Optical vs mechanical: the coming battle of the video-disc players (Jul, 1980)

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Optical vs mechanical: the coming battle of the video-disc players

Several incompatible disc machines will tease the eager buyer next year

By JOHN FREE

If you’re confused by ads citing advantages of one videotape machine over an incompatible competitor, brace yourself. More befuddlement is brewing. Early next year, makers of two— and perhaps three—mutually incompatible video-disc players will each be shouting the virtues of their products while cleverly knocking the others.

Battle lines between two differing disc technologies took shape in the early 1970′s with demonstrations of early lab prototypes. Despite attempts at standardization, the lines hardened for two types of disc players: Optical, involving touchless disc playback with a laser beam, and mechanical systems, requiring contact between the disc and pickup stylus.

Proponents of the mechanical systems point out the basic simplicity of their approach and its low costs for mass marketing. Those favoring optical systems stress the no-wear advantages of laser-beam playback. (Lasers last over 10,000 hours.) Proponents of the optical route also say that mass production of optics and a switch to solid-state lasers will cut prices.

Pictures I’ve seen from the newest Pioneer, Magnavox, and RCA players are all amazingly detailed and noise-free. What follows should help delineate the differences between these players.

Optical machines: laser playback Two optical video-disc players, made by Japan’s Universal Pioneer Corp. and by Magnavox here, are being test-marketed in a limited number of cities. Magnavox plans nationwide sales this year, Pioneer next year. The machines play compatible 12-inch discs by bouncing a focused laser beam from a spiral track of microscopic pits etched on the disc’s reflective surface. A clear plastic coating makes the disc immune to dust and smudges from handling. Two types of discs are sold: Those with a half hour per side of programming play at 1800 rpm. Player controls enable you to freeze a TV picture, quickly scan a disc, play forward and reverse slow motion, or pick a specific TV frame by displaying its number on the screen. Pioneer’s VP-1000 player and remote control have a numbered key pad for direct frame-number selection; Magnavox’s Magnavision requires scanning to the desired frame. Hour-per-side discs have more than one TV frame on each circular track, so freeze-frame and related features will not work. (Playback rpm gradually changes from inner to outer tracks.) Both players have output jacks for optional stereo hi-fi (or dual-language tracks). Pioneer Artists Inc. and other new software firms will provide a stream of stereo/video music performances. Also, movie makers plan to release films to theaters and for discs almost simultaneously. Discs cost from $6 to $25. Both players, with minor variations, have laser-based optics (left) to play discs standardized by Philips and MCA. A beam from a laser (1) is deflected by a prism (2) and mirrors (3, 4) through a lens (5) onto the disc (6). Metal between pits flashes light back to a photodetector (7) for conversion to an electronic TV signal. The entire mechanism moves radially on a slide (8) linked to the electronic servo circuits that control its movement.

RCA: grooved capacitance disc RCA’s SelectaVision video-disc player has been completely overhauled since it was introduced and field-tested several years ago [PS, Feb. '77]. The basic playback principle is unchanged: A stylus electrode, replaced every two or three years, senses the TV signal as electrical capacitance variations in disc grooves spinning at 450 rpm. Playing time was boosted to one hour per 12-inch disc side by doubling disc grooves to just under 10,000 per inch. Home tests showed that dust and other groove contaminants from handling messed up pictures. So RCA’s improved SelectaVision has sealed disc “caddies.” Slip the caddy into a player slot (photo) and the disc is loaded automatically. This contact-free, sealed-player approach sharply reduces groove contamination. Spiral grooves, with four TV frames per revolution, do not permit freeze-frame and similar features now. These operating features may go into future step-up models using electronic memories to store images. Two fast-search buttons, though, let you jump the stylus forward or back to quickly locate a scene visually. Also, two other search buttons move the tone arm and display its position as time on digital readouts. RCA does not plan to include stereo hi-fi capability on its initial model, slated for nationwide marketing early next year. The player’s simple construction, plus many microcircuits, should keep RCA’s price under $500. Discs will be $15 to $20, depending on content. RCA’s low-cost approach has gained powerful allies: Zenith and undoubtedly other TV firms will market or make SelectaVisions. CBS Inc. will help expand disc titles from 150 to 300 in the first year. Programs from several film companies range from classics, musicals, current films, and how-to, to TV series such as Star Trek (10 episodes) and Victory at Sea (a 90-minute version), and Heidi and Hans Brinker for children.

