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buttons in a circle, buttons in an arc, and rows of three buttons. The definitive study was published in 1960: "Human Factor
Engineering Studies of the Design and Use of Pushbutton Telephone Sets" by R. L. Deininger. This study concluded that the adopted layout was best, and that the calculator layout was about 3% slower than the adopted telephone keypad.
151:/window keypad image). Later, they were installed in many Tourist Information shop windows throughout the UK. Due to their ability to operate through thick glass, and be unaffected by spilt beer, in 1990 projected capacitance keypads were used by MHG (Music Hire Group) to replace the selection keys in Pub Juke Boxes.
249:
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,
321:
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
260:
Another explanation proposed is that at the time of the introduction of the telephone keypad, telephone numbers in the United States were commonly given out using alphabetical characters for the first two digits. Thus 555-1234 would be given out as KL5-1234. These alpha sequences were mapped to
176:
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. 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
261:
words. "27" was given out as "CRestview", "26" as "ATwood", etc. By placing the "1" key in the upper left, the alphabet was arranged in the normal left-to-right descending order for
English characters. Additionally, on a rotary telephone, the "1" hole was at the top, albeit at the top right.
234:
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.
132:
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.
159:
Apart from mechanical keypads, there are a wide range of technologies that can be used as keypads, each with distinctive advantages and disadvantages. These include
Resistive, Capacitive, Inductive, Piezoelectric, and Optical.
360:
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.
120:
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
257:
One popular theory suggests that the reason is similar to that given for the QWERTY layout, the unfamiliar ordering slowed users to accommodate the slow switches of the late 1950s and early 1960s.
215:, 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 * (
536:
253:
Despite the conclusions obtained in the study, there are several popular theories and folk histories explaining the inverse order of telephone and calculator keypads.
64:
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
732:
599:
706:
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851:
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signal for the host. If required, and if the processor allows, two keys can be pressed at the same time without ambiguity. Adding
299:
to ground, which is detected by the host. This design allows any number or combination of keys can be pressed simultaneously.
874:
455:
770:
622:
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147:
In 1984, the first projected capacitance keypad was used to sense through the shop window of a travel agency (see
740:
137:
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A mechanically-switched 16-key keypad can be connected to a host through 16 separate connecting
125:) is usually positioned on the right side of the keyboard because most people are right-handed.
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Figure 1. Keypad wiring methods: separate connections (left), x/y multiplexing (center),
783:
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763:"Human Factor Engineering Studies of the Design and Use of Pushbutton Telephone Sets"
380:
101:
779:
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and for product selection appear on many devices including ATMs, vending machines,
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may also bear letters which have had several auxiliary uses, such as remembering
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827:"Why is the keypad arrangement different for a telephone and a calculator?"
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477:"A Brief History of Projected Capacitance Development by Binstead Designs"
223:, "pound", "hex" or "hash") on either side of the zero key. The keys on a
68:. Keypads are found on devices which require mainly numeric input such as
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payment devices, time clocks, combination locks and digital door locks.
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707:"John E. Karlin, Who Led the Way to All-Digit Dialing, Dies at 94"
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or other more advanced mathematical functions on the keypad of a
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733:"Monmouth man, inventor of touch-tone keypad, dies at 94"
33:
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debuted with the
Sundstrand Adding Machine in 1911.
37:
Numeric keypad, integrated with a computer keyboard
683:"Sundstrand Adding Machine - Underwood Sundstrand"
348:(Figure 1, right) is used instead, which enables (
244:
881:
180:There is no standard for the layout of the four
875:Interfacing Matrix Keypad to 8051 Controller
295:lead (Figure 1, left). Pressing a key will
56:1984 flier for projected capacitance keypad
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330:, allowing multiple simultaneous presses.
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449:
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116:A computer keyboard usually has a small
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40:
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20:
810:
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301:Parallel-in serial-out shift registers
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663:"William and Hubert Hopkins machines"
450:Binstead, Ronald Peter (1985-04-16).
344:8 leads can detect many more keys if
111:
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815:. New York, USA: Harper & Row.
784:10.1002/j.1538-7305.1960.tb04447.x
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356:/2) keys to be detected with just
14:
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771:The Bell System Technical Journal
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326:in series with each key prevents
211:in Murray Hill, New Jersey. On a
207:, an industrial psychologist at
108:standard for their arrangement.
