| 摘要 |
741,354. Electron lenses. PHILIPS ELECTRICAL INDUSTRIES, Ltd. Nov. 2, 1951 [Nov. 6, 1950], No. 25676/51. Class 39 (1). An image converter has, in addition to the " depicting coil " 10 in the region of the photocathode 2, a further " control coil " 11 adjacent coil 10 and overlapping its field; by conjoint inverse control of the currents through coils 10 and 11 the magnification of the image on target 3 may be varied while maintaining the focus. The rotation of the image field may be corrected by a third coil in the region away from the lens field of anode 6; or, since it is found to be an inverse linear function of the magnification the tube may be mounted on rollers so as to be rotatable bodily by a friction disc on the common control shaft of the rheostats which vary the coil currents, Fig. 3 (not shown). Target 3 may be a luminescent screen or the storage electrode of a television pick-up tube. The coils are mounted within a shell 13 with end flanges 14, 15. In a modification the depicting coil 35, Fig. 5, and the control coil 36 are of tapered section and interfitted as shown. |
