Research and Study concerning Differences in Determination of Unity ofInvention among IP5 offices
The First International Affairs Committee
Japan Intellectual Property Association
Abstract: In recent years, the patent offices of major countries have been actively
working on harmonizing their patent systems. Since unity of invention is one of the
key issues addressed through such transnational efforts, the First International
Affairs Committee, one of the expert committees organized under the JapanIntellectual Property Association (JIPA), surveyed the situation of patent
prosecution in some major countries. Our survey ascertained that the percentage ofrecognizing lack of unity of invention in the first action was exceptionally high in
the United States. We would like to explain this peculiarity in US patent
prosecution, and hope that this document will assist in the practical patent
management of JIPA members. This document also introduces our suggestions forachieving patent system harmonization.
Table of Contents
1. Introduction
2. Comparison of Statutory Provisions
Concerning Unity of Invention
3. Statistical Survey Concerning Unity
of Invention Examinations
3.1 Preconditions for the Survey
3.2 Survey Results
4. Differences in Determination of
Unity
of
Invention
betweenInternational Searching Authorities
and National Patent Offices
5. Why Are Many Patent Applications
Rejected in the First Action on the
Grounds of Lack of Unity ofInvention in the US?
5.1 Differences in Judgment Criteria
between the US and OtherCountries
5.2 Differences in Practical Guidelines
for Judging STFs

5.3 Why Many Patent Applications in
the Field of Chemistry Are
Rejected in the First Action Due toLack of Unity of Invention
5.4 Coexistence of PCT Criteria and
Non-PCT Criteria
5.5 Other Conceivable Causes
6. Conclusion
1. Introduction
With the progress of globalizationof business, enterprises are becoming
increasingly willing to file patentapplications internationally for each
invention.
The
international
convergenceofpatentsystems(including patent filing procedures andthe criteria for judging patentability) is
keenly awaited by industry; if it isachieved, enterprises will be able to1034

Intellectual Property Management Vol.65 No.8 2015

reduce filing costs and more accurately
predict the possibility of successful
patent registration. To keep up with thistrend, the Five IP Offices (IP5), i.e., thepatent offices in Japan, the US, the EU,
China, and Korea, have recently beenworking on harmonizing their patent
systems. As part of such efforts, the IP5
agreed in the Meeting of IP5 Heads ofOffice held on June 6, 2014 that the IP5
would focus discussions on the three
key issues for the harmonization ofpatent systems: written description andsufficiency of disclosure, citation ofprior art, and unity of invention.1) In thewake of this IP5 agreement, we
conducted a fact-finding survey onunity of invention, the theory of which
had not yet been supported by actual
circumstances, in order to identify
differences among the IP5 patentoffices in terms of the assessment ofunity of invention. Then, we examinedsome differing tendencies identified in
the survey.
This document was written by themembers of the Third Working Groupof the FY2014 First International
Affairs Committee, consisting of:
Ryota Fukumoto (Aisan Industry,
serving as chairperson), Hajime
Inamori (Sumitomo Chemical), Hideki
Iwasaki (Ricoh), Daisuke Uchikawa(Seiko Epson), Daisuke Okamura(Panasonic Healthcare), Kenichi Kobiki(Mitsubishi Electric), Yoichi Hirata(Renesas
Electronics),
ChiekoFukuyama (Panasonic Healthcare), andMasayuki Tsutsumi (Nissan Motors,
serving as vice chairperson).

2. Comparison of Statutory
Provisions Concerning Unity ofInvention
Table 1 compares the provisions
concerning unity of invention enforcedin the respective countries (including a
region and a treaty): Japan, the US, theEU, China, Korea, and the Patent
Cooperation Treaty (PCT).
With regard to patent applicationsin the US (excluding those entering thephase of international application under
the PCT), there is no concept of unityof invention. However, the provisions
concerning restriction and election of
species in the US patent laws aretreated as the provisions concerning
unity of invention for the purpose ofcomparison of the provisions adopted
by the respective countries. Therefore,
in all subsequent descriptions in thisdocument explaining patent prosecution
in the US, the term “unity of invention”
includestheconceptofrestriction/election of species when it isused in such expressions as “failure tofulfill the unity of invention
requirement,” “non-compliance withthe requirement of unity of invention,”“finding of lack of unity of invention,”or the like.
Table 1: Comparison of Statutory Provisions
Concerning Unity of Invention

1035Intellectual Property Management Vol.65 No.8 2015

JP

US

EU

CH

KR

PC
T

Underlying
provision of therelevant law
Article 37 of the
Patent Act
Article 25-8 of theOrdinance for
Enforcement of
the Patent Act
35 U.S.C. 121(US patent law)
37 CFR 1.141(US patent
regulations)
Article 82 of theEuropean Patent
Convention (EPC)
Rule 44(1) of the
Implementing
Regulations of theConvention
Article 31 of the
Patent Law
Rule 35 of the
Implementing
Regulations of the
Patent Law
Article 45(1) of
the Patent Act
Article 6(1) of the
Enforcement
Decree of the
Patent Act
Article 17(3)(a) of
the PCT
Rule 13 of theRegulations under
the Patent
Cooperation
TreatyEssence of the referenced
provision
If two or more inventions havecommon “special technicalfeatures,” a group of thoseinventions is determined tofulfill the requirement of unityof invention.
“Independent and distinct
inventions” are determined tolack unity of invention.

