Hardware Reference
In-Depth Information
• Membrane
Pure Mechanical Switches
The pure mechanical type is just that—a simple mechanical switch that features metal
contactsinamomentarycontactarrangement.Theswitchoftenincludesatactilefeedback
mechanism, consisting of a clip and spring arrangement designed to give a “clicky” feel
to the keyboard and offer some resistance to the keypress (see
Figure 15.2
).
Figure 15.2
A typical mechanical switch used in older NMB Technologies keyboards. As the key is
pressed, the switch pushes down on the contacts to make the connection.
Mechanical switches are durable, usually have self-cleaning contacts, and are normally
rated for 20 million keystrokes (which is second only to the capacitive switch in longev-
ity). They also offer excellent tactile feedback.
Despite the tactile feedback and durability provided by mechanical keyswitch keyboards,
they have become much less popular than membrane keyboards (discussed later in this
chapter). In addition, many companies that produce keyboards that employ mechanical
keyswitches either use them for only a few of their high-priced models or have phased
out their mechanical keyswitch models entirely. With the price of keyboards nose-diving
along with other traditional devices, such as mice and drives, the pressure on keyboard
makers to cut costs has led many of them to abandon or deemphasize mechanical-key-
switch designs in favor of the less expensive membrane keyswitch.
The Alps Electric mechanical keyswitch is used by many of the vendors who produce
mechanical-switchkeyboards,includingAlpsElectric.Othervendorswhousemechanical
keyswitches for some of their keyboard models include Adesso, Inc. (
www.adesso.com
)
,
Avant Prime, and Stellar (revivals of the classic Northgate keyboards are available from
Ergonomic Resources;
www.ergonomicsmadeeasy.com
), Kinesis (
www.kinesis-
