Skip to main content Skip to footer
HomeHome
 
  • Homepage
  • Searching for patents

    Patent knowledge

    Access our patent databases and search tools.

    Go to overview 

    • Overview
    • Technical information
      • Overview
      • Espacenet - patent search
      • European Publication Server
      • Searching Asian documents: patent search and monitoring services
      • EP full-text search
      • Bibliographic coverage in Espacenet and OPS
      • Full-text coverage in Espacenet and OPS
    • Legal information
      • Overview
      • European Patent Register
      • European Patent Bulletin
      • European Case Law Identifier sitemap
      • Searching Asian documents
      • Third-party observations
    • Business information
      • Overview
      • PATSTAT
      • IPscore
      • Patent insight reports
    • Data
      • Overview
      • Linked open EP data
      • Bulk data sets
      • Web services
      • Coverage, codes and statistics
    • Helpful resources
      • Overview
      • First time here?
      • Asian patent information
      • Patent information centres
      • Patent Translate
      • Patent Knowledge News
      • Business and statistics
      • Unitary Patent information in patent knowledge

    UP search

    Learn about the Unitary Patent in patent knowledge products and services

  • Applying for a patent

    Applying for a patent

    Practical information on filing and grant procedures.

    Go to overview 

    • Overview
    • European route
      • Overview
      • European Patent Guide
      • Oppositions
      • Oral proceedings
      • Appeals
      • Unitary Patent & Unified Patent Court
      • National validation
      • Request for extension/validation
    • International route (PCT)
      • Overview
      • Euro-PCT Guide – PCT procedure at the EPO
      • EPO decisions and notices
      • PCT provisions and resources
      • Extension/validation request
      • Reinforced partnership programme
      • Accelerating your PCT application
      • Patent Prosecution Highway (PPH)
      • Training and events
    • National route
    • MyEPO services
      • Overview
      • Understand our services
      • Get access
      • Find a professional representative
      • File with us
      • Interact on your files
      • Online Filing & fee payment outages
      • Tutorials
    • Forms
      • Overview
      • Request for examination
    • Fees
      • Overview
      • European fees (EPC)
      • International fees (PCT)
      • Unitary Patent fees (UP)
      • Fee payment and refunds
      • Warning

    UP

    Unitary Patent

  • Law & practice

    Law & practice

    European patent law, the Official Journal and other legal texts.

    Go to overview 

    • Overview
    • Legal texts
      • Overview
      • European Patent Convention
      • Official Journal
      • EPC Guidelines
      • PCT-EPO Guidelines
      • Guidelines revision cycle
      • Extension / validation system
      • London Agreement
      • National law relating to the EPC
      • Unitary patent system
      • National law relating to the UP
    • Court practices
      • Overview
      • European Patent Judges' Symposium
    • User consultations
      • Overview
      • Ongoing consultations
      • Completed consultations
    • Substantive patent law harmonisation
      • Overview
      • The Tegernsee process
      • Group B+
    • Convergence of practice
    • Options for professional representatives

    legal text

    Legal texts

  • News & events

    News & events

    Our latest news, podcasts and events, including the European Inventor Award.

    Go to overview 

     

    • Overview
    • News
    • Events
    • European Inventor Award
      • Overview
      • About the award
      • Categories and prizes
      • Meet the finalists
      • Nominations
      • Watch the 2022 ceremony
    • Press centre
      • Overview
      • Patent Index and statistics
      • Search in press centre
      • Background information
      • Copyright
      • Press contacts
      • Call back form
      • Email alert service
    • Innovation and patenting in focus
      • Overview
      • Firefighting technologies
      • Green tech in focus
      • CodeFest on Green Plastics
      • Clean energy technologies
      • IP and youth
      • Research institutes
      • Women inventors
      • Fighting coronavirus
      • Lifestyle
      • Space and satellites
      • The future of medicine
      • Materials science
      • Mobile communications
      • Biotechnology
      • Patent classification
      • Digital technologies
      • The future of manufacturing
      • Books by EPO experts
    • "Talk innovation" podcast

    Podcast

    Listen to our podcast

  • Learning

    Learning

    The e-Academy – the point of access to your learning

    Go to overview 

    • Overview
    • European Patent Academy
      • Overview
      • Learning activities
      • Learning paths
    • Professional hub
      • Overview
      • EQE - European qualifying examination
      • EPAC - European patent administration certification
    • Learning resources by area of interest
      • Overview
      • Patent granting
      • Technology transfer and dissemination
      • Patent enforcement and litigation
    • Learning resources by area by profile
      • Overview
      • Business and IP managers
      • EQE candidates
      • Judges, lawyers and prosecutors
      • National offices and IP authorities
      • Patent attorneys and paralegals
      • Universities, research centres and technology transfer centres (TTOs)

