Patent Infringement (I)

Literal Infringement:

1. determining the meaning and scope of the patent claims asserted to be infringed
2. comparing the properly construed claims to the device accused of infringing

(Markman v. Westview Instruments, Inc.)

Doctrine of equivalents:

A product or process that does not literally infringe upon the express terms of a patent claim may nonetheless be found to infringe if there is 'equivalence' between of the elements of the accused product or process and the claimed element of the patented invention.

(Warner-Jenkinson Co. v. Hilton Davis Chem. Co.)

Limit of equivalence:

Each element contained in a patent claim is deemed material to defining the scope of the patented invention, and thus the doctrine of equivalents must be applied to individual element of the claim, not to the invention as a whole. It is important to ensure that the application of the doctrine, even as to an individual element, is not allowed such broad play as to effectively eliminate that element in its entirety.

Ref.
::Johnson & Johnson Assocs. Inc. v. R.E. Serv. Co.::