GB2025105A

GB2025105A - Data input system for calculator

Info

Publication number: GB2025105A
Application number: GB7912971A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-04-14
Filing date: 1979-04-12
Publication date: 1980-01-16
Also published as: GB2025105B

Abstract

A calculating machine has a recording medium on which a record of data being supplied to the machine is made by hand by the operator. A pressure sensitive device recognises data recorded on the recording medium or the data may be sensed by a device responsive to changes of resistance or impedance or capacitance. The device recognises numerals, arithmetical operation symbols and equals signs and supplies appropriate signals to the machine.

Description

SPECIFICATION Improvements in or relating to calculating machines This invention relates to improvements in the field of calculating machines, with particular reference to those machines which provide a permanent record of calculations performed.

In prior art, calculating machines have always been operated by means of a keyboard through which all data and instructions had to be entered.

It is the purpose of the present invention to dispense with the keyboard whilst providing a new and novel method of producing a permanent record of calculations performed.

As previously stated the basis of the invention is the elimination of the keyboard and the provision of novel means for entering data and commands into the machine. This is achieved by replacing said keyboard by a sensitive device which can generate the signals required by the calculating machine directly from handwriting on a suitable recording medium.

The recording medium can take a variety of forms, its principal requirements being that it be a substance suitable for writing upon by means of pencil, pen or similar instrument.

For purposes of description only, one way in which the invention can be embodied is described in conjunction with Figs. 1 and 2.

By reference to these figures, it will be seen that the calculating machine is composed of a number of items of which the major ones are: a power source A, by preference a battery, a supply of paper B, preferably in the form of a roll, an electronics sub-assembly C, with appropriate circuitry and a sensitized tablet D on which the recording medium i.e. the paper is placed. Also a form of display E, such as liquid crystal or suitable alternative is provided.

The method of operations is as follows. The sensitized tablet D consists of a pair of membranes which form for example a pressure sensitive device. One of these membranes could be omitted if the underneath of the recording medium is suitably coated.

In this particular means of interpreting the invention, the membranes are coated with a layer of conductive carbon on one side only and the carbon layers face one another without being in actual contact.

Pressure from the writing instrument will establish temporary local contact between the carbon faces. A voltage is applied alternatly to these faces, along the x-axis of one and the yaxis of the other.

The carbon layers act as potentiometers, when one is energized the other acts as a pick-up slider assuming a potential which is a function of the position at which the writing instrument finds itself.

Continuous reversal of the roles of the membranes causes the one to give out signals relating to the displacement along the x-axis and the other to give similar information relating to the y-axis. Thus as the writing instrument moves about the tablet, x and y positional signals are generated at a suitable switching rate.

These signals are processed electronically by circuitry similar to a conventional microcomputer which uses the techniques layed down by an algorithm of the type described by R.M. Brown. On line computer recognition of hand printed characters, I.E.E.E. Trans Electronic Computers (Dec. 1964), to convert said x and y positional signals into a suitable binary code or other sequence of impulses.

Other character recognition devices may be used for example a device as described in Patent Specification No. 863431 employing 'chip' circuits rather than relays may be used.

The data so produced is now the equivalent of that which would have been supplied by a keyboard and therefore can be used to drive an LSI calculator chip of the kind now marketed by several integrated circuit manufacturers.

The way in which this new type of calculating machine can be used can now be described with further reference to Fig. 2. Supposing that at some point in a calculation it is desired to multiply 12 by 12. As the digits one and two are written down, they are interpreted by the algorithm to the calculator, one by one. The writing of (X) on the tablet indicates the end of the first factor and simultaneously sets the calculator into the multiply mode. When the second factor is written down it is similarly interpreted and transmitted. The writing down of ( = ) indicates the end of data and causes the specified calculation to be performed. The result appears in the display as 144 and is copied down on the paper thus creating a complete record of the calculation.As this answer is written down it is also transmitted to the calculator in order that a zerocheck or something similar be performed to ensure that the answer has been crrectly copied down. The paper may be fed manually or by mechanical means.

