Patent Application
20200284973
This invention relates to illuminating devices for distributing light from a light source. In particular, the illuminating device is manufactured as a single piece to ensure robust and consistent lighting output.
Current light-emitting diode (LED) lighting for automobile interiors, such as ceiling lights, generally includes an illuminating device for distributing the light. Typically, the illuminating device contains two waveguides: a first waveguide conducting light in a first direction and extracting the light in a second direction orthogonal to the first direction as the light travels in the first direction; and, a second waveguide receiving the extracted light from the first waveguide and forming an illuminating surface. An example of such a lighting assembly is disclosed, e.g. in U.S. Patent Application Publication No. 2010/0315833 to Holman et al. The two waveguides must be aligned within a tight tolerance for reliable and consistent lighting output. Current illuminating devices, however, are prone to misalignment of the waveguides, either during assembly or during use of the light, resulting in poor and inconsistent light output and distribution.
Therefore, there remains a need for an illuminating device that provides reliable and consistent lighting output and distribution, by providing robust alignment of the waveguides.
An aspect of the present invention provides a light illuminating device containing a first waveguide and a second waveguide connected to the first waveguide by a bridge. The bridge is configured to align and to maintain the first waveguide and the second waveguide in spaced relation, such that an air gap exists between the first and second waveguides. The bridge aligns the first and second waveguides to ensure a consistent gap to provide reliable and consistent lighting output and distribution. The first waveguide is configured to receive light from a light source to a receiving end, conducting the light along its length in the x-direction, and reflecting the light in the y-direction toward the second waveguide. The second waveguide is configured to receive light from the first waveguide, conducting the light along its width in the y-direction, and reflecting the light in the z-direction through a bottom surface to illuminate a region below the second waveguide.
Another aspect of the present invention provides a lighting apparatus containing the illuminating device described above. The lighting apparatus may be used in interior lighting, such as for an automobile or a room
A further aspect of the present invention provides an automobile containing a lighting apparatus described above.
Methods for making and using the different aspects of the present invention are also provided.
Other aspects of the invention, including apparatuses, devices, kits, processes, and the like which constitute part of the invention, will become more apparent upon reading the following detailed description of the exemplary embodiments.
The foregoing background and summary, as well as the following detailed description, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
The exemplary embodiment of the present invention will now be described with the reference to accompanying drawings. The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
For purposes of the following description, certain terminology is used in the following description for convenience only and is not limiting. The characterizations of various components and orientations described herein as being “front,” “back,” “vertical,” “horizontal,” “upright,” “right,” ‘left,” “side,” “top,” “bottom,” “above,” “below,” or the like designate directions in the drawings to which reference is made and are relative characterizations only based upon the particular position or orientation of a given component as illustrated. These terms shall not be regarded as limiting the invention. The words “downward” and “upward” refer to position in a vertical direction relative to a geometric center of the apparatus of the present invention and designated parts thereof. The terminology includes the words above specifically mentioned, derivatives thereof and words of similar import.
Referring to
The first waveguide 102 is preferably an elongated bar having a length in the x-direction, a width in the y-direction, and a thickness in the z-direction, as noted in
As one example, the light source is an LED-based light emitter. The LED emitter may contain a single LED having one or more LED chips coupled with appropriate optics designed to collect and transport the light efficiently from the LED emitter to the receiving end 110 of the first waveguide 102. Preferably, the light entering the receiving end 110 is collimated in the x-direction. Other LED light emitters known in the art are also contemplated for use with the present invention.
