Typically 30 months after filing a non-provisional patent application, an examiner at the USPTO will review the claims written in your patent and determine if there are patents, applications or other references that were created before your filing date that have similar features as claimed in your patent application. In this regard, Office Actions are similar to a search report, but are conducted by an examiner at the USPTO.
If the examiner was unable to find any patents, alone or in combination, that have features that are similar to those claimed in your patent, then the Office Action may indicate that all the claims are allowed, and subsequently you will have a granted patent.
In most cases, however, the Office Action will identify a set of prior art references, which may be a combination of reference, patents and patent applications, that the examiner uses to reject the claims of your patent application as being anticipated (i.e., not new) or obvious in view of the previous patents, applications and other literature. The Office Action may provide insight as to the examiner’s train of thought and subject matter that the examiner may consider to be patentable.
If an examiner rejects the claims in the patent, you are given the opportunity to narrow the claims in your patent, which will result in limited scope of patent protection for your invention. This is a typical give-and-take between the examiner and an inventor. If you disagree with the examiner’s reasoning in the Office Action, you are able to present arguments which may lead to the examiner withdrawing his rejection.
The Office Action will provide a time period (e.g., three months) in which the applicant must file a response addressing each objection and rejection identified by the examiner. In certain situations, the response may be filed after the stated period upon payment of a late fee. No fee is filed if the response is filed within the stated time period. Generally two or three Office Actions and corresponding responses will be filed before a patent is obtained.
As a note, if you obtain a patent and are unhappy with the scope of the protection given by the claims, you can file additional patent applications that only require a governmental filing fee.