9The Enforcement of Patent Rights in Japan（*）
Invited Researcher: Christoph Rademacher（**）

A patent confers on its holder (the patentee) the privilege to exclude a non-authorized party from using
the technology protected by the patent. That said, a patent is only valuable if it is enforceable. Germany,
Japan and the US have made substantial efforts to develop an efficient system of patent enforcement andare currently the most important and arguably the most advanced jurisdictions when it comes to patentright enforcement. In Japan, the importance of strong patent rights was most notably expressed by former
Prime Minister Koizumi in February 2002, when he described Japan as an IP-based nation and initiated theenactment of the IP Basic Law in November 2002, leading, amongst other things, to the creation of the IP
High Court in 2005. This report will provide an in-depth examination and analysis of the current state ofenforcement-related measures and remedies available to patentees in Japan. It will focus on local andinternational jurisdiction rules as well as on the key elements of enforcement procedure including theevidence collection process, border measures, warning letters, preliminary injunction proceedings anddeclaratory judgment actions. Finally, my research will explain requirements for and scope of the remedies
available for patent holders, i.e. injunctive relief as well as damages awards.

Introduction
Around the globe, both politicians andbusiness leaders continue to recognize the needof an effective protection of innovation andintellectual property. This is particularly true indeveloped countries like Japan, the US, or many
countries in Europe. The wealth of thesedeveloped countries relies to a great extend on
their innovation and on the innovator’s ability toeffectively protect their intellectual property.
Protection of intellectual property such as patents
is only possible if an efficient enforcement system
is at the disposal of parties whose patents were
infringed.
Germany, Japan and the US have madesubstantial efforts to develop an efficient systemof patent enforcement and are currently the mostimportant and arguably the most advanced
jurisdictions and litigation venues when it comesto patent right enforcement. In Japan, theimportance of strong patent rights was notably
expressed by former Prime Minister Koizumi in
February 2002, when he described Japan as an
IP-based nation and initiated the enactment of the
IP Basic Law in November 2002, leading,amongst other things, to the creation of the IP
High Court in 2005.
This report will provide an in-depth
examination and analysis of the current state ofenforcement-related measures and remedies

available to patentees in Japan from theperspective of a German academic who isadmitted as a lawyer in the US. The report will
focus on local and international jurisdiction rules
as well as on the key elements of enforcement
procedure including the evidence collection
process, border measures, warning letters,
preliminary
injunction
proceedings
anddeclaratory judgment actions. Finally, myresearch will explain requirements for and scopeof the remedies available for patent holders, i.e.
injunctive relief as well as damages awards.

Ⅰ Jurisdiction
The Civil Procedure Code grants exclusive
jurisdiction for patent infringement cases to theDistrict Courts in Tokyo and Osaka. Notably inthe field of patent law was the enactment of theIntellectual Property High Court, which was
entrusted with all appeal cases in the areas ofpatent law and other intellectual property laws.
The judges at the Intellectual Property High
Court and at the intellectual property law
divisions at the Tokyo and the Osaka District
Court are supported by investigation officers(Saibansho chôsakan), who are predominantly
responsible for the analysis of technical details
and background, and by a pool of technicalexperts (Senmoniin). Technical experts are
involved in infringement proceedings during(*)

This is a summary of the report published under the Industrial Property Research Promotion Project FY2010
entrusted by the Japan Patent Office.
(**) Transatlantic Technology Law Forum, Stanford Law School, U.S.A.

IIP Bulletin 2011 Vol.20● 1 ●evidence examination as well as during mediation
discussions.
By creating special patent litigation venues
and concentrating patent litigation at only two
district courts which are in addition supported bytechnical experts, the Japanese legislator
certainly achieved a higher degree of continuity
and thus made patent litigation more reliable andpredictable. At the same time, the Japanese judge
rotation system, which obliges even senior judges
to rotate between courts and legal areas every
few years (the usual period to remain at one courtis three years) countermines the concentration
efforts made by the legislator, as judges who
gained experience in patent litigation matters
continue to be replaced by judges inexperienced
in the area of patent law, who then again require
some time to gain the level of experience theirpredecessors had.

