Patent ID: 6044130
Filing Date: 2000-03-28
Classification: H01J

Abstract:
An X-ray tube comprising:a ceramic bulb of a tubular configuration extending in an axial direction and having an inner peripheral surface, an outer peripheral surface, a first and, and a second end opposite the first and;a stem secured to the first and of said ceramic bulb;an output window secured to the second end of said ceramic bulb, said output window having a first surface deposited with a target metal and confronting said stem and a second surface from which X-rays are output, said ceramic bulb, said stem and said output window defining an airtight chamber having an inner space;a cathode disposed in the inner space of the airtight chamber;a focusing electrode including a tubular portion having an inner peripheral surface and an outer peripheral surface, the tubular portion being disposed in the inner space and along the inner peripheral surface of said ceramic bulb to have a space between the inner peripheral surf ace of said ceramic bulb and the outer peripheral surface of the tubular portion, said focusing electrode further including a lower end portion interposed between said stem and the first end of said ceramic bulb.