Keyboard entry system

• US 4,694,280 A
• Filed: 04/25/1986
• Issued: 09/15/1987
• Est. Priority Date: 01/30/1984
• Status: Expired due to Term

• Current Assignee: Quixote Corporation (Trinity Industries Incorporated)
• Original Assignee: Quixote Corporation (Trinity Industries Incorporated)
• Inventors: Endo, Yukio, Rollhaus, Philip E.
• Primary Examiner(s): Rowland, James L.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/856,644
• Time in Patent Office: 508 Days
• Field of Search: 340/365 R, 340/365 S, 340/365 E, 364/709, 400/91-93, 400/87, 400/100, 400/109-111, 400/482
• US Class Current: 341/26
• CPC Class Codes: B41J 5/10 Arrangements of keyboards , e.g. key button disposition
• CPC Class Codes: G06F 3/023 Arrangements for converting discrete items of information into a coded form, e.g. arrangements for interpreting keyboard generated codes as alphanumeric codes, operand codes or instruction codes
• CPC Class Codes: G06F 40/274 Converting codes to words; Guess-ahead of partial word inputs

Abstract

A keyboard entry system is disclosed which comprises a keyboard which includes a plurality of letter keys, one for each letter of a selected language. The entry system responds to conventional sequential activation of individual keys by providing output signals indicative of the respective individual letters associated with the activated keys to an application program such as a word processor or printer control program. The keyboard entry system also responds to chords of simultaneously activated multiple keys by using these chords to retrieve stored words from a dictionary. It is the stored words rather than the entered chords which are applied as inputs to the application program. This system allows an operator to use both conventional sequential key entry techniques and chorded entry techniques for rapid data entry. Chords are detected by comparing a stored constant with the elapsed time between a key release and the immediately preceding key depression of an overlapping key. The overlapping keys are characterized as a chord when the elapsed time is greater than the stored constant. A biofeedback mechanism alerts the operator of inadvertent chords.

Claims

1. A keyboard entry system for a selected language, said system comprising:

a keyboard comprising a plurality of keys, said plurality of keys comprising a set of letter keys comprising a respective key for each letter of said selected language;

first means, responsive to the plurality of letter keys, for generating keying signals in response to activation of the letter keys, each keying signal characterized by a respective depression time when the keying signal is generated in response to depression of the respective letter key, and a respective release time when the keying signal is generated in response to release of the respective letter key;

second means, responsive to the first means, for generating output signals in response to the keying signals, said second means comprising;

means for classifying a plurality of keying signals as a key chord in the event the respective depression and release times satisfy predetermined criteria, said criteria comprising the component criterion that the elapsed time between a first one of the release times and an immediately preceding one of the depression times is greater than a preselected time interval;

means for storing a list of stored texts, each corresponding to a respective chord;

means, responsive to the key chord, for utilizing the key chord to select the one of the stored texts in the list of stored texts which corresponds to the key chord;

means for setting the output signal to correspond to the selected one of the stored texts; and

means for setting the output signal to correspond to the letters corresponding to the activated letter keys in the event the respective depression and release times fail to satisfy said criteria.

2. The invention of claim 1 wherein the selected language is written in the Roman alphabet and said set of letter keys comprises a respective letter key for each letter of the Roman alphabet.

3. The invention of claim 2 wherein the keyboard comprises a QWERTY keyboard which comprises the plurality of letter keys.

4. The invention of claim 1 further comprising means for notifying an operator when a key chord fails to correspond to any of the stored texts in the list of stored texts.

5. The invention of claim 4 wherein the notifying means sounds a tone when a key chord fails to correspond to any of the stored texts.

6. A keyboard entry system for a selected language which comprises a multiplicity of words formed of the 26 letters of the Roman alphabet, said system operative to supply a plurality of output signals to a utilization device and comprising:

a keyboard comprising a plurality of keys, said plurality of keys comprising at least 26 letter keys, each corresponding to an associated one of the 26 letters of the Roman alphabet, said letter keys arranged in a QWERTY keyboard configuration;

means, responsive to the letter keys, for generating key signals in response to depression and release of the letter keys, each of said key signals comprising a key code identifying the activated key and a time code identifying the time of depression or release;

means, responsive to the key signals, for classifying a plurality of key codes as a key chord in the event the time codes of the corresponding plurality of key signals satisfy predetermined criteria and for classifying the plurality of key codes as a plurality of discrete letters in the event the time codes of the corresponding plurality of key signals fail to satisfy the predetermined criteria, said predetermined criteria comprising the component criterion that the elapsed time between the time of release of a selected key signal and the time of depression of a preceding key signal is greater than a stored value;

means for supplying the plurality of discrete letters as a plurality of the output signals;

means for maintaining a list of stored texts, each of which is identified with a respective stored index;

means, responsive to the key chord, for comparing the key chord with the stored indexes and for selecting the corresponding one of the stored texts in the event the key chord matches one of the stored indexes; and

means for supplying the selected stored text as one of the output signals, said system cooperating to allow conventional sequential key entry to be intermixed with chorded key entry.

