The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 31, 1995
Filed:
Oct. 04, 1993
Yasushi Watase, Hamamatsu, JP;
Masao Kinoshita, Hamamatsu, JP;
Hiroyuki Watanabe, Hamamatsu, JP;
Takeo Hashimoto, Hamamatsu, JP;
Takehiro Iida, Hamamatsu, JP;
Hiroaki Washiyama, Hamamatsu, JP;
Hamamatsu Photonics K.K., Hamamatsu, JP;
Abstract
A cathode for photoelectric emission or a cathode for secondary electron emission comprises a thin film made of a material which emits photoelectrons by an incident light or emits secondary electrons by an electron input on a base substrate. The average particle size of the particles forming the thin film is 200 nm to 2000 nm. It is preferred that the average particle size is nearly equal to an average diffusion length of the particle of an excited electron. Further, the average particle size is preferably larger than the mean value of penetration lengths of inputted electrons or incident lights in the particles. Moreover, preferably convexities and/or concavities formed of particles each having the average particle size are formed over the surface of a plane for the incident light or electron input. Further, it is preferred that the thin film is activated by an alkali metal and is made of compounds of at least one kind of alkali metal and an antimony metal. Moreover, a layer having high reflectance against light is preferably inserted between the base substrate and the thin film. Thus, according to the cathode for photoelectric emission or the cathode for secondary electron emission, photoelectrons or secondary electrons are generated effectively and emitted from the cathode for photoelectric emission or the cathode for secondary electron emission.