53:
33:
64:
261:
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.
45:
282:
162:/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.
260:
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,
332:
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
271:
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
187:
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
272:
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.
245:
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.
143:
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.
170:
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.
371:
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.
131:
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
268:
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.
226:, 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 * (
547:
264:
Despite the conclusions obtained in the study, there are several popular theories and folk histories explaining the inverse order of telephone and calculator keypads.
75:
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
743:
610:
717:
773:
862:
781:
333:
signal for the host. If required, and if the processor allows, two keys can be pressed at the same time without ambiguity. Adding
900:
310:
to ground, which is detected by the host. This design allows any number or combination of keys can be pressed simultaneously.
148:
885:
466:
633:
158:
In 1984, the first projected capacitance keypad was used to sense through the shop window of a travel agency (see
84:
751:
96:
673:
401:
327:
436:
356:
426:
211:
180:
159:
88:
653:
396:
303:
406:
798:
722:
299:
298:
A mechanically-switched 16-key keypad can be connected to a host through 16 separate connecting
136:) is usually positioned on the right side of the keyboard because most people are right-handed.
52:
507:
391:
112:
790:
590:
441:
250:
223:
104:
92:
285:
Figure 1. Keypad wiring methods: separate connections (left), x/y multiplexing (center),
794:
421:
386:
350:
315:
311:
286:
128:
76:
894:
774:"Human Factor Engineering Studies of the Design and Use of Pushbutton Telephone Sets"
307:
196:
184:
152:
100:
416:
411:
338:
151:
and for product selection appear on many devices including ATMs, vending machines,
238:
may also bear letters which have had several auxiliary uses, such as remembering
567:
431:
231:
215:
32:
837:
462:
381:
204:
200:
192:
80:
57:
693:
527:
239:
235:
219:
37:
838:"Why is the keypad arrangement different for a telephone and a calculator?"
487:
63:
488:"A Brief History of Projected Capacitance Development by Binstead Designs"
234:, "pound", "hex" or "hash") on either side of the zero key. The keys on a
79:. Keypads are found on devices which require mainly numeric input such as
227:
155:
payment devices, time clocks, combination locks and digital door locks.
17:
140:
281:
718:"John E. Karlin, Who Led the Way to All-Digit Dialing, Dies at 94"
334:
280:
116:
62:
51:
44:
43:
31:
203:
or other more advanced mathematical functions on the keypad of a
108:
744:"Monmouth man, inventor of touch-tone keypad, dies at 94"
188:
debuted with the
Sundstrand Adding Machine in 1911.
48:
Numeric keypad, integrated with a computer keyboard
694:"Sundstrand Adding Machine - Underwood Sundstrand"
359:(Figure 1, right) is used instead, which enables (
191:There is no standard for the layout of the four
8:
886:Interfacing Matrix Keypad to 8051 Controller
306:lead (Figure 1, left). Pressing a key will
67:1984 flier for projected capacitance keypad
711:
709:
341:, allowing multiple simultaneous presses.
127:A computer keyboard usually has a small
453:
312:Parallel-in serial-out shift registers
674:"William and Hubert Hopkins machines"
461:Binstead, Ronald Peter (1985-04-16).
355:8 leads can detect many more keys if
7:
826:. New York, USA: Harper & Row.
795:10.1002/j.1538-7305.1960.tb04447.x
367:/2) keys to be detected with just
25:
782:The Bell System Technical Journal
337:in series with each key prevents
222:in Murray Hill, New Jersey. On a
218:, an industrial psychologist at
119:standard for their arrangement.
548:"Mechanical push-button keypad"
469:from the original on 2018-01-31
772:Deininger, R. L. (July 1960).
256:Origin of the order difference
251:Telephone keypad § Layout
1:
36:A telephone keypad using the
750:. 2013-02-09. Archived from
716:Fox, Margalit (2013-02-08).
242:or whole telephone numbers.
