When does a patent become public?
In most countries, a patent application is published 18 months after it is filed. Therefore there is always a time lag between the invention and the publication of the patent application.
Generally, however, patents are granted long time ago before a patented product is introduced in the market. Very often this time gap is between 5 and 11 years.
As such, the publication of a patent application, despite the time lag, is invariably the earliest point in time at which the relevant information becomes available to the public.