If a patent application relates
to one invention only or to “agroup of inventions so linked
as to form a single generalinventive concept,” therequirement of unity of
invention is determined to be
fulfilled.
Two or more inventions
embodied in a single generalinvention concept may be
determined to fulfill the unityof invention requirement.
A group of inventions solinked as to form a single
general inventive concept may
be claimed under one patentapplication.
The requirement of unity of
invention will be fulfilled only
when there is a technicalrelationship among two or
more inventions involving one
or more of the same orcorresponding special
technical features.

Looking into the provisions
concerning unity of invention enforcedin the respective countries, Japan, theEU, China, Korea, and the PCT adopt acommon approach to judge unity of
invention,
regardlessofslightdifferences in details. Their judgments
are based on whether or not there is a

special technical feature (STF) making
a contribution over the prior art.
On the other hand, the US patentlaw says that independent and distinct
inventions lack unity of invention,
without considering whether there is an
STF or not (MPEP 806.02).
According to the first criterion thatan examiner must satisfy to issue a
notice of the reasons for rejection on
the grounds of lack of unity of
invention under MPEP 803, theclaimedinventions
mustbeindependent or distinct inventions. In
other words, the examiner need onlyshow
eitherindependenceor
distinctness. While 35 U.S.C. 121 (USpatent law) and 37 CFR 1.141 (USpatent regulations) stipulate thatindependent and distinct inventions are
determined to lack unity of invention,
the USPTO has been adopting apracticeof
explaining
eitherindependence or distinctness, not both,in its examination procedure, in light ofthe development of legislation (MPEP
802.01). The second criterion todetermine lack of unity of invention
under MPEP 803 is whether there
would be a serious burden in theexamination procedure, which is aseemingly abstract criterion. However,
the guidelines described in MPEP
808.02 expressly mention the threerequirements to establish a serious
burden: (A) separate classification, (B)separate status in the art, or (C)different field of search. Therefore, theexaminer must demonstrate that theclaimed inventions meet at least one of1036Intellectual Property Management Vol.65 No.8 2015

these three requirements. In practice,separate classification (pattern A)
seems to be the most frequently usedreasoning to show a serious burden andissue a notice of the reasons forrejection on the grounds of lack ofunity of invention.
Table 2 indicates the provisions
concerning examination of unity of
invention in the laws and regulations of
the respective countries which areapplicable to PCT applications entering
the national or regional phase. Japanand Korea have no particular provisions
in this respect. Under the provisions
enforced in the EU and China, theadequacyofafindingof
non-compliance with the unity of
inventionrequirement
intheinternational phase is supposed to bechecked in order to determine whether
or not to carry out the examination
process for the claims for which an
additional search fee was not paid intheinternational
phase.
These
provisions correspond to Article
17(3)(b) of the PCT. In other words,
applications directly filed with thenational or regional patent office(“non-PCT applications”) also arecontrolled by the provisions equivalent
to the judgment criteria under the PCT
in Japan, the EU, China, and Korea. In
these countries, therefore, there issubstantially no difference between
PCT applications and non-PCT
applications when they are treated by
the national patent or regional patentoffice.
In contrast, 35 U.S.C. 372(b)(2)(US patent law) stipulates that the
Director may cause the question ofunity of invention to be reexamined
under section 121, within the scope ofthe requirements of the treaty and theRegulations, after the PCT applicationenters the US national phase. This
provision means that unity of invention
may be reexamined in the US national
phase, regardless of whether lack ofunity of invention has been found or
not in the international phase. However,such reexamination is supposed to belimited to the scope of the requirementsof the treaty and the Regulations. Thismeans that the USPTO’s reexaminationof unity of invention must be based on
the PCT criteria.
Table 2: Provisions Concerning Examination ofUnity of Invention for PCT Applications

JP
US

EU

Underlying
provision of therelevant law
N/A
35 U.S.C.
372(b)(2) (USpatent law)
37 CFR 1.475,
1.499 (USpatentregulations)
Rule 164 of the
Implementing
Regulations of
the European
PatentConvention

Essence of the referenced
provision
N/A
The Director may cause thequestion of unity of invention to
be reexamined under section
121, within the scope of therequirements of the treaty andthe Regulations.
If the examiner considers thatthe application documents do notcomply with the requirement ofunity of invention, the examiner
will inform the applicant that afurther search fee must be paid
within a period of two months,
and then the examiner will draw
up the supplementary European
search report for the parts of theapplication relating to inventions
in respect of which search fees
have been paid.

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CH

KR
PC
T
(for
refe
renc
e)

Underlying
provision of therelevant law
Rule 115 of the
Implementing
Regulations of
the Patent Law

N/A
Article 17(3)(b)of the PCT

Essence of the referenced
provision

MPEP 803

If some parts of an international
application enter the Chinese
national phase without going
through international search orinternational preliminary
examination and the applicant
requests that such parts be thebasis of examination, thecompetent office must givenotice to direct the applicant to
pay the restoration fee for unityof invention within the specified
time limit.
N/A
The national law of any
designated state may stipulatethat the relevant parts of theinternational application shall beconsidered withdrawn unless theapplicant pays a special fee tothe competent office of thatstate.

