Image dissector

Philo Farnsworth's first electronic image, September 7, 1927 No spinning disk: Farnsworth's camera tube scanned the picture electronically, sweeping an electron image past a small aperture, and electronic scanning is the idea every later camera tube refined. The first image the 21-year-old sent, in his lab at 202 Green Street in San Francisco, was a single straight line painted on a glass slide. That modest line mattered because mechanical disks could not scale to sharp pictures, while electronic scanning could. Farnsworth's patents then fought a long battle with RCA, whose engineers under Vladimir Zworykin were racing toward the same goal, which is why American electronic television has more than one father.