September 7, 1927

Philo Farnsworth

Farnsworth’s image dissector transmits its first electronic image

The first image was not a face or a landscape. It was a line that rotated when an assistant turned a glass slide in the next room.

A line that moved when the slide moved

On 7 September 1927, at his laboratory at 202 Green Street in San Francisco, the 21-year-old Philo T. Farnsworth switched on an experimental television system built around his image dissector camera tube.

The tube converted an optical test image into an electronic signal sent to a receiver in another room, and a fuzzy line became distinct as the equipment was adjusted.

The test object was a backlit glass slide bearing a simple straight-line or geometric pattern; rotating or moving it made the received image move too, showing that the receiver was reproducing the optical input rather than generating a stationary trace.

Who was in the room

Cliff Gardner, Farnsworth's brother-in-law, had learned glassblowing specifically to fabricate the experimental vacuum tubes, and he manipulated the test slide. Elma "Pem" Farnsworth kept records and helped construct tube components.

The investor George Everson watched the test. He and Leslie Gorrell — professional fundraisers who became investors and business partners, not philanthropists — had supplied $6,000 in initial backing.

The dollar sign often described as television's first image belongs to a later demonstration for backers impatient to see a return.

"First fully electronic" depends on the definition

This was a private laboratory proof, not a public or press demonstration. Farnsworth's documented press demonstration followed on 3 September 1928, and live images of people came in 1929.

His system is credited with electronic image capture and electronic display, unlike systems using a mechanical scanning disc. But Kenjiro Takayanagi had displayed an image on a cathode-ray tube in December 1926 with a mechanical camera-side scanner, and earlier work by Vladimir Zworykin makes broad priority claims contentious.

The Patent Office examiner's priority decision in interference No. 64,027 was issued on 27 July 1935, after the final hearing on 24 April 1934.

Sources

Researched 24 Aug 2026 6 sources not yet audited Date disputed

How this was checked

Researched from the web into a fact sheet and rewritten from that sheet. This article has not yet had an independent model audit. How the pipeline works →

Date disputed. Sources disagree about when this happened.

What the sources leave uncertain

The date 7 September 1927 is strongly supported by the Farnsworth archive and Television Academy oral history. An Indiana state-history page gives 27 September, but that conflicts with the principal archival record.
Accounts describe the displayed form as a straight line, the edge of a black triangle, or a line painted on a glass slide. These likely describe the same or successive geometric tests, but the surviving narratives are not identical.
The “first fully electronic television” designation is definition-dependent. Farnsworth’s system is credited with electronic image capture and electronic display, unlike systems with a mechanical scanning disc. Kenjiro Takayanagi had displayed an image on a cathode-ray tube in December 1926, but his camera-side scanner remained mechanical.
Earlier work by Vladimir Zworykin and other experimenters also makes broad claims that Farnsworth simply “invented television” historically contentious.