公开(公告)号：US2540621A

公开(公告)日：1951-02-06

申请号：US942048

申请日：1948-02-19

Applicant: RCA CORP

Inventor： JOHNSON RALPH E

IPC: H01J3/02 ,  H01J29/48

CPC classification number: H01J3/02 ,  H01J29/48

公开(公告)号：US2498082A

公开(公告)日：1950-02-21

申请号：US79279747

申请日：1947-12-19

Applicant: RCA CORP

Inventor： JOHNSON RALPH E

IPC: H01J29/02 ,  H01J31/36 ,  H01J43/08

CPC classification number: H01J29/023 ,  H01J31/36 ,  H01J43/08

公开(公告)号：CA487478A

公开(公告)日：1952-10-21

申请号：CA487478D

Applicant: RCA CORP

Inventor： JOHNSON RALPH E

公开(公告)号：DE838472C

公开(公告)日：1952-05-08

申请号：DER0001585

申请日：1950-04-26

Applicant: RCA CORP

Inventor： JOHNSON RALPH E

IPC: H01J29/02 ,  H01J31/36 ,  H01J43/08

Abstract: 662,757. Cathode-ray tubes. RADIO CORPORATION OF AMERICA. Dec. 15, 1948 [Dec. 19, 1947], No. 32476/48. Class 39 (i). The emissive surface of the first dynode of a low-velocity scanning type of image tube is convexly curved towards the impinging electrons, the radius of curvature being small enough to give uniform collection of secondary electrons by the collector and large enough so that substantially no tangents to the emissive surface will intersect any part of the collector electrode. The electron gun structure of the tube comprises a cathode 26, control grid 28, accelerating electrode 30 and limiting apertures electrodes 32, 34, and provides a low velocity beam which is focused by a wall coating and coil, and scanned on to a conducting glass target, the beam being reflected in accordance with the charge image on the target. A fine mesh collector screen is mounted close to and on the image side of the glass target. The convexly-curved electrode 32 is the first stage of a multiplier section and is formed of a silver magnesium sheet to provide a dynode surface. The multiplier has further stages 44, 46, 48, 52 each maintained at progressively higher potentials, with a final collecting stage 50 at the highest potential. Each stage 44, 46, 48 consists of a thirty-two blade pin-wheel of silver magnesium alloy, the blades of consecutive pin-wheels being formed in an opposite sense and each stage has a 90 per cent transmission screen 51, 53, 55 preventing the suppression of the secondaries to be collected. The collector 50 comprises an annular ring with a metal screen stretched across it. A persuader electrode 42 encloses the first stage 32 and is slightly more negative than the enclosed stage, giving a practically field-free space above the surface of the anode. A finemesh screen is mounted close to the glass target on the photo-cathode side and is several volts positive relative to the equilibrium potential of the target collecting the secondaries emitted therefrom. The dynode surface 32 is located in the weak fringe field of the solenoid 16 (not shown).