Editing Rubik's Cube (section)

===Patent history===
Nichols assigned his patent to his employer Moleculon Research Corp., which sued Ideal in 1982. In 1984, Ideal lost the patent infringement suit and appealed. In 1986, the appeals court affirmed the judgment that Rubik's 2×2×2 Pocket Cube infringed Nichols's patent, but overturned the judgment on Rubik's 3×3×3 Cube.<ref>{{Cite web |title=Moleculon Research Corporation v. CBS, Inc |url=http://digital-law-online.info/cases/229PQ805.htm |access-date=20 June 2012 |publisher=Digital-law-online.info}}</ref>

Even while Rubik's patent application was being processed, Terutoshi Ishigi, a self-taught engineer and ironworks owner near Tokyo, filed for a Japanese patent for a nearly identical mechanism, which was granted in 1976 (Japanese patent publication JP55-008192). Until 1999, when an amended [[Japanese patent law]] was enforced, Japan's patent office granted Japanese patents for non-disclosed technology within Japan without requiring worldwide [[Novelty (patent)|novelty]].<ref>{{Cite web |title=Act on International Applications under the Patent Cooperation Treaty (Act No. 30 of April 26, 1978, as amended by Act No. 220 of 1999), Japan, WIPO Lex |url=https://www.wipo.int/wipolex/en/legislation/details/2657 |access-date=2025-05-23 |website=www.wipo.int}}</ref><ref>{{Cite web |title=Major Amendments to the Japanese Patent Law (since 1985) |url=http://www.patents.jp/Archive/20030210-02.pdf |url-status=dead |archive-url=https://web.archive.org/web/20120216125521/http://www.patents.jp/Archive/20030210-02.pdf |archive-date=16 February 2012 |access-date=20 June 2012}}</ref><ref>{{Cite web |title=An International Guide to Patent Case Management for Judges |url=https://www.wipo.int/patent-judicial-guide/en/full-guide/japan |access-date=2025-05-23 |website=www.wipo.int |language=en}}</ref> Hence, Ishigi's patent is generally accepted as an independent reinvention at that time.<ref name="hofstadter">{{Cite book |last=Hofstadter |first=Douglas R. |url=https://archive.org/details/metamagicalthema0000hofs |title=Metamagical Themas: Questing for the Essence of Mind and Pattern |publisher=Basic Books |year=1985 |isbn=0-465-04566-9 |location=New York |quote=Hofstadter gives the name as 'Ishige'. |author-link=Douglas Hofstadter |url-access=registration}}</ref><ref>{{Cite web |last=Longridge |first=Mark |year=2004 |title=Rubik's Cube Chronology |url=http://cubeman.org/cchrono.txt}}</ref><ref>{{Cite web |date=9 April 2012 |title=The History of Rubik's Cube – Erno Rubik |url=http://inventors.about.com/library/weekly/aa040497.htm |access-date=20 June 2012 |publisher=Inventors.about.com |archive-date=23 May 2020 |archive-url=https://web.archive.org/web/20200523015041/http://inventors.about.com/library/weekly/aa040497.htm/ |url-status=dead }}</ref> Rubik applied for more patents in 1980, including another Hungarian patent on 28 October. In the United States, Rubik was granted {{US patent|4378116}} on 29 March 1983 for the Cube. This patent expired in 2000.