    European Patent Academy

    Boost your IP knowledge with (e-)training from the European Patent Academy

  • About us

    About us

    Find out more about our work, values, history and vision

    Go to overview 

    • Overview
    • The EPO at a glance
    • 50 years of the EPC
      • Overview
      • A glimpse of the planned activities
      • Kids’ collaborative art competition
      • 50 Leading Tech Voices
    • Legal foundations and member states
      • Overview
      • Legal foundations
      • Member states of the European Patent Organisation
      • Extension states
      • Validation states
    • Governance
      • Overview
      • Communiqués
      • Calendar
      • Select Committee documents
      • Administrative Council
    • Principles & strategy
      • Overview
      • Our mission, vision, values and corporate policy
      • Public consultation on the EPO's Strategic Plan 2028
      • Towards a New Normal
    • Leadership & management
      • Overview
      • President António Campinos
      • Management Advisory Committee
    • Social responsibility
      • Overview
      • Environment and sustainability
      • Art collection
    • Services & activities
      • Overview
      • Our services & structure
      • Consulting our users
      • European and international co-operation
      • European Patent Academy
      • Chief Economist
      • Ombuds Office
      • Reporting wrongdoing
    • Procurement
      • Overview
      • Procurement forecast
      • Doing business with the EPO
      • Procurement procedures
      • About eTendering and electronic signatures
      • Procurement portal
      • Invoicing
      • General conditions
      • Archived tenders
    • Transparency portal
      • Overview
      • General
      • Human
      • Environmental
      • Organisational
      • Social and relational
      • Economic
      • Governance
    • Statistics and trends
      • Overview
      • Statistics & Trends Centre
      • EPO Data Hub
      • Clarification on data sources
    • History
      • Overview
      • 1970s
      • 1980s
      • 1990s
      • 2000s
      • 2010s
      • 2020s