MPEP 808.02

35 U.S.C.
372(b)(2)(US patent law)

As a result of comparing theprovisions
concerning
unityof
invention enforced in the respective
countries, as explained above, the US
applies its own judgment criteria to
non-PCT applications and the criteria
compatible with those of Japan, the EU,
China, and Korea to PCT applications.
Under the latter criteria, whether there
is an STF or not is checked to judge
unity of invention. For reference, theprovisions
concerning
unityof
invention in the US patent law are
excerpted in Table 3.
Table 3: Provisions Concerning
Invention in the US Patent Law
Underlying
provision of therelevant law
35 U.S.C. 121(US patent law)
37 CFR 1.141(US patent
regulations)

Unity

Essence of the referenced provision
Independent and distinct inventions are
determined to lack unity of invention.
Two or more independent and distinct
inventions may not be claimed in one
national application.

of37 CFR 1.475(US patent
regulations)

If an examiner intends to require that an
application be restricted to one of theclaimed inventions, those plural
inventions must be patentably distinct
inventions meeting the following
criteria:(A) Those inventions must be
independent or distinct.
(B) There would be a serious burden on
the examiner if restriction is not
required.
In order to explain why there would be aserious burden on the examiner, theexaminer must show one of thefollowing:(A) Separate classification(B) Separate status in the art(C) Different field of searchWith regard to a PCT application, theDirector may cause the question of unityof invention to be reexamined under
section 121, within the scope of therequirements of the treaty and theRegulations.
When a group of inventions claimed in
one PCT application forms a “single
general inventive concept” and involves
one or more STFs, this application isdetermined to fulfill the unity of
invention requirement.

3. Statistical Survey Concerning
Unity of Invention Examinations
For the purpose of grasping actual
examinations of unity of invention by
the respective national patent offices,
we gathered their patent prosecution
data and attempted to understand an
overall trend through a statistical
approach.
3.1 Preconditions for the Survey
The application filings to be
surveyed were chosen in accordancewith the following conditions.
(1) Countries surveyed
Patent application examinations in

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Japan, the US, the EU, and China weresurveyed. Korea was excluded from thesurvey described in this Section 3 since
it was difficult to gather Korean filewrapper information.
(2) Time periods surveyed
For the purpose of analyzing
examination
activities
performed
during the same time span, we tried to
set a specific time period. We initiallyintended to preferably choose patentapplications for which the first action
had been issued during the period from
October 1, 2013 to December 31, 2013.
In reality, however, we could not use
the same conditions for choosing datafrom all the surveyed countries becauseof restrictions arising from thefunctionality of their respective
databases. Alternatively, we chose
patent applications under the conditions
described
below,
which
were
determined in light of the average firstaction period of each country. Due tothe same restriction, US applications
were chosen separately from non-PCT
applications and PCT applications.
(i) Japan
Patent applications for which thefirst action was issued during the period
from October 1, 2013 to December 31,
2013(ii) US (non-PCT applications)
Patent applications filed during theperiod from April 1, 2012 to June 30,
2012 and pending on September 30,
2013(iii) US (PCT applications)
Patent applications filed during theperiod from October 1, 2010 to
December 31, 2010 and pending on
September 30, 2013(iv) EU
Patent applications for which an
extended European search report and apartial search report had been issued
during the period from October 1, 2013
to December 31, 2013(v) China
Patent applications for which arequest for examination had been filed
during the period from October 15,
2012 to January 15, 2013 and whichwere pending on September 30, 2013
(3) Classification of inventions andnumbers of surveyed applications
The patent applications meeting theconditions described above werechosen at random in accordance withthe following classification:
I. Electrical engineering
500
II. Instruments
500
III. Chemistry
500
IV. Mechanical engineering
500(applications in each country)

The identification of these areas
complieswiththetechnology
classification specified in the IPC andTechnology Concordance Table, which
has been prepared based on theInternational Patent Classification(IPC) established by the WorldIntellectual Property Organization(WIPO).
(4) Survey content and judgment
criteria

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We
reviewedthepatentapplications chosen in the way
described above, in order to check
whether or not a judgment about unityof invention had been exhibited in thefirst action. Then, we analyzed
differences by country and by category(technology area) through comparing
the percentages of applications facingsuch judgment.
3.2 Survey Results
Table 4 and Figure 1 indicate thepercentages of patent applications
resulting in a finding of lack of unity of
invention by category and by country.
Our comparison by country discoveredthat the US had an extremely highpercentage of applications resulting in afinding of lack of unity of invention ineach of the specified categories. We
also found that both PCT applications
and non-PCT applications in the US
showed almost the same percentage
resulting in a finding of lack of unity of
invention.
Looking into the percentages by
category, the area of chemistry showeda high percentage in each country.
Among others, in the US over 50% of
applications resulted in a finding oflack of unity of invention, which is anoteworthy figure.
The figures for the EU include
patentapplications
involving
non-compliance with the unity of
invention requirement, as well as patentapplications failing to comply with theprinciple of “one independent claim in

the same category” (Rule 43(2) of the
Implementing Regulations of theEuropean Patent Convention).
Table 4: Survey Results by Country and by
Category
Electricalengineering

Instruments

Mechanicalengineering

3%

2%

5%

1%

53%

15%

28%

28%

58%

15%

29%

28%

9%
(1%)
4%

7%
(1%)
1%

9%
(1%)
1%

4%
(1%)
2%

ChemistryJP
US(nonPCT)
US
(PCT
)
EU
CH

Note:The parenthesized figures for the EU are thepercentage of applications causing a violation of Article
43(2) of the Implementing Regulations of the EPC.

