Fujitsu FKB3000 Series
Fujitsu FKB3000 Series covers flat-surface keypads, known as “sheet key” (シートキー) type. Stock models were available in arrangements of 1×4, 4×3, 4×4, 5×4, 4×6, 4×12 and 5×13 keys. Fully custom types were also available. The fully-custom types were available with two switch types: third-generation leaf spring with 1.3 mm of travel (FES-301S), and “FES-310” with 0.3 mm of travel. The diagram of the latter makes no sense: it shows some sort of enclosed switch held down loosely with hoops, that despite its large size only offers 0.3 mm of travel.
Keyboards of this general type observed in production have used N860 codes in the 3100 and 3700 blocks, and it is not known whether those count as the same series or not. They also have a different construction to standard FKB3000 types, although the single stock photograph presented by Fujitsu of a custom FKB3000 keyboard is different again.
The specifications below are taken from the two datasheets. Note the the operating force as standard is very high.
|Total travel||1.3 mm||0.3 mm|
|Operating force||147 cN||196 cN|
|Lifetime||10 million times||5 million times|
|Contact resistance||1 Ω or less at 6 V DC, 10 mA|
|Bounce time||10 ms or less|