What is the significance of the ‘In re Preda’ case in understanding implicit disclosure?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

The In re Preda case is significant in understanding implicit disclosure as it provides a clear example of how the concept is applied in patent examination. According to MPEP 2144.01:

“A process for catalytically producing carbon disulfide by reacting sulfur vapor and methane in the presence of charcoal at a temperature of ‘about 750-830°C’ was found to be met by a reference which expressly taught the same process at 700°C because the reference recognized the possibility of using temperatures greater than 750°C.”

This case illustrates that a reference can implicitly disclose a range of temperatures even when it explicitly mentions a lower temperature. The key is that the reference acknowledged the feasibility of higher temperatures, which was considered an implicit disclosure of the claimed range.