Figure 1: Survey Results by Country and by
Category (graph)
Chemistry
Electricalengineering
Instruments
Mechanicalengineering

Japan

US
(non-PCT)

US
(PCT)

EU

China

4. Differences in Determination ofUnity of Invention between
International
Searching
Authorities and National Patent
Offices
Section 3 explains the result of thestatisticalsurveyconcerning

1040Intellectual Property Management Vol.65 No.8 2015

examinations of unity of invention by
the respective national or regional
patent offices. Section 4 analyzes
differences in determination of unity of
invention by those patent offices ingreater depth. For this analysis, wewould like to explain the result ofsurveying 108 patent families coveredby PCT applications filed from 2005 to2007 (extended to Japan, the US, theEU, China, or Korea), in order tounderstand differences between the
judgments about unity of invention by
International Searching Authorities(ISA) in the PCT phase and thejudgments made after entry into thenational phase in respective countries.
Since our survey was focused mainly
on applications filed by Japaneseenterprises, the PCT applications
surveyed were chosen from thoseexamined by the Japan Patent Officeacting as the ISA. The file wrapper
information of the patent families
surveyed was obtained from the First
Patent Committee of JIPA.
Regardingtheapplications
examined in the countries other thanthe US (Japan, the EU, China, andKorea), there was no international
search report (ISR) identifying lack ofunity of invention. After entry into thenational phase in each country, theapplications receiving a notice of thereasons for rejection on the grounds oflack of unity of invention were as
follows: one application (1%) in Japan,
nine applications (8%) in the EU, four
applications (4%) in China, and three
applications (3%) in Korea. Thus,

judgments about unity of invention
generally match each other in the ISA’s
examinations and each national office’s
examinations.
On the other hand, the USPTO
issued a notice of the reasons forrejection for 19 applications (18%) on
the grounds of lack of unity of
invention as a result of its own
examinations, even though their ISR
had not recognized lack of unity of
invention. Compared with othercountries, the US had a tendency torender judgments about unity of
invention differing from ISA’s
judgments.
The most typical reason for
determining non-compliance with theunity of invention requirement andissuing a notice of the reasons forrejection in the US is described asfollows: independent claims fallingunder separate categories (e.g., a claim
for products and a claim for amanufacturing method) do not involveany common STF based on citation ofprior art documents (11 of 19
applications).
Among
those
applications, given below are the caseexamples wherein the ISA and the
USPTO made different judgments
about unity of invention.
(1) Case where the USPTO judgedthat there was no STF by citing priorart documents determined to fallunder Category “Y” in an ISR
Regardinganinternational
application containing independentclaims falling under separate categories

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(International Application Number:
PCT/JP2006/319573),
theISR
determined that the cited documents
were classified into Category “Y” (acategory for documents to be cited todeny inventive step) and there was no
mention of lack of unity of invention.
However, in the process of theexamination of a US application after
entry into the US national phase(Application Number: 11/992646), theexaminer determined that there was no
STF by using the same documents as
those cited in the ISR and issued anotice of the reasons for rejection on
the grounds of lack of unity of
invention in accordance with Rule 13of the PCT Regulations.
(2) Case where unity of invention
was judged based on non-PCT
criteria
After an international application(International Application Number:
PCT/JP2006/319572) entered the US
national phase and was identified as a
US application (Application Number:
12/ 067996), this US application
received a notice of the reasons forrejection, without indication of any
prior art documents and the applicableprovision of the PCT Regulations. The
applicant was informed that the claim
for products and a manufacturingmethod should be divided to fulfill theunity of invention requirement based on
MPEP 806.05, while this provisionrefers to the criteria for non-PCT
applications.

(3) Case where no prior art
documents were indicatedRegardinganinternational
application containing independentclaims falling under separate categories(International Application Number:
PCT/JP2006/310780),
theISR
determined that the prior art documents
were classified into Category “A”(documents showing a technicalbackground that can be used only forreference) and there was no mention oflack of unity of invention. However, a
notice of the reasons for rejection was
issued for a US application after
enteringthenationalphase(Application Number: 11/914843) on
the grounds of lack of unity of
invention, without indicating any priorart documents, while reference to Rule
13 of the PCT Regulations was made.
In this decision, each of the
independent claims was determined to
be independent or distinct and to fallwithin a separate technology area andthe examiner demonstrated a serious
burden by insisting on the necessity ofsearching in different fields, etc. In fact,
the examiner relied on the criteria for
non-PCT applications in this case.
5. Why Are Many Patent
Applications Rejected in the First
Action on the Grounds of Lack ofUnity of Invention in the US?
As explained in Section 3, the US
has a higher percentage of issuing a
notice of the reasons for rejection on
the grounds of non-compliance with the1042Intellectual Property Management Vol.65 No.8 2015

