DIRECT LINK: http://ncbarblog.com/2016/11/file-early-how-provisional-patent-applications-increase-protection/
PDF of the article: fileearly-provisionals.pdf
and text repeated here:
Many applicants make the mistake of waiting until they have an ideal embodiment reduced to a high degree of precision before drafting a patent application. While skillful application drafting is important to the value of the patent, it is a mistake to presume that one should wait to file until the invention is crafted to a state of perfection.
The value to the public of a granted patent is a fulsome disclosure that advances the state of the art. Patent protection effected by the application extends to the degree that the applicant’s claims are adequately supported by that disclosure. The requirement that the disclosure must be at least as much as is claimed seems logical with respect to the benefit of the patent to the public. However, for the applicant, it creates an inverse relationship between depth of disclosure and breadth of protection.
A generic disclosure with very little specificity may be enough to facilitate claimable scope. However, broad scope risks a higher likelihood of rejection over prior art that might otherwise have been irrelevant to protection of a narrower embodiment. A more specific disclosure provides support for narrower claims, to decrease the risk of rejection, but it provides more teachings to the public. As a practical effect: the greater the teachings made to the public, the greater the likelihood of infringement or imitation in the marketplace.
A provisional application provides a mechanism for enhancing the value of the final application. Unlike non-provisional applications, provisional applications must provide disclosure, but do not require claims. Claim drafting requires perception of which embodiments must not be excluded. As a result, the task of drafting a non-provisional, without following a provisional, provides a condensed roadmap between broadest notion and which embodiment is known by the savvyinventor, to have value.
Filing a provisional application enables the inventor to protect broad disclosure with an early filing date. The inventor can then follow that provisional application up with a later non-provisional application that focuses on the key embodiments, ultimately leading to a more valuable issued patent.