Appeal No. 1998-2983 Application No. 08/481,230 The basic dispute between appellants and the examiner is based upon the definition of the term “window” in the claims. (See brief at page 12.) Appellants rely upon the express definition in the specification and the examiner relies upon the ordinary usage in the relevant field. Before addressing the examiner's rejections based upon prior art, it is an essential prerequisite that the claimed subject matter be fully understood. Analysis of whether a claim is patentable over the prior art under 35 U.S.C. §§ 102 and 103 begins with a determination of the scope of the claim. The properly interpreted claim must then be compared with the prior art. Claim interpretation must begin with the language of the claim itself. See Smithkline Diagnostics, Inc. v. Helena Laboratories Corp., 859 F.2d 878, 882, 8 USPQ2d 1468, 1472 (Fed. Cir. 1988). Accordingly, we will initially direct our attention to appellants' claim to derive an understanding of the scope and content thereof. Before turning to the proper construction of the claims, it is important to review some basic principles of claim construction. First, and most important, the language of the claim defines the scope of the protected invention. Yale Lock Mfg. Co. v. Greenleaf, 117 U.S. 554, 559 (1886) ("The scope of letters patent must be limited to the invention covered by the claim, and while the claim may be illustrated it cannot be enlarged by language used in other parts of the specification."); Autogiro Co. of America 4Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 NextLast modified: November 3, 2007