Center for Advanced Study & Research on Intellectual Property

 

CASRIP Newsletter - Winter 1998, Volume 5, Issue 1

The Supreme Court Affirmed the Presence of the Doctrine of Equivalents under Japanese Patent System

JAPAN

On February 24, 1998, the Supreme Court of Japan handed down the judgment long-awaited by the patent community--acknowledging the presence of the doctrine of equivalents under the Japanese Patent System.1 Recently, in determining infringement of Japanese patents, Japanese courts have expressly admitted the need to find infringement under the doctrine of equivalents.2 Explaining the policy justification for finding infringement under the doctrine of equivalents, and clarifying the tests for applying the doctrine of equivalents, the Supreme Court endorsed the recent case law directions of its lower courts.

The Court also emphasized doctrines that limit the application of the doctrine of equivalents and thus remanded the case to the Tokyo High Court for further examination of whether the defense of the free state of the art would prevent the patentee from claiming infringement under the doctrine of equivalents. The judgment is relatively short but packed with important theoretical discussions, which would have significant impact on future case law developments in understanding the scope of Japanese patent protection. Thus, the full translation of the judgment is included hereinafter, followed by my comments from a comparative law perspective.

Decision of Supreme Court of Japan (Saikou Saibansho), February 24, 1998
Case No. Heisei 6 (o) 10831No. Heisei 6 (o) 1083

Disposition

The Tokyo High Court Judgment must be reversed. This case must be remanded to the Tokyo High Court.

Reasons

Concerning the reasons of this joukoku3 appeal advanced from the representative of Joukoku Appellant, Mr. Youhei Kinoshita:

I. This case relates to the appellant's alleged infringement of the appellee's patent and the appellee's request for compensatory damages. The facts found by the Tokyo High Court are as follows:

1. The appellee owns a patent right for the invention entitled "a ball spline bearing for infinite sliding" (the filing date: April 26, 1971; the publication date for opposition: July 7, 1978; and the issuance date: May 3, 1980) (Patent No. 999,139) (hereunder, the said patent right is called "this patent right" and the invention of this patent right is called "this invention").

2. The claim of the specification included in the patent application (hereinafter, it is called "this specification") reads as follows:

A ball spline bearing for infinite sliding, provided by assembling an outer tube with a holder wherein:

(A) said outer tube (to be addressed as "the element A" hereinafter) is provided on the inner wall thereof with torque transfer loaded ball guide grooves having a U-shape cross section and torque transfer unloaded ball guide grooves; said loaded ball guide grooves and said unloaded ball guide grooves being alternatively provided in the axial direction ; said outer tube further provided on the both ends thereof with grooves having the same depth as the deeper grooves extending in the periphery direction;

(B) said holder (to be addressed as "the element B" hereinafter) includes thick wall portions and thin wall portions; said thick wall portions and thin wall portions being so structured as to correspond with said loaded ball guide grooves and said unloaded ball guide grooves that are alternatively provided in the axial direction on the inner wall of s aid outer tube; a through hole provided on the separating wall between said thick and thin wall portions; and an infinite orbit groove for providing a smooth ball transfer to unloaded ball guide grooves provided on said thick wall portions;

(C) said bearing is further comprised of a spline shaft (to be addressed as "the element C" herein after) provided with plural protruding portions in the axial direction thereof, and

(D) said plural protrusions being structured to correspond to the plurality of space defined by said holder and balls provided in said outer tube (to be addressed as "the element D" hereinafter).

3. The appellee commercially manufactured and sold the accused device (please note that a step of 50 micron exists between the unload ball guide grooves and the tube portion, i.e. the portion in the peripheral direction 7) specified in the appendix to the judgment of the Tokyo High Court during the period of January 1983 to October 1988.

II. The appellee alleged that the accused device falls within the technical scope of this invention because the appellant's device had infringed this invention literally or under the doctrine of equivalents. The Tokyo High Court determined the following and awarded the appellee damages for patent infringement.

1. The elements C, D, and E of this invention read on the appellant's device.

2. Regarding the element A, the claim recites "U-shaped cross section" and "grooves provided in the axial direction." In contrast, the structures corresponding to these limitations in the appellant's device are "half-circle cross-section" and "the peripherally extending steps 7".