Ⅱ Costs
Patent infringement proceedings cause court
and attorney’s fees. While the court fees are in
general to be borne by the party loosing the trial,
all other costs such as attorney’s fees, travel
costs, costs for experts’ opinions etc. are to beborne by the party which commissioned suchcosts.
1

Court Fees

Court Fees are calculated based on thesubject matter value. The subject matter value ininfringement proceedings is computed pursuant
to the value of the demanded injunction plus thedemanded damage claim. Generally, the loosing
party has to cover the court fees.
2

Attorney’s Fees

A substantial cost factor other than court
fees are costs incurred by the parties for advice
and representation by attorneys, patent attorneys
as well as for preparation of expert opinions. Suchcosts will customarily have to be borne by eachparty.
Attorneys’ and patent attorneys’ fees arecharged on a time base, i.e. per billable hour, orbased on a representation fee agreed upon whencommencing the lawsuit. Depending on thecomplexity of the issue, fixed representation fees
frequently amount to 5 MN to 20 MM Yen. In
extraordinary complex situations, representation
fees of up to 50 MN Yen have been heard of. Alsoin case of time-based representation it is rare thatattorneys’ and patent attorneys’ fees will exceed
50 MN Yen. A survey conducted by the US law
firm Finnegan resulted in average litigation costsof 150,000 USD (approximately 15 MN Yen) for
representation in a patent infringement litigationcase.

Ⅲ Procedure
1

Evidence Collection

The plaintiff has to demonstrate infringementof a patent during the enforcement proceedings.
One of the main objectives during the reform of
the Japanese civil procedure system was toinvigorate the evidence collection process. To
enable potentially infringed parties to obtain abetter assessment of their legal position prior tofiling a lawsuit and to foster the preparations ofinfringement proceedings, the legislator createdin the judicial reform of 2003 the instrument of“evidence collection prior to initiating a lawsuit.”
An evidence preservation system had alreadybeen introduced during earlier reforms.
(1) Evidence collection prior to initiating alawsuitTo initiate the procedure of evidencecollection prior to filing of the lawsuit, thepotential plaintiff has to express his intent offiling a lawsuit to its adversary in writing
pursuant to Article 132-2 CPC. The plaintiff
needs to demonstrate the necessity of therequested information for the assessment andenforcement of its claim. However, the plaintiff
cannot compel the adversary to supply any
information requested pursuant to Article 132-2
CPC. If the adversary doesn’t react or refuses tosupply evidence, the plaintiff can at any time file amotion for evidence collection at a competentcourt pursuant to Article 132-4 CPC. If the court
requests examination by a court-appointed officer
pursuant to Article 132-4-1-4 CPC, it has toindicate the time and the location of theexamination to the plaintiff and to the adversary.
In general, both the plaintiff and the adversary areentitled to be present during the examination.
Under certain conditions, the adversary canrefuse to comply with the order or the request of
the court, for example if such request would
require disclosure of trade secrets. However,even if the adversary refuses to comply with thecourt’s request without showing a valid reason,
the current civil procedure law doesn’t grant the● 2 ●IIP Bulletin 2011 Vol.20

courts any mechanism to enforce their request.
(2) Evidence preservation
The evidence preservation procedurepursuant to Article 234 CPC is the strongest
mechanism to seize evidence under Japanese civil
procedure law. Evidence preservation can beordered if the court is convinced that the existing
circumstances could result in exacerbating theuse of evidence if such evidence is not reviewed
or secured before the beginning of the trial. In
order to convince a court to order evidence
preservation, a plaintiff has to show a likelihood ofevidence being lost, damaged, modified or hidden.
If such likelihood is not very high, application of
the evidence preservation procedure is notdeemed appropriate. Furthermore, the impact on
the adversary is evaluated by the court looking at
the proportionality of the evidence preservation.
Thus, as the requirements for the application ofevidence preservation are generally very high, it
is very rare to see courts ordering evidence
preservation, and basically never happens in thecontext of evidence collection for a patent
infringement analysis. The practical difficulties
still existing for patentees in collecting non-public
evidence prior to initiating a lawsuit, especially incases where a prior warning to the alleged patent
infringer comes with a risk of loss or alteration ofevidence, still remains as a significant barrier toan efficient patent enforcement procedure.
(3) Evidence collection after initiating lawsuit(i) Obligation of document production pursuant
Article 104-2 Patent Act
Article 104-2 Patent Act contains a generalrule providing for the obligation of the defendant
to contribute to the clarification of facts bysubmission of disputed products or by disclosing
disputed processes. While Article 104-2 Patent
Act also provides for the possibility to withhold
the disclosure of information regarding the
disputed facts, such withholding has to be
sufficiently substantiated.
(ii) Court order
Following a motion of a party, the court canorder the other party to submit information or
disclose processes deemed relevant by the court
for establishing infringement or for computationof damages pursuant to Article 105-1-1 Patent Act.
Having said so, the addressee of such court ordercan refuse submission of information or
disclosure of processes pursuant to Article105-1-1 Patent Act if there is a valid reason for

