What Happens After Expiry
Patents protect the rights of the inventor, but at the same time the very purpose of issuing patents is to "promote science and useful arts" wherein the inventor agrees to share the knowledge to the world after a period of exclusive right to commercially exploit the knowledge. Therefore, the inventor retains monopoly over the invention during the pendency of the patent. After expiry, the knowledge becomes public domain that anyone can access and use. The government makes public the description of the product, filed at the time of application. The inventor no longer has exclusive rights over the knowledge or invention, and anyone can access the patent office records and copy the invention.
When patents expire, many businesses usually launch similar products, very often innovating on the product to bring out better quality and/or lower priced products to serve the same purpose. This is particularly noticeable in pharmaceutical drugs. When the patent of a drug expires, other pharmacies sell “generic" drugs with very similar components to the name brand drug.
Companies or inventors looking to retain their monopoly may file for a second generation patent after the original patent expires. Such second generation applications seek to protect some form of variation or improvement of the original. For instance, a drug manufacturer may claim further medical use of a product, such as trying to patent aspirin for fluidifying blood when the original patent may patent aspirin as a pain killer, or on a different dosage regimen. The patent office, however, need not always grant the second generation patent.
Inventors and businesses need to have a thorough knowledge about patent lifecycles, and what happens after expiry to harness the commercial benefits of the invention during the time they have monopoly rights.