DE2154596B2 - DATA ENTRY DEVICE WITH A KEYBOARD - Google Patents

Description

The invention relates to a data input device with a keyboard, in particular for calculating machines, their buttons at least when the switching state of buttons is changed by an interrogation arrangement sequentially interrogated, whereby when interrogating a pressed key at an output of the keyboard the code data of the pressed key appear after the bouncing process has subsided and this output is connected to the input of a memory arrangement with first memory elements that contain the on Store the code data of a pressed key appearing at the output of the keyboard and its outputs are connected to an output terminal via an output arrangement with an enable input.

Usually keys are pressed one after the other, whereby a following key may only be pressed when the previous key is no longer pressed. However, if the following key is pressed too early, functional errors can occur. To prevent this, a release signal can be derived from releasing the first key. So that the second button is checked only after the release or are the code data of later gedrüc ¹ th key provided can be achieved. However, if the second button is released first, this safety system becomes ineffective.

From DT-OS 15 24 201 is a keypad arrangement known, for which the following key can already be pressed before the previous key has been released. This known arrangement uses a capacitor for each key, the is discharged by pressing the key. The discharge pulse is decoded via a diode matrix and stored in a storage register. In addition, the arrival of a code is triggered by a blocking circuit decoded to temporarily block the next incoming code. The timing of the However, the content of the memory register is passed on directly by the actuation of the key.

This known arrangement is more suitable for use with only very slow external systems, and it should be used between successive Key presses of the same or a different key are at least 20 ms long. Meet in the process the code data into the connected system at random times, which is the case with faster Systems is not permitted because they often work in time interleaving and only a fraction the time can be used for the keyboard, so that a passive keyboard is necessary. Furthermore, in the known arrangement, a coincident actuation of two keys can result in a normal, however, resulted in completely wrong code.

It is therefore the object of the invention to provide a keyboard

fl

πύ to specify the query arrangement, with a following Key may already be pressed, regardless of whether any previously printed key has already been pressed was released. The invention solves this problem by the features specified in the main claim. This makes it possible to save all code data of previously pressed and not yet released keys in static To store storage elements, e.g. flip-flops. As a result, the energy requirement is relatively small, and the circuit can be fabricated as an integrated device. Through the pulse-controlled query and processing of the key code data a synchronous input of the keys is possible, what a fast working central computer The preprocessing, i.e. the comparison of the data, can take place outside the central computer, and the invention can therefore also be used for an intelligent peripheral device, for the capacity of the central computer is only used slightly. Furthermore, there is little additional Memory capacity required for just a few keys.

The invention is also advantageous door very large numbers of keys, because it is possible a matrix-like structure, reducing the number of terminals smaller and the decoding can be easier because each first example query a single row and a single column of buttons together can be. The signaling can take place in the keyboard through a single contact per key, after which the code can be recorded as a binary code in the memory.

Embodiments of the invention are explained below with reference to the drawing.

1 shows a keyboard with an interrogation device for storing the code data of three keys, 3s

2 shows a device with a matrix-type query of the keys,

3 shows a keyboard with an interrogation device without the use of a sleep key.

F i g. 1 shows a keyboard with seven keys Al ... Al, a rest key Λ 8 , an interrogation arrangement B, a pulse generator C, a detector D, a decoder E, four memories Fl ... F4, each consisting of three bistable elements, an output arrangement G, an output terminal H, a logic unit /, nine comparison arrangements 71, Jl, 73, Kh Kl, K3, Ql, Ql and Q3, four control units L. / V, O and P and a pulse distributor M.