3. Regarding the element B, the holder of this invention is structured in one piece, providing functions to balls for infinite sliding guide, maintaining balls in the bearing when the spline shaft is removed, and providing space for receiving the protruding portions on the shaft. In contrast, in the appellant's device, three discrete members, including the upper part of the protruding portions in the loaded ball guide grooves provided on the outer tube, plate members 11 and a pair of return caps 31, cooperate together to provide the functions of the holder of this invention as discussed above. Thus, with respect to these features, this invention and the appellant's device are different.

4. However, the object to be solved by the invention, the fundamental technical idea to solve the object, and the effect resulting from the adoption of structures to solve the object are common to this invention and the appellant's device. Regarding the structure of the holder recited as the element B, the court found that the structure adopted by the appellant was interchangeable with the structure of this invention, and that one skilled in the art would have known the interchangeability as of the application date of this patent. Regarding the element A, there is no technically substantial difference between "U-shaped cross-section" and "grooves provided in the axial direction" of this invention and "half-circle cross-section" and "the peripherally extending steps 7" in the appellant's device. Therefore, it is proper to determine that the appellant's device is within the technical scope of this invention.

III. However, we cannot affirm the judgment of the Tokyo High Court for the following reasons:

1. In determining whether a product or process adopted by an accused infringer (to be addressed as "an accused product" hereinafter) falls within the technical scope of a patented invention, courts must ascertain the technical scope of the patented invention in light of the description in the specification accompanying an application (Patent Law, Article 70, Paragraph 1). If there is any claimed element which is different from the corresponding structure of the accused product, the accused product does not fall within the technical scope of the patented invention. However, even if some claimed elements are different from the corresponding structures of the accused product, the accused product may fall within the technical scope of the patented invention for having equivalents to the structures recited in the claim if the following conditions are met: (1) the elements are not an essential portion of the patented invention; (2) the objective of the patented invention can be attained even if the elements are replaced with the structures in the accused product, and thus the accused product results in the identical functions and effects as the patented invention; (3) a person with ordinary skill in the field of the patented invention (the person will be addressed as "one skilled hereinafter) would have readily conceived the interchangeability between the claimed portion and the replaced structures in the accused product as of the time of exploitation, such as the manufacturing of the accused product by the accused infringer; (4) the accused product is novel and would not have been able to be conceived by one skilled as of the application time of the patented invention; and (5) the accused product was not intentionally removed from the technical scope of the claim by the applicant during the patent prosecution. This is because (1) it is very difficult to describe claims to cover all possible infringing embodiments of the patented invention. If a competitor can escape from patent enforcement, including injunction, etc., by simply replacing some claimed elements with materials, technical means, etc. that are developed after the patent application, incentive for innovation is significantly reduced, which conflicts with the goal of the patent system to contribute to industrial developments through the protection and encouragement of inventions. Further, such an interpretation of law to allow competitors to escape from the charge of infringement would be unfair to the sense of justice in the society and conflict with the concept of fairness. (2) In considering these points, the substantial value of a patented invention extends to a structure which would have been readily conceived by a third party from the structure recited in the claim as being substantially identical to a patented invention. It is proper to assume that a third party must anticipate such an extension of the patent protection. (3) On the other hand, the technical scope of a patent cannot extend to an accused product which is part of the state of the art as of the application time of the patented invention, or would have been readily conceived by one skilled from the state of art, because no one could have obtained a patent on such accused product (Patent Law, Article 29). (4) Additionally, under the rule of estoppel, a patentee is prevented, during the patent prosecution, from claiming a patent right on an accused product which was intentionally removed by an applicant from the claim scope where the applicant admitted that the accused product did not fall within the technical scope of the patented invention or the applicant's behavior indicated such removal of the accused product from the claim scope.

