SU1456945A1 - Information input device - Google Patents

Abstract

The invention relates to automation and computing and can be used to organize manual entry of information into control or computing systems. The purpose of the invention is to increase the reliability of the device. The device contains a touch keyboard I, switches 6 and 7, elements 8 and 11, trigger 9, pulse generator 10, counter 12 and delay element 13. With

Description

one

The invention relates to automation and computing and can be used to organize manual entry of information into control and computing systems.

The aim of the invention is to increase the reliability of the device.

Figure 1 shows the functional diagram of the device; on r; 2 - time diagrams that explain his work

The device contains a touch keyboard 5, the outputs of the first 2 and second 3 groups of the touchpad keyboard, touch electrodes 4, input 5 of the touch keyboard, first 6 and second 7 switches, first element 8, trigger 9, pulse generator 10, second element 11, counter 12, delay element 13 and the outputs of the high 4 and low 15 bits of the counter.

Figure 1 also indicates the recipient 16 of information (for example, a computer).

The device works in the following way.

After switching on the power supply voltage of the computer 16, a setup pulse is reset to the R input of the trigger 9, under the influence of which a logical one is set at the inverse output of the trigger 9, the prohibition signal is removed from the second input of the And 11 element, which allows clock pulses from the generator output 10 pulses to the input of the counter 12, to the input 5 of the keyboard 1 and to the input of the element 13 delay.

A positive clock pulse changes the state of the counter 12, accordingly

the output changes the code of the first and second groups, corresponding to the older 14 and lower 15 bits of the binary counter, while the code values cyclically change from the lowest possible to the maximum possible value.

Thus, in accordance with the output code of the counter 12, the switches 6 and 7 sequentially connect the signals from the vertical and horizontal buses of the keyboard 1 to their outputs. If the operator does not touch the touch electrodes 4, the negative pulse difference at the output of the And 8 element (Fig. 2b) it appears with a delay equal to the sum of the minimum signal delay of one of the switches 6 or 7 (t) and the additional constant delay (t.) of the signal due to the charge time of a constant capacitance of the corresponding sensor electrodes 4 and inputs 2 and 3 1 relative to the total air tours point device circuitry. For simplicity, the time delay of the signal in AND 8 and the change in its duration are not shown in Figure 2b. The delay time (t) of the signal of the delay element 13 is greater than the maximum delay time of the signal at the output of the element 8 and 8 with respect to the input 5 of the keyboard 1 (Fig. 26) At the inverse output of the trigger 9 (Fig. 2d) a high potential is constantly present. sensor electrodes 4 by connecting to the information inputs of switches 6 and 7 additional capacity of the operator’s body relative to the common point of the device circuit is negative

the difference of the output signal of the switches 6 and 7, and hence the negative difference of the signal at the output of the AND 8 element (Fig. 2b) relative to the negative difference of the signal at input 5 of the keyboard 1 appears with an additional delay (t), as a result of which the inverse At the exit of the trigger 9, a low level potential appears (FIG. 2d), which locks the AND element, stops the clock pulses to enter the counter 12 and signals the computer 16 to read the output code of the counter 12. After reading the code of the computer symbol 16, it issues an imp the pulse of installation on the K-input of the trigger 9 (fig. 2d), under the influence of which the device is set to the initial state and ready to enter into the computer 16 the next character code.

As follows from the diagrams (figs. 2a, b, c, d) to eliminate the formation of spurious control signals at the inverse output of the flip-flop 9, the delay time of the element 13 should exceed the sum

1.0 -j -c SfMovc j

where t is the minimum additional constant signal-delay. la, determined by the minimum number of sensor electrodes 4 connected to the horizontal or vertical transducer buses;

- the maximum amount of signal delay by the switch when it goes from 1 to O (from closed to open state). The 1K-trigger of the proposed device - CTBai performs the functions of a phase comparator. Such a device design .0

569454

technology allows to avoid the use of special detection schemes

signals from touch sensors that

increases the reliability of the device for 5

scrap and simplifies its design.

Claims (1)

Invention Formula 10 A device for entering information containing two switches, a counter, two elements And, a pulse generator, a trigger and a touch keyboard, the outputs of the first group of which are connected 15 with the information inputs of the first switch, the output of which is connected to the first input of the first element I, the outputs of the touch keyboard of the second group are connected to the information inputs of the second switch, the outputs of the low bits of the counter are connected to the address inputs of the first switch, the outputs of the counter are information outputs of the device 5 VA, characterized in that, in order to increase the reliability of the device, it contains a delay element, the output of the pulse generator is connected to the first input of the second 30 element And, the output of which is connected to the input of the counter, the input of the touch keyboard and the input of the delay element, the output of which is connected to the trigger input of the trigger, the output of which 35 is connected to the second input of the second element I and is the gate output of the device, the outputs of the higher bits of the counter are connected to the address inputs of the second switch, the output 40 of which is connected to the second input of the first element I, the output of which is connected to the 1 input of a trigger, the R input of which is the device reset input, the K input of the trigger connected 45 with a tire of zero potential of the device. Phia.2