light guide plate is fixed between the engaging portion and the supporting portion. The light traveling space is between the engaging portion and the front portion.
In some embodiments, a plurality of the microstructures are distributed on the first major surface in a random order.
In some embodiments, the front portion of the lamp cover includes an anti-glare optical microstructure pattern.
In some embodiments, the lamp cover is a diffuser sheet.
In some embodiments, the microstructure further includes a convex surface protruding in a direction away from the second major surface. The convex surface is at higher elevation than the first major surface from the second major surface.
In some embodiments, the microstructure further includes a protrusion protruding in the direction away from the second major surface. The protrusion connects the annular groove and the first major surface.
In some embodiments, the protrusion has curvature greater than curvature of the convex surface.
It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the disclosure as claimed.
Embodiments of the present disclosure can be more fully understood by reading the following detailed description of the embodiments, with reference made to the accompanying drawings as follows.
Reference will now be made in detail to the present embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.
Because the above-mentioned light traveling space LT is defined between the light source module 24 and the front portion 14 and each side portion 18 of the lamp cover 12, when the light source module emits light, the light L of the light source module can reach the front portion 14, each side portion 18 and each joint 20 between the side portion 18 and the front portion 14 unobstructedly. Therefore, brightness of each joint 20 between the side portion 18 and the front portion 14 is improved, a peripheral dark region is effectively reduced, and an improved optical performance is achieved, which in turn will improve brightness uniformity of the lamp cover 12 and an illumination area of the panel light. For example, when the lamp cover 12 is rectangular, the front portion 14, the four side portions 18 and each joint 20 between the side portion 18 and the front portion 14 can be illuminated sufficiently.
It is understood that in the present embodiments, the above-mentioned light traveling space LT between the lamp cover 12 and the light source module 24 is an air gap layer free from any physical structure, but the present disclosure is not limited in this regard. In other embodiments, as long as a luminous intensity standard is satisfied, the above-mentioned light traveling space can include light transmissive materials.
In the present embodiments, the light source module 24 includes a light guide plate 26 and a light bar 34. In some embodiments, the light bar 34 can be equivalently referred to as a light source. The light guide plate 26 is fixed on the frame bar 40 and has a light outgoing surface and a light incident surface. The light bar 34 is fixed on the frame bar 40 and configured to emit light toward the light incident surface. In particular, the light guide plate 26, such as a rectangular plate with a uniform thickness or a wedge with a decreasing thickness, has a front surface 28, a rear surface 30 opposite to the front surface 28, and four side surfaces 32 surrounding the front surface 28 and the rear surface 30. The front surface 28 or the rear surface 30 has an area greater than an area of any one of the side surfaces 32. The front surface 28 of the light guide plate 26 can serve as the aforementioned light outgoing surface of the light guide plate 26. Any one of the side surfaces 32 of the light guide plate 26 can serve as the aforementioned light incident surface. The light bar 34 faces toward one of the side surfaces 32 (i.e., the light incident surface) of the light guide plate 26. The light bar 34 includes at least one circuit board 36 and a plurality of light emitting diodes (LED) 38. The light emitting diodes 38 are arranged linearly and fixed on the circuit board 36. The light emitting diodes 38 face the aforementioned light incident surface and emit light toward the light incident surface. The circuit board 36 can be, for example, a printed circuit board (PCB), a metal core printed circuit board (MCPCB), or a flexible printed circuit board (FPC).
In some embodiments, a spacing G between the front portion 14 and the front surface 28 of the light guide plate 26 is in a range from 1.5 mm to 20 mm. That is, a shortest distance between the inner surface of the front portion 14 and the front surface 28 of the light guide plate 26 is in a range from 1.5 mm to 20 mm, but the present disclosure is not limited in this regard. In other embodiments, the spacing between the front portion and the front surface of the light guide plate may be greater than 20 mm.
