7 May
2012
7 May
'12
3:56 p.m.
Tony Duell wrote:
As I said, cost. It's not that they don't do it because it is
difficult; they don't do it because more difficulty means higher cost.
If customers weren't willing to buy it without n-key rollover, they'd
manage to include the diodes, by surface-mounting them on the back side
of the PCB. However, the vast majority of customers are willing to buy
the cheapest crap they can get.
The reason is
that they don't want the expense of adding a diode in the
matrix along with each switch, to prevent the phantom keys.
I suspect it's
also the physcial problem of adding all the diodes. It's
OK if the kkeyboard is separate switches soldered to a PCB, but most are
membrand devices, and it's non-trivial to add idodes to a membrane.