WO2011086042A1

WO2011086042A1 - Light cover, manufacturing method thereof, and lamp having such a cover

Info

Publication number: WO2011086042A1
Application number: PCT/EP2011/050203
Authority: WO
Inventors: Nimchung Ku; Qing Liu; Yabin Luo; Zesheng Ye
Original assignee: Osram Gesellschaft mit beschränkter Haftung
Priority date: 2010-01-18
Filing date: 2011-01-10
Publication date: 2011-07-21
Also published as: CN102128420A

Abstract

A light cover, a method for manufacturing the same, and a lamp having the same are disclosed. The light cover (210, 310, 410, 510, 610, 710, 810) includes a light transmitting portion (211, 311, 411, 511, 611, 711, 811), and further includes a reflective portion (213, 313, 413, 513, 613, 713, 813)which is formed integrally with the light transmitting portion, projects inwardly from the light transmitting portion, and is capable of reflecting light emitted from a light source so that the light passes through the light transmitting portion. By the reflective portion formed integrally with the light transmitting portion and projecting inwardly inside the cover, the luminance of the lamp can be enhanced and the distribution of the light emitted from the light source in the lamp can be changed, without the need of adding any extra mechanism onto the lamp.

Description

Light Cover, Manufacturing Method Thereof, and Lamp Having Such a Cover

Field of the Invention [0001] The present invention relates to the field of lighting, and particularly to a light cover, a method of manufacturing the cover, and a lamp having such a cover.

Background of the Invention

[0002] In the existing lighting industry, in order to achieve a certain optical effect, some optical features are usually attached onto a lamp. For example, a prism may be added on the cover, lenses may be attached on the Light Emitting Diodes (LEDs), or a reflector may be applied around a tube. This needs extra mechanical structure to support the attached optical features, which makes the manufacturing and assembling processes more complicated, and imposes much stricter requirements on the tolerance control.

Summary of the Invention

[0003] The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an exhaustive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.

[0004] Some embodiments of the invention provide a light cover and a lamp having such a cover, without any extra mechanical supporting structure while achieving a certain optical effect, such as enhancing the luminance of the lamp, and changing the distribution of light emitted from the light source, etc.

[0005] According to an aspect of the invention, there is provided a light cover. The light cover includes a light transmitting portion, and further includes a reflective portion which is formed integrally with the light transmitting portion and projects inwardly from the light transmitting portion. The reflective portion is capable of reflecting light emitted from a light source so that the light passes through the light transmitting portion.

[0006] The end part, which projects inwardly, of the reflective portion is separated from the end part(s) of the light transmitting portion. That is, the surface, which does not face the light source, of the reflective portion and the inside surface of the light transmitting portion form a certain angle. In other words, the surface, which does not face the light source, of the reflective portion is not covered over the inside surface of the light transmitting portion.

[0007] Optionally, the cover may be a bar-shaped cover. In this case, the light transmitting portion and the reflective portion may be integrally formed using a two-color extrusion process.

[0008] Optionally, the light transmitting portion and the reflective portion may be integrally formed using a two-color injection molding process or other appropriate process.

[0009] Optionally, the reflective portion may include a supporting layer and a reflective layer. The supporting layer may be formed of the same material as that of the light transmitting portion, and the reflective layer may be formed of a reflective material.

[0010] Optionally, the reflective portion may be disposed symmetrically or asymmetrically with respect to the light source.

[0011] Optionally, the surface (i.e. the reflective surface), which faces the light source, of the reflective portion may be a plane or may be a curved surface.

[0012] Optionally, the tangency plane of the surface (i.e. the reflective surface), which faces the light source, of the reflective portion and the plane mounting the light source may form an angle ranging from about 10° to about 90°.

[0013] Optionally, the light transmitting portion may be formed of a clear or diffuse material. The reflective portion may be formed of a reflective material.

[0014] According to another aspect of the invention, there is provided a lamp which includes a base for mounting the light source and further includes a cover described above. The cover is mounted on the base.

