## Facts

- Arnold G. Klein filed a patent application for a “convenience nectar mixing device” used to prepare sugar-water nectar for bird and butterfly feeders.
- The device used a container with fixed receiving structures (rails) and a movable divider to form two compartments with predetermined proportional volumes corresponding to recognized nectar ratios for hummingbirds, orioles, and butterflies.
- The divider could be repositioned to create different volume ratios; after filling the compartments to the same level with sugar and water, removal of the divider allowed mixing.
- The PTO rejected claims as obvious under 35 U.S.C. § 103(a) based on combining five references: three drawer-organizer patents with movable dividers (Roberts, O’Connor, Kirkman) and two two-compartment mixing containers with fixed separations (Greenspan, De Santo), along with known sugar-water ratios.
- The Board affirmed, finding the references analogous art and sufficient to support obviousness; Klein appealed to the Federal Circuit.

## Issues

1. Whether substantial evidence supported the Board’s finding that the cited drawer-organizer and two-compartment container references were analogous art to Klein’s nectar-mixing claims.
2. Whether a § 103(a) obviousness rejection can stand when the asserted combination relies on references not in the same field of endeavor and not reasonably pertinent to the inventor’s specific problem.

## Decision

- The Federal Circuit reversed the Board’s decision.
- The court held the Board’s analogous-art finding was not supported by substantial evidence.
- The court concluded the cited references were neither in Klein’s field of endeavor nor reasonably pertinent to Klein’s problem of conveniently producing multiple predetermined nectar ratios using a movable divider guided by rails.
- Because the references were non-analogous, they could not support the § 103(a) obviousness rejections.

## Legal Principles

- A prior-art reference is analogous art only if it is (1) from the same field of endeavor as the claimed invention, or (2) reasonably pertinent to the particular problem the inventor faced.
- Reasonable pertinence depends on whether the reference would logically have commended itself to an inventor’s attention in addressing the specific problem, not merely on superficial structural similarity.
- The PTO may not define the “problem” at an overly general level to sweep in remote references; the problem must reflect the invention’s actual objective and context.
- If the PTO’s obviousness theory depends on non-analogous art, the § 103 rejection cannot be sustained.

## Conclusion

The Federal Circuit set aside the PTO’s obviousness rejections because the asserted prior art—drawer organizers and fixed-compartment mixing containers—did not qualify as analogous art to a nectar-mixing device designed to produce selectable, predetermined sugar-water ratios using a movable divider system.


In re Klein, 647 F.3d 1343 (Fed. Cir. 2011)