Notebook keyboards ?

[no.top.post]

This query perhaps applies to desktop-PC keyboards too.

My notebook's 3 keys on the left botton: Ctrl, Alt, Fn started getting
unreliable and then failed. When I opened it up, I saw, as expected
that these 3 keys are the only ones on one of the 'ribbon's tracks'.
So obviously if the continuity was broken after the key closest to the
connector, then all 3 keys would fail.

But what I'm realy interest to know is what technology is used ?
Is it galvanic [actual contact] or capacitive ?
The 2 transparent plastic-sheets with the tracks 'meeting' at the
'key-points' are 'sealed together' so I can't see/feel what's inside,
at the actual 'key-points'.

If the key-press causes the top-sheet's track to connect with the
bottom-sheet's track, then what keeps them apart when no key
is pressed ?

The one plastic track-sheet, mounts against an aluminum plate
which might be relevant if capacative-pulsing is used.

Thanks for any explantion/s on the workings of this strange thing.

 

[Paul]

This query perhaps applies to desktop-PC keyboards too.

My notebook's 3 keys on the left botton: Ctrl, Alt, Fn started getting
unreliable and then failed. When I opened it up, I saw, as expected
that these 3 keys are the only ones on one of the 'ribbon's tracks'.
So obviously if the continuity was broken after the key closest to the
connector, then all 3 keys would fail.

But what I'm realy interest to know is what technology is used ?
Is it galvanic [actual contact] or capacitive ?
The 2 transparent plastic-sheets with the tracks 'meeting' at the
'key-points' are 'sealed together' so I can't see/feel what's inside,
at the actual 'key-points'.

If the key-press causes the top-sheet's track to connect with the
bottom-sheet's track, then what keeps them apart when no key
is pressed ?

The one plastic track-sheet, mounts against an aluminum plate
which might be relevant if capacative-pulsing is used.

Thanks for any explantion/s on the workings of this strange thing.

Try classifying the keyboard using this article. Based on
what I see here, the pattern where the conductors meet,
may tell you something.

http://en.wikipedia.org/wiki/Keyboard_technology

Paul

 

[david]

This query perhaps applies to desktop-PC keyboards too.

My notebook's 3 keys on the left botton: Ctrl, Alt, Fn started getting
unreliable and then failed. When I opened it up, I saw, as expected
that these 3 keys are the only ones on one of the 'ribbon's tracks'. So
obviously if the continuity was broken after the key closest to the
connector, then all 3 keys would fail.

But what I'm realy interest to know is what technology is used ? Is it
galvanic [actual contact] or capacitive ? The 2 transparent
plastic-sheets with the tracks 'meeting' at the 'key-points' are
'sealed together' so I can't see/feel what's inside, at the actual
'key-points'.

If the key-press causes the top-sheet's track to connect with the
bottom-sheet's track, then what keeps them apart when no key is pressed
?

The one plastic track-sheet, mounts against an aluminum plate which
might be relevant if capacative-pulsing is used.

Thanks for any explantion/s on the workings of this strange thing.

Try classifying the keyboard using this article. Based on what I see
here, the pattern where the conductors meet, may tell you something.

http://en.wikipedia.org/wiki/Keyboard_technology

Paul

The old IBM buckling-spring keyboard is the best one I ever used. I
still have my old IBM-PC keyboard, one of these days I'll make up an
adapter to map the old keycodes and format into the AT(PS2) standard,
just haven't had time to get around to it.

 

[no.top.post]

This query perhaps applies to desktop-PC keyboards too.

My notebook's 3 keys on the left botton: Ctrl, Alt, Fn started getting
unreliable and then failed. When I opened it up, I saw, as expected
that these 3 keys are the only ones on one of the 'ribbon's tracks'.
So obviously if the continuity was broken after the key closest to the
connector, then all 3 keys would fail.

But what I'm realy interest to know is what technology is used ?
Is it galvanic [actual contact] or capacitive ?
The 2 transparent plastic-sheets with the tracks 'meeting' at the
'key-points' are 'sealed together' so I can't see/feel what's inside,
at the actual 'key-points'.

If the key-press causes the top-sheet's track to connect with the
bottom-sheet's track, then what keeps them apart when no key
is pressed ?

The one plastic track-sheet, mounts against an aluminum plate
which might be relevant if capacative-pulsing is used.

Thanks for any explantion/s on the workings of this strange thing.

Try classifying the keyboard using this article. Based on
what I see here, the pattern where the conductors meet,
may tell you something.

http://en.wikipedia.org/wiki/Keyboard_technology

Paul

Wow, that's good, thanks !
wikipedia has got everty thing, and google didn't show me.