公开(公告)号：US3852608A

公开(公告)日：1974-12-03

申请号：US30971072

申请日：1972-11-27

Applicant: PHILIPS CORP

Inventor： JOHANNS J ,  HASKER J

IPC: H01J29/48 ,  H01J29/62 ,  H01J29/02 ,  H01J29/56

CPC classification number: H01J29/48 ,  H01J29/624

Abstract: A cathode-ray tube, in particular a shadow mask colour tube, having at least one electron gun which comprises at least three grids. The second grid serves as an accelerating electrode. An astigmatic lens element is present in the region of the second and the third grid. As a result of this an elongate spot is formed on the picture display screen of an electron beam in the case of low beam current, while the spot remains substantially unchanged in the case of high beam current. This is of importance, inter alia, for removing moire patterns in a shadow mask colour tube without it being necessary to choose a particular distance of the mask holes.

Abstract translation: 具有至少一个电子枪的阴极射线管，特别是荫罩彩色管，其包括至少三个栅格。 第二格栅用作加速电极。 散光透镜元件存在于第二和第三格栅的区域中。 由此，在短波束电流的情况下，在电子束的图像显示屏上形成细长的点，而在远光束电流的情况下，斑点保持基本不变。 这尤其重要的是去除荫罩彩色管中的莫尔图案，而不需要选择掩模孔的特定距离。