The first waveguide 102 preferably has a substantially, square (or rectangular) cross-section and transmits input light flowing within the waveguide by total internal reflection. The side 112 of the first waveguide 102 (the side farthest from the second waveguide 104) contains one or more light extracting structures 114 for extracting a fraction of the light flowing within first waveguide 102 as the light strikes the light extracting structure 114 along the length of the first waveguide 102, and redirecting the extracted light uniformly over the length of the first waveguide 102 substantially in the y-direction through the air gap 108 and to the second waveguide 104. The light extracting structure 114 may be those known in the art, such as gratings, focusing lens, microprisms, other microoptical features, or combinations thereof, with microprisms being the preferred light extracting feature. One light extracting structure 114 is shown, e.g., in U.S. Patent Application Publication No. 2010/0315833, which is incorporated herein by reference. The light extracting structure 114 may be formed directly on the side 112 of first waveguide 102 or attached thereto, e.g. as a film layer. In an embodiment, the light extracting structure 114 may be in the form of a micro-patterned layer and/or having one or more reflecting surfaces (e.g. mirrors). In another embodiment, the extracting structure 114 may be a plurality of protruding structures on the side 112 of the first waveguide 102. Preferably, the plurality of protruding structures may have a triangular cross-sectional shape forming a series of microprisms. Depending on the size of the light source, the first waveguide 102 may have a thickness of about 1 mm to about 5 mm, a width of about 1 mm to about 5 mm, and a length of about 10 to about 600 mm. For example, the first wave guide 102 may have a cross-section of about 2 mm×3 mm, about 3 mm×2 mm, about 4 mm×5 mm, etc.
The second waveguide 104 is preferably a flat, square (or rectangular) plate having a length in the x-direction, a width in the y-direction, and a thickness in the z-direction, as noted in
The first and second waveguides 102 and 104 are aligned relative to each other, so that the air gap 108 separates the two waveguides. In proper alignment, the receiving surface 116 of the second waveguide 103 faces the emitting surface 115 of the first waveguide 102, with the gap 108 separating the two surfaces 115 and 116. Preferably, the gap 108 is made as small as possible and is usually limited by production methods. Depending on the application of the illuminating device 100, the gap 108 may be from about 0.8 mm to about 1.5 mm. The width of the gap 108 may vary along the length of the waveguides 102 and 104; however, preferably, the width of the gap 108 is the same along the length of the waveguides 102 and 104.
To properly align the first and second waveguides 102 and 104, the bridge 106 is used to connect the two waveguides 102 and 104 and to rigidly hold them apart. The bridge 106 provides a robust mechanism to align the first and second waveguides 102 and 104 to control the width of the gap 108. The bridge 106 contains a first end 122 attached to the bottom surface 124 of the first waveguide 102 and a second end 126 attached to the bottom surface 118 of the second waveguide 104. Importantly, the bridge 106 does not intrude into the gap 108, so that it does not interfere with the light transmission through the gap 108. As such, as shown in
The waveguides 102 and 104 may be made of a transparent material, e.g., an optically transparent material. For example, the (optically) transparent material may be optically transmissive to an electromagnetic radiation of the visible light spectrum emitted from the light source. The material is preferably an optically transparent plastic, preferably polymethyl methacrylate acrylate (PMMA), polycarbonate, or combinations thereof. The waveguides 102 and 104 and the bridge 106 may be formed by injection molding, a technique known in the art, of the optical transparent plastic. Preferably, the waveguides 102 and 104 and the bridge 106 are form, e.g. molded, from the same material as a single piece.
In use, the illuminating device 100 receives light from the light source and distributes the light through the bottom surface 118 of the second waveguide 104 to provide illumination in the region below the second waveguide 104. In doing so, the first wave guide 102 receives light from the light source at the receiving end 110, and conducts the light along its length in the x-direction. As the light is being conducted in the first waveguide 102, the light is extracted and directed in the y-direction toward the second waveguide 104 due to the light extracting structure 114 on the first waveguide 102. The reflected light traverses the gap 108 and enters the second waveguide 104 at the receiving edge 116. The second waveguide 104 conducts the light along its width in the y-direction. As the light is being conducted in the first waveguide 102, the light is extracted and directed in the z-direction due to the light extracting structure 119 on the second waveguide. 104. The extracted light exits the second waveguide 104 at its bottom surface 118, to illuminate in the region below the second waveguide 104. The disclosed illuminating device 100 may be used in lighting assembly to provide aesthetically pleasing, sturdy, cost effective lighting for use in interior lighting, such as for an automobile or a room.
Although certain presently preferred embodiments of the invention have been specifically described herein, it will be apparent to those skilled in the art to which the invention pertains that variations and modifications of the various embodiments shown and described herein may be made without departing from the spirit and scope of the invention.
