Mitsumi KPR Type
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This article requires photographic illustration |
| Manufacturer | Mitsumi |
|---|---|
| Family | Mitsumi hybrid switch |
| Switch type | Progressive rate |
| Rated lifetime | 10 M |
| Bounce time | 5 ms |
| Preload | 25±15 g |
| Actuation force | ca. 45 g |
| Peak force | 85±30 g |
| Total travel | 4.0±0.5 mm |
| Keycap mount | Mitsumi mount |
Mitsumi KPR Type is a "linear" (in reality progressive rate) Mitsumi hybrid switch type; the tactile equivalent is Mitsumi KPQ Type. KPR Type also covers stock keyboards and full custom OEM products made with these switches.
Description[edit | edit source]
KPR Type keyboards use a conductive rubber foot to bridge traces on a single membrane sheet. A coil spring is placed under the keycap to return the switch. The equivalent PCB-backed switch is Mitsumi KKR Type.
The specification below specifically notes the 4 mm travel; no KPR 3 mm specification has been found, but the Custom-Made Keyboard Profile specifications indicate that 3 mm KPR Type was available.
The switch is classified as linear, although the force curve shows it to be progressive rate.
Keyboards[edit | edit source]
The example below matches the KPR specification but has no Mitsumi model number. Model KPR-A77YC was found on a hand-made prototype Commodore 65 keyboard sold on eBay, made in December 1989;<ref name="C65-1" /> no pictures of this keyboard are known, but a photo of the membrane sheet exists of another C65 keyboard.<ref name="C65-2" />
- OASYS 30LX keyboard (1990)<ref name="OASYS" />
Specifications[edit | edit source]
References[edit | edit source]
<references> <ref name="OASYS">ちゃたりたいね — MITSUMI D86L-7007-0029 03C 親指シフト MITSUMIメンブレン リニア</ref> <ref name="C65-1">cbm-hackers mailing list — Re: C65 keyboard repair</ref> <ref name="C65-2">cbm-hackers mailing list — C65 keyboard repair</ref> </references>