IIP Bulletin 2011 Vol.20

refusal. Valid reasons for refusal of submission
exist if the requested documents containtechnical or other trade secrets, or if said
documents were prepared exclusively for internal
purposes.
(iii) In-camera proceedings
If the party in possession of evidence
demanded by the court can demonstrate a valid
reason against disclosure, the court has theoption to examine such documents during an
in-camera procedure pursuant to Article 105-1-2
Patent Act. During the in-camera proceedings the
documents in questions are examined in a closed
session, whereafter the court determines therelevancy of the document in question for proving
infringement and balances such relevancy against
the reasonable interest of non-disclosure asserted
by the party. If the court acknowledges that the
party requested to submit evidence has a valid
reason of non-disclosure of specific information, it
can issue a protective order (Himitsu hoji meirei)
pursuant Article 105-4 Patent Act.
2

Border Measures(1) Application period
To initiate border measures, the patentee has
to complete an application for detention at thecustoms office. The application has todemonstrate the patentee’s entitlement to use
the patent and has to explain why the goods to beimported infringe the patent.
(2) Detention period
After detention and storing of the imported
goods by the custom authorities, both theapplicant and the importer are notified. The
patentee can inspect the detained goods pursuant
to Article 69-16-1, 2 Customs Act. The importer
is notified of the patentee’s application to inspect
the detained goods, and can attend the inspection
if desired. Both parties can request an opinion by
the Commissioner of Japanese Patent Office. If an
opinion by the Commissioner of JPO had beenrequested, the custom office usually follows such
opinion. If the custom office determines that the
goods are infringing a patent, it can order its
destruction.
3

Warning Letter(1) Practical significance
As Japanese entities were at least
traditionally reported to be hesitant of court● 3 ●litigation, it only seems logical that warning
letters or other out-of court settlement
approaches are an important factor in resolving
disputes. Indeed sending warning letters to
manufacturers and their customers is a common
practice in Japanese patent disputes.
(2) Claims for wrongful warning letters
A wrongful warning letter sent to a
manufacturer of allegedly infringing goods isgenerally not regarded as unlawful. Sending awrongful warning letter to a manufacturer’s
customer alleging that the manufacturer’s goods
infringe upon the sender’s patents and urging thecustomer to cease purchasing or trading theaccused manufacturer’s goods (kokuchi)) canresult in a damage claim by the manufacturer
against the sender. In case of wrongful warning
letter sent to customers, the sender of thewarning letter has to demonstrate that he acted
without negligence. Recent case law developed
abstract criteria which could lead to an absence orat least a reduction of the degree of thetortfeasor’s negligence.
4

Declaratory Judgment Action

The importance of the declaratory judgment
action in the Japanese patent enforcement
procedure system is somehow limited. It
becomes mostly relevant in the context of bordermeasures. If an importer files a declaratory
judgment action after detention of the importer’s
goods by the custom authorities, the custom
authorities tend to stay the detention until thedeclaratory judgment action is resolved.
5

Preliminary Injunction

Preliminary injunctions are generally
considered an important instrument to enforce
patents and other intellectual property rights.
A few years ago, court statistics andcommentators showed an increase of the use of
preliminary injunctions in patent enforcement, atendency which was generally expected tocontinue. However, looking at more recent
numbers, it seems that the number of preliminary
injunctions sought has steadily decreased since
2002. One major reason for the decreased demandfor preliminary injunctions can be seen in theconsiderable speed development of the mainproceeding, which is currently almost as fast the
preliminary proceeding. Furthermore, it seems
convincing that the results of the Kilby-Decision1