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537:"Mechanical push-button keypad"
458:from the original on 2018-01-31
761:Deininger, R. L. (July 1960).
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245:Origin of the order difference
240:Telephone keypad § Layout
1:
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25:A telephone keypad using the
739:. 2013-02-09. Archived from
705:Fox, Margalit (2013-02-08).
231:or whole telephone numbers.
7:
813:Why Do Clocks Run Clockwise
557:"Resistive membrane keypad"
364:
10:
906:
337:
314:
237:
104:. Many devices follow the
452:"Touch operated keyboard"
136:Keypads for the entry of
203:keypad is attributed to
168:The first key-activated
890:Computer keyboard types
391:Keyboard matrix circuit
317:Keyboard matrix circuit
811:Feldman, Dave (1987).
426:Silicone rubber keypad
346:tri-state multiplexing
279:
170:mechanical calculators
78:push-button telephones
57:
49:
38:
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416:Push-button telephone
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238:Further information:
219:) and # (octothorpe,
201:push-button telephone
199:The invention of the
149:projected capacitance
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44:
36:
24:
580:"Capacitive keypads"
517:"Mechanical keypads"
386:Keyboard (computing)
283:Separate connections
600:"Inductive keypads"
497:"Mechanical keypad"
396:Keyboard technology
266:Keypad track design
155:Keypad technologies
712:The New York Times
280:
112:Uses and functions
102:digital door locks
74:television remotes
58:
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39:
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643:"Optical keypads"
381:Digital door lock
94:combination locks
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431:Telephone keypad
311:X/Y multiplexing
213:telephone keypad
184:operations, the
82:vending machines
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623:"Piezo keypads"
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66:numeric keypads
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869:External links
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852:"Touch sensor"
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411:Numeric keypad
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376:Charlieplexing
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340:Charlieplexing
338:Main article:
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334:Charlieplexing
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276:Charlieplexing
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205:John E. Karlin
174:cash registers
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118:numeric keypad
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793:on 2014-01-24
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855:. Retrieved
846:
835:. Retrieved
833:. 2001-05-22
830:
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806:
795:. Retrieved
788:the original
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769:
756:
745:. Retrieved
741:the original
736:
727:
716:. Retrieved
710:
686:. Retrieved
677:
666:. Retrieved
657:
646:. Retrieved
637:
626:. Retrieved
617:
606:. Retrieved
594:
583:. Retrieved
574:
563:. Retrieved
551:
540:. Retrieved
531:
520:. Retrieved
511:
500:. Retrieved
491:
480:. Retrieved
471:
460:. Retrieved
445:
406:Mobile phone
401:Key rollover
357:
353:
352:-1) × (
349:
343:
328:key ghosting
320:
286:
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179:
167:
158:
146:
135:
127:
122:
115:
61:
59:
18:
16:Input device
421:Rotary dial
221:number sign
92:terminals,
70:calculators
857:2023-08-04
837:2014-02-07
797:2014-02-07
747:2013-02-09
718:2013-02-09
688:2017-07-18
668:2017-07-18
648:2023-12-17
628:2023-12-17
608:2023-12-17
585:2023-12-17
565:2023-12-19
542:2023-12-17
522:2023-12-17
502:2023-12-17
482:2023-08-27
462:2018-01-30
437:References
371:Arrow keys
315:See also:
229:area codes
194:calculator
190:equal sign
182:arithmetic
164:Key layout
47:calculator
291:, plus a
225:telephone
209:Bell Labs
172:and many
29:standard.
27:ITU E.161
884:Category
456:Archived
365:See also
278:(right).
778:: 995.
324:diodes
293:ground
130:laptop
123:numpad
100:, and
62:keypad
791:(PDF)
766:(PDF)
603:(PDF)
560:(PDF)
297:short
289:leads
128:Many
106:E.161
98:safes
217:star
138:PINs
86:ATMs
780:doi
886::
829:.
776:39
774:.
768:.
735:.
709:.
697:^
454:.
307:.
196:.
188:,
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840:.
800:.
782::
750:.
721:.
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671:.
651:.
631:.
611:.
588:.
568:.
545:.
525:.
505:.
485:.
465:.
358:n
354:n
350:n
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