[0015] According to another aspect of the invention, there is provided a two-color extrusion process for manufacturing the above mentioned bar-shaped cover, by which the light transmitting portion and the reflective portion of the cover are formed integrally.

[0016] According to another aspect of the invention, there is provided a two-color injection molding process for manufacturing the above mentioned cover, by which the light transmitting portion and the reflective portion of the cover are formed integrally.

Brief Descriptions of the Drawings

[0017] The invention can be better understood with reference to the description given below in conjunction with the accompanying drawings, throughout which identical or like components are denoted by identical or like reference signs, and together with which the following detailed description are incorporated into and form a part of the specification and serve to further illustrate preferred embodiments of the invention and to explain principles and advantages of the invention. In the drawings: [0018] Figure 1 (A) is a schematic perspective diagram showing an existing light cover in the art;

[0019] Figure 1(B) and Figure 1(C) are schematic perspective diagrams showing LED tubes having the cover as shown in Figure 1(A), respectively;

[0020] Figure 2(A) is a schematic perspective diagram illustrating the structure of a light cover according to an embodiment of the invention; [0021] Figure 2(B) is a schematic diagram showing the cross section of the cover as shown in Figure 2(A);

[0022] Figure 3 is a schematic diagram illustrating the cross section of a light cover according to another embodiment of the invention;

[0023] Figure 4 is a schematic diagram illustrating the cross section of a light cover according to another embodiment of the invention;

[0024] Figure 5 is a schematic perspective diagram illustrating the structure of a light cover according to another embodiment of the invention;

[0025] Figure 6(A) is a schematic perspective diagram illustrating the structure of a light cover according to another embodiment of the invention; [0026] Figure 6(B) is a schematic diagram showing the cross section of the cover along the dotted line AA as shown in Figure 6(A);

[0027] Figures 7 and 8 are schematic perspective diagrams illustrating the structures of light covers according to other embodiments of the invention; and

[0028] Figures 9(A) is a schematic perspective diagram illustrating a LED tube having the cover as shown in Figures 2(A) and 2(B), and 9(B) is a schematic diagram showing the cross section of the LED tube as shown in Figure 9(A).

[0029] Those skilled in the art will appreciate that the parts shown in the figures are illustrated in a simplified manner, rather than being plotted in proportion. For example, the sizes of some parts shown in the drawings may be zoomed with respect to some other parts, to facilitate the understanding of the embodiments of the invention.

Detailed Descriptions of the Embodiments

[0030] The embodiments of the present invention will be described in conjunction with the accompanying drawings hereinafter. For the sake of clarity and conciseness, not all the features of actual implementations are described in the specification. However, it is to be appreciated that, during developing any of such actual implementations, numerous implementation-specific decisions must be made to achieve the developer's specific goals, for example, compliance with system-related and business-related constraints which will vary from one implementation to another. Moreover, it is also to be appreciated that, such a development effort might be very complex and time-consuming, but may nevertheless be a routine task for those skilled in the art having the benefit of this disclosure.

[0031] It shall further be noted that only device structures and/or processing steps closely relevant to solutions of the invention will be illustrated in the drawings while omitting other details less relevant to the invention so as not to obscure the invention due to those unnecessary details.

[0032] Figure 1(A) shows a conventional light cover 110; and Figure 1(B) and Figure 1(C) shows LED tubes having the cover 110 as shown in Figure 1(A), respectively. The LED tubes as shown in Figure 1(B) and Figure 1(C) each include a cover 110, a base portion 120 and a LED light source 130. The cover 110 is mounted on the base portion 120, and the light source 130 is also mounted on the base portion inside the cover 110. In such structures, to add an optical feature such as a reflector needs extra mechanical supporting structure to fix the reflector.

