In re Iwahashi, 1989

This case marked quite a change from earlier positions. In this case, the Federal Circuit held that a general purpose computer, running an new algorithm for pattern recognition, could be patentable subject matter.

Iwahashi’s invention related to an auto-correlation unit for use in a pattern recognition to obtain auto-correlation coefficients as for stored signal samples. One particular embodiment related to using pattern recognition in voice recognition.

The claim on appeal was:
[a] An auto-correlation unit for providing auto-correlation coefficients for use as feature parameters in pattern recognition for N pieces of sampled input values Xn(n = 0 to N – 1), said unit comprising:

[b] means for extracting N pieces of sample input values Xn from a series of sample values in an input pattern expressed with an accuracy of optional multi-bits;

[c] means for calculating the sum of the sample values Xn and Xn-r (t = 0 – P, P ≤ N);

[d] a read-only memory associated with said means for calculating;

[e] means for feeding to said read-only memory the sum of the sampled input values as an address signal;

[f] means for storing in said read-only memory the squared value of each sum, (Xn + Xn-r )2;

[g] means for fetching and outputting the squared values of each sum of the sample input values from said read-only memory when said memory is addressed by the sum of the sample input values; and

[h] means responsive to the output (Xn + Xn-r)2 of said read-only memory for providing an auto-correlation coefficient for use as a feature parameter according to …[a certain formula].

The Court stated that this case was one more in the line of cases stemming from the Supreme Court decision in Gottschalk v. Benson, decided by the Federal Circuit’s predecessor, the CCPA. Out of these cases came the Freeman-Walter test to determine whether a claim defines nonstatutory subject matter. It was stated in Freeman as follows:

Determination of whether a claim preempts nonstatutory subject matter as a whole, in the light of Benson, requires a two-step analysis. First, it must be determined whether the claim directly or indirectly recites an “algorithm” in the Benson sense of that term, for a claim which fails even to recite an algorithm clearly cannot wholly preempt an algorithm. Second, the claim must be further analyzed to ascertain whether in its entirety it wholly preempts that algorithm.

The opinion next discussed the meaning of “algorithm”:

Over-concentration on the word “algorithm” alone, for example, may mislead. The Supreme Court carefully supplied a definition of the particular algorithm before it [in Benson], i.e., “[a] procedure for solving a given type of mathematical problem.” The broader definition of algorithm is “a step-by-step procedure for solving a problem or accomplishing some end.”

The Federal Circuit stated that the claim as a whole certainly defined apparatus in the form of a combination of interrelated means and the Court could not discern any logical reason why it should not be deemed statutory subject matter as either a machine or a manufacture as specified in § 101. The fact that the apparatus operates according to an algorithm does not make it nonstatutory. The Court referred to Abele, and also to the discussion of that case in Grams. We Court therefore held that the claim was directed to statutory subject matter.

The Federal Circuit noted that the Solicitor’s brief the summary of argument stated that the claim “encompasses any and every means for performing the functions recited therein.” The Federal Circuit pointed out that the claim is a combination of means all but one of which is a means-plus-function limitation, the one exception being the ROM, clause [d], which is a specific piece of apparatus. The claim is therefore subject to the limitation stated in 35 U.S.C. § 112 ¶ 6 that each means-plus-function definition “shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.” This provision precludes the Solicitor’s interpretation of the claim. The Solicitor’s summary also contends that since the claim should be interpreted as he does, the Court should regard it as though it were a method claim.

The Court then stated that since the Solicitor was wrong on the first score, he was wrong on the second.

The Federal Circuit, in its decision In re Iwahashi, effectively opened up the doors of the patent system to algorithms, particularly if some hardware, such as a ROM, was recited.

In response to this case, the U.S. Patent and Trademark Office issued their own interpretation of this case in 1122 O.G. 445. They were not very happy with this case and still tended to reject applications that contained algorithms. US patent attorneys would go out of our way to avoid using words such as “algorithm” anywhere in an application. Some of us older patent attorneys still tend to cross out the word algorithm when we see it in draft patent applications.