The pulse generator C emits clock pulses, as a result of which the interrogation arrangement B interrogates the keys in succession. If a key is pressed, for example A1, the detector D detects this. If a key is now pressed again within a certain period of time, the detector D detects this again and emits an error signal. As a result, for example, the pulse generator C is stopped and an error signal is visible on a display arrangement (not shown). The above-mentioned period of time is determined by the fact that it takes a certain time to process the code data of a newly interrogated pulse, but mainly through mechanical tolerances and bouncing, whereby a key contact is interrupted a few more times before it is permanently closed. This time can be a total of 10 ms, for example. If the pulse generator C continuously emits pulses, the key A1 is queried at some point in the query sequence. The polling arrangement sends a signal to the pulse distributor M, and the address of the key A2 appears at the input of the decoder E, for example via eight parallel lines (not shown). The pulse distributor M, which can also be part of C, for example, emits 5 pulses. The first pulse is fed to the decoder E , which decodes the address of the key Al and feeds the code data to the memory Fl. The second pulse of the pulse distributor M is fed to the comparison arrangements 71, 72, 73, Kh Kl, K3, Ql, Q2 and Q3, which each contain the information of a bistable element of the memory F1, the information of the corresponding bistable element of one of the memories F2 .. .F4 and the second pulse of the pulse distributor M received. Each of the comparison arrangements Jl ... Q3 emits a signal when the mentioned pulse of Λ / arrives and if the information of the elements to be compared also matches. The outputs of three comparison arrangements, for example 71, 72 and 73, are fed to an AND element , which forms part of the logic unit /, while the outputs of the (in this case three) AND elements are fed to the inputs of an associated NOR element.

Only if the code data stored in Fl differ from all other stored code data does the last-mentioned NOR element deliver a pulse to the output arrangement G, which causes the latter to feed the information stored in Fl to the output terminal // for some time. This is possible, for example, in that the mentioned pulse sets a monostable multivibrator to the "1" position, the output of which, together with the output of the memory unit F1, is connected to the inputs of an AND element. The third, fourth and fifth pulse of the pulse distributor M are fed to the control units L, V, O and P , whereby the information in the memories Fl. . . F4 is moved one element at a time. A code of 3 bits therefore needs 3 pulses to move a memory unit on, i.e. from F1 to F2, etc. If it was also a new key, the code data also appear via the output arrangement G at the output terminal //.

If no second key was pressed, the idle key is queried at the end of the query sequence of query arrangement B , and the code data are stored in F2, while those of key / 12 are shifted to F3. If key A 3 is also pressed in the following query sequence, the content of the memory elements after querying is:

Depressed Last Saved Code Data

Keys down

asked
Button Fi Fl A3 FA

Al A3 Al AZ Al , 4 8 Al A3 Al Al , 48 Al Al A3 A3 A3 Al / 18th Al A3 AS A8 A3 Al

Assume that A3 is released afterwards

Al Al - .48 A3 Al

Al Al - Al , 48 A3

Al A3 - Al Λ8 A3

Al AS - / 48 al , 48

Now a new key can be pressed again. If, on the other hand, Al is also released, only the rest key is stored in the next cycle, so that all memories ultimately contain only the code data of the rest key.

The system described can be modified in various ways. First and foremost, the number of storable keys can be supplemented by assigning several memories / ^ ... etc. In order to be able to keep two keys pressed at the same time, four memories F1 to FA must be available in accordance with the system described, because the rest key is always saved as well. Furthermore, the pulse distributor M emits five pulses, preferably between two pulses from the pulse generator C. However, it is also possible to have the pulse generator C emit a lower frequency when the pulse distributor M is in operation. The required control line is not shown in FIG The time for a query sequence is shorter because the querying of ^{unpressed keys can take place at a very high frequency, for example 1} AMHz. Nevertheless, there is enough time for the other functions of the comparison arrangement, etc., because the pulse frequency of C is lower it is possible that B, E and Fl together form a switching element.

Another embodiment is shown in FIG. These are those corresponding to FIG. 1 Elements have been given the same reference numbers.

