Interpretation of core features

Basic feature: typing

Core features: typing, gaming

Equation for evaluation of features

Speed= key switches (key travel and press) +transmission way+ enhancement technology

Hand feel= key switches (key travel, press and sense of depth) + key caps (materials and structure) + steel plate + fixed mode of bigger keys + palm rest

Visual effect = modeling + lights (colors) + key caps (coatings, colors, carvings, patterns) + shells (materials)

Gaming performance = key switches + enhancement technology+ key conflicts

Playability = customization (key switches/lights/batter board/shell/key cap/cable)

Playability = batter board (materials) + light holes + wiring mode

Portability = key position + weight +wiring mode

Customer loyalty = brand + legend + public recognition + logo + modelling

Portability= configuration files + multimedia shortcut keys

Durability = key switches (types) + key types (materials)

Physical structure

• Key switch: switches of keys Mechanical key switches: mechanical key switch; mechanical structure; keys with metal contacts. The switch is composed of cover, substrate, spring, metal contact and key switch core. Key caps: hollow quadrangular part which is used in key switch body with carvings. Batter board: steel plate made of various materials to stabilize key switch body PCB: printed circuit board which provide support for electronic components or key switch body. This part is connected to key switch body and the host Controller: MCU which is used to cope with signals and complicated functions

Interpretation of key switch body structure

Concept of trace curve

It refers to the curve when the key switch touches the bottom under even pressure.

Red line represents the curve of pressing down the key switch and the black line stands for the rebound of the key switch

Take the curve of the red key switch as an example

• The initial pressure is 30g, which means the sliding block can be only moved when the pressure exceeds 30g.
• When bearing a pressure of 60g, the key will travel 2mm to the key switch body. Then, the switch will be closed and send an effective signal to complete typing of a character.
• When bearing a pressure of 85g, the key will travel 4mm. In other words, the key switch will touch the bottom. Resilience force of the spring reduces after the user releases his or her fingers. Then, the key will travel 4mm back to its starting point.
• cN: 1 GF (gram force) refers to the gravity imposed on an object of 1gram; 1N=102cN

A coin of 1 yuan (6.1g) weighs about 6cN

• ±: error value. 2±1 mm means the design value is 2 mm with a tolerance of ±1 mm.
• Triggering: the switch is closed and the latch moves down to the metal contact under pressure
• Total travel/key travel: the length of the key switch core to strike to bottom
• Triggering travel: the length to trigger the key switch core
• Initial pressure: pressure imposed on the key switch core when it is about to move
• Triggering pressure: the pressure to trigger the switch
• Depth pressure: the pressure to move the key switch core to certain depth
• Bottom-striking pressure: the pressure to make the key switch core strike the bottom

Characteristics of key switch body

The following sequence was analyzed according to key switch data and verified by key switch tester.

Cherry MX key switch:

Higher resistance, pressing pressure

Silent red=red=silver=brown<cyan<natural white<silent black=black<green=milky<linear grey

Softness (when touching the bottom)

Silent red=red=brown=cyan<silver<black=silent black<green=milky<natural white<linear grey

Quick Triggering

Silver<silent red=silent black<red=black=natural white=linear grey=brown<cyan=milky=green

Quick Rebound

Silent red<red<brown<cyan<silver<silent black<black=natural white=milky<green<linear grey

Common spare parts:

• Spring data cable
• Key switch tester: the best solution to exploring characteristics of key switch
• Silence ring: O-type sound damper
• Key cap with no carvings
• Key puller
• Light-emitting diode: refitted and customized gadgets
• Converter of PS/2 to USB: for professional copywriters and those who have no passions for refitting
• Peripheral keypad

Terms:

Layout

• Arrangement/physical layout: standard for size, shape, and location of keys

Physical layouts can be categorized into three types: American standard, European standard, and Japanese standard

These three types are designated by ANSI (American National Standards Institute), ISO (International Organization for Standardization), JIS (Japanese Industrial Standards Committee)

• Size: by the standard of full-size keyboard and on basis of its complete key functions

100%: standard full-size layout

80% Tenkeyless (TKL), a keyboard without the keypad

60%: not officially defined keyboard without Function keys

Ten-key: keys on the right side of the standard layout, also known as keypad

• Keyboard layouts: US QWERTY, UK QWERTY, DE QWERTZ, Colemak, Windows, and Macintosh etc.

Key caps

• ABS: acrylonitrile-butadiene-styrene copolymer. As common resin material, it is massively used as engineering plastic with outstanding performance in overall aspects.
• PBT: a material with no coatings. It is durable with obvious particles on its surface and higher frictional resistance.
• POM: polyformaldehyde, a material of thermoplastic crystalline polymer with outstanding performance in strength, stiffness, elasticity, anti-attrition and wearing-resistance. It is characterized by smooth surface and smaller frictional resistance.
• Polishing surface: key caps present polishing and glistening surface due to wear
• RGB: an industrial color standard used by keyboard to define its backlights
• Height: SP-DSA, SP-DCS, SP-SA, CHERRY, TAIHAO, OEM
• Times: width of keycap

Interfaces

• P/S2: an interface standard defined by IBM in 1987, originating from IBM Personal System/2 launched in 1987
• USB: universal serial bus which is a common interface with the B-type as its mainstream standard.
• Bluetooth: a common short distance wireless communication technology
• Conflicts of keys: computers fail to process signals when users press several keys at the same time because of operating principles of keyboards
• Conflict-free: Computer can process signals when users press several keys at the same time on basis of operating principles of keyboards