    about us

    Patent Index 2022

 
en de fr
  • Language selection
  • English
  • Deutsch
  • Français
Main navigation
  • Homepage
  • New to patents
    • Go back
    • Overview
    • What's your big idea?
    • Are you ready?
    • What to expect
    • How to apply for a patent
    • Your business and patents
    • Is it patentable?
    • Are you first?
    • Why do we have patents?
    • Patent quiz
    • Unitary patent video
  • Searching for patents
    • Go back
    • Overview
    • Technical information
      • Go back
      • Overview
      • Espacenet - patent search
        • Go back
        • Overview
        • National patent office databases
        • Global Patent Index (GPI)
        • Release notes
      • European Publication Server
        • Go back
        • Overview
        • Cross-reference index for Euro-PCT applications
        • EP authority file
        • Help
      • Searching Asian documents
      • EP full-text search
      • Bibliographic coverage in Espacenet and OPS
      • Full-text coverage in Espacenet
    • Legal information
      • Go back
      • Overview
      • European Patent Register
        • Go back
        • Overview
        • Release notes archive
        • Register documentation
          • Go back
          • Overview
          • Deep link data coverage
          • Federated Register
            • Go back
            • Overview
            • BG - Federated Register Service
            • GB - Federated Register Service
            • NL - Federated Register Service
            • MK - Federated Register Service
            • ES - Federated Register Service
            • GR - Federated Register Service
            • SK - Federated Register Service
            • FR - Federated Register Service
            • MT - Federated Register Service
          • Register events
      • European Patent Bulletin
        • Go back
        • Overview
        • Download Bulletin
        • EP Bulletin search
        • Help
      • European Case Law Identifier sitemap
      • Searching Asian documents
      • Third-party observations
    • Business information
      • Go back
      • Overview
      • PATSTAT
      • IPscore
        • Go back
        • Release notes
      • Patent insight reports
    • Data
      • Go back
      • Overview
      • Linked open EP data
      • Bulk data sets
        • Go back
        • Overview
        • Manuals
        • Sequence listings
        • National full-text data
        • European Patent Register data
        • EPO worldwide bibliographic data (DOCDB)
        • EP full-text data
        • EPO worldwide legal event data (INPADOC)
        • EP bibliographic data (EBD)
          • Go back
          • EBD files (weekly download) - free of charge
            • Go back
            • Secure EBD ST.36 files (weekly download) - for national patent offices only
        • Boards of Appeal decisions
        • EP full-text data for text analytics
      • Web services
        • Go back
        • Overview
        • Open Patent Services (OPS)
        • European Publication Server
      • Coverage, codes and statistics
        • Go back
        • Weekly updates
        • Updated regularly
    • Helpful resources
      • Go back
      • Overview
      • First time here? Patent information explained.
        • Go back
        • Overview
        • Basic definitions
        • Patent classification
          • Go back
          • Overview
          • Cooperative Patent Classification (CPC)
        • Patent families
          • Go back
          • Overview
          • DOCDB simple patent family
          • INPADOC extended patent family
        • Legal event data
          • Go back
          • Overview
          • INPADOC classification scheme
      • Asian patent information
        • Go back
        • Overview
        • China (CN)
          • Go back
          • Overview
          • Facts and figures
          • Grant procedure
          • Numbering system
          • Useful terms
          • Searching in databases
        • Chinese Taipei (TW)
          • Go back
          • Overview
          • Grant procedure
          • Numbering system
          • Useful terms
          • Searching in databases
        • India (IN)
          • Go back
          • Overview
          • Facts and figures
          • Grant procedure
          • Numbering system
        • Japan (JP)
          • Go back
          • Overview
          • Facts and figures
          • Grant procedure
          • Numbering system
          • Useful terms
          • Searching in databases
        • Korea (KR)
          • Go back
          • Overview
          • Facts and figures
          • Grant procedure
          • Numbering system
          • Useful terms
          • Searching in databases
        • Russian Federation (RU)
          • Go back
          • Overview
          • Facts and figures
          • Numbering system
          • Searching in databases
        • Useful links
      • Patent information centres (PATLIB)
      • Patent Translate
      • Patent Knowledge News
      • Business and statistics
      • Unitary Patent information in patent knowledge
  • Applying for a patent
    • Go back
    • Overview
    • European route
      • Go back
      • Overview
      • European Patent Guide
      • Oppositions
      • Oral proceedings
        • Go back
        • Oral proceedings calendar
          • Go back
          • Calendar
          • Public access to appeal proceedings
          • Public access to opposition proceedings
          • Technical guidelines
      • Appeals
      • Unitary Patent & Unified Patent Court
        • Go back
        • Overview
        • Unitary Patent
          • Go back
          • Overview
          • Legal framework
          • Unitary Patent Guide
          • Main features
          • Applying for a Unitary Patent
          • Cost of a Unitary Patent
          • Translation and compensation
          • Start date
        • Unified Patent Court
      • National validation
      • Extension/validation request
    • International route
      • Go back
      • Overview
      • Euro-PCT Guide
      • Entry into the European phase
      • Decisions and notices
      • PCT provisions and resources
      • Extension/validation request
      • Reinforced partnership programme
      • Accelerating your PCT application
      • Patent Prosecution Highway (PPH)
        • Go back
        • Patent Prosecution Highway (PPH) programme outline
      • Training and events
    • National route
    • MyEPO services
      • Go back
      • Overview
      • Understand our services
        • Go back
        • Overview
        • Online Filing 2.0 pilot
        • MyEPO Portfolio - pilot phase
        • Online Filing 2.0 pilot continuation
        • Exchange data with us using an API
      • Get access
        • Go back
        • Overview
        • Installation and activation
      • Find a professional representative
      • File with us
        • Go back
        • Overview
        • What if our online filing services are down?
        • Release notes
      • Interact on your files
      • Online Filing & fee payment outages
      • Tutorials
    • Fees
      • Go back
      • Overview
      • European fees (EPC)
        • Go back
        • Overview
        • Decisions and notices
      • International fees (PCT)
        • Go back
        • Reduction in fees
        • Fees for international applications
        • Decisions and notices
        • Overview
      • Unitary Patent fees (UP)
        • Go back
        • Overview
        • Decisions and notices
      • Fee payment and refunds
        • Go back
        • Overview
        • Payment methods
        • Getting started
        • FAQs and other documentation
        • Technical information for batch payments
        • Decisions and notices
        • Release notes
      • Warning
    • Forms
      • Go back
      • Request for examination
  • Law & practice
    • Go back
    • Overview
    • Legal texts
      • Go back
      • Overview
      • European Patent Convention
        • Go back
        • Overview
        • Archive
          • Go back
          • Overview
          • Documentation on the EPC revision 2000
            • Go back
            • Overview
            • Diplomatic Conference for the revision of the EPC
            • Travaux préparatoires
            • New text
            • Transitional provisions
            • Implementing regulations to the EPC 2000
            • Rules relating to Fees
            • Ratifications and accessions
          • Travaux Préparatoires EPC 1973
      • Official Journal
      • EPC Guidelines