2. Applying the aforementioned rules to this case, the Tokyo High Court found that some limitations of the claimed elements A and B were different from the corresponding structures in the appellant's device, but concluded that the appellant's device fell within the technical scope of this invention because the claimed elements and the structures adopted by the appellant were interchangeable and the interchangeability was known to one skilled. However, the Tokyo High Court found the following facts: (1) An ball spline bearing consisting of an outer tube, spline shaft and an holder was publicly known prior to the application time of this invention. "Said bearing is further comprised of a spline shaft (to be addressed as "the element C" hereunder) provided with plural protruded portions in the axial direction thereof; and said plural protrusions being structured to correspond to the plurality of space defined by said holder and balls provided in said outer tube" is a conventional structure to provide a shaft for a ball spline bearing; (2) (i) The holder of this invention is structured in one piece to provide functions for infi nite sliding guide of the balls, to maintain balls in the bearing when the spline shaft is removed, and to provide space for receiving the protruding portions on the shaft (the element B). In contrast, the holder of the appellant's device consists of three discrete members, including the protruding portions in the loaded ball guide grooves provided on the outer tube 25, 27 and 29, plate members 11 and a pair of return caps 31, and these members cooperate together to provide the functions discussed above. (ii)The holder consisting of discrete members in the appellant's device which includes the three plate members 11 and a pair of return caps 31 is discussed in a ball spline bearing for infinite sliding disclosed in the specification of U.S. Patent No. 3,360,308, which was a publication distributed prior to the application time of this invention. (iii) To maintain balls by a holder consisting of discrete members, it is necessary to provide protrusions in the loaded ball guide grooves provided on the outer tube. Such protrusions, however, are discussed in the ball bearing disclosed in the U.S. Patent No. 3,398,999, which was a publication distributed prior to the application time of this invention. Based on the above facts, the appellant's holder which consists of discrete members and has the protrusions in the loaded ball guide grooves provided in the outer tube was disclosed in a ball spline bearing, which was published prior to the application time of this invention.

In addition, the Tokyo High Court found that the appellant's device was identical to this invention in that unloaded balls slid in the axial direction and an angular contact structure of a plurality of lines was adopted so that the space of the spline shaft was structured to sandwich balls in the torque transfer loaded ball guide grooves. The court, however, recognized that unloaded balls for sliding in the axial direction and an angular contact of a plurality of lines were disclosed in detail in Japanese Patent Publication Shouwa 44-2361, German Patent No. 1,450,060, and U.S. Patent No. 3,494,148, which had been distributed prior to the application time of this invention. Based on these findings, it seems that adopting these features in a ball spline bearing was publicly known prior to the application time of this invention.

Accordingly, assuming that the technical idea for a ball spline bearing which included unloaded balls for sliding in the axial direction and an angular contact structure of a plurality of lines were published before the application time of this invention, because the Tokyo High Court found that the difference in the structure of having the balls contact with the wall resulted in no substantial difference in the structure of the holder, the appellant's device was simply a combination of a ball spline bearing provided with publicly known structures of unloaded balls for sliding in the axial direction and an angular contact structure having plural lines and a holder of discrete members. If one skilled would have readily conceived the combination, the appellant's device would have been conceived by one skilled from the state of the art prior to the application date of this invention. This means that it is improper to find equivalents between the structure recited in the claim included in the specification and the appellant's product. Therefore, the technical scope of this invention should not be understood to include the appellant's device.

In this case, as discussed earlier, some elements recited in the claim are different from the corresponding structures in the appellant's device. The Tokyo High Court focused its analysis mainly on the questions of whether the claimed elements and the corresponding structures were interchangeable and whether one skilled would have readily conceived the interchangeability but did not examine the relationship between the appellant's device and the state of the art as of the application time of this invention, which resulted in a conclusion that the appellant's device was equivalent to the structure recited in the claim and thus fell within the technical scope of this invention. Therefore, without reaching the question whether the Tokyo High Court properly found equivalency between the claimed elements and the structures in the appellant's device with respect to the interchangeability and the readiness of conceiving the inter-changeability, it is clear that the court improperly interpreted and applied the patent statute.

IV. As discussed above, the Tokyo High Court erroneously interpreted and applied the patent statute, which resulted in an unlawful judgement because it was based on an improper finding of facts and provided inappropriate reasons. These errors clearly affected the conclusion of the judgment of the Tokyo High Court.

Appellant's reasons for this appeal are lawful as pointed out in the discussions above. Therefore, the judgement of the Tokyo High Court must be reversed. This case must be remanded to the Tokyo High Court for further examination of the points discussed above. In conclusion, all judges unanimously agreed to the disposition of this case as indicated above.

Comments:

Those who are familiar with U.S. case law must see a lot of similarity between this judgement and a most recent U.S. Supreme Court decision, Warner-Jenkinson v. Hilton Davis,4 in which the Court remanded the case to the lower court for further examination finding of infringement by equivalency in the light of one of the doctrines to limit the application of the doctrine of equivalents. However, to those who are familiar with German patent law, this is a Japanese version of the German Supreme Court decision, Foremstein.5 There is a fundamental difference between the theoretical background of the U.S. Supreme Court decision and those of the Japanese and German Supreme Court decisions. The Japanese and German Supreme Courts' decisions are based on their sympathy for the applicants' impossibility to predict all possible modifications adopted by future infringers in drafting their claims. This thought premised on incomplete information regarding the prior art and future modifications does not punish an applicant who explained his invention based on his limited knowledge during the prosecution. His contribution to the state of the art must be reexamined by courts when more complete information on the state of the art and modifications created by competitors is available in patent infringement proceedings.