[0033] Figure 2(A) is a schematic perspective diagram illustrating the structure of a light cover

210 according to an embodiment of the invention; and Figure 2(B) illustrates the cross section of the cover 210 as shown in Figure 2(A). [0034] As shown in Figures 2(A) and 2(B), the cover 210 includes a light transmitting portion

211 and reflective portions 213. The light transmitting portion 211 is clear or diffusive, so as to allow the light emitted from the light source within the lamp to pass through. The reflective portions 213 each project inwardly from the light transmitting portion 211. The side that faces the light source of each of the reflective portions 213 is a reflective surface that can reflect the light from the light source to transmit through the light transmitting portion 211. By the reflective portions 213, the luminance of the lamp may be enhanced and the distribution of the light emitted from the light source may be changed. For example, the light from a light source that is usually divergently distributed can be converged to a certain range by using the reflective portions. In addition, the reflective portions 213 and the light transmitting portion 211 are formed in integrity, thereby no extra mechanical structure is needed to support the reflective portions 213. In this way, the manufacturing and assembling processes of the lamp may be simplified while achieving the above optical effects.

[0035] In the example as shown in Figures 2(A) and 2(B), the surface at the side of each reflective portion 213 not facing the light source is separated from the inside surface of the light transmitting portion 211. Each of the reflective portions 213 is a part projecting inwardly from the outer contour (in Figures 2(A) and 2(B), the light transmitting portion 211 constitute the outer contour of the cover) of the cover. In other words, the end parts projecting inwardly of the reflective portions 213 are separated from the end parts of the light transmitting portion 211. As shown in the cross section in Figure 2(B), the light transmitting portion 211 may be divided into two parts by the reflective portions, i.e. the first part which faces the reflective surfaces (i.e. the surfaces facing the light source) of the reflective portions and the second parts which face the surfaces (i.e. the surfaces not facing the light source) opposite to the reflective surfaces of the reflective portions. The inside surfaces of each of the second parts of the light transmitting portion 211 and the surface of the reflective portion not facing the light source form a certain angel. That is, the surface at the side, not facing the light source, of each reflective portion is separated from the inside surfaces of the second parts of the transmitting portion.

[0036] As an example, the light transmitting portion and the reflective portions may be formed of plastic materials, such as PC (Polycarbonate) material, and PMMA (Polymethylmethacrylate, also referred to as Acrylic) material, etc. The light transmitting portion and the reflective portions may be formed of different plastic materials. For example, the light transmitting portion may be formed of a clear or transparent material or a diffusive material, and the reflective portions may be formed of a reflective material (e.g. by adding toner material into the clear or transparent material, which makes the manufacturing more simplified).

[0037] In an example, the cover may be manufactured by a two-color extrusion process. In Figures 2(A) and 2(B) the cover as shown is bar shaped (or tubular), and the light transmitting portion and the reflective portions thereof are also bar shaped. Such cover can be manufactured by a two-color extrusion process, so as to form the light transmitting portion and the reflective portions integrally. It should be noted that any appropriate two color extrusion process or apparatus may be used to make the cover. For example, firstly the materials for making the cover may be provided (different materials are used for the light transmitting portion and the reflective portions), then the extrusion opening may be configured according to the cross section of the cover (e.g. the cross sections as shown in Figure 2-5), and finally the cover may be made by the extrusion processes. The detailed description of the extrusion processes is omitted herein.

[0038] In another example, the cover may be manufactured by a two-color injection molding process. It should be noted that any appropriate injection molding process or apparatus may be used to make the cover. For example, the mould for the cover may be configured according to the structure of the cover (e.g. the structures as shown in Figures 2-8), the injection molding process may then be performed using the configured mould, and finally the mould is removed to form the cover. The detailed description of the injection molding processes is omitted herein. [0039] It should be noted that the process of manufacturing the cover according to the above and following embodiments/examples of the invention is not limited to the two color extrusion or two color injection molding process stated above. Instead, the cover may be manufactured by any other appropriate process, such as hot-pressing process, and fusion process, etc.