unity of invention requirement than theother countries. In this Section 5, we
consider the causes of such tendency
based on a comparison of the statutory
provisions explained in Section 2 andthe survey results described in Section
4. The conceivable causes that weinferred are listed as follows.
(i) Compared with the criteria enforcedin the other countries, issuing a
notice of the reasons for rejection iseasier under the US criteria.
(ii) Since judgments about STFs in the
US differ from those in the othercountries or under the PCT, noticesof the reasons for rejection due tolack of unity of invention in the US
outnumber those in other countries.
(iii) Since the US maintains criteria
different between PCT applications
and non-PCT applications, US
examiners are apt to mistakenly issue
a notice of the reasons for rejection.
(iv) Other
Section5
providesdetailed
explanations about these conceivablecauses. As shown in Section 3, theUS has a particularly high percentage
of applications resulting in a findingof lack of unity of invention in thearea of chemistry. The causes of thissituation also are considered in
Section 5.
5.1 Differences in Judgment
Criteria between the US andOther Countries
As described in Section 2, thecriteria for judging unity of invention
for non-PCT applications in the US
deviate significantly from the judgment
criteria adopted in the other countries.
We therefore consider that suchdifference in the judgment criteria
constitutes one of the causes of a highpercentage of issuing a notice of thereasons for rejection due to lack ofunity of invention in the US.
As noted before, patent applications
are
to
be
rejecteddue
tonon-compliance with the unity of
invention requirement under MPEP 803
when the claimed inventions are
determined to be “independent or
distinct” and expected to cause a“serious burden” on the examiner. We
take a look at these two viewpoints
based on differences in judgment
criteria between the US and the othercountries.
(1) Being independent or distinct
This viewpoint refers to theassessment to judge whether theclaimed inventions are independent or
distinct. Under MPEP 802.01, the term“independent” means that there is nodisclosed relationship between the twoor
moreinventions
claimed.
Understandably, there is no STF among
two or more independent inventions. If
such independent inventions areclaimed in one application, no
significant difference will arise injudgments about unity of invention
between the US and the other countries.
In the meantime, judging whether“distinct” or not seems to be based on

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different ideas and criteria, while boththe US and the other countries focus on
the relationship between the claimed
inventions in some way.
The countries other than the US
judge unity of invention based on STFs,
as explained in Section 2; if the claims
falling under separate categories are
determined to be related, they are to betreated as a single invention in theexamination procedure in thosecountries. In contrast, the scope of
inventions determined to be “distinct”
is broader under the US criteria,
whereby the claims falling under
separate
categories
arereadily
recognized as being distinct.
Let us take an application claiming
products and a manufacturing method
as an example. In the countries otherthan the US, if the claimed
manufacturing method is determined
appropriate for the manufacture of theclaimed products, those manufacturingmethod and products will be
determined to be related to each otherand unity of invention will beacknowledged. In the US, if theinvention claimed for the products canbe manufactured by any method otherthe claimed manufacturing method, theclaimed products and manufacturingmethod will be determined to be
distinct based on the patterns of“related invention” listed in MPEP
806.05 (MPEP 806.05(f)). In reality, asituationwhere
theclaimedmanufacturing method is the only way
to manufacture the claimed products isvery rare. In most cases, therefore, theinventions of products and amanufacturingmethodinone
application are considered to be
independent or distinct under the US
criteria.
In this way, the claimed inventions
examined under the US criteria are
more likely to be recognized as being
independent or distinct, compared withthe assessment in the other countries.
(2) Serious burdenThis viewpoint refers to theassessment to judge whether or notthere would be a “serious burden” inthe examination process. No similar
judgment criteria are established in the
countries other than the US. This ruleseems to allow US examiners to easily
demonstrate that there would be aserious burden. Below are the reasonsfor such inference.
As explained in Section 2, MPEP
808.02 provides guidelines for applying
this rule. If multiple claims in one
application involve different patentcategories (separate classification),separate technology areas (separate
status in the art), or different scopes ofprior art search (separate field of
search), they are considered to cause aserious burden on the examiner.
If the claimed inventions fall under
different categories, they will be readily
recognized as being distinct, as
explained in (1) above. In this event,
the requirements for demonstrating aserious burden also will be readilysatisfied. For example, even when aclaim for products and a claim for a1044Intellectual Property Management Vol.65 No.8 2015

manufacturing method are closely
related to each other, these claims are,in general, to be classified into separate
patent categories. Therefore, theexaminer has only to show separate
classification, and then the requirement
for a serious burden can be readilysatisfied.
With regard to at least the “separate
field of search” requirement, it isconsidered possible to insist on thenecessity to examine a different scopeof search merely because one
application involves separate claims.
This means that a “separate field of
search” is applicable based on eachexaminer’s subjectivity. In other words,
if the examiner judges that there would
be some burden in examination, theexaminer can conclude that it would bea serious burden. In this way, it is easy
for examiners to apply the serious
burden criterion.
Owing to these criteria which arereadily applicable based on either“independent or distinct” or “serious
burden,” patent applications examinedin the US are apt to be rejected in thefirst action on the grounds of
non-compliance with the unity of
invention requirement.
If these judgment criteria peculiar
to the US impose a heavier burden on
applicants in the US national phasealone, such criteria must be corrected
for the sake of patent system
harmonization. As with the othercountries, the US should introduce theassessment of unity of invention basedon STFs in conformity with the PCT

