Posted by Barry Watzman on 01/08/07 19:52

You are talking about the CED disc system. I have two working players
and about 100 discs here (I also have, separately, a Pioneer 12" laser
disc play and about another 100 of those discs)(and, yes, a still
working beta VCR).

There IS a stylus (needle) in the CED disc system, and grooves in the
media. In fact, one of my CED players has a removable panel on the top
for user stylus (needle) replacement (later, RCA decided that the stylus
would last long enough that they no longer needed to provide for user
replacement ... and the later of the two players has no such stylus
access panel (but it does still have a stylus)). The pitch of the
grooves was incredible ... it is .00267mm, center to center. However,
the technology was capacitance based. The needle (Stylus is really the
correct term) was used for positioning, but the technology did not work
like a phonograph, where mechanical variations in the groove were picked
up by the stylus.


M.I.5¾ wrote:
> "JoeBloe" <joebloe@thebarattheendoftheuniverse.org> wrote in message
> news:p6ksp21rsv4rv6155q0vpg7b791elqengq@4ax.com...
>> On Fri, 5 Jan 2007 08:11:07 -0000, "M.I.5?"
>> <no.one@no.where.NO_SPAM.co.uk> Gave us:
>>
>>> "JoeBloe" <joebloe@thebarattheendoftheuniverse.org> wrote in message
>>> news:gparp2t4rbmfg2952ucgiqcq4853263cc5@4ax.com...
>>>> On Thu, 04 Jan 2007 10:05:13 -0600, chrisv <chrisv@nospam.invalid>
>>>> Gave us:
>>>>
>>>>> JoeBloe wrote:
>>>>>
>>>>>> LD is too huge, too bulky, and it presents the hardware designers
>>>>>> with too many technical hurdles to make good gear for it. The wobble
>>>>>> at the edge of a twelve inch platter can be huge.
>>>>> Too bad that the market didn't go for the "needle and groove" video
>>>>> disk that RCA tried to make work, eh?
>>>>>
>>>> That's not what it was.
>>>>
>>>> It was a capacitive pick up stylus. No needle at all. No groove.
>>>>
>>>> http://en.wikipedia.org/wiki/SelectaVision
>>> The 'needle' is just a synonym for a 'stylus' left over from the 78 era.
>> Wrong. He specifically stated "needle and groove".
>>
>> There is NO needle, and there is most certainly no grooves.
>>
>
> Knowing wikipedia to be anything but an authoritative source, I had a look.
> I took me all of 12 seconds to find, "A keel-shaped needle with a titanium
> electrode layer would ride in the groove ..." from the article.
>
> So we are in agreement then and it would appear that you are wrong.
>
>

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