[0040] As another example, the light transmitting portion may be formed of other clear or diffusive materials, such as glass, and the reflective portion may be formed of a different material such as plastic. In this case, the glass light transmitting portion may be made first by using an appropriate process, then the plastic reflective portion may be formed in integral with the light transmitting portion by a fusion process.

[0041] Figure 3 illustrates the cross section of a light cover according to another embodiment of the invention. The embodiment as shown in Figure 3 is similar to that as shown in Figure 2 in that the cover 310 includes a light transmitting portion 311 and a reflective portion 313. The difference lies in that the reflective portion 313 includes two layers, i.e. a supporting layer 313-1 and a reflective layer 313-2. For example, the supporting layer 313-1 may be made of the material same as that of the light transmitting portion 311, and the reflective layer 313-2 may be made of a reflective material. For example, the supporting layer and the light transmitting portion may be formed integrally by using a single-color or two-color extrusion or injection molding process, and then the reflective material may be laminated onto the supporting layer by a hot pressing process, thereby forming the reflective layer integrally with the supporting layer and the light transmitting portion.

[0042] In addition, the reflective portions 213 of the cover 210 as shown in Figure 2 include two parts that are disposed symmetrically. In contrast, the reflective portion 313 of the cover 310 as shown in Figure 3 is asymmetrically disposed. In fact, the reflective portion may be disposed symmetrically or asymmetrically with respect to the light source according to the actual requirements to achieve different optical effects. The invention should not be limited to the particular examples or embodiments.

[0043] In the covers as shown in Figures 2 and 3, the reflective surfaces of the reflective portions are planes. In some other examples, the reflective surface may be a curved surface of arbitrary shape. Figure 4 illustrates the cross section of a light cover according to another embodiment of the invention, in which the reflective portion has a concave shaped reflective surface. Similar to those as shown in Figures 2 and 3, the cover 410 as shown in Figure 4 also includes a light transmitting portion 411 and a reflective portion 413 formed integrally with the light transmitting portion 411. The difference lies in that the reflective surface of the reflective portion 413 is a curved surface. [0044] It will be appreciated that the reflective surface of the reflective portion in the cover according to the embodiments of the invention is not limited to the particular shapes shown above and below. Covers of different shapes may have reflective portions having differently shaped reflective surfaces, to achieve different optical effects. That is, the reflective surface of the reflective portion may configured as any curved surface with an appropriate shape (e.g. a convex or concave paraboloid, or a curved surface with other shapes), or may be configured as a plane.

[0045] In the above embodiments/examples, the reflective portion of the cover is shown as a contiguous part in the whole. As another embodiment, the reflective portion may include a plurality of intermittent parts. Figure 5 illustrates such an example. Similar to those as shown in Figures 3-4, the cover 510 as shown in Figure 5 also includes a light transmitting portion 511 and a reflective portion 513 formed integrally with the light transmitting portion 511. The difference lies in that the reflective portion 513 includes a plurality of intermittent parts, rather than a contiguous part in the whole. Each of the parts of the reflective portion 513 is formed integrally with the light transmitting portion 511. For example, if a plurality of light sources are disposed inside the cover 510, each part may correspond to a light source. This may reduce the weight of the lamp. For another example, each part of the reflective portion 513 may have a corresponding part (not shown) disposed symmetrically therewith with respect to the light source. As an example, the light transmitting portion 511 and a contiguous reflective portion may be formed integrally by a two color extrusion process, and then the unwanted parts on the reflective portion may be removed using an appropriate process, thereby forming the reflective portion 513 including the plurality of intermittent parts. As another example, the light transmitting portion 511 and the reflective portion 513 including the plurality of intermittent parts may be formed integrally by a two color injection molding process.

[0046] Figures 9(A) is a schematic perspective diagram illustrating a lamp having the cover as shown in Figures 2(A) and 2(B), and 9(B) is a schematic diagram showing the cross section of the lamp as shown in Figure 9(A).

