Inorganic lenses for high performance optical systems
Publication Date: 2005-Nov-24
The IP.com Prior Art Database
Inorganic lenses for high performance optical systems.
Background of the invention
State of the art lenses for DVD/Blu-ray Disc optics are manufactured by moulding an organic resin over a glass substrate. These lenses have several disadvantages. The organic polymer degrades due to high light loads and the elevated operating temperatures (100-120°C). Lens design is also difficult as the polymers have a large thermal expansion coefficient (80-100 ppm). Materials with increased stability, especially for blue light and in the future UV light are required. These lens materials are desired in order to have small optics with high light loads and the corresponding elevated operating temperatures.
Problems or disadvantages overcome by the invention
Commonly, inorganic materials need processing at high temperatures (400°C+). These temperatures are needed, either to shape the material, or to obtain the desired material properties. The product often needs a post-processing step to give it a desired low optical roughness.
We are able to produce inorganic lenses. The shape can be fixated at low temperatures (between 100°C and 200°C) in, for example, a silicone rubber mould. The inorganic material exhibits low shrinkage on curing (<10%) and has a low thermal expansion coefficient (+- 30 ppm).
The inorganic material is a methyl modified silicon oxide. The silicon-carbon bond is thermally stable up to 400°C in air and UV stable for wavelengths down to 250 nm.
The essential feature(s) of the invention
The methylated silicon oxide has an index of refraction of 1.45 . To increase the index of refraction, nano particles can be incorporate...