        • Go back
        • Overview
        • Archive
      • PCT-EPO Guidelines
        • Go back
        • Overview
        • Archive
      • Guidelines revision cycle
      • Extension / validation system
      • London Agreement
      • National law relating to the EPC
        • Go back
        • Overview
        • Archive
      • Unitary Patent system
      • National measures relating to the Unitary Patent 
    • Court practices
      • Go back
      • Overview
      • European Patent Judges' Symposium
    • User consultations
      • Go back
      • Overview
      • Ongoing consultations
      • Completed consultations
    • Substantive patent law harmonisation
      • Go back
      • Overview
      • The Tegernsee process
      • Group B+
    • Convergence of practice
    • Options for professional representatives
  • News & events
    • Go back
    • Overview
    • News
    • Events
    • European Inventor Award
      • Go back
      • Overview
      • About the award
      • Categories and prizes
      • Meet the finalists
      • Nominations
      • Watch the 2023 ceremony
      • European Inventor Network
        • Go back
        • Activities granted in 2023
    • Press centre
      • Go back
      • Overview
      • Patent Index and statistics
      • Search in press centre
      • Background information
        • Go back
        • Overview
        • European Patent Office
        • Q&A on patents related to coronavirus
        • Q&A on plant patents
      • Copyright
      • Press contacts
      • Call back form
      • Email alert service
    • In focus
      • Go back
      • Overview
      • Firefighting technologies
        • Go back
        • Overview
        • Detection and prevention of fires
        • Fire extinguishing
        • Protective equipment
        • Post-fire restoration
      • Green tech in focus
        • Go back
        • Overview
        • About green tech
        • Renewable energies
        • Energy transition technologies
        • Building a greener future
      • CodeFest on Green Plastics
      • Clean energy technologies
        • Go back
        • Overview
        • Renewable energy
        • Carbon-intensive industries
        • Energy storage and other enabling technologies
      • IP and youth
      • Research institutes
      • Women inventors
      • Fighting coronavirus
        • Go back
        • Overview
        • Vaccines and therapeutics
          • Go back
          • Overview
          • Vaccines
          • Overview of candidate therapies for COVID-19
          • Candidate antiviral and symptomatic therapeutics
          • Nucleic acids and antibodies to fight coronavirus
        • Diagnostics and analytics
          • Go back
          • Overview
          • Protein and nucleic acid assays
          • Analytical protocols
        • Informatics
          • Go back
          • Overview
          • Bioinformatics
          • Healthcare informatics
        • Technologies for the new normal
          • Go back
          • Overview
          • Devices, materials and equipment
          • Procedures, actions and activities
          • Digital technologies
        • Inventors against coronavirus
      • Lifestyle
      • Space and satellites
        • Go back
        • Overview
        • Patents and space technologies
      • Healthcare
        • Go back
        • Overview
        • Medical technologies and cancer
        • Personalised medicine
      • Materials science
        • Go back
        • Overview
        • Nanotechnology
      • Mobile communications
      • Biotechnology
        • Go back
        • Overview
        • Red, white or green
        • The role of the EPO
        • What is patentable?
        • Biotech inventors
      • Classification
        • Go back
        • Overview
        • Nanotechnology
        • Climate change mitigation technologies
          • Go back
          • Overview
          • External partners
          • Updates on Y02 and Y04S
      • Digital technologies
        • Go back
        • Overview
        • About ICT
        • Hardware and software
        • Patents and standards
        • Artificial intelligence
        • Fourth Industrial Revolution
      • Additive manufacturing
        • Go back
        • Overview
        • About AM
        • AM innovation
      • Books by EPO experts
    • Podcast
  • Learning
    • Go back
    • Overview
    • European Patent Academy
      • Go back
      • Overview
      • Learning activities
      • Learning Paths
    • Professional hub
      • Go back
      • Overview
      • EPAC - European patent administration certification
      • EQE - European Qualifying Examination
        • Go back
        • Overview
        • Archive
        • Candidates successful in the European qualifying examination
        • Compendium
          • Go back
          • Overview
          • Pre-examination
          • Paper A
          • Paper B
          • Paper C
          • Paper D
    • Learning resources by area of interest
      • Go back
      • Overview
      • Patent granting
      • Technology transfer and dissemination
      • Patent enforcement and litigation
        • Go back
        • Overview
        • Patent enforcement in Europe
        • Patent litigation in Europe
    • Learning resources by profile
      • Go back
      • Overview
      • Business and IP managers
        • Go back
        • Overview
        • Innovation case studies
          • Go back
          • Overview
          • SME case studies
          • Technology transfer case studies
          • High-growth technology case studies
        • Inventors' handbook
          • Go back
          • Overview
          • Introduction
          • Disclosure and confidentiality
          • Novelty and prior art
            • Go back
            • Overview
            • Is the idea ‘obvious’?
            • Prior art searching
            • Professional patent searching
            • Simple Espacenet searching
            • What is prior art?
            • Why is novelty important?
          • Competition and market potential
            • Go back
            • Overview
            • Research guidelines
          • Assessing the risk ahead
            • Go back
            • Overview
            • Exploitation routes
            • Significant commercial potential
            • Significant novelty
            • What about you?
            • What if your idea is not novel but does have commercial potential?
          • Proving the invention
            • Go back
            • Overview
            • Help with design or redesign
            • Prototype strategy
          • Protecting your idea
            • Go back
            • Overview
            • Forms of IPR
            • Patenting strategy
            • The patenting process
          • Building a team and seeking funding
            • Go back
            • Overview
            • Building a team
            • Sources of funding
            • Sources of help for invention
          • Business planning
            • Go back
            • Overview
            • Constructing a business plan
            • Keep it short!
          • Finding and approaching companies
            • Go back
            • Overview
            • First contact
            • Meetings
          • Dealing with companies
            • Go back
            • Overview
            • Advance or guaranteed payment
            • Companies and your prototype
            • Full agreement – and beyond
            • Negotiating a licensing agreement
            • Reaching agreement
            • Royalties
        • Best of search matters
          • Go back
          • Overview
          • Tools and databases
          • EPO procedures and initiatives
          • Search strategies
          • Challenges and specific topics
        • Support for high-growth technology businesses
          • Go back
          • Overview
          • For IP professionals
          • For business decision-makers
          • For stakeholders of the innovation ecosystem
        • IP clinics
      • EQE Candidates
        • Go back
        • Overview
        • Coffee-break questions
        • Daily D questions
        • European qualifying examination - Guide for preparation
      • Judges, lawyers and prosecutors
        • Go back
        • Overview
        • Compulsory licensing in Europe
        • The jurisdiction of European courts in patent disputes
      • National offices and IP authorities
        • Go back
        • Overview
        • Learning material for examiners of national officers
        • Learning material for formalities officers and paralegals