criteria and abolish the criteria allowing
for subjective and discretionary
operation by examiners. We havealready proposed this reform inconferences discussing patent system
harmonization and on other occasions,and the proposal has gained some
support by associations organized bypatent applicants or owners, among
others. The First International Affairs
Committee will continue to advocate
this proposal on appropriate occasions.
With the full-scale launch of the
Cooperative
PatentClassification(CPC) system in the US from FY2015,
the patent classification used toestablish a serious burden has beenshifted from the United States PatentClassification (USPC) to the CPC
system. We are observing how thischangeover will affect the percentage
of issuing a notice of the reasons forrejection on the grounds of lack ofunity of invention in the US.
5.2 Differences in Practical
Guidelines for Judging STFs
As
described
before,USapplications filed through the PCTroute are supposed to undergo a processof judging unity of invention based on
the PCT criteria in principle, namely,
based on the criteria for judging STFs,
before commencement of substantive
examination at the USPTO. Since some
applications may be rejected on the
grounds of non-compliance with theunity of invention requirement in thisprocess, the number of applications to1045Intellectual Property Management Vol.65 No.8 2015

be covered by substantive examination
can be reduced in advance. To enforce
this operation, the examiner is required
to demonstrate that there is no STF forthe inventions claimed in theapplication being examined.
The
practical
procedure byexaminers starts with the assessment of
an STF or STFs in the claims incomparison with the prior art
mentioned in the International Search
Report (ISR). Since the criteria for
judging STFs are strict in the US, we
inferred that such strict criteria
contributed to a high percentage ofrejection notices on the grounds of lackof unity of invention in the US.
The survey as described in Section
4 discovered 16 PCT applications
resulting in a finding of lack of unity of
invention in the US national phase
whereas their ISR had not recognizedlack of unity of invention. As a result of
scrutinizing these 16 applications, wefound that three of them had received anotice of the reasons for rejection on
the grounds of lack of unity of
invention, based on the citation of the
documents classified into Category “X”(a category for documents to be cited todeny novelty) in their ISR todemonstrate that there was no STF. We
also found that four of the 16
applications had received a notice ofthe reasons for rejection on the groundsof lack of unity of invention, based on
the citation of the documents classified
into Category “Y” to demonstrate that
there was no STF. Each of the three
applications first mentioned contained

multiple independent claims, but atleast one of those claims wasdetermined to lack novelty in their ISR.
It is therefore not surprising that eventhough the ISR had stated that there
was no STF, the judgment made in the
US national phase is considered tomatch the PCT criteria in this respect.
With regard to the four applications
mentioned above, the notice of thereasons for rejection based on lack ofunity of invention describes the reasonsfor judging that there was no STF. In
this sense, the US examination of eachof those four applications is considered
to match the PCT criteria. In summary,
while judgments about STFs in the US
meet the PCT criteria in general, thepractical guidelines for making such
judgments in the US are more stringent
than those in the other countries. This isconsidered to raise the percentage of
issuing a notice of the reasons forrejection due to lack of unity of
invention in the US. While such notices
state the reasons for judging that there
was no STF, we discovered that thosestatements are detailed in some casesand simplified in other cases. To
ascertain whether the reasons for such
judgments are sufficiently explained ornot, we are going to continue ourobservations and considerations in thisrespect.
We need to encourage efforts forpatent system harmonization in termsof judgments about STFs in the US. At
the same time, however, we would liketo remind applicants of the highlikelihood of receiving a notice of the1046Intellectual Property Management Vol.65 No.8 2015

reasons for rejection on the grounds oflack of unity of invention in the US
whendocuments
falling
under
Category X or Category Y are cited in
the ISR. With this in mind, applicantsarerecommended
toconsidersubmitting a preliminary amendment inadvancetomodifyaclaim
appropriately
accordingtocircumstances.
5.3
Why
Many
PatentApplications in the Field ofChemistry Are Rejected in theFirst Action Due to Lack of Unity
of Invention
As explained in Section 3, thepercentage of applications resulting in afinding of lack of unity of invention(i.e., the restriction requirement ratio in
the US) is remarkably high in the areaof chemistry. In this subsection, welook into characteristics identified inpatent applications in the area ofchemistry.
(1) Composition of claims
As a result of analyzing types ofrestriction, frequently used reasons forrequiring restriction are listed asfollows in descending order: MPEP
806.05(h) (Product and Process of
Using) accounted for 62%, MPEP
806.05(j) (Related Products; Related
Processes) for 35%, and MPEP 806.06(Independent Inventions) for 15%. Two
or more types of the foregoing werementioned at the same time in somecases. A finding of lack of unity of

invention relies on these provisions
probably because applications filed in
the area of chemistry are usuallydrafted in such a form to claim a new
substance as the first invention and toclaim a method for synthesizing or
using this new substance or acomposition of matter formed bymixing the new substance and otheringredients as the second andsubsequent
inventions.
Suchcomposition of claims is apt to receive
a judgment acknowledging unity of
invention in the surveyed countries
other than the US. On the contrary, theUS tends to determine that such claims
are “independent or distinct” and would
potentially cause a “serious burden.”(2) Restriction requirement ratios by
art unit
Subsequently, our analysis focusedon examinations in the area ofchemistry by the respective units of the
USPTO. The area of chemistry is
broadly divided into the chemical field
and the medical and pharmaceuticalfield. We reviewed the file wrappers foreach of the patent families chosen,
constituting 108 applications in total.
These 108 applications include 12
applications in the chemical field and
11 applications in the medical andpharmaceutical field, for which a noticeof the reasons for rejection was issued
on the grounds of lack of unity of
invention in the US. The units in chargeof the examinations of those
applications in the USPTO are as
follows: five applications in the1047Intellectual Property Management Vol.65 No.8 2015