[0047] The lamp as shown in Figures 9(A) and 9(B) includes the cover 210, a base portion 220 and a light source 230. The cover 210 includes the light transmitting portion 211 and the reflective portions 213 formed integrally with the light transmitting portion 211. The cover 210 is similar to that shown in Figure 2, the description of which is not repeated herein. As shown in Figure 9, (the light transmitting portion 211 of) the cover 210 is engaged with the base portion 220, and the light source 230 is mounted on the base portion 220. The reflective portions 213 of the cover 210 are capable of reflecting the light from the light source to transmit through the light transmitting portion 211. As an example, the reflective portion 213 may be non-transparent and thus the wires and/or other electronic devise except the light source may be disposed at the side not facing the light source, i.e. disposed between the reflective portions 213 and the base portion 220, so that the lamp may have a neater and better appearance.

[0048] As shown in Figure 9(B), the angle between the tangent plane of the reflective portion 213 and the plane mounting the light source is denoted by Θ. The value of the angle Θ may be of any value between 0° and 90°. Preferably, the value of Θ ranges from about 10° to about 90°, such as about 10°, 15°, 20°, 45°, 50°, 55°, 60°,..., 75°, 80°, 85°, etc. Different values of the angle Θ may lead to different distributions of the light reflected by the reflective portion. The value of the angle Θ may be set according to actual requirements.

[0049] The light source 230 shown in Figure 9 may be a LED. The lamp as shown in Figure 9 may a LED tube. It should be noted that the cover according to the invention may be applied to other appropriate types of light sources, and should not be limited to the particular embodiments. In addition, the lamp as shown in Figure 9 may include a plurality of light sources. In some embodiments, the lamp having a cover according to the invention may include only one light source. [0050] The cross sections of the covers in Figures 2-5 each are of a semicircular shape. It will be appreciated that the cross section of the cover according to the invention is not limited to these particular shapes, for example, the cross section may be of a circular, square, rectangle, trapezium, ellipse, semi-ellipse, parabola shape, or any other appropriate shapes. [0051] In addition, the covers in Figures 2-5 are bar shaped (tubular). However, the cover according to the invention is not limited to the particular shape, for example, the cover may have a shape similar to a cube, a cuboid, a ball, a ellipsoid or any other appropriate shapes. Figures 6(A) and 6(B) illustrate a cover 610, the top part of which is ball-like, according to an embodiment of the invention, in which Figure 6(A) is a schematic perspective diagram illustrating the structure of the cover 610; and Figure 6(B) is a schematic diagram showing the cross section of the cover 610 cut along the dotted line AA' as shown in Figure 6(A).

[0052] As shown in Figures 6(A) and 6(B), the cover 610 includes a light transmitting portion 611 and a reflective portion 613 formed integrally with the light transmitting portion 611. Similar to the above described embodiments/examples, the light transmitting portion 611 may be made of a clear or diffusive material, so as to allow the light emitted from the light source to pass through. As shown, the reflective portion 613 projects inwardly from the light transmitting portion 611. The side, which faces the light source (not shown), of the reflective portion 613 is a reflective surface, the shape of which is similar to the surface of a cone. In an example, the shape of the reflective surface may be similar to the surface of a cylinder. In other examples, the shape of the reflective surface may be any other appropriate shape.

[0053] Figure 7 is a schematic perspective diagram illustrating the structure of a light covers according to an embodiment of the invention. Similar to the cover 610 as shown in Figure 6, the cover 710 includes a light transmitting portion 711 and a reflective portion 713 which is formed integrally with the light transmitting portion 711 and projects inwardly from the light transmitting portion 711. The side, which faces the light source (not shown), of the reflective portion 713 is a reflective surface, the shape of which is similar to the surface of a cone. The difference lies in that the reflective portion 713 is not a contiguous part in a whole, but includes a plurality of intermittent parts. Particularly, the reflective portion 713 includes 4 intermittent parts, which are disposed symmetrically around the light source (not shown). As another example, the reflective portion may include a plurality parts which are disposed asymmetrically around the light source. For example, the cover 810 as shown in Figure 8 includes a reflective portion 813 including 3 parts which are disposed asymmetrically around the light source (not shown). The other components as shown in Figure 8 are similar to those shown in Figure 7, the description of which is omitted herein. [0054] As an example, the covers as shown in Figures 6-8 may be manufactured by using two color injection molding process, so as to form the light transmitting portion and the reflective portion integrally. Of course, other appropriate processes may be used.