      • Patent attorneys and paralegals
      • Universities, research centres and TTOs
        • Go back
        • Overview
        • Academic Research Programme
          • Go back
          • Overview
          • Completed research projects
          • Current research projects
        • Pan-European Seal Young Professionals Programme
          • Go back
          • Overview
          • For students
          • For universities
            • Go back
            • Overview
            • IP education resources
            • University memberships
          • Our young professionals
          • Professional development plan
        • IP Teaching Kit
          • Go back
          • Overview
          • Download modules
        • Intellectual property course design manual
  • About us
    • Go back
    • Overview
    • The EPO at a glance
    • 50 years of the EPC
      • Go back
      • Overview
      • 50 Leading Tech Voices
      • Kids’ collaborative art competition
    • Legal foundations and member states
      • Go back
      • Overview
      • Legal foundations
      • Member states
        • Go back
        • Overview
        • Member states by date of accession
      • Extension states
      • Validation states
    • Governance
      • Go back
      • Overview
      • Communiqués
        • Go back
        • Overview
        • 2022
        • 2021
        • 2020
        • 2019
        • 2018
        • 2017
        • 2016
        • 2015
        • 2014
        • 2013
      • Calendar
      • Documents and publications
        • Go back
        • Overview
        • Select Committee documents
      • Administrative Council
        • Go back
        • Overview
        • Composition
        • Representatives
        • Rules of Procedure
        • Board of Auditors
        • Secretariat
        • Council bodies
    • Principles & strategy
      • Go back
      • Overview
      • Mission, vision, values & corporate policy
      • Strategic Plan 2028
      • Towards a New Normal
      • Data protection & privacy notice
    • Leadership & management
      • Go back
      • Overview
      • About the President
      • Management Advisory Committee
    • Procurement
      • Go back
      • Overview
      • Procurement forecast
      • Doing business with the EPO
      • Procurement procedures
      • About eTendering
      • Procurement portal
        • Go back
        • Overview
        • e-Signing contracts
      • Invoicing
      • General conditions
      • Archived tenders
    • Services & activities
      • Go back
      • Overview
      • Our services & structure
      • Quality
        • Go back
        • Overview
        • Foundations
          • Go back
          • Overview
          • European Patent Convention
          • Guidelines for examination
          • Our staff
        • Enabling quality
          • Go back
          • Overview
          • Prior art
          • Classification
          • Tools
          • Processes
        • Products & services
          • Go back
          • Overview
          • Search
          • Examination
          • Opposition
          • Continuous improvement
        • Quality through networking
          • Go back
          • Overview
          • User engagement
          • Co-operation
          • User satisfaction survey
          • Stakeholder Quality Assurance Panels
        • Patent Quality Charter
        • Statistics
          • Go back
          • Overview
          • Search
          • Examination
          • Opposition
      • Consulting our users
        • Go back
        • Overview
        • Standing Advisory Committee before the EPO (SACEPO)
          • Go back
          • Overview
          • Objectives
          • SACEPO and its working parties
          • Meetings
          • Single Access Portal – SACEPO Area
      • Our user service charter
      • European and international co-operation
        • Go back
        • Overview
        • Co-operation with member states
          • Go back
          • Overview
        • Bilateral co-operation with non-member states
          • Go back
          • Overview
          • Validation system
          • Reinforced Partnership programme
        • Multilateral international co-operation with IP offices and organisations
        • Co-operation with international organisations outside the IP system
      • European Patent Academy
        • Go back
        • Overview
        • Partners
      • Chief Economist
        • Go back
        • Overview
        • Economic studies
      • Ombuds Office
      • Reporting wrongdoing
    • Statistics and trends
      • Go back
      • Overview
      • Statistics & Trends Centre
      • EPO Data Hub
      • Clarification on data sources
    • Social responsibility
      • Go back
      • Overview
      • Environment
      • Art collection
        • Go back
        • Overview
        • The collection
        • Let's talk about art
        • Artists
        • Media library
        • What's on
        • Publications
        • Contact
    • History
      • Go back
      • Overview
      • 1970s
      • 1980s
      • 1990s
      • 2000s
      • 2010s
      • 2020s
    • Transparency portal
      • Go back
      • Overview
      • General
        • Go back
        • Overview
        • Annual Review 2022
          • Go back
          • Overview
          • Foreword
          • Executive summary
          • Goal 1: Engaged and empowered
          • Goal 2: Digital transformation
          • Goal 3: Master quality
          • Goal 4: Partner for positive impact
          • Goal 5: Secure sustainability
      • Human
      • Environmental
      • Organisational
      • Social and relational
      • Economic
      • Governance
  • Boards of Appeal
    • Go back
    • Overview
    • Decisions of the Boards of Appeal
      • Go back
      • Overview
      • Recent decisions
      • Selected decisions
    • Procedure
    • Annual reports
      • Go back
      • Overview
    • Organisation
      • Go back
      • Overview
      • President of the Boards of Appeal
      • Enlarged Board of Appeal
        • Go back
        • Overview
        • Pending referrals (Art. 112 EPC)
        • Decisions sorted by number (Art. 112 EPC)
        • Pending petitions for review (Art. 112a EPC)
        • Decisions on petitions for review (Art. 112a EPC)
      • Technical Boards of Appeal
      • Legal Board of Appeal
      • Disciplinary Board of Appeal
      • Presidium
        • Go back
        • Overview
        • Composition of the Presidium
          • Go back
          • Overview
          • Archive
    • Code of Conduct
    • Business distribution scheme
      • Go back
      • Overview
      • Technical boards of appeal by IPC in 2023
      • Archive
    • Annual list of cases
    • Communications
    • Publications
    • Case Law of the Boards of Appeal
      • Go back
      • Overview
      • Archive
    • Case Law from the Contracting States to the EPC
    • Oral proceedings
  • Service & support
    • Go back
    • Overview
    • Website updates
    • Availability of online services
      • Go back
      • Overview
    • FAQ
      • Go back
      • Overview
    • Publications
    • Ordering
      • Go back
      • Overview
      • Terms and conditions
        • Go back
        • Overview
        • Patent information products
        • Bulk data sets
        • Open Patent Services (OPS)
        • Fair use charter
    • Procedural communications
    • Useful links
      • Go back
      • Overview
      • Patent offices of member states
      • Other patent offices
      • Legal resources
      • Directories of patent attorneys
      • Patent databases, registers and gazettes
      • Disclaimer
    • Contact us
      • Go back
      • Overview
      • Filing options
      • Locations
      • Specific contact
      • Surveys
        • Go back
        • Overview
        • Search services
        • Examination services, final actions and publication
        • Opposition services
        • Patent filings
          • Go back
          • Overview
          • Detailed methodology
          • Archive
        • Online Services
        • Patent information
          • Go back
          • Overview
          • Innovation process survey
        • Customer services
        • Filing services
        • Website
        • Survey on electronic invoicing
        • Companies innovating in clean and sustainable technologies
    • Subscription centre
      • Go back
      • Overview
      • Subscribe
      • Change preferences
      • Unsubscribe
    • Official holidays
    • Forums
    • Glossary
Board of Appeals
Decisions