chemical field and 11 applications in
the medical and pharmaceutical field by
Art Unit 1600 (Biotechnology andOrganic Chemistry), and sevenapplications in the chemical field andzero in the medical and pharmaceuticalfield by Art Unit 1700 (Chemical andMaterials Engineering). In general, it
seems that Art Unit 1600 is responsible
for examinations in the medical andpharmaceutical field and that Art Unit
1700 is responsible for examinations in
the chemical field.
According to “PATENTLYO,” awebsite launched on June 15, 2010 tooffer information on published patentapplications that have been disposed of(http://patentlyo.com/patent/2010/06/likeliho
od-of-office-action-rejections.html), therestriction requirement ratio is 54% in
Art Unit 1600 and 21% in Art Unit
1700. In other words, a higher
restriction requirement ratio is found in
the chemical field than in the medical
and pharmaceutical field.
(3) Characteristics in the medical
and pharmaceutical field
Of the 108 patent families reviewed
as described in Section 3, we
scrutinizedthepatentfamiliesclassified in the medical andpharmaceutical field. The applications
scrutinized here are seven patentfamilies filed through the PCT routeand subsequently entering the US
national phase, involving the same
compositions of claims in the PCT
phase and the US national phase, andresulting in the USPTO’s finding oflack of unity of invention while the ISR
acknowledged unity of invention in the
PCT phase.
Why does the medical andpharmaceutical
field
show
a
remarkably high restriction requirement
ratio in the area of chemistry? We
presume that this situation depends onwhether inventions of diagnostic ortherapeutic methods are claimed or not,since diagnostic and therapeutic
methods are not eligible for patent
protection in the countries other thanthe US. In other words, such a situationis considered to be caused by thedifference in the scope of patentable
inventions.
Two of the seven surveyed patentfamiliesinthemedicalandpharmaceutical field received a noticeof the reasons for rejection due to lackof unity of invention recognized inconnection
withdiagnostic
ortherapeutic methods. The rejection
notice for each of those two patentfamilies refers separately to the claimed
invention for products and the claimed
invention for a diagnostic or therapeutic
method using the products.
International Application Number
PCT/JP2006/311073 (US Application
Number: 11/916356) mentioned before
is considered in more detail below. In
the examination process in the US, theclaimed invention for the products wasdetermined to lack novelty based oncited references which had not been
mentioned in the ISR. As a result, theclaimed invention for a diagnostic or

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therapeutic method in a separate
category was determined to lack unityof invention on the grounds that there
was no STF. Looking at the patentapplication bearing the International
Application
Numberof
PCT/JP2006/319912 (US Application
Number: 11/992817), a therapeutic(preventive) drug was claimed in the
PCT phase and the subject matter of theclaim was changed to a therapeutic(preventive) method when entering the
US national phase. However, thisapplication was determined to fail tofall under any of the specified
categories (37 CFR 1.475) and resulted
in a finding of lack of unity of
invention in the US examination,
without citing any references.
While the propriety of a judgment
by a US examiner can be controversial,
this is a problem peculiar to the medical
and pharmaceutical field. Diagnostic ortherapeutic methods are not eligible forpatent protection in the countries otherthan the US. If a claim contains aninvention for a diagnostic or therapeutic
method when entering the US national
phase, US examiners seem to have atendency to recognize lack of unity of
invention. Therefore, the difference inthe scope of patent protection between
the US and the other countries ispresumed to be a major factor leading
to a high restriction requirement ratio in
the medical and pharmaceutical field
than in other fields in the area ofchemistry.
(4) Summary of Subsection 5.4

The area of chemistry as a wholetends to show a high restriction
requirement ratio, especially in the
medical and pharmaceutical field.
Since our survey this time covers
only a limited number of patentapplications, we are going to continue
to observe and consider this issue.
5.4 Coexistence of PCT Criteria
and Non-PCT Criteria
As explained in the preceding
sections, the US adopts separate criteria
for PCT applications and for non-PCT
applications to judge unity of invention.
US examiners are therefore forced touse different criteria according to thefiling route, even though their judgment
is made for the same claim within thesame nation. This may sometimes leadto their misunderstanding or confusion
when adopting the judgment criteria,
and some applications may mistakenly
result in a finding of lack of unity of
invention which should otherwise be
avoided.
As a result of analyzing the detailsof 16 applications resulting in a findingof unity of invention, we found that twoof them were examined and judged
under the non-PCT criteria while theyshould have been controlled by the
PCT criteria.
While we cannot conclude atpresent that such situations raise thepercentage of recognizing lack of unityof invention in the US, erroneous
judgments are never acceptable toapplicants. If an applicant faces such

