Talk:Electronic Video Recording

point of confusion

GE had a system called (I believe) Electronic Video Recording, derived from the Eidophor projection system. It, in effect, froze the patterns on the oil-covered surface of the Eidophor mirror on the surface of a plastic medium. My feeling is that this page needs additional research. WilliamSommerwerck (talk) 13:32, 10 June 2011 (UTC)[reply]

GE did, indeed, use the same principle as the EVR system described in this article. Articles about it appeared in 1960-61 or thereabouts. Current online availability unknown, but they can be identified by searching for "thermoplastic recording" (or "recording, thermoplastic"?) in the Reader's Guide for those years, as that is what the technique was initially called. I believe those first experiments used the same unperforated quarter-inch plastic base employed by ordinary magnetic (audio) recording tape. A wonderfully low-cost way of preserving video at a time when an hour of 2" videotape cost nearly $300 (equivalent to at least $2000 today), except that the plastic could only be "painted" with an electrostatic image by an electron beam in a high vacuum, which made the recorder itself bulky and expensive. After the electrostatic charge was deposited, the plastic tape was briefly heated to soften its surface so that Eidophor-like micro-ripples were created, proportional in degree of deformation to the strength of the charge at each point. They were permanently fixed as the surface cooled. A Schlieren optical system was used to project the image onto a screen (or the face of a TV camera tube?) rather than scanning it with a flying spot, IIRC. I believe a method of incorporating the color information as superimposed gratings of different pitches was already envisioned if not actually implemented, but my memory is not at all clear about that aspect. AVarchaeologist (talk) 21:51, 29 October 2011 (UTC)[reply]

Googling "thermoplastic recording" and "electronic video recording" (the latter a deplorably ambiguous name, IMHO) turns up plenty of raw material to work with, but this is off my beaten path and outside my area of expertise. Some other editor(s) will have to attend to it. Not otherwise covered in WP and it certainly merits more than a stub. A very interesting and promising technology with applications in various fields including holography. It appears that it never quite made the leap into any sort of actual commercial use, and no clear reason why. According to that ubiquitous reference work The Great Soviet Encyclopedia[1] (doesn't every family have a copy on the bookshelf?) the use of a multilayered tape with a photoconductive layer obviates the need for a vacuum chamber, making the process more nearly resemble xerography, but then the recording medium is bound to be more expensive, throwing some cold water on what was arguably the system's greatest attraction. Possibly another technological loose end which may yet be picked up and profitably applied to some new digital-age use. AVarchaeologist (talk) 01:50, 31 October 2011 (UTC)[reply]

flying-spot scanner or full-frame camera?

Are you sure it used a flying-spot scanner? The demonstration I've just watched (https://www.youtube.com/watch?v=U966TEFwsvQ) showed it doing pause, and the demonstrator winding it back and forth - which looked very much like what you'd see winding film back and forth in front of a camera. To achieve that with a flying-spot scanner would require a frame store, impractical (certainly in the size of box shown) in 1968.

Or do you mean a spot that flew in two dimensions, i. e. more or less a full frame camera anyway? G6JPG (talk) 11:38, 19 April 2024 (UTC)[reply]