Recent decisions

Overview
  • 2023 decisions
  • 2022 decisions
  • 2021 decisions
https://www.epo.org/en/node/t880543eu1
  1. Home
  2. T 0543/88 24-08-1989
Facebook Twitter Linkedin Email

T 0543/88 24-08-1989

European Case Law Identifier
ECLI:EP:BA:1989:T054388.19890824
Date of decision
24 August 1989
Case number
T 0543/88
Petition for review of
-
Application number
83307551.8
IPC class
G11C 27/02
Language of proceedings
EN
Distribution
-

Download and more information:

Decision in EN 622.1 KB
Documentation of the appeal procedure can be found in the European Patent Register
Bibliographic information is available in:
EN
Versions
Unpublished
Application title

Improvements in or relating to sample-and-hold circuits

Applicant name
Western Electric Company
Opponent name
-
Board
3.5.01
Headnote
-
Relevant legal provisions
European Patent Convention Art 56 1973
European Patent Convention Art 84 1973
Keywords

Clarity of Claim and support by the description

Inventive step (yes)

Catchword
-
Cited decisions
T 0032/82
Citing decisions
-

I. European patent application No. 83 307 551.8, claiming priority of 20 December 1982, filed on 12 December 1983 and published on 1 August 1984 under No. 0 114 475, was refused by a decision of the Examining Division 067 dated 24 June 1988.

The decision was based on Claims 1 to 4, received on 2 November 1987 with a letter dated 28 October 1987.

The reason given for the refusal was that the independent claim did not comply with the requirements of Article 84 EPC since it was not clear because essential features were missing.

In respect of inventive step, the Examining Division had indicated that grant could be envisaged provided the claims were clarified. Suggestions to this effect were made. The Examining Division had come to this conclusion by taking into account the following pertinent prior art documents:

D1:"Modern Electronic Circuits Reference Manual" McGraw-Hill Book Company, 1980, page 886; D2: Patents Abstracts of Japan, Vol. 6, No. 59 (P-110) [937] April 16, 1982; & JP-A-56-169 291.

II. On 17 August 1988, the Appellant lodged an appeal against this decision. The appeal fee had been paid on 15 August 1988. Together with a Statement of Grounds, received on 21 October 1988, the Appellant filed two different versions of Claims 1 to 4, designated as "SET A" and "SET B" respectively, as auxiliary requests.

The Appellant, however, challenged the Examining Division's view in respect of the question concerning the clarity of Claim 1 and made the said auxiliary requests "without prejudice to the claims at present on file". This must be interpreted as a main request to grant a patent on the basis of the same application documents as recited in the impugned decision of the Examining Division.

III. In a communication, dated 20 January 1989, the Rapporteur was prepared only to follow the Appellant's arguments to some extent. He suggested to pursue the application on the basis of the claims designated "SET B" with some amendments regarded necessary in view of Article 84 EPC.

IV. The Appellant filed with letter of 15 March 1989, received 20 March 1989, a new set of Claims 1 to 4 to replace the former "Set B", but requested the revision of the application in the light of the submissions already made in an earlier application (EP-A-107 337) and in the present proceedings, since the Applicants still felt that their contribution to the art justified a comparably extensive claim.

Consequently, the Appellant's request to grant a patent has to be divided up into one main request and two auxiliary requests:

IV(a) As the main request, the Appellant maintains Claims 1 to 4, filed on 2 November 1987 together with adapted parts of the description.

IV(b) The first auxiliary request is based on "SET A" of Claims 1 to 4, filed on 21 October 1988 together with a further adapted part of the description.

IV(c) The second auxiliary request is based on the following application documents:

- description, pages 1, 2a, 4, 5, 7, 8 received on 2 November 1987 with letter dated 28 October 1987; page 2, received with the statement of grounds filed 21 October 1988; pages 3, 6 and 9 as published;

- Claims 1 to 4, filed with letter of 15 March 1989;

- drawings, sheet 1/2 as published; sheet 2/2 filed with letter of 28 October 1987.

V. Claim 1 of the main request reads as follows:

"1. A sample-and-hold circuit including a sampling switch (30) connected between a signal input and an input of a buffer (42), the buffer including an enhancement mode transistor (46) having a gate serving as the input of the buffer and its drain-to-source conduction path connected to bias current means (47), a holding capacitor (32) connected at a first side to the input of the buffer and at a second side to a reference potential, and feedback means (52,54,24) connected between the output of the buffer and an input of an amplifier, and CHARACTERISED IN THAT there is provided a correction switch (34) connected at its first side to the output of the amplifier, and a correction holding capacitor (36) connected at its first side to a reference potential and at its second side to the second side of the correction switch, and the buffer includes means (44) coupling the second side of the correction switch (34) to the drain of the enhancement mode transistor (46)."

VI. Claim 1 of the first auxiliary request reads as follows:

"1. A sample-and-hold circuit including a sampling switch (30) connected between a signal input and an input of a buffer (42), the buffer including an enhancement mode transistor (46) having a gate serving as the input of the buffer and its drain-to-source conduction path connected to bias current means (47), a holding capacitor (32) connected at a first side to the input of the buffer and at a second side to a reference potential, and feedback means (52,54,24) connected between the output of the buffer and an input of an amplifier, and characterised in that there is provided means for providing a signal for correcting switching charge feedthrough error on the holding capacitor which occurs when the sampling switch is opened, the providing means including a correction switch (34) connected at its first side to the output of the amplifier, and a correction holding capacitor (36) connected at its first side to a reference potential and at its second side to the second side of the correction switch, and the buffer includes means (44) coupling the second side of the correction switch (34) to the drain of the enhancement mode transistor (46)."

