DATA INPUT DEVICES

• US 3,836,909 A
• Filed: 01/08/1973
• Issued: 09/17/1974
• Est. Priority Date: 04/06/1972
• Status: Expired due to Term

• Current Assignee: David Cockerell
• Original Assignee: David Cockerell
• Inventors: Cockerell, David
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Curtis, Marshall M.
• Application Number:
  US05/321,799
• Time in Patent Office: 617 Days
• Field of Search: 340/365C 84/1.01,1.27,DIG.7,23,1.04,1.03,445,446,DIG.4
• US Class Current: 341/26
• CPC Class Codes: G10H 1/20 for transposition
• CPC Class Codes: Y10S 84/07 Electric key switch structure

Abstract

A keyboard is disclosed having static, conductive, pads and means for sensing the change in charge on said pads produced by finger proximity, these means being respective gating circuits each having a plural emitter transistor, one emitter in each case being connected to an associated pad and the other emitters being supplied with gating signals which will cause the associated pad to be charged by way of the one emitter. Such a keyboard is disclosed for musical use having additional such pads for creating signals defining transposition intervals by means of pulse width modulation, and means responsive to impact on the keyboard.

Claims

1. A data input device comprising:

a data input member which is a conductive member having capacitance with its environment and positioned so that the finger of an operator may be placed in proximity with the member to change its capacitance;

a gating circuit having an output, a plurality of inputs to a first of which said member is connected, and means, including a transistor having a plurality of emitters coupled to respective ones of said inputs, for producing a predetermined output signal condition at said output when voltages of predetermined values exist at said inputs;

gating signal means operable to supply the associated predetermined voltage to the remaining at least one other of said inputs to define the beginning of a gating interval, which voltage has a polarity to cause a current to flow via the first input to change the voltage at the input member towards the predetermined value for the first input;

sensing means connected to receive the output signal of the gating circuit and having an enabling input to receive a signal to render the sensing means responsive to the output signal condition; and

means operable to provide said enabling signal for said enabling input at such a time in relation to the beginning of the gating interval that the sensing means is responsive to signal the presence and absence of said proximity.

2. A device as claimed in claim 1, wherein said transistor is an NPN transistor whereby said current will flow to increase the charge on said capacitance.

3. A device as claimed in claim 1, wherein said gating circuit is a NAND circuit.

4. A device as claimed in claim 2, wherein the sensing means is a bistable circuit responsive to the output signal condition of said gating circuit being absent at a predetermined time in relation to the beginning of said interval to indicate that said capacitance has at least a certain value, corresponding to finger proximity, greater than the intrinsic capacitance of said member, and the means to provide the enabling signal comprising a pulse generating circuit operable to produce a pulse and a first circuit path to said enabling input, the gating signal means comprising a second circuit path from said pulse generating means to the gating circuit and the two circuit paths having different signal transit times to produce the difference between the predetermined time and the beginning of the gating interval.

5. A device as claimed in claim 1, wherein there are a plurality of said conductive members and associated gating circuits, and said gating signal supply means are operable to address said gating circuits sequentially by providing them with voltage defining successive gating intervals.

6. A device as claimed in claim 5, and comprising digital register means having data input means connected for receiving gating signals from said supply means which signals define respective ones of said members, and also having write input means connected to receive a signal signifying the response of the sensing means to cause the thEn existing gating signals, identifying the member concerned, to be entered into the register means.

7. A device as claimed in claim 6, and comprising a digital-to-analog converter for producing from the data in said register means a corresponding signal level.

8. A device as claimed in claim 6, and suitable for operating an electronic sound producing apparatus, said register means including a register stage with a data input coupled to the sensing means to register a signal representing finger proximity with any of said conductive members, thereby to provide data to control the attack of a sound produced by such apparatus.

9. A device as claimed in claim 5 and suitable for operating an electronic sound producing apparatus, the device including a transposing arrangement operable to provide signal levels corresponding to required transposition intervals, the transposing arrangement having data input members additional to said conductive members to define transposition by respective intervals and pulse width modulation means connected to receive modulating signals derived from said data input members to produce a signal of duration dependent on which of the additional input members supplies a signal.

10. A device according to claim 9, wherein the pulse width modulation means has a plurality of inputs and means for producing a pulse of unit duration from a signal at any one of said inputs, and the data input members being coupled to supply some of said inputs with said signals whilst others of said inputs are connected to the output of the means for producing a pulse, the pulse width modulation means having means for sequentially scanning said inputs and each of said some inputs being followed in the scanning sequence by a number of the other inputs dependent in each case upon the transposition interval required by the associated input members.

11. A device according to claim 10, wherein said data input members are further of said conductive members with associated gating circuits connected to be gated by said gating signal means.

12. A data input device for operating an electronic sound producing apparatus responsive to electrical signals which define sound pitch, the device having means for selectively setting up said signals to define sound pitch and the device having in addition to said means a transposing arrangement to provide an additional signal of a duration defining a desired transposition interval, the transposing arrangement comprising a plurality of input means actuable to provide respective signals to define transposition by respective intervals, and pulse width modulation means responsive to said signals from said input means to produce a signal of duration dependent on which of said input means supplies a signal.

13. A device as claimed in claim 12, wherein the pulse width modulation means is a circuit having a plurality of inputs, means to produce a pulse of unit duration from a signal at any one of said inputs and the input means being coupled to supply some of said inputs with said signals whilst others of said inputs are connected to the output of the means to produce a pulse, the pulse modulation means also having means for sequentially scanning said inputs and each of said some inputs being followed in the scanning sequence by a number of the other inputs dependent in each case upon the transposition interval required by the associated input means.

14. A device as claimed in claim 12 and comprising integrating means for producing a signal representing the sum of the durations produced as a result of more than one of said input means of the transposing arrangement supplying a signal to said pulse width modulation means.

15. A device as claimed in claim 5 and suitable for operating an electronic sound producing apparatus, said device having means responsive to the impact of a finger on any of said conductive members to produce a signal the amplitude of which depends upon the level of said impact.

16. A device as clAimed in claim 15 wherein said means responsive to impact comprises a microphone and a circuit connected to receive a signal from the microphone and operable to produce therefrom a transient signal of maximum amplitude directly dependent upon the level of said signal from the microphone.