leading to a higher risk of patent invalidity
decisions during the infringement proceeding
were another cause in the reduced demand.
(1) Scope of preliminary injunction
The purpose of a preliminary injunction is topreserve the status quo. A preliminary injunction
in a patent infringement context is typicallydirected to ensure that the defendant refrainsfrom a certain conduct such as producing or
distributing patent-infringing goods (Sashidome
no Karishobun).
As it is impossible for the court to prepare
expert opinion as well as to request submission of
documents or other evidence during the course of
preliminary proceedings, it is often difficult toshow the prima-facie evidence of infringement
required for a preliminary injunction. This isparticularly true in the context of patent law,where the courts tend to demand a level ofevidence corresponding to the level required in
the main proceedings. Thus a preliminary
injunction will only be realistic to expect in clear
infringement constellations where a defendantcommitted literal infringement of the plaintiff’s
patent claims, the validity of the underlying
patent is not in questions, no procedural
complications are to be expected, and the plaintiff
can demonstrate the infringement by referencing
to the infringing product being in the plaintiff’s
possession.
(2) Requirement for preliminary injunction
Pursuant Article 23-2 Civil Preservation Act,a preliminary injunction requires showing of
immediate harm or substantial damages. To showsuch requirement, the courts require the plaintiff
to show the necessity (hi¬tsu¬yôsei) of thepreliminary injunction, which has to beestablished by a balance of hardships between theplaintiff and the defendant. A showing ofnecessity is facilitated in cases of infringement
likely to result in damages which would be
difficult to compensate monetarily.

Ⅳ Remedies
1

Injunctive Relief(1) Requirements
A claim for injunctive relief requires theshowing of a currently present infringement or
the likelihood of a future infringement. If the
defendant committed an infringing conduct in thepast and stopped such conduct before the plaintiff● 4 ●IIP Bulletin 2011 Vol.20

initiated the enforcement proceeding, a likelihoodof infringing conduct is assumed by courts if the
defendant has the ability to resume the infringing
conduct.
(2) Scope
The party entitled to a claim for injunctive
relief can request the defendant to cease theinfringing
conduct(kyôginosashitome
seikyûken) and to refrain from such conduct in
the future (yobô). In addition, the plaintiff canrequest the defendant pursuant Article 100-2
Patent Act to destroy the equipment used to
produce the patent-infringing goods. The claim
for injunctive relief typically encompasses only
the infringing conduct identified by the court.
Accordingly, the injunction orders issued by the
courts are usually concise and very specific. The
patentee needs to enforce its patent again if the
defendant only slightly modifies his conduct andnevertheless still infringes the same patent.
2

Damages

The patentee or the exclusive licensee canrequest from the infringer compensation ofdamages incurred as a consequence of theinfringing conduct pursuant Article 709 Civil
Code. The provision of Article 102 Patent Act
serves to facilitate the computation of the damage
claim(1) Requirements
A damage claim pursuant to Article 709 Civil
Code always requires fault, i.e. intend or
negligence, by the tortfeasor. Article 103 Patent
Act provides for a presumption of negligence by
the infringer in case infringement is established.
Accordingly, the infringer has to show theabsence of negligence in order to avoid being held
liable for damage claims. Has the court followed
the plaintiff and found infringement, it will only invery exceptional cases deny all damage claims byfinding an absence of any negligence. Pursuant to
Article 102-4 Patent Act, courts can lower thedamage award if the defendant shows a lower
degree of negligence. Slight negligence might beconsidered e.g. in cases where the technicalevaluation of the factual circumstances and thus
the evaluation whether a conduct constitutes
infringement or not would be extraordinarily
difficult and complex.
(2) Scope of the damage claim
Article 102 Patent Act provides for three

IIP Bulletin 2011 Vol.20

methods of computing damages: (1) lost profits,(2) accounting for infringer’s profit or (3)accounting for a reasonable royalty fee. It is fairly
common that the plaintiff requests compensation
pursuant to multiple calculations methods, andselects the method yielding the highest damage
award. In practice, it is recommendable in manycases that the plaintiff requests compensation
based upon lost profits, while requesting thatcourt awards a damage award calculated pursuant
to the reasonable royalty fee in case that suchaward would be higher than the lost profit.
3

Claim for Destruction

Usually the plaintiff will simultaneously
request the court to issue an injunction order andto order destruction of the patent-infringing
products. In addition, the plaintiff can request the
court to issue an order for removal of materials
and equipment which has been used for the
production of the infringing products. Pursuant tocurrent case law, the entire infringing product isin principle subject to the claim for destruction
even if the infringing element within the productcould be separated. Having said so, in case oflarger equipment is found to be infringing, thecourts usually examine whether the entire
product is considered patent-infringing and has tobe destroyed, or whether a patent-infringing partwithin the larger equipment can be localized,
extracted and separately destroyed without
requiring destruction of the entire equipment.