It will be appreciated that many symbols could be used besides the obvious ones of (=), (X ),(x), ( and (-). to indicate all manner of operations and that underlining could be used in conjunction with ( = ) to permit the writing down of algebraic expressions and so on.

It will be seen that this invention provides a method new in calculating machine art of producing a permanent record which is in the handwriting of the operator and gives a more logical presentation of the calculations performed than has been possible hitherto.

The invention also makes it practicable to record all manner of calculation in the correct algebraic form, something impossible on present day print calculators.

The invention also envisages the use of changes of resistance or impedance or capacitance in response to a writing action instead of changes of pressure.

Claims

1. A calculating machine producing a permanent record of calculations performed which is operated by the recognition of handwriting.

2. A calculating machine producing a permanent record of calculations performed which is operated by the recognition of handwriting on a suitable recording medium placed upon a device sensitive to changes of pressure or resistance or impedance or capacitance.

3. A calculating machine producing a permanent record of calculations performed which is operated by the recognition of handwriting on a suitable recording medium placed upon a sensitive device in which the recording medium forms part of the sensitive device.

4. A calculating machine producing a permanent record of calculations performed which is operated by the recognition of handwriting on a suitable recording medium placed upon a sensitive device in which the information derived from said sensitive device relates to the position of the writing instrument on the recording medium.

5. A calculating machine producing a permanent record of calculations performed which is operated by the recognition of handwriting on a suitable recording medium placed upon a sensitive device in which the information derived from said sensitive device relates to the position of the writing instrument on the recording medium, the information thus obtained being in the form of x and y positional co-ordinates of the writing instrument.

6. A calculating machine as described in one or more of the claims above in which the x and y co-ordinates derived from the sensitive device are generated serially at a predetermined rate as writing progresses on the recording medium.

7. A calculating machine as described in one or more of the claims above in which the x and y co-ordinates derived from the sensitive device are in the form of electrical signals suitable for being processed by means of an algorithm which forms part of the electronic complement of said calculating machine.

8. A calculating machine as described in one or more of the claims above in which the algorithm used for the recognition of the handwriting is suitable for the interpretation of alpha-numeric characters as well as symbols.

9. A calculating machine as described in one or more of the claims above in which alphabetic characters and or symbols can be used to set the machine into different modes of operation.

10. A calculating machine as described in one or more of the claims above in which the machine is so organized as to differentiate between numbers and coded instructions.

11. A calculating machine as described in one or more of the claims above in which answers are displayed to the operator for the purpose of being written down to create a complete record of calculations performed.

12. A calculating machine as described in one or more of the claims above in which the writing down of a result is then checked for no error in the transcription.

13. A calculating machine as described in one or more of the claims above which is so organized as to accept problems written into it in a wide range of mathematical notations.

14. A calculating machine as described in one or more of the claims above in which paper from the roll is advanced manually or otherwise across the sensitized tablet.

1 5. A calculating machine sustantially as described above in which the calculating capability is arranged to cover the generation of mathematical functions.

16. A calculating machine as described in one or more of the claims above which incorporates programming facilities.

17. A calculating machine as described in one or more of the claims above in which the lifting of the writing instrument out of contact with the paper is interpreted as an end of character message.

18. A calculating machine as described in one or more of the claims above in which the lifting of the writing instrument out of contact with the paper for a time greater than a predetermined amount is interpreted as an end of character message.

19. A calculating machine as described in one or more of the claims above in which advancing the paper after one or more characters have been written down automatically resets the machine to accept further information.

20. A calculating machine as described in one or more of the claims above in which copying down a result from the display after a calculation is interpreted as an end of calculation message.

21. A calculating machine as described in one or more of the claims above in which the writing down of a predetermined character indicates the end of a calculation.

22. A calculating machine substantially as described in this application in which control keys are provided for various control purposes.