"Light-writing telegraph" copy telegraph

In 1901 the German physicist Gustav Grzanna developed a transmitting and receiving device that used "rays of light" to send text and hand drawings via a telephone connection in the space of 10 seconds. The position of the writing pins moved 2 reflectors in the receiver, which led a focused beam of light over photosensitive paper. Since it was developed directly in the device, the receiver could remove the photographic telegram immediately. In 1905, after only 4 years, he discontinued the production of the device.