Color facsimile transmission system

Claim 2

A color transmission system for transmitting to a remote point a series of electrical signals representing the color components of a color transparency, said system comprising a facsimile transmitter capable of transmitting electrical signals representing continuous tones of a photographic image, scanning means synchronized to said facsimile transmitter for scanning the transparency with a moving light spot, means for directing the light passed by the transparency through a different filter for each of the color components, a photoelectric device associated with each filter for receiving the light of the color component passed by that filter and producing an electrical output signal representative of that color component, means for modifying the electrical signals for each color component to take into account the characteristics of a subsequent printing process, means for feeding to said facsimile transmitter, said modified electrical signals representative of the color components required to produce a printed reproduction of said original color transparency, a facsimile receiver located at said remote point for reproducing a facsimile image of each of said color components, and a signal channel connecting said facsimile transmitter to said facsimile receiver for the passage of said modified electrical component signals from said transmitter to said receiver.

Claim 3

A system as claimed in claim 1, including a beam splitting device to split the light passed by the transparency into a plurality of paths, each of which is directed through a filter representing one of the color components onto the associated photoelectric device.

Claim 4

A system as claimed in claim 1, wherein said modified electrical signals are fed sequentially to the facsimile receiver.

Claim 5

A system as claimed in claim 1, wherein the scanning means consists of a cathode ray device operating as a flying spot scanner.

Claim 6

A system as claimed in claim 1, wherein the scanning means operates at a relatively slow speed and the color component signals so produced are employed for generating facsimile images and said scanning means is also arranged selectively to operate at a higher scanning speed at which the output signals from the photoelectric devices are fed to energize a color television picture reproducing device in order to monitor the signals prior to being transmitted.

Claim 7

A system as claimed in claim 1, including means for generating a black overprint signal in order to compensate for imperfections in the printing inks employed to print a reproduction of the received image.

Claim 8

A system as claimed in claim 6, in which the color component signals are transmitted sequentially and the black overprint signal is derived from the signals at the facsimile transmitter and is transmitted as an additional signal in the sequence.

Claim 9

A system as claimed in claim 1, wherein the photoelectric device producing each electrical color component signal comprises a photomultiplier tube producing an electrical output signal representing that color component and said output signal is fed to a color balance amplifier, the output of said color balance amplifier feeding color correction circuits operating to correct for deficiencies in the printing inks employed to printing the reproduced image, and an amplifier fed from the output of the color correction circuits to match the balanced color channel outputs to the signal transmission channel.

Claim 10

A system as claimed in claim 8, wherein the color correction circuits comprise a logarithm to base 10 circuit feeding an adder-subtractor circuit and wherein the output from the adder-subtractor circuit feeds an anti-log circuit.

Claim 11

A color transmission system for transmitting to a remote point a series of electrical signals representing the color components of a color transparency, said system comprising A facsimile transmitter capable of transmitting electrical signals representing continuous tones of a photographic image, scanning means synchronized to said facsimile transmitter for scanning the transparency with a moving light spot, means for directing the light passed by the transparency through red, green and blue filters to produce the respective color components, a photoelectric device associated with each filter for receiving the light of the color component passed by that filter and producing an electrical output signal representative of that color component, means for modifying the electrical signals for each color component to take into account the characteristic of a subsequent printing process, means for feeding to said facsimile transmitter said modified electrical signals representative of cyan, magenta and yellow respectively for the red, green and blue color componentS as required to produce a printed reproduction of said original color transparency, a facsimile receiver located at said remote point for reproducing a facsimile image of each of said color components, and a signal channel connecting said facsimile transmitter to said facsimile receiver for the passage of said modified electrical color component signals from said transmitter to said receiver.

Claim 12

A color transmission system for transmitting to a remote point a series of electrical signals representing the color components of a color transparency, said system comprising A facsimile transmitter capable of transmitting electrical signals representing continuous tones of a photographic image, scanning means synchronized to said facsimile transmitter for scanning the transparency with a moving light spot, means for directing the light passed by the transparency through red, green and blue filters to produce the respective color components, a photoelectric device associated with each filter for receiving the light of the color component passed by that filter and producing an electrical output signal representative of that color component, means for modifying the electrical signals for each color component to take into account the characteristic of a subsequent printing process, means for feeding to said facsimile transmitter said modified electrical signals representative of cyan, magenta and yellow respectively for the red, green and blue color componentS as required to produce a printed reproduction of said original color transparency, a facsimile receiver located at said remote point for reproducing a facsimile image of each of said color components, and a signal channel connecting said facsimile transmitter to said facsimile receiver for the passage of said modified electrical color component signals from said transmitter to said receiver.