7. The invention of claim 6 wherein the stored value is in the range of 70-85 milliseconds.

8. The invention of claim 6 wherein the means for generating the key signals is included in the keyboard.

9. The invention of claim 6 wherein the classifying means is included in a computer, and wherein the means for generating the key signals is included in a module interconnected between the keyboard and the computer.

10. The invention of claim 6 further comprising means for notifying an operator in the event the key chord fails to match any of the stored indexes.

11. The invention of claim 10 wherein the notifying means sounds a tone in the event the key chord fails to match any of the stored indexes.

12. A keyboard entry system for a language comprised of a plurality of letters, said system comprising:

a keyboard comprising a plurality of letter keys, each associated with a respective letter;

first means, responsive to the letter keys, for generating keying signals in response to depression and release of the letter keys;

second means, responsive to the first means, for generating output signals in response to the keying signals, said second means comprising;

means for storing a list of stored texts, each of which is associated with a respective stored index;

means for measuring a plurality of time intervals, each characteristic of the elapsed time separating a keying signal generated in response to release of the respective letter key and the immediately preceding keying signal generated in response to depression of the respective letter key;

means for classifying a set of keying signals as a nonchord in the event the respective time interval is less than a predetermined value, and for setting the output signal to correspond to respective ones of the letters corresponding to the set of keying signals;

means for classifying the set of keying signals as a key chord in the event the respective time interval is greater than the predetermined value;

means, responsive to the key chord, for comparing the key chord with the stored indexes and for selecting the corresponding one of the stored texts in the event the key chord matches one of the stored indexes; and

means for setting the output signal to correspond with the selected stored text;

said keyboard and first and second means cooperating automatically to set the output signal to correspond to associated ones of the letters in response to nonchorded activation of the letter keys, and to set the output signal to correspond to an associated one of the stored texts in response to chorded activation of the letter keys.

13. The invention of claim 12 wherein the plurality of letter keys comprises a respective letter key for each of the 26 letters of the Roman alphabet.

14. The invention of claim 12 wherein the keyboard comprises a QWERTY keyboard which includes the plurality of letter keys.

15. The invention of claim 12 further comprising means for storing the predetermined value such that the predetermined value remains unchanged over multiple chords.

16. The invention of claim 12 further comprising means for notifying an operator in the event the key chord fails to match any of the stored indexes.

17. The invention of claim 16 wherein the notifying means sounds a tone in the event the key chord fails to match any of the stored indexes.

18. A keyboard entry system comprising:

a keyboard comprising a plurality of keys, each of which is movable between a released state and a depressed state;

means for generating keying signals in response to depression and release of the keys, selected ones of said keying signals comprising key depression timing signals, each indicative of a respective time of key depression, and selected other ones of said keying signals comprising key release timing signals, each indicative of a respective time of key release;

means for storing a parameter indicative of a selected time interval;

means for comparing the elapsed time between a selected one of the key release timing signals and an immediately preceding key depression timing signal with the selected time interval;

first means for classifying the keying signals corresponding to the keys in the depressed state at a time immediately prior to generation of the selected one of the key release timing signals as a key chord when the comparing means indicates that the elapsed time is greater than the selected time interval;

second means for classifying the keying signals corresponding to the keys in the depressed state immediately prior to generation of the selected one of the key release timing signals as indicative of individual character signals when the comparing means indicates that the elapsed time is less than the selected time interval;

means for storing a plurality of texts, each associated with a respective index;

means for comparing the key chord with the indexes and, in the event the key chord matches one of the indexes, for supplying a respective one of the stored texts as an output signal;

means for supplying the individual character signals as the output signal.

19. The invention of claim 18 wherein the storing means maintains the parameter in an unchanged state while the first and second means classify a plurality of key chords and individual character signals, respectively.

20. The invention of claim 18 wherein the selected time interval is in the range of about 70-85 milliseconds.

21. A keyboard entry system comprising:

a keyboard comprising a plurality of keys each corresponding to a respective character;

first means for generating keying signals in response to activation of the keys, each keying signal characterized by a respective activation time;

second means for generating output signals in response to the keying signals, said second means comprising;

means for classifying a plurality of keying signals as a key chord in the event the respective activation times satisfy predetermined criteria indicative of near simultaneous key activation;

means for storing a list of stored texts, each associated with a respective index;

means for comparing the key chord with the indexes and, in the event the key chord corresponds to one of the indexes, for selecting the one of the stored texts associated with the index which corresponds to the key chord;

means for setting the output signal to correspond to the selected one of the stored texts; and

means for setting the output signal to correspond to the characters corresponding to the activated keys in the event the respective activation times fail to satisfy said criteria; and

biofeedback means for alerting an operator when the key chord fails to correspond to any of the indexes.

22. The invention of claim 21 wherein the biofeedback means comprises means for sounding a tone when the key chord fails to correspond to any of the indexes.