In the present embodiments, the frame bar 40 includes a base 42, a supporting portion 46, a positioning member 50 and an engaging portion 54. The base 42 is configured to support the light bar 34. The supporting portion 46 is connected to a side of the base 42 and is configured to support the light guide plate 26 and the lamp cover 12. The engaging portion 54 is connected to another side of the base 42 such that the light guide plate 26 is fixed between the engaging portion 54 and the supporting portion 46. The light traveling space LT is between the engaging portion 54 and the front portion 14. The positioning member 50 is disposed on a surface of the supporting portion 46 which is opposite to the base 42 and is configured to hold at least one support 52, so as to be suspended from a wall or a ceiling by the support 52. For example, the supporting portion 46 includes a supporting surface 48 configured to support the light guide plate 26 and the side portion 18 of the lamp cover 12. The base 42 stands on the supporting surface 48 of the supporting portion 46 and is disposed between the side portion 18 and the light guide plate 26. A clamping space 350 is defined between the supporting portion 46 and the engaging portion 54. Therefore, when the light guide plate 26 is fixed between the engaging portion 54 and the supporting portion 46, the side surface 32 of the light guide plate 26 is in the clamping space 350. A base 42 of one of the frame bars 40 has a slot 44 communicating the clamping space 350 such that the light bar 34 can be inserted in the slot 44.
In the present embodiments, the frame bars 40 include metal and are formed using a punching process or a continuous extrusion process (e.g., an aluminum extrusion frame bar), but the present disclosure is not limited in this regard.
In the present embodiments, the lamp cover 12 is a diffuser sheet, such as an integrated cover diffuser sheet. The diffuser sheet has a transmittance of 57%, a haze of 99% and a thickness of 3 mm, but the present disclosure is not limited in this regard.
In the present embodiments, the lamp cover 12 is locked on each frame bar 40 by bolts 60. After the bolts 60 lock the lamp cover 12 to each frame bar 40, an outer surface of the lamp cover 12 facing away from the frame bar 40 is covered by a plate 58, such that the bolts 60 on the lamp cover 12 are covered.
In some embodiments, the light guide plate 26 may include various geometries for improving device performance, which will be discussed in detail below.
Referring to
Moreover, in some embodiments, a bottom 122b of the annular groove 122 is at a position lower than the bottom 121b of the recess 121. In other words, the bottom 121b of the recess 121 is at higher elevation than the bottom 122b of the annular groove 122 from the second major surface 114. In further embodiments, the bottom 122b of the annular groove 122 is at a position lower than the first major surface 112. Stated differently, the bottom 122b of the annular groove 122 is at lower elevation than the first major surface 112 from the second major surface 114. In some embodiments, the annular groove 122 has a protruding portion 122p protruding from the bottom 122b of the annular groove 122.
In some embodiments, the bottom 122b of the annular groove 122 is curved more than the recess 121. For example, the bottom 122b of the annular groove 122 has curvature greater than the recess 121. Stated in another way, the bottom 122b of the annular groove 122 has a curvature radius less than a curvature radius of the recess 121.
In some embodiments, the microstructure 120 further includes a convex surface 123 around the recess 121. The convex surface 123 protrudes in a direction away from the second major surface 114 and extends in a circular direction to encircle the recess 121. The convex surface 123 is at higher elevation than the first major surface 112 from the second major surface 114. The convex surface 123 connects a sidewall 121s of the recess 121 and a sidewall 122s of the annular groove 122. The convex surface 123 has a smooth convex contour in a cross-sectional view as illustrated in
In some embodiments, the microstructure 120 further includes a protrusion 124 around the annular groove 122. The protrusion 124 protrudes in a direction substantially the same as that the convex surface 123 protrudes in. For example, the protrusion 124 protrudes in the direction away from the second major surface 114 and extends in a circular direction to encircle the annular groove 122. Thus, the protrusion 124 connects the annular groove 122 and the first major surface 112.
In some embodiments, the protrusion 124 has a smooth convex contour in a cross-sectional view as illustrated in
In some embodiments, the protrusion 124, the annular groove 122, the convex surface 123 and the recess 121 are arranged in a concentric fashion. A structure encircled by the annular groove 122 is also referred to as a spherical protrusion 125 that protrudes from the annular groove 122. The recess 121 is recessed from a top of the spherical protrusion 125.