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misjudgments, it would be worth
considering traversing the examiner’s
decision or action.
Needless to say, patent systems
must be properly operated in such a
way as not to cause incorrect judgments.
More importantly, however, such
misjudgments as explained here would
never occur if the PCT criteria alone
were used as the standard for assessing
unity of invention. We therefore intend
to advocate proper operation of patent
systems, as well as integrated adoptionof the PCT criteria as the standard for
judging unity of invention.
5.5 Other Conceivable Causes
As illustrated in Section 2, thisdocument is based on the assumptionthat the concept of a “finding of lack ofunity of invention” when used withreference to the US includes arequirement for restriction or electionof species. The provisions concerning a
restriction requirement refer to unity of
invention between the claimed species,
which is intended to require theapplicant to elect a single group(species). On the other hand, anelection of species requirement isrelated to a patent application for asingle generic claim covering multiple
species and this is intended to require
the applicant to elect a species whensuch a generic claim is not patentable.
Since each species corresponds to a
specific embodiment in general, theapplicantusuallyelectsone
embodiment accompanied by one

species, resulting in the election of theclaim corresponding to the elected
embodiment. Determination of unity of
invention in the countries other than the
US is a process of assessing unity of
invention between the claims in one
application, which resembles theconcept of restriction between theclaims in the US. However, there is noconcept equivalent to election of
species in the assessment of unity of
invention in the countries other than the
US. After the applicant elects one
species in response to an election of
species recruitment, its claim may
eventually be accepted as one
application if the generic claim
withdrawn is considered. If, however,the claim is determined not to cover
one species, the applicant will need todivide the application. The burden on
the applicant in this event is similar tothe burden in case of a restriction
requirement. This is why we consider
that an election of species requirementissimilartoafindingof
non-compliance with the unity of
invention requirement.
According to our survey, thepercentage of rejection notices due tolack of unity of invention involving anelection of species requirement only
was 14% in the area of chemistry, 6%in the area of electrical engineering,
12% in the area of instruments, and
10% in the area of mechanicalengineering. These figures show thatthe concept of election of species
contributes to raising the total
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reasons for rejection due to lack ofunity of invention in the US.
Another
conceivablefactorcontributing to such a high ratio of
rejection notices is the trend toward
timely patent prosecution in the US.
The USPTO is promoting a strategy toachieve timely examination withspecified goals. When former Director
David J. Kappos took office in the
USPTO, the 2010-2015 Strategic Plan
was established to enhance patentquality and timeliness. Under this plan,
examiners were encouraged to identify
patentable subject matter early andstrive for “compact prosecution” tooptimize patent pendency.2) This planset out the target time periods for patent
prosecution practices to be followed byeach examiner for each application.
Such targets require examiners tocomplete the whole process fromsearch through examination to first
office action within this time constraint.
US examiners therefore seem to preferto narrow the scope of examination
with the intention of reducing the timespent for reviewing each application.
Furthermore, there are some
opinions that the USPTO’s patentexaminer count system, i.e., theperformance evaluation system for
examiners, contributes to a highpercentage of rejection notices on the
grounds of lack of unity of invention. It
is a fact that examiners are supposed to
be granted reward points according to
the number of applications processed,
and this reward point system may
motivate examiners to process as many

applications as possible. Therefore, it ishighly likely that US examiners are
eager to issue a rejection notice basedon non-compliance with the unity of
invention requirement.
6. Conclusion
In this survey, we compared majorcountries’ systems concerning unity of
invention and investigated trends intheir judgments in patent prosecution.
The survey showed that the US is
peculiar in terms of the unity of
invention scheme, as well as in terms of
the percentage of issuing a notice of thereasons for rejection on the grounds oflack of unity of invention. With a focus
on the US, which has a particularlyhigh percentage of rejection notices in
the first action, we considered its
reasons and identified the key points inlight of patent system harmonization.
Regarding non-PCT applications in
the US, we ascertained that they tend to
face a notice of the reasons for rejection
due to lack of unity of invention
primarily because the US examination
criteria are prone to such judgments.
Regarding PCT applications in the US,
US statutory provisions concerning
unity of invention conform to the PCT
criteria, as is the case with other majorcountries. Nevertheless, we found astrong tendency of willingly issuing a
notice of the reasons for rejection on
the grounds of lack of unity of
invention, while conforming to the
PCT-compatible criteria.
When asking the US to harmonize

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the patent system in terms of unity of
invention, it is not enough to call foralignment with the other countries’
criteria, but it is also important to ask
for harmonization in terms of operationof the criteria in parallel.
From the standpoint of applicants,
the decision to issue a notice of thereasons for rejection due to lack ofunity of invention in the US national
phase appears to have been somewhat
unsatisfactory, but many of those
applicants may not have bothered toobject. Going forward, however, werecommend
applicants
toraiseobjections when the examiner’s
decision does not meet the criteria,
recognizing the judgment criteria in the
US and their peculiarity. We expectthat such responses by applicants will
help improve the level of individual
examiners in the US. If their
examination quality is improved, thenumber of applications that are easily
rejected on the grounds of lack of unityof invention is expected to be reduced,
which will surely be advantageous forapplicants. We hope the survey
outlined in this document will help
promote the harmonization of patent
systems among the IP5 nations in termsof determination of unity of invention,and help JIPA members develop anunderstanding of the criteria concerning
unity of invention of the IP5 nations.

Notes:
1)“Results of the Seventh Meeting of
the IP5 Heads of Office Held in
Busan, ROK,” News Release dated
June 6, 2014 (published in English
on April 18, 2014)
http://www.meti.go.jp/english/press/index.html (accessed and confirmed
in 2016)
2)「米国特許商標庁の改革に伴う審査環境の変化とそれに対応した実
務 ｣ ( 知 財 管 理 (IP Management)
Vol. 61, No. 8, 2011)(Manuscript received on March 30,
2015)

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