If Japan and Asia first commercialized white LEDs in 1996, the history of white LEDs can be said to be very complicated. In the United States, the patent situation is generally as follows:
Bell Laboratories uses single or multiple phosphors to emit light on the fluorescent screen, which is protected by the U.S. patent (3,6914,82) and also establishes the principle of wavelength conversion of light. The patent acceptance time is 1970 65438+ 10/7.
Japan applied for the Japanese patent of199111.25 by the method of "phosphor for resin and molding". This technology was released on1June, 19931August, but it was applied in1June, 1998.
On February 2, 65438, Riya withdrew this application.
The first Japanese-Asian patent 5,998,925 in the application of white LED was granted in the United States on February 7, 1999/kloc-0, and its acceptance date was July 29, 1997. It was integrated into the later Japanese-Asian patents 6,069,440 and 6,665,438+04. As expected, this patent relates to garnet-based GaNLED phosphor, which describes a commercial white LED in Nichia.
. Although the American patent disclosure of Japan and Asia involves their early patents, it is also a strong irony to the statement that "the first commercial white LED supplier has the latest priority date".
Kerui owns the patent number 6600 175 (originally granted to AMTI), and the acceptance date is 1996.
On March 26th, 2003, the authorization date was July 29th, 2003. This patent claims to protect a "device for generating white light from a single LED by down-converting phosphor", which attempts to protect all related technologies and processes. However, the patent only mentions the excitation of fluorescent powder by light sources other than white light, and does not seem to cover the excitation of yellow fluorescent powder by ordinary blue led. Riya mentioned in the patent that blue led excites yellow phosphor, but did not discuss or discuss garnet-based phosphor technology.
Patent No.6,245,259 of Osram was accepted in the United States on August 29th, 2000, and the date of authorization was June 12, 2006, but before that, the patent was protected by international patents on June 26th 1997. Since then, the problem of patent overlap has appeared. The original patents described blue, green and ultraviolet LEDs and phosphors doped with cerium, terbium or thiogarnet. This point was not mentioned in the previous Niya white LED and Niya Japanese patent application. The focus of this technical protection seems to be the size specification of the phosphor (the size should be below 5 microns).
The acceptance date of HP (Agilent) Patent No.5,847,507 was 65438+1July 1997 14, and the authorization date was 65438+1February 8, 1998. The description of this patent relates to the existing Nichia products, and the protection focuses on the luminous principle (mode) of phosphors, which covers various types of phosphors.
Toyoda Gosei has a patent of 6,809,347 to protect the use of europium-doped alkaline-earth orthosilicate phosphors and blue or ultraviolet LEDs. The priority date of this patent is 65438+February 28th, 2000, and the authorization time is 65438+20041October 26th. It seems to focus on a special phosphor design with clear outline. It is not as vague as other patents, and the protection content is clear and definite.