VII. Claim 1 of the second auxiliary request reads as follows:

"1. A sample-and-hold circuit including a sampling switch (30) connected between a signal input and an input of a buffer (42), the buffer including an enhancement mode transistor (46) having a gate serving as the input of the buffer and its drain-to-source conduction path connected to bias current means (47), a holding capacitor (32) connected at a first side to the input of the buffer and at a second side to a reference potential, and feedback means (52,54,24) connected between the output of the buffer and an input of an amplifier, and characterized in that there is provided means for correcting switching charge feedthrough error on the holding capacitor which occurs when the sampling switch is opened, the providing means including a correction switch (34) connected at its first side to the output of the amplifier, and a correction holding capacitor (36) connected at its first side to a reference potential and at its second side to the second side of the correction switch, and the buffer includes means (44) for coupling a correction signal from the second side of the correction holding capacitor (36) to the holding capacitor (32) via the gate-to-drain capacitance (56) of the enhancement mode transistor (46) during an interval between the opening of the sampling switch (30) and the opening of the correction switch (34)."

1. The appeal complies with Articles 106-108 and Rule 64 EPC and is admissible.

2. Novelty The different versions of Claim 1 have identical precharacterising portions which represent prior art as disclosed in document D1.

The lower diagram of D1, page 886, shows a sample-and-hold circuit including a sampling switch Q1 connected between a signal input and an input of a buffer. The buffer includes an enhancement mode transistor Q2 having a gate serving as the input of the buffer. The drain-to-source conduction path of the buffer transistor is connected to a 30K resistor as a bias current means. A holding capacitor (.0047) is connected at a first side to the input of the buffer and at a second side to a reference potential (ground). A feedback connection is provided between the output of the buffer and an input of an amplifier IC1.

Claim 1 of the main request differs from this prior art by the additional provision of a secondary sample-and-hold circuit comprising a correction switch and a correction holding capacitor connected to the output of the amplifier and to a reference potential just in the same way as the sampling switch and the holding capacitor of the known circuit. However, whereas the second side (i.e. the side which is not connected to the signal input) of the sampling switch is connected to the gate of the buffer transistor, Claim 1 of the main request specifies that the second side of the correction switch is coupled to the drain of the enhancement mode transistor. The sample-and-hold circuit of document D2 differs from that of the present application already in respect of the precharacterising portion since it does not comprise a feedback arrangement.

The description of the present application acknowledges on page 4, first paragraph, as prior art the content of an earlier European patent application published under No. EP-A-107 337 after the filing date of the present application and disclosing the dual feedback sample-and-hold principle with a primary sample-and-hold circuit and a secondary sample-and-hold circuit, the secondary circuit providing the primary circuit with voltage error correction. The subject-matter of all three versions of Claim 1 in the present application differ from this document (that represents prior art under Article 54(3) EPC) by details concerning the buffer including an enhancement mode transistor.

The subject-matter of Claim 1 in all three versions is thus to be considered novel.

3. It has, however, to be examined whether the different versions of Claim 1 meet the requirements of clarity and support by the description (Article 84 EPC).

The description deals on page 1, line 14 to page 2, line 1 with a so-called fixed pattern noise, which problem arises from a switching charge feedthrough error on the holding capacitor following the operation of the sampling switch from "ON" condition to "OFF" condition.

Claim 1 of the first auxiliary request differs from Claim 1 of the main request in that it additionally specifies the purpose of the correction arrangement, viz. to provide a signal for correcting the said switching charge feedthrough error. However, as set forth below, neither Claim 1 of the main request, nor Claim 1 of the first auxiliary request can be regarded as sufficiently clear in respect of the necessary means to ensure this desired function.

The description deals, furthermore, on page 2, lines 2 to 11 with the power "supply rejection problem", which arises from a parasitic coupling of power supply noise to the holding capacitor via the drain-to-gate capacitance of the enhancement mode transistor. Also in respect of a solution to this problem, Claim 1 in its version according to the main request and first auxiliary request cannot be regarded as sufficiently clear.

The following details can be understood from the description as relevant for the solution of the said two problems in the context of the present disclosure:

- The second side of the correction switch need not be directly coupled to the drain of the enhancement mode transistor. The embodiment of Figure 1 shows, in contrast, that the correction signal from the second side of the correction holding capacitor is coupled to the said drain through a depletion mode transistor (44), which serves as a unity gain buffer to the source node (48) of transistor (44) and consequently also to the drain of the enhancement mode transistor (46), (see page 7, lines 1 to 3). In order to avoid any inconsistency between claim and description, it is therefore more correct to specify that it is the correction signal that is coupled to the drain of the enhancement mode transistor.

- The present invention is based on the principle to correct the charge feedthrough error introduced by the opening of the sampling switch by subsequently effecting a feedback control of the output voltage by means of the said secondary sample-and-hold circuit. This requires that there is a time interval between the opening of the sampling switch and the opening of the correction switch during which the correction switch is closed (see page 6, lines 16 to 34).

This essential timing condition is neither specified in Claim 1 according to the main request nor in Claim 1 of the first auxiliary request

- The correction signal is coupled to the holding capacitor via the gate-to-drain capacitance of the enhancement mode transistor.

