Patente del adaptador cromoscópico (1940) by Guillermo González CamarenaArchivo General de la Nación - Mexico
Have you ever wondered how color first appeared on television screens? Well, the documents you see here are part of the "Chromoscopic Adapter" for television devices, which was created by the Mexican engineer, Guillermo González Camarena. These documents make up the patent registration he would obtain under number 40235, on August 19th, 1940.
Patente del adaptador cromoscópico (1940) by Guillermo González CamarenaArchivo General de la Nación - Mexico
In the description, González Camarena defined his invention as a simple and novel adapter that would serve for the transmission and reception of color images that could be conditioned to any of the current black and white television sets of the time.
Patente del adaptador cromoscópico (1940) by Guillermo González CamarenaArchivo General de la Nación - Mexico
The characteristics and details of the adapter are explained in illustrations that Camarena included in the document.
Laminas del adaptador cromoscópico (1940) by Guillermo González CamarenaArchivo General de la Nación - Mexico
The first figure describes a wooden disk with three perforated holes that occupy most of the surface and within them, three glass filters are fixed, where the lights, red, green, and blue are represented with the letters A, B, and C respectively.
In the center there is a small hole to fix the object to an axis, and the circle made up of the dotted lines represents the size that the camera television lens should have.
In the second figure we can see another similar disk with the same windows and filters, the only difference is that it is larger. This is due to the fact that the filters had to cover the complete screen when placed in front.
Figures three and four explain how to place the aforementioned discs in the television camera and receiver.
Laminas del adaptador cromoscópico (1940) by Guillermo González CamarenaArchivo General de la Nación - Mexico
Already in figure five you can see a complete adapter, with a view of all the parts that make it up, as well as the technicalities used for electrical connections.
Laminas del adaptador cromoscópico (1940) by Guillermo González CamarenaArchivo General de la Nación - Mexico
In figure six, the internal details of the synchronous motor first shown in figure five are represented as M-2.
Finally, figure 7 is the electrical circuit of amplifier A (transmitter of the red color), in this Camarena indicates that the same symbols used in radio and telephone devices are used.
Laminas del adaptador cromoscópico (1940) by Guillermo González CamarenaArchivo General de la Nación - Mexico
Here Camarena explains the more theoretical aspects of the adapter, which is based on a television system of cathode rays and electron currents in vacuum tubes that work in a certain number frame changes.
Laminas del adaptador cromoscópico (1940) by Guillermo González CamarenaArchivo General de la Nación - Mexico
By placing the disks in front of the receiver screen and by rotating them on their axis clockwise, this would make the filters move up and down in front of the lens. This would make each frame change coincide with the color changes, achieving synchronicity that would allow the motor to rotate and adapt to the screen.
Patente del adaptador cromoscópico (1940) by Guillermo González CamarenaArchivo General de la Nación - Mexico
While it wasn't recognized as color television, it was determined that this invention improved the previously patented black and white television sets. On January 21, 1963 the first color TV transmission in the history of Mexican television was carried out in Channel 5 with the TV show, "Children's Paradise" to be broadcast under this innovative procedure.
Reference
Patent for a chromoscopic adapter for television sets.
Guillermo González Camarena
August 19, 1940
Mexico
AGN, Expired Patents and Trademarks, Box 49, Exp. 10, Patent No. 4023
