Facsimile Picture Transmission

A facsimile picture transmitting system is described. The chief object of the design of this system was to produce a simple, rugged apparatus for practical usage, which would not require the attention of a skilled operator. The system does not require a special preparation of the original, and the receiver records the copy directly on the photographic paper. The usually delicate problem of photo-cell current amplification has been simplified to such an extent that only three stages of resistance coupled amplification suffice between the photo-cell and modulator of the broadcasting station. This was made possible through the design of a very efficient optical system, which supplies to the photo-cell quite enough light reflected from the picture even though only a small incandescent lamp for illumination is used. The synchronizing and framing have also been simplified to such a degree that they do not require any special channels or special amplifiers. Automatic starting devices obviate the use of any complicated scheme of signal dispatch for starting the apparatus. In spite of the simplicity of operation, it is capable of transmitting a 5 in. by 8 in. picture either in black and white or in half-tone in 48 seconds, or a message at the rate of 630 words per minute over short distances. The resulting picture prints are of a quality quite satisfactory for newspaper reproduction and clear facsimile of messages may be made from typewritten originals.