Browse Prior Art Database

Method and System for Fabricating Light Pipes with a Molded Light Guide

IP.com Disclosure Number: IPCOM000238902D
Publication Date: 2014-Sep-24
Document File: 4 page(s) / 100K

Publishing Venue

The IP.com Prior Art Database

Abstract

A method and system is disclosed for fabricating a cost effective and high quality light guide. The light guide is made out of glass and molded polymer.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 48% of the total text.

Page 01 of 4

Method and System for Fabricating Light Pipes with a Molded Light Guide

Glass is a material with good optical properties such as good transparency , and resistance to intense optical irradiation. However, it is costly to produce with accurate dimensions and a smooth optical finish. There has been a trend to produce plastic light pipes, made out of Polymethyl methacrylate (PMMA) or Silicone materials, which are molded at very low cost, but with high precision. However, transparency and aging characteristics of such materials are usually inferior to that of glass .

Disclosed is a method and system for fabricating a cost effective and high quality light guide. The light guide is made out of glass and molded polymer . The light guide is utilized in solar photovoltaics where some of the light guiding process uses total internal reflection on side faces of the light guide. The side faces of the light guide can be made out of a molded polymer and the center core of the light guide comprises a glass material. The center core can also comprise several glass inclusions. The light guide can be of a prismatic shape, with a square entrance and a square exit face, and four trapeze side faces. The light guide can also be of a prismatic shape with a circular entrance face and a square exit face. Further, the side faces can connect the circular entrance face to the square exit face. In addition, the light guide can include a Graded Index (grin) glass.

In one implementation, the method and system utilizes the good optical quality of glass and the lower cost of a molded polymer by designing a hybrid light pipe that consists of a glass core embedded in a relatively thin shell of the molded polymer . Glass fills the core of the light guide where most of the light rays travel, thereby minimizing the aging and absorption losses in the polymer. Dimensional tolerances on the glass core are loose, enabling low cost production of the glass core. Molded polymer makes the side faces of the light guide, which provide for optical guiding via total internal reflection on the side faces.

In one implementation, the light pipe includes a piece of molded glass within an outer shell of molded transparent silicone.

Fig. 1 illustrates an embodiment of the method and system , where a plurality of glass cores fills a portion of the interior of the light pipe .

1


Page 02 of 4

Figure 1

As illustrated, the glass core fills a large fraction of the overall volume, in the order of half of the volume or more. The glass core can be mass produced as a small glass ingot, having a rough shape within some overall dimensional constraints and with limited surface smoothness. The outer shell material is selected from a range of transparent plastic materials that have sufficient adhesive property to effectively bond to the glass shell and to be readily molded in very cost-effective ways. Such plastic materials include, but are not limited to, PMMA, Polyimide, and Silicone.

In an implem...