A lawsuit of HSM Portfolio LLC and Technology Properties Limited LLC against Micron shows how easy image sensor company can be accused in patent infringement. Some of Micron image sensor products allegedly infringe on some of 3 patents:
US5001367 "High speed complementary field effect transistor logic circuits" filed in 1989 and describing an inverter chain with a sequential size scaling.
US5030853 "High speed logic and memory family using ring segment buffer" filed in 1990, describing an inverter chain with a positive feedback.
US5391949 "Differential latching inverter circuit" filed in 1995, describing a latched logic buffer.
Neither patent has a direct relation to the image sensor technology.
It looks like all these patents have expired. Prior to June of 1995 the term of a patent was 17 years from the data of issue. So these all expired 2008 - 2012. So they can only sue for infringement before that date.
ReplyDeleteIt seems reasonable that image sensors would use many patented circuits that have nothing to do with image sensors.
Indeed, these other patented circuits always made us a bit paranoid back in the early Photobit days in considering suing Agilent or some other company with deep IP pockets. Many "textbook" circuits are patented, even if they are junk patents in the hands of trolls.
Delete