This clear separation of the roles of the patent office and the court signifies German scholarship of determining the protection scope through identical and equivalent use of the inventive idea.6 The scope of identical use of the inventive idea is examined by the patent office, and thus German courts cannot override the power of the patent office within that scope. In contrast, German courts can freely examine the patentability of the scope of equivalent use and find infringement. Following this German scholarship, the Japanese Supreme Court limited the application of the doctrine of equivalents to (1) when the accused embodiment is anticipated or obvious from the prior art (the defense of Formstein or the extended doctrine of the free state of the art)7 or (2) the applicant intentionally removes the accused embodiment from the scope of claims.

The first doctrine, the defense of the free state of the art, parallels the U.S. doctrine of limitation by the prior art in Wilson Sporting Goods,8 except for the burden of proof to establish the patentability of an accused embodiment. The justification of using this doctrine to limit infringement by equivalents is that a patentee cannot claim protection on the embodiment which was not patentable even if she drafted and included a claim literally covering the embodiment as of the application time. Thus, to apply this doctrine, the appropriate time frame is the application time. In contrast, the timing to examine the equivalency is the infringement time because the patentee can occupy the scope on which competitors cannot obtain a patent. Since no one can lawfully obtain a patent on embodiments obvious from the patented invention, the patentee can occupy the obvious scope under the doctrine of equivalents.9This practice is perfectly in line with the patent policy in encouraging innovation, rather than imitation.

Intentional removal from the claim scope must be distinguished from the U.S. doctrine of prosecution history estoppel, because the applicability of the former doctrine is much narrower than the latter. As Judge Rich in Wilson Sporting Goods10 correctly pointed out, because most accused embodiments are developed by competitors after the issuance of the patent in suit, applicants cannot remove such embodiments during the patent prosecution. Applicants can only intentionally remove the prior art cited during the prosecution by amending the claims and the specification or some embodiments in the specification or by drafting claims clearly excluding the embodiments. Regarding a variation from the prior art cited during the prosecution, courts must determine the appropriateness of capturing such a variation under the doctrine of equivalents by using the doctrine of the free state of the art to examine the patentability of the variation over the prior art.

This practice is highly contrasted with the practice discussed by the U.S. Supreme Court in Warner-Jenkinson,11 which heavily relies on the subjective agreement between the applicant and the USPTO by introducing a new presumption to apply the patent prosecution history estoppel. The U.S. doctrine consists of the premises that an applicant and the patent office have complete information on the prior art and future modifications created by competitors, and that courts try to figure out what was given up by the applicant during the prosecution. Although Judge Rich explained the realistic view in understanding accused embodiments,12 the thought did not take root in U.S. jurisprudence. As a result, to define the scope that the applicant has given up, the Federal Circuit requested the paten tees and the USPTO to keep good records on the patent prosecution. To those who are familiar with the German doctrine, this view seems to be based on an unrealistic premise that the applicant and the examiner of the USPTO can agree to exclude an accused embodiment which has not developed during the prosecution. As a result, the instruction from the Federal Circuit created a big headache in the patent community, particularly the patent office.

In following the German doctrine of equivalents, the Japanese Supreme Court made a good choice in avoiding a confusion relating to prosecution history records. Further, by emphasizing that the intent to remove particular embodiments must be indicated by claims and specifications, the competitors' duty for patent search is limited to patent publications, excluding the patent prosecution records. Considering the number of patents issued every day and the lengthy records related to these patents, Japanese courts made a wise decision by not imposing an impossible burden on competitors.

The Japanese Supreme Court used the same term to define the test for inventive step and the test for equivalency and thus avoided confusion about whether a separate patent can prevent a claim of infringement under the doctrine of equivalents. Both German and U.S. courts faced this difficult question.13 So far, only German courts reached a conclusion that a separately patented accused embodiment cannot infringe an earlier patent under the doctrine of equivalents.14 Implicitly admitting the same test for the patentability and infringement, Japanese courts have already resolved the question.