[0055] Though not shown, the covers as shown in Figures 6-8 may be applied to any appropriate light source, such as LED. According to an embodiment of the invention, a lamp may include the cover as shown in Figure 6 or 7 or 8, and a light source and a base portion. The light source is mounted on the base portion and the light transmitting portion of the cover is engaged with the base portion.

[0056] In the above embodiments and examples, the thickness of the light transmitting portion or the reflective portion of the cover is not limited. It will be appreciated that the thickness of the reflective portion may be configured in accordance with the light transmitting portion, or may be configured according to actual requirements, the description of which is omitted herein.

[0057] While some embodiments and examples have been disclosed above, it should be noted that these embodiments and examples are only used to illustrate the present invention but not to limit the present invention. Various modifications and changes can be made by those skilled in the art without departing from the scope of the present invention.

[0058] Furthermore, the terms "comprise," "include," "have" and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Claims

CLAIMS What is claimed is:

1. A light cover (210, 310, 410, 510, 610, 710, 810), comprising a light transmitting portion (211, 311, 411, 511, 611, 711, 811), characterized by further comprising a reflective portion (213, 313, 413, 513, 613, 713, 813) which is formed integrally with the light transmitting portion, projects inwardly from the light transmitting portion, and is capable of reflecting light emitted from a light source so that the light passes through the light transmitting portion.

2. The cover according to claim 1 , characterized in that the cover (210, 310, 410, 510) is bar shaped.

3. The cover according to claim 1 or 2, characterized in that the reflective portion (313) comprises a supporting layer (313-1) and a reflective layer (313-2), and wherein the reflective layer is formed of a reflective material.

4. The cover according to claim 1 or 2, characterized in that the reflective portion (213, 613, 713) is disposed symmetrically with respect to the light source.

5. The cover according to claim 1 or 2, characterized in that a surface, which faces the light source, of the reflective portion (213, 313, 413, 513, 613, 713, 813) is a plane or a curved surface.

6. The cover according to claim 5, characterized in that a tangency plane of the surface, which faces the light source, of the reflective portion (213, 313, 413, 513, 613, 713, 813) and the plane mounting the light source form an angle ranging from about 10° to about 90°.

7. The cover according to claim 1 or 2, characterized in that the light transmitting portion (211, 311, 411, 511, 611, 711, 811) is formed of a clear or diffuse material.

8. The cover according to claim 1 or 2, characterized in that an end part, which projects inwardly, of the reflective portion (213, 313, 413, 513, 613, 713, 813) is separated from end parts of the light transmitting portion (211, 311, 411, 511, 611, 711, 811).

9. A lamp, comprising a base (220) for mounting a light source (230), characterized by further comprising a cover (210, 310, 410, 510, 610, 710, 810) according to any one of the preceding claims, which is mounted on the base (220).

10. A two-color extrusion process for manufacturing a cover (210, 310, 410, 510) according to any one of claims 1-8, by which the light transmitting portion (211, 311, 411, 511) and the reflective portion (213, 313, 413, 513) of the cover are formed integrally.

11. A two-color injection molding process for manufacturing a cover (210, 310, 410, 510, 610, 710, 810) according to any one of claims 1-8, by which the light transmitting portion (211, 311, 411, 511, 611, 711, 811) and the reflective portion (213, 313, 413, 513, 613, 713, 813) of the cover are formed integrally.