What is the smallest CRT that people here know of?

[John]

My Sony CCD TR55e camcorder which I got as a faulty item
won't play tapes but does have a working viewfinder ....

Looking through this unit it looks like a black and white CRT picture
but if you take the eyepiece off there is a small square white screen
about 1x1 cm across. Anyone know if this is indeed a CRT and if
so how small can you make the little buggers?

Also how to get the whole viewfinder apart. It had one screw in the barrel
which is now not there but the barrel still holds together fast. Mind you I am
suspect I may have to get the rest of the housing off to access the viewfinder
so that's another issue.

Anyone with info here if you can help?

 

[mark jb]

Looking through this unit it looks like a black and white CRT picture

but if you take the eyepiece off there is a small square white screen
about 1x1 cm across. Anyone know if this is indeed a CRT and if
so how small can you make the little buggers?

I would very much doubt it's a CRT.
Probably a B&W LCD with a variable focus lens for those who need to wear
specs.

Good luck with the fixing, though. If you do have to rip it apart to get to
the screen, might as well have a crack at fixing the mechanism (if you can
be bothered)

-mark

 

[Phil Allison]

"mark jb"

I would very much doubt it's a CRT.

** I think it very much is a tiny CRT.

There is one on my old Sony.



......... Phil

 

[Trevor Wilson]

I would very much doubt it's a CRT.

**You'd be wrong. CRTs were very common in old video cameras. In fact, they
were prized above early LCDs, since they provided far better deatil, albeit
in monchrome.

Probably a B&W LCD with a variable focus lens for those who need to wear
specs.

**Nope.

 

[Phil Allison]

"Trevor Wilson"

"mark jb"


**You'd be wrong. CRTs were very common in old video cameras. In fact,
they were prized above early LCDs, since they provided far better deatil,
albeit in monchrome.

** I just opened up the viewfinder part of my old Sony CCD300AU and had a
peek.

Amazing.

A tiny CRT, about 56mm long, with a 5/6 pin plug on the base and a set of
deflection coils around the neck covered in a ( tin plate ?) metal shield.

The phosphor screen is about 18 mm diameter, masked down to about 9 mm by 12
mm actual viewing area ( 14mm diagonal).

The B&W image is sharp as a pin.




......... Phil

 

[Trevor Wilson]

"Trevor Wilson"


** I just opened up the viewfinder part of my old Sony CCD300AU and had a
peek.

Amazing.

A tiny CRT, about 56mm long, with a 5/6 pin plug on the base and a set of
deflection coils around the neck covered in a ( tin plate ?) metal shield.

**It may even be mu-metal. You never know your luck.

The phosphor screen is about 18 mm diameter, masked down to about 9 mm by
12 mm actual viewing area ( 14mm diagonal).

The B&W image is sharp as a pin.

**Yep. MUCH better resolution than the first generation LCD viewfinders. In
fact, probably better resolution than the best current generation LCDs as
well.

 

[John]

I would very much doubt it's a CRT.
Probably a B&W LCD with a variable focus lens for those who need to wear
specs.

Good luck with the fixing, though. If you do have to rip it apart to get to
the screen, might as well have a crack at fixing the mechanism (if you can
be bothered)

Fixing?
That wasn't really my intention. I was only interested more out of curiosity
as to what was inside then fixing it. The parts in the mechanism are very
tiny and hard to see and I'd more then likely lose them .

I have had to say bye bye to that side of my electronics hobby. I am finding
the parts way too tiny most of the time even in kits to do anything with and
its been hard to say bye bye to this..

 

[bodgy]

Toshiba have an experimental 20" flat panel screen that has individual
CRT's for each pixel - still in R&D at the moment, though they've
shown it at one of the European Expos -- they hope it to be the
successor to Plasma - cheaper and less juice and better picture
contrast.

Colin

 

[Phil Allison]

"bodgy"

Toshiba have an experimental 20" flat panel screen that has individual
CRT's for each pixel - still in R&D at the moment, though they've
shown it at one of the European Expos -- they hope it to be the
successor to Plasma - cheaper and less juice and better picture
contrast.


** So each ''CRT " is about 0.3mm diameter ???

Obviously there is no deflection system and no internal grid or anode
structure so the title " CRT " is just a TAD misleading.

But if high speed electrons are striking a phosphor to make light
...............




........ Phil

 

[matt2-amstereo]

"bodgy"

Toshiba have an experimental 20" flat panel screen that has individual
CRT's for each pixel - still in R&D at the moment, though they've
shown it at one of the European Expos -- they hope it to be the
successor to Plasma - cheaper and less juice and better picture
contrast.


** So each ''CRT " is about 0.3mm diameter ???

Obviously there is no deflection system and no internal grid or anode
structure so the title " CRT " is just a TAD misleading.

But if high speed electrons are striking a phosphor to make light
..............




....... Phil

sounds like a plasma to me........similar system...

 

[Franc Zabkar]

My Sony CCD TR55e camcorder which I got as a faulty item
won't play tapes but does have a working viewfinder ....

Looking through this unit it looks like a black and white CRT picture
but if you take the eyepiece off there is a small square white screen
about 1x1 cm across. Anyone know if this is indeed a CRT and if
so how small can you make the little buggers?

I once had to replace a faulty flyback transformer in a National VHS
camcorder viewfinder. It had a monochrome CRT.

-- Franc Zabkar

Please remove one 'i' from my address when replying by email.

 

[bodgy]

Matt said

:: sounds like a plasma to me........similar system..

Phil said

:: But if high speed electrons are striking a phosphor to make light


Well yes, I was on my way to bed when I typed that.

Toshiba & Canon using Surface-conduction Electron-emitter Display
technology (SED) hope to have by 2007 50" displays of 1920*1080
contrast ratio of 100,000:1 at a rate of 75,000/month ---- I'm quoting
from their blurb here, so some hypebole is to be expected.

The technology is similar to Plasma, but without using noble gasses.

The HT is supplied between two glass plates, with the low voltage
electron emitter being in a 10nanometre slit that on one side has the
phosphor.

A better description and nice drawings are at

http://www.canon.com/technology/display/ and here for links to
white papers.

http://searchwin2000.techtarget.com/sDefinition/0,,sid1_gci797765,00.h
tml

Off to bed now!

Colin

 

[Bob Parker]

Ummm... I had the idea that plasma occurs in a gas, not in a hard
vacuum. I'm sure that Phil can elaborate on the details.

Bob

 

[Lord-Data]

How big is the FBT for a CRT that size?

I once had to replace a faulty flyback transformer in a National VHS
camcorder viewfinder. It had a monochrome CRT.

-- Franc Zabkar

Please remove one 'i' from my address when replying by email.

 

[Phil Allison]

"Lord-Data"

How big is the FBT for a CRT that size?

** It could be carried on a fly's back.



........ Phil ;- )

 

[Alf Katz]

Ummm... I had the idea that plasma occurs in a gas, not in a hard
vacuum.

A plasma is an ionised gas. Kinda hard to ionise a vacuum.

Cheers
Alf

 

[Franc Zabkar]

How big is the FBT for a CRT that size?

Well, its p/n is ETF14L20B. The service manual has a scaled up circuit
layout. Using the H&V oscillator IC (AN2510S) for comparison, I'd say
the scale factor is about 4:1 which means the FBT's footprint would
have been about 21mm x 16mm. In the exploded diagram the FBT looks
about as high as it is wide, so my best guess is 21 x 16 x 16mm.

-- Franc Zabkar

Please remove one 'i' from my address when replying by email.