The Supreme Court's determination to change the traditional Japanese case law is clear by its discussions of patent policy and justification for finding infringement under the doctrine of equivalents. In civil law countries, particularly Japan, courts' opinions do not include an extensive discussion on legal theory and policy, because their power is limited to solve the dispute arising in a particular case. The contribution of this decision to Japanese patent law jurisprudence is enormous due to its explicit use of the term "equivalent." This is the first decision that the Supreme Court has ever used the term "equivalent" in determining infringement. In the past, only very few lower courts used the term "equivalents." The Tokyo High Court in the judgment from which this appeal is filed avoided the term" equivalent" but used the term "substantially identical," although the same test for finding equivalents developed by German courts was adopted to find infringement by substantial identity. In adopting the term "equivalents" uniformly adopted by other jurisdictions, the Japanese Supreme Court corrected a misunderstanding that Japanese courts do not have the doctrine of equivalents.

The only possible flaw of this judgement is that the Supreme Court did not clarify the burden of proof for establishing the patentability of the accused embodiment over the prior art. If the German doctrine is followed, the burden is on defendant, In contrast, if the U.S. counterpart is followed, the burden is on patentees. After the adoption of the known interchangeability test, the major differences between the German and U.S. doctrines of the equivalents are the use of the prosecution history estoppel and the burden of proof on the patentability of the accused embodiment. A recent Osaka High Court decision revealing a strong influence from U.S. jurisprudence suggested that the burden was on patentees. However, the Japanese Supreme Court made it clear that they would follow German jurisprudence, which suggests placing the burden on the defendant. It is interesting to see how jurisprudence in Germany and U.S. will affect the future case law developments in Japan on the doctrine of equivalents.

Toshiko Takenaka


Notes:

1. Judgment of Supreme Court of Japan, February 24, 1998. An English translation of the judgment of the Tokyo High Court was reported in 26 Int'l Rev. Indus Prop. & Copyright L. 683 (19 95).
2. Genentech Inc. v. Sumitomo Seiyaku K.K., Judgment of Osaka High Court, March 29, 1996, Hanrei Jiho No. 1586, 117 (1996). An English translation of and comments on the case are reported in Toshiko Takenaka, New Policy in Interpre ting Japanese Patents, CASRIP Newsletter 3 (CASRIP, U. Wash. Seattle, WA) (Spring/Summer 1996); Fujitsu v. Texas Instruments Inc., Judgement of Tokyo High Court, Sept. 10, 1997 (Unreported Opinion). An English Translation of and comments on the cas e are reported in Toshiko Takenaka, Japanese Developments, CASRIP Newsletter 4 (CASRIP. U. Wash. Seattle, WA) (Winter 1997).
3. An appeal to the Supreme Court is called Joukoku appeal.
4. Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 137 L.Ed. 2d 146, 117 S. Ct. 1040, 41 U.S.P.Q.2d 1865 (1997).
5. "Moulded Curbstone" (Formstein), 18 Int'l Rev. Indus' Prop. & Copyright L. 795 (1987) (BGH).
6. For a general discussion of the German doctrine of equivalents, see Toshiko Takenaka, Interpreting Patent Claims: The United States, Germany and Japan, 17 Int'l Rev. Indus' Prop. & Copyright L. Studies 59 (1995).
7. This defense is generally known by Japanese scholars as the defense of the free state of the art (jiyuu gijutu no kouben). German scholars, however, distinguish an old doctrine to examine only the novelty of the accused embodim ent from another extended doctrine to review both the novelty and inventive step of the accused embodiment and address the former as "the defense of the free state of the art" and the latter as "the Formstein defense," named after the Supreme Court decision adopting the defense.
8. Wilson Sporting Goods Co. v. David Geoffrey & Associates, 904 F.2d 677, 14 U.S.P.Q.2d 1942 (Fed. Cir. 1990), cert. denied, 111 S. Ct. 537 (1990).
9. Toshiko Takenaka, Doctrine of Equivalents after Hilton Davis: A Comparative Law Analysis, 22 Rutgers Computer and Technology L. J. 479, 494 (1996).
10. Wilson Sporting Goods Co., 904 F.2d 677.
11. Warner-Jenkinson Co., 137 L.Ed. 2d 146.
12. Wilson Sporting Goods Co., 904 F.2d 677.
13. Takenaka, supra note 9, Doctrine of Equivalents, 500.
14. "Segmentation Device for Tree Trunks" (Zerlegvorttichtung fur Baumstamme), 26 Int'l Rev. Indus' Prop. & Copyright L. 261 (1995) (BGH 1994); Jochen Pagenberg, More Refined Rules of Claim Interpretation in Germany Are They Necessary?, 26 Int'l Rev. Indus' Prop. & Copyright L. 228 (1995).

Last updated 4/27/2012