824:Why Do Clocks Run Clockwise
568:"Resistive membrane keypad"
917:
348:
325:
248:
115:. Many devices follow the
463:"Touch operated keyboard"
147:Keypads for the entry of
214:keypad is attributed to
179:The first key-activated
901:Computer keyboard types
402:Keyboard matrix circuit
328:Keyboard matrix circuit
822:Feldman, Dave (1987).
437:Silicone rubber keypad
357:tri-state multiplexing
290:
181:mechanical calculators
89:push-button telephones
68:
60:
49:
41:
427:Push-button telephone
284:
249:Further information:
230:) and # (octothorpe,
212:push-button telephone
210:The invention of the
160:projected capacitance
66:
55:
47:
35:
591:"Capacitive keypads"
528:"Mechanical keypads"
397:Keyboard (computing)
294:Separate connections
611:"Inductive keypads"
508:"Mechanical keypad"
407:Keyboard technology
277:Keypad track design
166:Keypad technologies
723:The New York Times
291:
123:Uses and functions
113:digital door locks
85:television remotes
69:
61:
50:
42:
654:"Optical keypads"
392:Digital door lock
105:combination locks
16:(Redirected from
908:
873:
872:
870:
869:
859:
853:
852:
850:
849:
834:
828:
827:
819:
813:
812:
810:
809:
803:
797:. Archived from
778:
769:
763:
762:
760:
759:
740:
734:
733:
731:
730:
713:
704:
703:
701:
700:
690:
684:
683:
681:
680:
670:
664:
663:
661:
660:
650:
644:
643:
641:
640:
630:
624:
623:
621:
620:
615:
607:
601:
600:
598:
597:
587:
581:
580:
578:
577:
572:
564:
558:
557:
555:
554:
544:
538:
537:
535:
534:
524:
518:
517:
515:
514:
504:
498:
497:
495:
494:
484:
478:
477:
475:
474:
458:
442:Telephone keypad
322:X/Y multiplexing
224:telephone keypad
195:operations, the
93:vending machines
21:
916:
915:
911:
910:
909:
907:
906:
905:
891:
890:
882:
877:
876:
867:
865:
861:
860:
856:
847:
845:
842:How Stuff Works
836:
835:
831:
821:
820:
816:
807:
805:
801:
776:
771:
770:
766:
757:
755:
748:The Star-Ledger
742:
741:
737:
728:
726:
715:
714:
707:
698:
696:
692:
691:
687:
678:
676:
672:
671:
667:
658:
656:
652:
651:
647:
638:
636:
634:"Piezo keypads"
632:
631:
627:
618:
616:
613:
609:
608:
604:
595:
593:
589:
588:
584:
575:
573:
570:
566:
565:
561:
552:
550:
546:
545:
541:
532:
530:
526:
525:
521:
512:
510:
506:
505:
501:
492:
490:
486:
485:
481:
472:
470:
460:
459:
455:
450:
378:
353:
347:
330:
324:
314:may be used to
296:
279:
258:
253:
177:
168:
125:
77:numeric keypads
28:
23:
22:
15:
12:
11:
5:
914:
912:
904:
903:
893:
892:
889:
888:
881:
880:External links
878:
875:
874:
863:"Touch sensor"
854:
829:
814:
764:
735:
705:
685:
665:
645:
625:
602:
582:
559:
539:
519:
499:
479:
452:
451:
449:
446:
445:
444:
439:
434:
429:
424:
422:Numeric keypad
419:
414:
409:
404:
399:
394:
389:
387:Charlieplexing
384:
377:
374:
351:Charlieplexing
349:Main article:
346:
345:Charlieplexing
343:
323:
320:
295:
292:
287:Charlieplexing
278:
275:
274:
273:
269:
257:
254:
216:John E. Karlin
