A keypad is a block or pad of buttons set with an arrangement of digits, symbols, or alphabetical letters. Pads mostly containing numbers and used with computers are numeric keypads. Keypads are found on devices which require mainly numeric input such as calculators, television remotes, push-button telephones, vending machines, ATMs, point of sale terminals, combination locks, safes, and digital door locks. Many devices follow the E.161 standard for their arrangement.
A computer keyboard usually has a small numeric keypad on the side, in addition to the other number keys on the top, but with a calculator-style arrangement of buttons that allow more efficient entry of numerical data. This number pad (commonly abbreviated to numpad) is usually positioned on the right side of the keyboard because most people are right-handed.
Many laptop computers have special function keys that turn part of the alphabetical keyboard into a numerical keypad as there is insufficient space to allow a separate keypad to be built into the laptop's chassis. Separate external plug-in keypads can be purchased.
Keypads for the entry of PINs and for product selection appear on many devices including ATMs, vending machines, point of sale payment devices, time clocks, combination locks and digital door locks.
Apart from mechanical keypads, [1] [2] [3] there are a wide range of technologies that can be used as keypads, each with distinctive advantages and disadvantages. These include Resistive, [4] Capacitive, [5] Inductive, [6] Piezoelectric, [7] and Optical. [8]
The first key-activated mechanical calculators and many cash registers used "parallel" keys with one column of 0 to 9 for each position the machine could use. A smaller, 10-key input first started on the Standard Adding Machine in 1901. [9] The calculator had the digit keys arranged in one row, with zero on the left, and 9 on the right. The modern four-row arrangement debuted with the Sundstrand Adding Machine in 1911. [10]
There is no standard for the layout of the four arithmetic operations, the decimal point, equal sign or other more advanced mathematical functions on the keypad of a calculator.
The invention of the push-button telephone keypad is attributed to John E. Karlin, an industrial psychologist at Bell Labs in Murray Hill, New Jersey. [11] [12] On a telephone keypad, the numbers 1 through 9 are arranged from left to right, top to bottom with 0 in a row below 789 and in the center. Telephone keypads also have the special buttons labelled * (star) and # (octothorpe, number sign, "pound", "hex" or "hash") on either side of the zero key. The keys on a telephone may also bear letters which have had several auxiliary uses, such as remembering area codes or whole telephone numbers.
The layout of calculators and telephone number pads diverged because they developed at around the same time. The phone layout was determined to be fastest by Bell Labs testing for that application, and at the time it controlled all the publicly connected telephones in the United States.
Although calculator keypads pre-date telephone keypads by nearly thirty years, the top-to-bottom order for telephones was the result of research studies conducted by a Bell Labs Human Factors group led by John Karlin. They tested a variety of layouts including a Facit like the two-row arrangement, buttons in a circle, buttons in an arc, and rows of three buttons. [11] The definitive study was published in 1960: "Human Factor Engineering Studies of the Design and Use of Pushbutton Telephone Sets" by R. L. Deininger. [13] [14] This study concluded that the adopted layout was best, and that the calculator layout was about 3% slower than the adopted telephone keypad.
Despite the conclusions obtained in the study, there are several popular theories and folk histories explaining the inverse order of telephone and calculator keypads.
A mechanically-switched 16-key keypad can be connected to a host through 16 separate connecting leads, plus a ground lead (Figure 1, left). Pressing a key will short to ground, which is detected by the host. This design allows any number or combination of keys can be pressed simultaneously. Parallel-in serial-out shift registers may be used to save I/O pins.
These 16 + 1 leads can be reduced to just 8 by using x/y multiplexing (Figure 1, center). A 16-key keypad uses a 4 × 4 array of 4 I/O lines as outputs and 4 as inputs. A circuit is completed between an output and an input when a key is pressed. Each individual keypress creates a unique signal for the host. If required, and if the processor allows, two keys can be pressed at the same time without ambiguity. Adding diodes in series with each key prevents key ghosting, allowing multiple simultaneous presses.
8 leads can detect many more keys if tri-state multiplexing (Figure 1, right) is used instead, which enables (n-1) × (n/2) keys to be detected with just n I/O lines. 8 I/O can detect 28 individual keys without ambiguity. Issues can occur with some combinations if two keys are pressed simultaneously. If diodes are used, then the number of unique keys detectable is doubled. [16]
A keyset or chorded keyboard is a computer input device that allows the user to enter characters or commands formed by pressing several keys together, like playing a "chord" on a piano. The large number of combinations available from a small number of keys allows text or commands to be entered with one hand, leaving the other hand free. A secondary advantage is that it can be built into a device that is too small to contain a normal-sized keyboard.
An electronic calculator is typically a portable electronic device used to perform calculations, ranging from basic arithmetic to complex mathematics.
