Monoscope

The widely used Indian Head test pattern was generated by a monoscope.
A monoscope
Early Cinema Television (UK) monoscope advertisement

A monoscope was a special form of video camera tube which displayed a single still video image. The image was built into the tube, hence the name. The tube resembled a small cathode ray tube (CRT). Monoscopes were used beginning in the 1950s to generate TV test patterns and station logos. This type of test card generation system was technologically obsolete by the 1980s.