185:cash registers
176:
173:
167:
164:
129:numeric keypad
124:
121:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
913:
902:
899:
898:
896:
887:
884:
883:
879:
864:
858:
855:
843:
839:
833:
830:
825:
818:
815:
804:on 2014-01-24
800:
796:
792:
788:
784:
783:
775:
768:
765:
754:on 2013-02-13
753:
749:
745:
739:
736:
725:
724:
719:
712:
710:
706:
695:
689:
686:
675:
669:
666:
655:
649:
646:
635:
629:
626:
612:
606:
603:
592:
586:
583:
569:
563:
560:
549:
543:
540:
529:
523:
520:
509:
503:
500:
489:
483:
480:
468:
464:
457:
454:
447:
443:
440:
438:
435:
433:
430:
428:
425:
423:
420:
418:
415:
413:
410:
408:
405:
403:
400:
398:
395:
393:
390:
388:
385:
383:
380:
379:
375:
373:
370:
366:
362:
358:
352:
344:
342:
340:
336:
329:
321:
319:
317:
316:save I/O pins
313:
309:
305:
301:
293:
288:
283:
276:
270:
267:
266:
265:
262:
255:
252:
247:
243:
241:
237:
233:
229:
225:
221:
217:
213:
208:
206:
202:
198:
197:decimal point
194:
189:
186:
182:
174:
172:
165:
163:
161:
156:
154:
153:point of sale
150:
145:
142:
137:
135:
130:
122:
120:
118:
114:
110:
106:
102:
101:point of sale
98:
94:
90:
86:
82:
78:
74:
65:
59:
54:
46:
39:
34:
30:
19:
866:. Retrieved
857:
846:. Retrieved
844:. 2001-05-22
841:
832:
823:
817:
806:. Retrieved
799:the original
786:
780:
767:
756:. Retrieved
752:the original
747:
738:
727:. Retrieved
721:
697:. Retrieved
688:
677:. Retrieved
668:
657:. Retrieved
648:
637:. Retrieved
628:
617:. Retrieved
605:
594:. Retrieved
585:
574:. Retrieved
562:
551:. Retrieved
542:
531:. Retrieved
522:
511:. Retrieved
502:
491:. Retrieved
482:
471:. Retrieved
456:
417:Mobile phone
412:Key rollover
368:
364:
363:-1) × (
360:
354:
339:key ghosting
331:
297:
263:
259:
244:
209:
190:
178:
169:
157:
146:
138:
133:
126:
72:
70:
29:
27:Input device
432:Rotary dial
232:number sign
103:terminals,
81:calculators
868:2023-08-04
848:2014-02-07
808:2014-02-07
758:2013-02-09
729:2013-02-09
699:2017-07-18
679:2017-07-18
659:2023-12-17
639:2023-12-17
619:2023-12-17
596:2023-12-17
576:2023-12-19
553:2023-12-17
533:2023-12-17
513:2023-12-17
493:2023-08-27
473:2018-01-30
448:References
382:Arrow keys
326:See also:
240:area codes
205:calculator
201:equal sign
193:arithmetic
175:Key layout
58:calculator
302:, plus a
236:telephone
220:Bell Labs
183:and many
40:standard.
38:ITU E.161
895:Category
467:Archived
376:See also
289:(right).
789:: 995.
18:Keypads
335:diodes
304:ground
141:laptop
134:numpad
111:, and
73:keypad
802:(PDF)
777:(PDF)
614:(PDF)
571:(PDF)
308:short
300:leads
139:Many
117:E.161
109:safes
228:star
149:PINs
97:ATMs
791:doi
897::
840:.
787:39
785:.
779:.
746:.
720:.
708:^
465:.
318:.
207:.
199:,
107:,
99:,
95:,
91:,
87:,
83:,
71:A
56:A
871:.
851:.
811:.
793::
761:.
732:.
702:.
682:.
662:.
642:.
622:.
599:.
579:.
556:.
536:.
516:.
496:.
476:.
369:n
365:n
361:n
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