Conclusion
The Japanese patent enforcement system
has been subject to numerous revisions in the lastfifteen years. Amongst other procedural changes,
the evidence collection process and the damage
award calculation methods were fundamentallyrevised in order to strengthen the position ofplaintiffs. The most obvious improvement of thepatent enforcement system was the substantial
reduction of the duration of enforcement
proceedings. As a result, patent litigation, inparticular the main proceedings, in Japan
nowadays are amongst the fasted in the world.
Having said so, and taking into consideration
thesubstantial
procedural
improvements
achieved during the last years, the following
suggestions remain as a conclusion of my report:(1) Expertise on the bench: All patent cases inJapan have to be brought at either the Tokyo
District Court or the Osaka District Court.

● 5 ●From a standpoint of uniformity, such highdegree of concentration is certainly an
important factor supporting the predictabilityof patent cases. At the same time, the highdegree of concentration of litigation prevents
parties from conducting excessive forum
shopping, which in some other leading
jurisdictions has become a problem. However,the Japanese court system incorporates astrict rotation system, according to whichjudges are to relocate every three to five
years. Such relocations are not only ofgeographical nature, but also affect the
subject matters of cases over which judges
preside. While such rotations system might
be efficient in less specialized fields of law, it
may be a disadvantage in patent litigation, afield in which judges have to make decisions
on highly technical questions. Though being
supported by a large group of investigation
officers and technical experts, it will take awhile until a newly-appointed judge will be at
the level his or her predecessor who wasafter three years of exclusive exposure topatentlitigation.
Considering
such
exceptional position of the patent courts, it
may be beneficial to implement exceptions to
the rotation system for judges interested anddevoted to patent law.
(2) ‘Surprising’ evidence collection: While theevidence collection system has been subject
to fundamental revisions in the last years, it
is impossible to collect non-public evidence
which is in the possession of the defendant
without the defendant’s consent or a court
order issued after a hearing. Especially in thecase of infringement of process patents,
onsite evidence collection is crucial for adetermination of the facts. However, as such
onside inspection is practically impossible
without giving prior notice, the defendantalways has the opportunity to conceal certain
steps of a production process prior to an
inspection.
The two-tier inspection system, as it ispracticed by leading patent courts inGermany, might – also in Japan – serve as abridge between the plaintiff’s interest incollecting unmodified non-public informationand the defendant’s interest in protecting
non-public know-how and trade secrets.
Under a two-tier inspection system, if aplaintiff can show a certain likelihood of
infringement as well as the need to inspect
non-public information such as a production

plant of the defendant in order tosubstantiate the infringement, the court cansend a court-appointed specialist, who could
be a member of the group of technicalexperts available to the courts, to theapplicable facility of the defendant in order toinspect the production process in question.
Such inspection could occur without priornotice to the defendant. Following theinspection, the expert would thereafter
prepare a confidential report covering theinspected process, which would initially beavailable only to the court, and possibly tothe plaintiff’s attorney, who however would
at least initially be prohibited to share suchconfidential information with the plaintiff
under a protective order. The court could
review the report and determine whether the
initial likelihood of infringement was
substantiated by the evidence collected in
the course of the inspection while
maintaining the defendant’s interested inprotecting trade secrets and non-publicconfidential information. If the inspection
revealsanincreased
likelihoodofinfringement, an additional inspection of the
defendant’s facilities, which then could be
conducted in the presence of the plaintiff andhis counsel, could be ordered for further fact
finding.
(3) Damage award calculation: Also in the area ofdamage calculation, substantial revisions
were made in the last years. However,amongst the three calculation methods
available to the plaintiff, the method of
accounting for infringer’s profits is generally
regarded as the least relevant method as thedefendant can usually deducting not only costof sales, but also part of its general andadministration expenses from the revenue
generated with infringing goods. It might behelpful if the courts could give more concise
guidelines on what kind of expenses aninfringing party should be able to deduct andwhat kind of expenses should generally not
be deductible. Limiting the deductibility of
expenses other than the cost of goods would
make it more attractive for plaintiffs to seek
compensation based on infringer’s profits.
1

S. Ct. 54-4 Minshû (2000), pp. 1368 – „Kilby“● 6 ●IIP Bulletin 2011 Vol.20