Disc-shaped information carrier and method of manufacturing it
CA 1249884 A · Owner: Philips Electronics N.V. · Inventors: Schuddekopf, Hans; Benne, Karsten; Koop, Hermann
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
17, ABSTRACT:, Disc-shaped information carrier and method of manufacturing it. The invention relates to disc-shaped information carriers which can be read optically in reflection and which contain an annular information zone which is bounded by a concentric inner zone and a concentric outer zone. The information carrier consists of a transparent substrate and has a readout side and an opposite side (back) which at least in the information zone has a reflective coating. The light entering the outer zone from the readout side is reflected at least partially diffusely or absorbed by the information carrier. In this way manufacturing, defects such as, for example inclusions, inhomogeneities, …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted February 7, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 7, 2006.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.