In some embodiments, the protrusion 124 is at a position higher than the first major surface 112. Stated in another way, the protrusion 124 is at higher elevation than the first major surface 112 from the second major surface 114. In further embodiments, the protrusion 124 is at a position lower than the convex surface 123. In other words, the protrusion 124 is at lower elevation than the convex surface 123 from the second major surface 114.
In some embodiments, the depth D1 of the recess 121 ranges from about 1.5 um to about 2.1 um. For example, the depth D1 of the recess 121 is about 1.8 um. In some embodiments, the depth D2 of the annular groove 122 ranges from about 2.5 um to about 3.5 um. For example, the depth D2 of the annular groove 122 is about 3 um. In some embodiments, two bottoms 122b of the annular groove 122 geometrically farthest away from each other are separated by a distance D3, which is in a range from about 50 um to about 65 um. For example, the distance D3 separating opposite bottoms 122b of the annular groove is about 57 um. In some embodiments, the bottom 121b of the recess 121 and the bottom 122b of the annular groove 122 are separated by a vertical distance D4, which is in a range from about 2.5 um to about 3.7 um. For example, the vertical distance D4 separating bottoms 121b and 122b of the recess 121 and annular groove 122 is about 3.1 um. In some embodiments, the top of the protrusion 124 and the second major surface 114 are separated by a vertical distance D5, which is in a range from about 1.981 mm to about 2.021 mm. For example, the vertical distance D5 separating the top of the protrusion 124 and the second major surface 114 is about 2.001 mm. In some embodiments, the bottom 121b of the recess 121 and the second major surface 114 are separated by a vertical distance D6, which is in a range from about 1.981 mm to about 2.021 mm. For example, the vertical distance D6 separating the bottom 121b of the recess 121 and the second major surface 114 is about 2.001 mm.
One or more geometries of the microstructure 120 as discussed above are advantageous for achieving a desired light distribution provided by light guide plate 100. Fabrication of the light guide plate 100 having one or more microstructures 120 as discussed above is described below with reference to
For example, the laser process for forming the microstructure 210 is carried out via a neodymium-doped yttrium aluminum garnet laser (Nd—YAG) or the like. The wavelength of the laser ranges from about 900 nanometers to about 1800 nanometers. The laser is focused on the mold core 200, rapidly increasing a temperature of the focus point. As a result, the mold core 200 material at the focus point disintegrates due to high temperature oxidation, thus forming the spherical recess 211. During the laser process, the mold core 200 material around the focus point is melted, which in turn forms the ring 212 enclosing the spherical recess 211.
After formation of the mold core 200, the light guide plate 100 can be molded in a mold having the mold core 200 using a thermoforming process. The spherical protrusion 125 is formed on the light guide plate 100 corresponding to the spherical recess 211 of the mold core 200, and the annular groove 122 are defined in the light guide plate 100 corresponding to the ring 212 of the mold core 200. The recess 121 of the spherical protrusion 125 may be formed because of air gap between the mold core 200 and the material of the light guide plate 100 during the thermoforming process.
The light guide plate 100 may be made from a material such as polycarbonate, polymethyl methacrylate, polystyrene, copolymer of methylmethacrylate and styrene, the like, or combinations thereof. In alternative embodiments, the laser process may be implemented by ruby laser, alexandrite laser, and so on. The wavelength of the laser may also be selected from other desired values, such as 266 nanometers, 355 nanometers, 532 nanometers, and so on.
Microstructures 120 can be distributed in various fashions. For example, referring now to
The light guide plate(s) as discussed above can be employed in any of a variety of light source modules (e.g., the light source module 24 as shown in
Referring to
In the present embodiments,
For example, the connecting components 62 include a connecting portion 64 and a plurality of bolts 66. The connecting portion 64 is locked on frame bars 40 of any adjacent two of the frameless panel lights 10 by the bolts 66, such that the frameless panel lights 10 can be arranged side by side steady and spliced into one piece, but the present disclosure is not limited in this regard. Other conventional fixing methods can be used for fixing the frameless panel lights.
Although the present disclosure has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims.
This is a continuation-in-part (CIP) application of U.S. patent application Ser. No. 15/791,429, filed Oct. 24, 2017.
Number | Date | Country | |
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Parent | 15791429 | Oct 2017 | US |
Child | 16228708 | US |