Magazine article American Cinematographer

New Low-Cost Video Recording and Playback Systems Unveiled

Magazine article American Cinematographer

New Low-Cost Video Recording and Playback Systems Unveiled

Article excerpt

A video system for home viewing, with playback unit less than $300 and one-hour video discs to cost the same as LP recordings

At a recent series of private demonstration meetings, i/o Metrics/Videonics unveiled working models of the first home video recording and playback systems priced low enough to be within easy reach of today's homeowner.

Demonstrating the systems to industry leaders and members of the press during three days of private showings, Peter G. Wohlmut, president of i/o Metrics, stated that playback.units can be marketed at less than $300 and recorded discs should sell at about the same price as LP records. The discs will hold one full hour of color television or 500 hours of high-fidelity music, Wohlmut also noted that the unit can be used for such applications as mass memories and industrial control. At the 10-megahertz bandwidth which has been used for recording, some 100 billion bits of data can be stored and retrieved from a disc at a rate of 20 million bits per second per channel.

Master recordings are made on holographic film which has a 10 MHz bandwidth using a recorder system that will cost less than $30,000. In video applications, the analog input signal on the recorder modulates a helium-neon laser beam so that the beam prints a continuous spiral track on the film. Variations in the diameter and density of the track represent signal amplitudes. As the film spins on a turntable at 30 revolutions a second, the laser beam exposes a spiral track through a lens that moves along the radius of the turntable. Using the inherent film properties, the analog signal can be compacted 6 to 1, providing 60 minutes-rather than 10 minutes -of playing time.

To play the stored information, the recorded disc is placed on a transparent turntable which is illuminated from below by a 25-watt light bulb. The light projects an image of the track through a magnifying lens and associated optical system to three photodiodes. Two of the diodes detect track position and the outputs control the position of a servo-driven mirror that keeps the lens properIy positioned as it moves across the turntable. The third diode reads the modulated video track itself. As the track varies in density and width, the diode integrates the light energy and regenerates the analog signal.

This signal is converted to TV broadcast frequency and is fed into the TV set's antenna leads.

Wohlmut noted that, prior to the development of the system, the firm had no commitment to any present video systematics. As a result, they were able to draw from new, proven technologies to develop a simple, reliable, durable, and cost-effective video recording and playback system. For the programming and software manufacturer, the system will offer a fast, economical means of reproducing discs through simple contact photographic printing techniques. For the consumer, the system offers new vistas in viewing using a playback unit that is no more expensive than his stereo receiver.

In explaining the low-cost video recording and playback system to industry leaders and members of the press, Wohlmut noted that i/o Metrics/Videonics presently has no plans of manufactgring or marketing the system on their own. Instead, the 'company is negotiating with a number of major manufacturers presently in the field. They expect to conclude manufacturing and marketing agreements with one of the firms in the near future. Wohlmut was optimistic that systems would be available to the consuming public by the end of the year.

Headquartered at 1050 Stewart Drive in Sunnyvale, California, i/o Metrics specializes in recording and retrieval of film-stored information.


In the late '60's, the television industry began to explore the possibility of markets available in packaging and selling video entertainment and educational materials. At the time, market research indicated that by 1980, home entertainment would be a business amounting to $2 billion annually. …

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