Patent ID: 8220954
Filing Date: 2012-07-17
Classification: G02F,H01J

Abstract:
1. A discharge tube comprising: a glass tube having a substantially cylindrical shape; an outer lead arranged to project from an end portion of said glass tube and arranged to receive power supply from a power source; and a ferrule having a body defined by a stainless steel plate mounted to an outer circumference of said glass tube and a conductive portion extending from said body, said body having a substantially cylindrical shape that is substantially concentric with said glass tube, said conductive portion being connected to said outer lead; wherein said body is arranged to be borne by a bearing device, and has a contact portion arranged to be electrically connected to said power source; a plurality of elastic gripping portions in contact with the outer circumference of said glass tube are provided on said body so as to be circumferentially spaced apart; and a gap is located between the outer circumference of said glass tube and an inner circumference of said body so as to extend over substantially an entire distance of the outer circumference of said glass tube or the inner circumference of said body.