A game controller, gaming controller, or simply controller, is an input device or input/output device used with video games or entertainment systems to provide input to a video game. Input devices that have been classified as game controllers include keyboards, mice, gamepads, and joysticks, as well as special purpose devices, such as steering wheels for driving games and light guns for shooting games. Controllers designs have evolved to include directional pads, multiple buttons, analog sticks, joysticks, motion detection, touch screens and a plethora of other features.
A telephone keypad is a keypad installed on a push-button telephone or similar telecommunication device for dialing a telephone number. It was standardized when the dual-tone multi-frequency signaling (DTMF) system was developed in the Bell System in the United States in the 1960s – this replaced rotary dialing, that had been developed for electromechanical telephone switching systems. Because of the abundance of rotary dial equipment still on use well into the 1990s, many telephone keypads were also designed to be backwards-compatible: as well as producing DTMF pulses, they could optionally be switched to produce loop-disconnect pulses electronically.
Microsoft has designed and sold a variety of ergonomic keyboards for computers. The oldest is the Microsoft Natural Keyboard, released in 1994, the company's first computer keyboard. The newest models are the Sculpt Ergonomic Keyboard (2013), the Surface Ergonomic Keyboard (2016), and the Microsoft Ergonomic Keyboard (2019).
Arrow keys or cursor movement keys are keys on a computer keyboard that are either programmed or designated to move the cursor in a specified direction.
Predictive text is an input technology used where one key or button represents many letters, such as on the physical numeric keypads of mobile phones and in accessibility technologies. Each key press results in a prediction rather than repeatedly sequencing through the same group of "letters" it represents, in the same, invariable order. Predictive text could allow for an entire word to be input by single keypress. Predictive text makes efficient use of fewer device keys to input writing into a text message, an e-mail, an address book, a calendar, and the like.
Apple Inc. has designed and developed many external keyboard models for use with families of Apple computers, such as the Apple II, Mac, and iPad. The Magic Keyboard and Magic Keyboard with Numeric Keypad designed to be used via either Bluetooth and USB connectivity, and have integrated rechargeable batteries; The Smart Keyboard and Magic Keyboard accessories for iPads are designed to be directly attached to and powered by a host iPad. All current Apple keyboards utilize low-profile key designs, and common modifier keys.
Japanese input methods are used to input Japanese characters on a computer.
The Fn key, short form for function, is a modifier key on many keyboards, especially external keyboards, and is not available for mobile devices. For use in a compact layout, combine keys which are normally kept separate. It-Alt + FN is typically found on laptops due to their keyboard size restrictions. It is also found on many full-sized "multimedia" keyboards as the F-Lock key. It is mainly for the purpose of changing display or audio settings quickly, such as brightness, contrast, or volume, and is held down in conjunction with the Caps Lock to change the settings.
ISO/IEC 9995Information technology — Keyboard layouts for text and office systems is an ISO/IEC standard series defining layout principles for computer keyboards. It does not define specific layouts but provides the base for national and industry standards which define such layouts.
A text entry interface or text entry device is an interface that is used to enter text information in an electronic device. A commonly used device is a mechanical computer keyboard. Most laptop computers have an integrated mechanical keyboard, and desktop computers are usually operated primarily using a keyboard and mouse. Devices such as smartphones and tablets mean that interfaces such as virtual keyboards and voice recognition are becoming more popular as text entry systems.
E.161 is an ITU-T Recommendation that defines the arrangement of digits, letters, and symbols on telephone keypads and rotary dials. It also defines the recommended mapping between the basic Latin alphabet and digits. Uses for this mapping include:
A computer keyboard is a peripheral input device modeled after the typewriter keyboard which uses an arrangement of buttons or keys to act as mechanical levers or electronic switches. Replacing early punched cards and paper tape technology, interaction via teleprinter-style keyboards have been the main input method for computers since the 1970s, supplemented by the computer mouse since the 1980s.
In computing, an input device is a piece of equipment used to provide data and control signals to an information processing system, such as a computer or information appliance. Examples of input devices include keyboards, computer mice, scanners, cameras, joysticks, and microphones.
A push-button telephone is a telephone that has buttons or keys for dialing a telephone number, in contrast to a rotary dial used in earlier telephones.
A keyboard layout is any specific physical, visual, or functional arrangement of the keys, legends, or key-meaning associations (respectively) of a computer keyboard, mobile phone, or other computer-controlled typographic keyboard.
A numeric keypad, number pad, numpad, or ten key, is the palm-sized, usually-17-key section of a standard computer keyboard, usually on the far right. It provides calculator-style efficiency for entering numbers.
David Sundstrand (1880-1930) was a Swedish-born American inventor of the 10-key adding machine, 10-key calculator keyboard, a 10-keypad now used on computer keyboards, and a co-founder of Sundstrand Corporation.
MessagEase is an input method and virtual keyboard for touchscreen devices. It relies on a new entry system designed by Saied B. Nesbat, formatted as a 3x3 matrix keypad where users may press or swipe up, down, left, right, or diagonally to access all keys and symbols. It is a keyboard that was designed for devices like cell phones, mimicking the early cell phones' limited number of 12 keys.
