Television by electron image scanning
Television by electron image scanning
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DOI：
10.1016/s0016-0032(34)90415-4
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发表时间：
1934-10
影响因子：
4.1
通讯作者：
P. T. Farnsworth
中科院分区：
文献类型：
--
作者：
P. T. Farnsworth
聚焦在均匀光电表面上的光学图像从每个点产生与该点的光强度成比例的电子发射。如果从表面发射的所有电子都被抽走，这样的放电可以归类为电子图像。然而，图像只在阴极平面上清晰。为了通过将电子图像偏转到小孔来扫描电子图像，必须在距离阴极适当的距离处存在与光学图像相对应的图像。有几种可能的方法来满足这一要求。请参看图3。I，如果所有离开阴极P点的电子都能被约束为彼此平行运动，那么束流的任何横截面都将代表一个完美的电子图像。要使所有电子路径平行，必须没有横向速度分量。然而，光电子以随机的速度发射，范围从零到一伏特或更多。另请参阅Farnsworth的美国专利号1,773，98。
An optical image focused upon a uniform photoelectric surface produces an electron emission from each point proportional to the intensity of the light at that point. If all of the electrons emitted from the surface are drawn away from it, such a discharge is classifiable as an electron image. The image, however, is sharp only in the plane of the cathode. In order that the electron image may be scanned by deflecting it over a small aperture, the correspondence to the optical image must be present at a suitable distance from the cathode. There are several possible methods f6r fulfilling this requirement. Referring to Fig. I, if all of the electrons leaving point" P" on a cathode, could be constrained to travel parallel to one another, then any transverse section of the beam would represent a perfect electron image. For all electron paths to be parallel there must be no component of transverse velocity. The photoelectrons, however, are emitted with random velocities, ranging from zero to a volt or more. Another x See Farnsworth's US Patent No. 1,773, 98o.