IP High Court, 2021 (Ne) 10086 [Lamp] <Honda> *Prior-use right established
更新日：2 日前
Article information
Article type: Case note
Category: Patents
Topics: Numerical limitations and parameters, Novelty
First published on this website: 2026-11-01
Display and classification checked: November 2, 2026
Originally published on Ameblo: 2024-10-07 (Japan time). Full English translation.
IP High Court, 2021 (Ne) 10086 [Lamp] <Honda> *Prior-use right established
*For a numerically limited invention, products after design changes were also held within the scope of the prior-use right.
⇒ After finding the variation of the prior-use products (slightly broader than the actual prior-used articles), the court identified the range permitting appropriate adjustment as the range of identity covered by the prior-use right.
⇒ A prior-use right is established even without recognition of the parameter.
“There are no circumstances indicating that Kanaden … participated through joint research or otherwise …; given that … in April 2012, when delivery to Kanaden occurred … the product was already being sold to the public …, it is difficult to regard delivery … to Kanaden as presupposing … a duty of confidentiality.
⇒ Public working: novelty not satisfied
[Claim 1] …A lamp satisfying the relationship y ≧ 1.09x, where y (mm) is the full width at half maximum of the luminance distribution obtained when light from each of the multiple LED chips passes through the outermost perimeter of the lamp, and x (mm) is the distance between emission centers of adjacent LED chips.
(Excerpts from the court's reasoning)
…For all 24 of the appellee's 403W products, y/x was measured for the 25th and 50th LEDs from the left. For the 25th LED, the minimum was 1.303, the maximum 1.388, and the mean-value 3σ limits were 1.281 and 1.397; for the 50th, the minimum was 1.297, the maximum 1.381, and the mean-value 3σ limits were 1.272 and 1.403. Industrial products exhibit quality variation due to various causes even when produced in the same process, and the same can be said of lighting fixtures. As noted, each of the appellee's 403W products showed numerical variation. It is also understood that one commonly adopted quality-control method compares inspection results with the required quality standard and keeps the difference (manufacturing error) within three standard deviations (3σ)…. In light of these matters, the measured y/x values of the appellee's 403W products were approximately 1.27–1.38. For 3σ, taking ordinary manufacturing error into account, although the required quality standard for the 403W product is unknown, ordinary control methods would treat the measured mean as that standard; the products' y/x values can therefore be found to have been approximately 1.27–1.40. …
In light of the foregoing, the range of y/x extending above 1.4 to 1.7 or beyond 1.7 in the invention embodied in the 403W product was a range the appellee had achieved by appropriately adjusting x and controlled as its own. …Further, reducing the grainy appearance of LED lighting, the problem addressed by Inventions 1, was known to persons skilled in LED lighting before the claimed priority date. They can be said to have manufactured lighting fixtures without that grainy appearance through trial and error without using the parameter at issue. In such technical circumstances, where a formula is used to define a product invention, a product practiced or prepared for practice before filing (the claimed priority date) may fall within the technical scope defined by the formula of an invention subsequently filed and patented. The appellee's lack of recognition of the parameter at issue should therefore not negate establishment of a prior-use right. …
Translator’s notes (editorial)
The quoted source uses the unclear phrase 平均値3σ, here “mean-value 3σ limits,” and gives measured values of approximately 1.27–1.38 despite the preceding individual minima/maxima. The supplied figures are preserved without correction. The source opening quotation concerning Kanaden has no closing quotation mark; retained.
Update history
The first-published date remains unchanged. Display maintenance, classification changes, related-article updates, and text corrections are recorded separately.
November 1, 2026: First published on this website.
November 2, 2026: Added article information, classification, topics, language navigation, related articles where the same case was confirmed, consultation guidance, and SEO. The original text and first-published date were preserved.
