Path: utzoo!utgpu!news-server.csri.toronto.edu!dgp.toronto.edu!sheasby
Newsgroups: comp.sys.amiga.graphics
From: sheasby@dgp.toronto.edu (Michael C. Sheasby)
Subject: Re: Single Frame recorders
Message-ID: <1991Mar24.144916.6803@jarvis.csri.toronto.edu>
References: <5240@mindlink.UUCP>
Date: 24 Mar 91 19:49:16 GMT
Lines: 37

Ken_Cooper@mindlink.UUCP (Ken Cooper) writes:

>Brian YAMANAKA/Sony Corporation, Personal Video Group writes:

>> single-frame recording.  The problem is not in the electronics, but in
>> the mechanical constraints.  Single frame recording records the VCR
>> to remain in pause for a considerable amount of the time. Contrary
>> to what some might believe, this puts the most amount of wear on a
>> VCR and the tape.  (That's why most VCR's will release pause after

>As limited as my knowledge is regarding the mechanics of VCR's, it seems that
>there should be a simple solution for single framing. Just look at how a 35mm
>cine setup is constructed. The film is in position, registered and just sits
>there. No stretching, no motors running etc. When some data is finally dumped

Unfortunately, that just ain't gonna happen. The tape is pulled out of
its case and into the guts of the machine into an 'M' shape (for VHS..
for Beta, it looks like a Beta, thus the name)... It's wrapped around 
a drum which is rotating against the tape, which allows a greater
bandwidth of information to be pulled off the tape than if the tape
was just running past a stationary head (like an audio tape). As long
as this 'M' shape has to be maintained, the tape is going to have to 
lie against the drum. I suspect that the reason we don't see the drum
starting and stopping has something to do with a cushioning air   
boundary between tape and drum when it is at speed, or some such
reason.

What would be awfully nice would be if the mechanism used in some
1" machines could be transferred to a consumer single-frame recorder,
where the tape does remain static but the head goes whistling by
to slice in a single frame across the tape (called a flying record
head, like a flying erase head). This makes a lot more sense to me
than getting the whole vcr up to speed, as is being suggested here.

total charge: $.02

---Mike.