JVC: grooveless capacitance disc Victor Company of Japan (or JVC here) rolled out a disc system in 1978 that combines the low-cost aspects of SelectaVision (above) with the operating options—freeze-frame, slow-motion, etc.—of optical machines. Not only that, JVC included options for a super-hi-fi audio disc. It calls the whole package its VHD/AHD system (video and audio high density). Matsushita, Victor’s parent firm in Japan, could offer VHD/AHD through its Panasonic and Quasar subsidiaries. An announcement about marketing is expected this summer. VHD/AHD hour-per-side discs are just over 10 inches in diameter and rotate at 900 rpm. Signals are stored as capacitance variations, produced by minute pits in the conductive plastic. The stylus rests over several spiral tracks, distributing pressure and minimizing wear. (Stylus life is 2000 hours, roughly 10 times RCA’s.) But the metal stylus electrode “reads” just one information track and the tracking signals on either side of it. These tracking signals keep the stylus on the right path by feeding current to a coil/magnet combination on the arm, which can move sideways. The cantilever arm can also be stretched or shortened instantly to correct for speed variations (time-base errors). Signals sent to coils can be used to make the stylus replay one frame continuously, move ahead or back at slow speed, etc. JVC has also demonstrated an optional random-access unit with a wireless remote control for the main VHD/AHD player. It has memories and numbered key pads for preprogrammed display of selected TV frames. Another plug-in option unscrambles digitally coded audio discs that have a dynamic range over 90 dB and other super-fidelity specifications. At this writing, JVC has not revealed video software sources needed to sell its system successfully. Europe’s Thorn-EMI Ltd., though, has agreed to produce both players and software.

15 comments
  1. G. L. Tyrebyter says: August 9, 20114:22 am

    I Still have the Pioneer Laser Disc Player that’s pictured in this article. It works too. This thing has a optical bench in it. The laser was a huge HE/NE gas laser tube. This has all since been squashed down to the size of a walnut in DVD and Bluray players.
    The recording was analog but it had the full bandwidth of professional video tape machines. The reason this format didn’t make it was the fact you couldn’t record on them. This was a medium for cinemaphiles because the video was so much better than the prevailing VHS. The disks seem to have a varying lifespan. The early laservision MCA discs suffered from “laser rot”. It wasn’t caused by the laser. It was a chemical interaction between the glue used on the two sides on the reflective coating. Some of the others are as good as they were 30 years ago. These were from Pioneer. My favorite is the original theatrical version of Star Wars. All DVDs contain the re-edited version. There still are people looking for disks. Pioneer has a unit (DVL 919)that playes all optical media. CDs, DVDs and Laser Discs. Best of all, no macrovision copy protection. Only down side was the required disk flip in the middle of the movie.

  2. Stephen says: August 9, 20115:44 am

    The need to flip the disc was one problem; another was the cost of the machinery. The He-Ne laser couldn’t be made cheaply, whereas prices for the electromagnetic circuitry used in magnetic tape machines fell fast. There’s an excellent page about these and other video recording technology here:
    http://www.totalrewind….

  3. lwatcdr says: August 9, 20116:57 am

    Yep these failed for a couple of reasons. You had three incompatible standards, a lack of movies, and the inability to record.
    Recording was a big thing that mattered less and less. Video tapes where expensive to buy to people used VCRs more for time shifting shows. You wanted to go out on Saturday but still wanted to see SNL? No problem. I used it to record Nightflight and other light night music video shows before we got MTV. Once video tape rentals started to be a big thing many people recorded fewer and fewer shows. If they had started rental with VideoDisks they might have really done well.

  4. Scott B. says: August 9, 20118:00 am

    I’m a technical dolt with a question sure to set heads here shaking in pity. I still own a Pioneer LaserDisc player I bought new in the early ’90s. My teenage son is in love with it, and has purchased several Laserdiscs cheap at the local used book store. The problem we have is balancing the sound. When the volume is turned up so that the dialog is audible, the sound effects and music BLAST out of the speakers in our (2009 LCD Toshiba) TV. Is there a way to correct this? Thanks.

  5. Casandro says: August 9, 20118:33 am

    Actually my LaserDisk player can flip over the disks mid film.

