## Facts

- Alberto Lee Bigio sought patent claims directed to a “hair brush” with an hourglass-shaped bristle substrate and an hourglass bristle array.
- Representative claim language described a handle segment and a bristle substrate segment on a common axial centerline, with a smoothly curved, radially narrower central region and radially larger end regions, carrying bristle bundles arranged in an hourglass configuration.
- A PTO examiner rejected claims 1, 2, and 4–7 as obvious under 35 U.S.C. § 103(a).
- The examiner relied on a British toothbrush patent (Flemming) combined with one of two U.S. design patents for toothbrush configurations (Tobias or Cohen).
- Bigio argued that “hair brush” should be limited to brushes for scalp hair, making toothbrush references non-analogous art.
- The Board of Patent Appeals and Interferences affirmed the rejection, applying a broader construction of “hair brush” and treating the toothbrush references as analogous art.
- Bigio appealed to the U.S. Court of Appeals for the Federal Circuit.

## Issues

1. Whether the PTO properly applied the broadest reasonable interpretation standard to construe “hair brush” broadly enough to include brushes for human and animal hair generally, rather than only scalp-hair brushes.
2. Whether, under the proper claim construction and analogous-art framework, toothbrush references could be treated as analogous prior art supporting a § 103(a) obviousness rejection.

## Decision

- The Federal Circuit affirmed the Board’s claim construction applying the broadest reasonable interpretation consistent with the specification.
- The court held that “hair brush” was reasonably construed to cover brushes for human hair as well as animal hair, and was not limited to scalp hair absent clear limiting language or disavowal.
- Applying the analogous-art test, the court held the toothbrush references were in the same field of endeavor as the claimed invention, given shared structural features (handle and bristle substrate) and related brushing function.
- The court concluded substantial evidence supported the Board’s determination that the claimed hourglass configuration would have been obvious in view of Flemming combined with Tobias or Cohen.
- The court affirmed the § 103(a) rejection; a dissent argued the field-of-endeavor and analogous-art determinations were too expansive.

## Legal Principles

- During PTO examination, claims receive their broadest reasonable interpretation consistent with the specification; ordinary meaning governs unless the applicant clearly defines terms or disavows scope.
- Analogous prior art for § 103 includes (1) references from the same field of endeavor regardless of the problem addressed, or (2) references reasonably pertinent to the problem faced by the inventor.
- A reference may qualify as within the same field of endeavor when it shares relevant structural characteristics and functional attributes with the claimed invention, even if the products’ end uses differ.
- If the PTO’s claim construction and analogous-art determination are upheld, an obviousness rejection may be affirmed where substantial evidence supports the conclusion that differences from the combined prior art are insubstantial.

## Conclusion

The Federal Circuit affirmed the PTO’s obviousness rejection because the term “hair brush” was reasonably construed broadly under PTO practice, bringing toothbrush designs within analogous art and supporting a finding that the claimed hourglass-shaped brush configuration would have been obvious.


In re Bigio, 381 F.3d 1320 (Fed. Cir. 2004)