Image intensifier and method of making an electron multiplier therefor

Abstract

Abstract The invention includes a channel-type electron multiplier incorporating a glass plate having holes therethrough. The plate is treated so that the holes will support secondary emission. When the primary electrons from a photo-cathode enter the holes, an increased current density is produced at the output of the holes. When the output is directed onto a phosphor screen, an intensified image of the scene being viewed is produced. Night scenes may thus be brightened for use in military reconnaissance or the like. However, channel-type electron multipliers have what is known as a saturation level of operation beyond which an increase in input current produces little or no increase in output current. The device of the present invention alleviates this problem by increasing electrical resistance near the output. This construction makes it possible to produce a special electrical field distribution in the holes. This field distribution then causes the gain of the multiplier to saturate at substantially higher input current levels. In addition, a multiplier of this type will exhibit a nonlinear input versus output relationship such that, if incorporated in an image tube (direct view or TV pickup) it imparts to this tube highly desirable contrast enhancing characteristics. The invention also includes a method of making the special type of electron multiplier having the hole surface resistivity variation.

Inventors

• 👤 R Orthuber

Bibliographic Details