Appeal No. 1998-0200
Application No. 08/698,193
embodiment, and arriving within the Claim 12 range of permeability would have resulted from routine
experimentation and optimizing.
We note that Jeffers was confronted with the same problem as appellants -- overcoming the
deleterious effect of the required electrically insulating intermediate layer. The reference teaches
replacing the prior art layer with a material that promotes coupling of the magnetic flux between the flux
conducting limb and the magnetoresistive element. However, appellants have chosen to use a material
of relatively low permeability (see, e.g., specification, page 2, lines 10 through 16), as opposed to the
material of relatively high permeability disclosed by Jeffers. Appellants chose a material of relatively
low permeability for purposes of simpler construction. (See specification, page 2, line 29 through page
3, line 9).
2
Appellants’ specification gives a range of “relatively low permeability ,” and provides an
example of what is considered a relatively high relative magnetic permeability -- 1000 -- albeit with
respect to material suitable for flux guides. (See specification, page 1, lines 11 through 15). Jeffers, at
column 2, lines 43 through 62, discloses that the electrically non-conductive material is of “relative high
magnetic permeability,” and refers to U.S. Patent 4,477,319 for details of depositing a thin film of the
magnetically conductive layer. U.S. Patent 4,477,319 (to Abe et al.) does not deal with permeability of
2We note in passing that appellants’ Figure 18 appears to show as an ordinate F ranging from 1.100
r
3 0 3
(= 1) to 1.10 (= 1.331). However, we assume that the range shown is 1 x 10 (= 1) to 1 x 10 (= 1000),
and the curve shows the selected range of F , consistent with the written description, of 1.1 to 25.
r
- 6 -
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