What Is a Patent?
A patent grants the inventor an exclusive right to practice an invention for 20 years from the filing date (Patent Act, Article 67). An invention is defined as "a highly advanced creation of technical ideas utilizing natural laws" (Article 2, Paragraph 1).
Patentability Requirements
To receive a patent, all of the following requirements under Article 29 must be met:
| Requirement | Details |
|---|---|
| Industrial applicability | Must be usable in industry |
| Novelty | Not publicly known or used before filing |
| Inventive step | Not easily conceivable by a person skilled in the art |
Japan uses a first-to-file system (Article 39): when multiple applications cover the same invention, only the earliest applicant receives the patent.
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Try for free →Application Process
1. Prior Art Search
Before filing, search for existing patents using J-PlatPat (Japan's patent information platform) to assess novelty.
2. Drafting the Application
Required documents (Article 36): - Claims: Define the scope of protection — the most critical document - Description: Detailed explanation of the invention - Drawings (if needed) - Abstract
3. Filing with the JPO
The filing date is established upon submission and serves as the priority date.
4. Publication
The application is published in the Patent Gazette 18 months after filing (Article 64).
5. Request for Examination
Substantive examination does not begin automatically. An examination request must be filed within 3 years of the application date (Article 48-3). Failure to do so results in the application being deemed withdrawn.
6. Substantive Examination
An examiner reviews novelty, inventive step, etc. Average examination time after request: approximately 14 months.
7. Office Action Response
If the examiner issues an office action (Notice of Reasons for Rejection), the applicant may submit a written opinion (argument) or amendment to address the rejections (Article 50).
8. Patent Grant and Registration
Upon overcoming all rejections, a patent decision is issued. Payment of patent fees completes registration (Article 66).
Cost Estimate
| Item | Approximate Cost |
|---|---|
| Patent attorney fees (filing) | ¥150,000–300,000 |
| JPO filing fee | ¥14,000 |
| Examination request fee | ¥138,000 (varies by claim count) |
| Patent fees (years 1–3) | ¥50,000 |
| Total (estimate) | ¥300,000–600,000 |
Foreign Filing
Foreign applications filed within 12 months of the Japanese application can claim the Japanese priority date (Paris Convention Article 4; Patent Act Article 43). PCT (Patent Cooperation Treaty) applications allow simultaneous filing in multiple countries.
Summary
The key principles of patent filing are: file early, draft claims broadly but accurately, and work with a qualified patent attorney. Under Japan's first-to-file system, delay can cost you the right entirely.