Differential-permeability field-concentrating magnetic writing head
CA 1189969 A · Owner: Ferix Corporation · Inventors: Springer, Gilbert D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure A magnetic-image writing head including inner and outer, substantially co-planar, symmetrically arranged pole portions. In one embodiment, the head is disclosed with the inner pole portion presentinq a substantially full-circular facial expanse, and with the outer pole portion presenting an annular facial expanse surrounding that of the inner pole portion. In another embodiment, each of the two pole portions presents a substantially annular facial expanse. In both embodiments, the inner pole portion has a magnetic permeability which is significantly lower than that of the outer pole portion. An image unit written on a magnetic-image-storage medium by the head …
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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 July 2, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 2, 2002.
- 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.