    There was actually a recordable version of LaserDisk for professional use. In fact there even was the DMX6000 LaserDisk based editing system. Apparently some episode of US sci-fi series “90210 Beverly Hills” were edited on that device.

  6. Mike says: August 9, 201112:10 pm

    People here might also remember the short lived DAT players, Digital Audio Tape which came out after CDs but was suppose to make them obsolete.

  7. Hirudinea says: August 9, 20112:04 pm

    I remember seeing a load of RCA SelectaVision discs at a yard sale once, if only I had had a working player.

  8. JediaKyrol says: August 9, 20113:00 pm

    US *sci-fi* series “90210 Beverly Hills”… … …Ok from what I remember 90210 was a bad teen drama series…if it had wizards or aliens it might have been watchable…

    but yeah, I have an old RCA laserdisk player, a big gox of styluses and gears, and a copy of Caveman

  9. Andrew L. Ayers says: August 9, 20113:56 pm

    Every time I see a stack of laserdiscs, I have to go thru them, just on the rarest of chances that somebody, somewhere missed a copy of the Criterion edition of Bladerunner. Unfortunately, I have yet to be that lucky (I think my luck in this regard was used up when I found my Altair 8800 at a junkyard for $100.00). -sigh-

  10. G. L. Tyrebyter says: August 9, 201110:21 pm

    Stephen-
    Great site for consumer video history. Thanks. There is a company in Maine that does restoration transfers for almost every format of video and audio that ever existed. The site has a section on almost all the audio and video equipment and formats that ever existed. This covers consumer and professional equipment. Good info on archival retrieval too.
    http://www.videointerch…

    Scott B.-
    While I don’t have enough information about your hookup or system, I think your problem may be an audio phase issue. Check to see if your surround sound setting is turned off. Your audio should be set for stereo.

    We had Laser Disc recorders at NBC years ago. They were extremely expensive and not meant for consumer use. This was the first attempt at nonlinear editing. Everything is now on hard drive systems using Avid, Final Cut Pro and Adobe editing software.

  11. Scott B. says: August 10, 20116:06 am

    Thanks for the tip, G.L. I’ll get my whiz-kid son on it immediately! The laserdisc player sat unused for more than a decade. I’m now remembering that back in the day, we had it plugged into my old Technics stereo system, and had to turn down the TV sound while viewing movies. Again, thanks!

  12. jayessell says: August 10, 20116:57 am

    Stephen… What’s this I hear about the new Final Cut Pro being a disaster?
    Fewer features? Interface badly redesigned? Different hardware requirements?

  13. Casandro says: August 10, 201110:25 pm

    I personally don’t understand the fuzz about Final Cut Pro. Look at the contract you signed and you can be lucky you still have anything at all.

    BTW, before the Laserdisk based system CMX-6000 there was a CMX-600 which copied everything from tapes to harddisks, you then make edit lists with it, to be edited automatically with 2 normal VTRs. Here’s a demo video of it:
    http://www.youtube.com/…

  14. G. L. Tyrebyter says: August 11, 20112:14 am

    Casandro-
    That CMX system was essentially an “off line” editing system. When edit suite time was very expensive, you could use that system to create your edit decision list (EDL) which could later be used in an edit suite to put together the entire edited tape in short time. The video was recorded as an analog signal on a magnetic disc. This was the same technology that was used for instant replay and slo-mo. This was a period when 2″ quad video tape was used and this just made editing a little easier. Working with a light pen for hours could get very tiring.

    The main negative point on Final Cut Pro X is that you can’t import your old projects or workflows into the new version or vice versa. For Apple, five years is “forever”. They missed the fact that there is still a lot of video tape systems still being used. The tapeless video production idea has worked as well as the paperless office. Most of the user interface and controls are very different and requires a whole new learning period. Apple decided to get rid of the time line “gotchas” that experienced editors knew how to work with already. Export to digital video tape has also vanished So we went from Laser Disc to Final Cut. 30 years bucko. A lot has changed but tape is still with us.

  15. blast says: August 12, 20116:55 pm

    Hey, Scott B. …

    Your TV or other equipment probably needs to decode Dolby Surround for discs like that to work. If you have a receiver with a “Dolby Pro Logic” setting, for instance, use that to pick the dialogue channel out of the mix and steer it to a center channel speaker. It even offers a passable (not great) surround channel for rear speakers.

    http://en.wikipedia.org…
    http://en.wikipedia.org…

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