The gate-to-drain capacitance has the effect of attenuating the coupling of the correction capacitor to the holding capacitor, thereby correspondingly attenuating the effect of the charge feedthrough error generated by the opening of the correction switch in the secondary sample-and-hold circuit (cf. page 6, lines 8 to 34). A similar attenuation effect is attained by the said gate-to-drain capacitance for the parasitic coupling of noise in the power supply rail (page 7, lines 5 to 14).

Consequently, a suitable gate-to-drain capacitance is necessary for carrying out the invention. However, this gate-to-drain capacitance is neither specified in Claim 1 according to the main request nor in Claim 1 of the first auxiliary request.

4. Since, as set out above, the versions of Claim 1 according to the main request and to the first auxiliary request do not clearly specify all the essential features of the invention, these claims are not allowable with regard to Article 84 EPC (cf. decision T 32/82, OJ EPO 8/1984, 354-356, in particular No. 15 of the Reasons).

The Appellant's submission that, even if essential features were missing, lack of clarity is not a logical or necessary consequence, and that the test for clarity of a claim is whether the scope of protection is clear, cannot be accepted. A necessary condition of patentability is that the scope of protection is clearly restricted to what can be regarded as the invention (in the sense of Article 52(1) EPC) as disclosed in the description (according to Article 83 EPC). That means that a speculative broadening of the scope of protection over that what has been really disclosed as the invention cannot be allowed (the claim must "be supported by the description", Article 84 EPC).

5. There are no objections under Article 84 to Claim 1 according to the second auxiliary request.

All the features discussed above, and which concern the coupling of the correction signal to the holding capacitor via the said gate-to-drain capacitance and the necessary timing for the sampling switch and the correction switch, have been incorporated in the last six lines of Claim 1 of the second auxiliary request.

The Board is satisfied that it is not necessary to specify in Claim 1 that the input of the sampling switch (of the primary sample-and-hold circuit) is connected to the output of the amplifier (in contrast to the suggestion in point 4.2 of the Rapporteur's communication of 20 January 1989).

The Appellant's broader wording is backed by the originally filed Claim 1. Therefore, no objection under Article 123(2) arises.

The Board agrees to the said broader wording of Claim 1, also in respect of Article 84 for the following reasons: The present invention realises a concept in which, in a first step the holding capacitor of a primary sample-and-hold circuit is to be charged to a voltage approximately equal to the input voltage.

Remaining small differences to the input voltage can be reduced in a second step, by the secondary sample-and-hold circuit which has to correct the error voltage on the holding capacitor. The amplifier and feedback arrangement as well as the coupling of the correction signal via the said gate-to-drain capacitance are necessary means for this function. However, it is clear that the first step, i.e. the charging of the holding capacitor of the primary sample-and-hold circuit to only approximately the input voltage, can already be effected by a sample-and-hold circuit in its simpler form, i.e. without an amplifier and feedback arrangement. Such simpler sample-and-hold circuits belong to the background knowledge in this technical field (see, for instance, document D2). The Board is therefore satisfied that the connection of the sampling switch of the primary sample-and-hold circuit directly to the input signal node is an embodiment which the skilled person might readily envisage with the knowledge of the general teaching of the present application and which should not be excluded by a restricted wording of Claim 1.

Since it is now clear that the essential features of the claimed invention concern the details of the sample-and-hold arrangement on the input side of the buffer whereas the buffer output may be modified (e.g. by additional circuits as suggested in the Appellant's reply of 15 March 1989, page 2, last paragraph), the Board also refrains from requiring a closer specification of the buffer output.

6. Inventive step It remains to examine whether the subject-matter of Claim 1 of the second auxiliary request is based on an inventive step.

Document D1, from which the present invention starts, comprises only a single sample-and-hold circuit and does not disclose any means of correcting a switching charge feedthrough error.

Document D2 discloses such means, but comprises also only a single sample-and-hold circuit. The switching charge feedthrough effect is compensated for by a pulse via a capacitor which is series-connected to the holding capacitor. But, this pulse is not generated in a secondary sample-and-hold circuit, nor is there provision made for a feedback arrangement. Therefore, the Board is satisfied that the Examining Division's finding in its first communication (dated 3 July 1987) is correct, according to which a modification of the sample-and-hold circuit of D1 by incorporating the teaching of D2 would not render the subject-matter of the application obvious.

The content of EP-A-107 337, which as set out in Section 2 above, is not prejudicial to novelty of the subject-matter claimed, is not to be considered in deciding whether there is an inventive step (Article 56, second phrase).

7. Claim 1 of the second auxiliary request is thus allowable. Claims 2 to 4 are dependent claims specifying particular embodiments and are also allowable.

There are no objections to the description which has been brought into accordance with the amended scope of protection.

Order

ORDER

For these reasons, it is decided that:

1. The decision under appeal is set aside.

2. The main request and the first auxiliary request for granting a patent are refused.

3. The case is remitted to the first instance with the order to grant a European patent on the basis of the second auxiliary request with the documents recited in Section IV(c) of this decision.

Footer - Service & support
  • Service & support
    • FAQ
    • Contact us
    • Subscription centre
    • Official holidays
    • Publications
    • Procedural communications
    • Ordering
    • Glossary
Footer - More links
  • Jobs & careers
  • Press centre
  • Single Access Portal
  • Procurement
  • Boards of Appeal
SoMe facebook 0
European Patent Office
EPO Jobs
SoMe instagram
EuropeanPatentOffice
SoMe linkedIn
European Patent Office
EPO Jobs
EPO Procurement
SoMe twitter
EPOorg
EPOjobs
SoMe youtube
TheEPO
Footer
  • Legal notice
  • Terms of use
  • Data protection and privacy
  • Accessibility