Fig. 2 shows a keyboard with fourteen keys Al, Al. . . A 14 and two rest buttons Λ15 and / 116, which are arranged according to a matrix, two query arrangements Bl urd Bl, two pulse generators C and Cl. two detectorsDl and Dl, a decoder / f, a logic unit / 1, three storage units Ul, Ul and i / 3, each consisting of four bistable flip-flops and one additional bistable flip-flop t / 15, i / 25 or i / 35 exist, an output arrangementSl. two comparison arrangements 7Ί and Tl, three control units V, W and X, a pulse distributor Y, a number of output terminals Hl and a bistable multivibrator Z.

If a key is pressed, the detector Dl sends a pulse to the pulse generator C. The detection can for example take place with the help of an additional closing contact in the key or by a coil drawing current under the influence of the key being pressed. The pulse generator C then gives (16-n) Pulses and a reverse pulse, where η is the number of keys pressed.This can be done, for example, so that C contains two counters, namely a first counter that counts from 16 to zero and therefore normally emits 16 pulses per counting series, and a second Counter whose counting input is connected to Dl and whose counting down input is connected to Dl . This second counter is a static counter. If the counter settings are the same, a reset pulse is generated with a short delay, and the output for the set pulses of the first counter is also blocked. The detector Dl determines in a manner similar to Dl that a key is released wnxL The output pulses of the pulse generator C are fed to the interrogation arrangement S1, which thereby always interrogates a number of keys in cyclic order. At the beginning, the interrogation arrangement ß 2 asks the first column of keys until it receives an interrogation pulse after the fourth pulse of the pulse generator C via the pulse generator Cl, after which it asks the second column of keys . The key at the intersection of the queried row and the queried column is therefore queried. Thus, UTaslen and an idle tab are queried one after the other. The interrogation is then terminated by the reset pulse, whereby the interrogation arrangements Bi and Bl are also reset to the initial position. When a printed key is queried, the address of this key is decoded under the control of a first pulse of a pulse distributor Y in the Dckodcrf and supplied to the first memory unit Ui. Then Y gives five impulses to the control cinhciten KW and X, whereby the information of the storage units about the additional flip-flops i / 15, i / 25 and i / 35 circulates once. For this purpose, the storage units are designed as a shift register. The information in flip-flop i / 15 is always compared serially with that in flip-flops i / 25 and i / 35 by means of the comparison arrangements Π and 72, respectively. This can be done, for example, so that each match in the comparison arrangements 7Ί and Tl results in a pulse at an input of the logic unit / 1, which contains two binary four counters, while the carry ("carry"), thus reaching the rest position through this counter is passed on as a pulse to the inputs of a NOR element. In this way, the output arrangement Si can be opened, whereas the code data of Ul appear by a seventh pulse of the pulse distributor Y at the output terminals Hl. An existing already in the memory key is not supplied Hl.

Assume that a key was pressed. The rest key Λ15 is queried at any point in time. You will never get the output terminals //! fed. This is possible, for example, in that the fifteenth and sixteenth pulses of the pulse generator C of the logic unit / 1 via a not shown Connection is supplied and in this way blocks the output unit 51.

If a key is now pressed, the above is repeated with the difference that the pulse generator C now only emits 14 interrogation pulses and one reset pulse, so that no rest key is interrogated. After this query sequence, the memory contains the code data of the two keys pressed. In order to avoid that the code of a key can appear twice at the output, a bistable multivibrator Z is provided, which is set by the pulse of the detector Dl in the first position in which its output emits a logic "0" by the output pulse of the logic unit / 1, however, it is set to the second position, whereby its output emits a logic "1". If this output is connected to an input of the above-mentioned NOR element in / 1, this element can only read the code data of one key per query sequence release. (If necessary, a small delay can be provided.)

