公开(公告)号：US20020126798A1

公开(公告)日：2002-09-12

申请号：US09802517

申请日：2001-03-09

Applicant: MARCONI MEDICAL SYSTEMS, INC.

Inventor： Jason P. Harris ,  Salvatore Perno

IPC: H01J035/06

CPC classification number: H01J35/06 ,  H01J2235/068

Abstract: A dual filament x-ray tube assembly (16) includes an evacuated envelope (52) having an anode (54) disposed at a first end of the evacuated envelope (52) and a cathode assembly (62) disposed at a second end of the evacuated envelope (52). The cathode assembly includes a variable-length filament assembly (72, 74; 100) which emits electron beams for impingement on the anode (54) at focal spots having varying lengths. The cathode assembly (62) further includes a cathode cup (64, 66, 68; 110, 112) which is subdivided into a plurality of electrically insulated deflection electrodes (64, 66, 68; 110, 112). A filament select circuit (80) selectively and individually heats a portion of the variable-length filament assembly (72, 74). Electron beams emitted from the filament assembly (72, 74) are electrostatically focused and controlled by applying potentials to different ones of the deflection electrodes (64, 66, 68; 110, 112). The x-ray tube assembly (16) provides longer focal spots for thick-slice scanning applications and shorter focal spots for thin-slice scanning applications along with the benefit of electrostatic focusing and control.

Abstract translation: 双丝X射线管组件（16）包括抽真空的外壳（52），其具有设置在所述真空外壳（52）的第一端的阳极（54）和设置在所述真空外壳的第二端处的阴极组件 抽空信封（52）。 阴极组件包括可变长度的灯丝组件（72,74; 100），其在具有不同长度的焦点处发射用于在阳极（54）上冲击的电子束。 阴极组件（62）还包括阴极杯（64,66,68,110,112），其被细分为多个电绝缘的偏转电极（64,66,68; 110,112）。 灯丝选择电路（80）选择性地且单独加热可变长度灯丝组件（72,74）的一部分。 从灯丝组件（72,74）发射的电子束通过向不同的偏转电极（64,66,68,110,112）施加电位来静电聚焦和控制。 X射线管组件（16）为薄片扫描应用提供了更长的焦点，并为薄片扫描应用提供了较短的焦斑，同时还具有静电聚焦和控制的优点。