| 摘要 |
1,163,460. Image converter tubes. COMPAGNIE FRANCAISE THOMSON HOUSTON-HOTCHKISS BRANDT. 22 Feb., 1967 [11 March, 1966], No. 8562/67. Heading HID. An image converter tube 5 comprises an envelope containing an electron emissive electrode 4, accelerating and focusing electrodes 1, 2 and a movable target screen 3 urged against the envelope by a spring 12 between one electrode and the screen. The annular electrodes 1, 2 are attached together by ceramic rods 9 and secured in the tube by a ring 13; electrode 4 is a photo-cathode. The screen 3 comprises a circular glass plate covered with an activated ZnS phosphor coating and an A1 reflective layer. It is mounted in a tubular member 10 slidable in electrode 2 and urged against the end face 7 of the tube by the spring 12, a stop-plate 21b retains member 10 before assembly. A flange 11 of member 10 between the screen and face 7 acts as a dust shield. In another embodiment, Figs. 2, 3 (not shown), a frusto-conical spring is compressed between diaphragm plates (18), (20) in the anode 2 preventing unwanted radiation, one of the plates may be mesh covered. The connections 15, 16 include respectively a leaf-spring (32) and a coil-spring (22) which can be considerably extended. The photo-cathode comprises a dished screen with a peripheral support sealing the space above the screen. A layer 401 of photoemissive material is vapour deposited on this screen from tubes (23) containing Sb, Na, K and Cs mounted behind electrode 1. A Ba getter wire (31) is mounted in the same space. A releasable shutter as described in Specification 1,060,381 may protect the target screen during deposition. |
