28 May 2004
The pick of this week’s patent applications including an LED based on a silicon substrate.
• Title: Semiconductor light-emitting device and method for manufacturing the same
Applicant: Sanken Electric Co., Ltd., Japan
International application number: WO 2004/042832
An LED based on a low-resistance silicon substrate is the subject of patent application WO 2004/042832. Alleged to have improved emission characteristics, the device comprises a buffer layer, n- and p- type semiconductor layers and a multi quantum well active layer. The active layer is said to contain two sets of auxiliary layers made from AlGaInN which prevent indium evaporating or diffusing out of the InGaN quantum well layers.
• Title: Method for manufacturing an optical fiber preform by MCVD
Applicant: LG Cable Ltd, Korea
International application number: WO 2004/041737
Manufacturing an optical fiber preform by MCVD improves the fiber’s bandwidth and polarization mode dispersion, according to LG Cable of Korea. Described in patent application WO 2004/041737, the technique uses two simultaneous processes. The first is an etching process for injecting a reaction gas and the second is a collapsing process to minimise or eliminate an index dip at the center of the preform’s core.
• Title: Flexible device and method of manufacturing the same
Applicant: Koninklijke Philips Electronics N.V, the Netherlands
International application number: WO 2004/042780
Philips is trying to patent a rollable device, such as an organic display. Described in application WO 2004/042780, the device is based on an insulating substrate and is said to have apertures extending from one side to the other. “On the first side, switching elements are present, as well as interconnect lines covered by an organic material,” say the inventors. “On the second side, a functional layer is present.” The inventors list examples of functional layers as capacitors, antennas and electro-optic layers. This could result in a rollable display that includes an antenna and a driver circuit.
• Title: Laser apparatus for treating hard tissues and method for using the apparatus
Applicant: Universita' Dgli Studi di Padova, Italy
International application number: WO 2004/041104
Patent application WO 2004/041104 describes a way to combine a semiconductor laser and a chromophore to treat hard tissues such as teeth. The laser is fiber-coupled and focused onto the tissue using a lens while the delivery of the chromophore is electronically controlled. The applicants stress that the chromophore much have a high absorption co-efficient at the laser wavelength.