If a third key is then pressed, the static counter present in the pulse generator C can, for example, emit a false signal. If, on the other hand, a key is released so that only one is pressed, this is detected by the detector Dl , whereby the static counter hn pulse generator C öm pays back one unit and a query sequence of fifteen pulses and a reset pulse is emitted. When the last key is released, Dl stiffens this again and the static counter counts

back one unit again. The last query sequence of the pulse generator C then contains 16 pulses and a reset pulse. The following example gives the process again:

Indented
button

Last button queried

Saved
Keys

A3 A3 Al Al A3 A3 A3 A3

A3 A3

A5 AS

/ 416

A3

.415

Al

A3

A3

/ 115

A3

AS

Λ 15

A3 * / 415

AV

AT

A3

/ 415

A3 AS *

AXf, / 115

A3

/ 415

Al

A3

A3

As

A3

A “new key” is indicated with an asterisk and a “pseudo-ncuc key” with a circle. The last-mentioned one is not fed to the output terminals because a key was already fed to the query sequence Hl.

If a button is pressed while the pulse generator C is still busy emitting the mentioned (16-w) impulses, this results in a false signal, whereby the query sequence is stopped and an error signal a jf to a display element, not shown appears.

An example of a keyboard without an idle key is then shown in FIG. 3. Here all keys can fulfill the function of the idle key. The keyboard includes eight buttons Al ... / 48, a ImpulsverteilerMl, two Zählcr / L / U and AAI, a VergleicherQ4. an AND gate E / V, two DctektorenDl and Dl. two logic units / 2 and / 3 and a pulse generator Cl- Otherwise, the same. Keyboard of the one shown in FIG.

The keyboard is queried when the detector Dl detects the pressing of a key or when the detector Dl detects the release of a key. In the first case Cl outputs interrogation pulses, and the counter AA 1 is supplied to a counting pulse and that thereby in the position, "pressed" A key brought This initial position together with the output pulse from Dl to AND gate ßVzugeführt, whereby the logical unit Il a pulse is applied. The purpose of this is that a pulse from a pressed key that has been queried appears at output H even if the code data of this key are stored in the memory. The output arrangement G is opened by / 2. After that, Ml emits as many pulses as are necessary to bring the information from Fl to F4. These can be the pulses 3 up to and including U of Ml . In contrast to FIG. 1, the unit F1 is coupled in a circle so that after the 11th pulse all memory units contain the code data of the one pressed key. The number of pulses from Ml is linked to the position of the counter AAl , for example by generating the pulses from Ml after the first two pulses (which have a different function) by a ring counter whose carry pulse counts down the counter AAl by one unit, for example 4 to 0. When the positions of AA 1 and AAl become the same, the comparator QA emits a signal, whereby the pulse generator Ml is stopped and AAl goes into its starting position (for example 4) per query sequence at most the code data of a key appear at output H. The logic unit / 3 can therefore be in two states, whereby in the first state the code data of a "new" key, which is not stored, can appear at the output while this is not possible in the second position. The signal from Dl changes / 3 into the first and the

ίο Inequality signal from 11 set in the second position. The mentioned inequality signal opens the output arrangement G and is generated like the inequality signal of the unit / 1 in FIG. If the AND gate EN is excited, the non-occurrence of the inequality signal is negated, and since the signals from £ 7V and / 3 arrive together at / 2, the code data of the interrogated and (single) pressed key is always fed to the output terminal H. . The interaction between the signals from EN and / 3 can take place, for example, in that these two are fed with the mentioned inequality signal to the inputs of a majority circuit which outputs a signal when at least two of its three inputs are high. This majority detector is built into II and acts both statically and dynamically. When the one pressed key is released again, the detector Dl gives a countdown pulse to the counter AA 1 and a pulse to the pulse generator Cl. AAl is now in the position: »Zero keys pressed«. All keys are queried once, but because none is pressed, this can be omitted. Assuming that (for example AS) and a second (for example Al) is printed after the first key pressed. The counter AAl moves to the position: "two buttons pressed". As a result, the pulse distributor Λ / l emits eight pulses (2 + 2X3) when a key is queried and pressed, whereby the code data is shifted into the memory twice. The logic unit / 3 ensures that only the code data of a key appear on the output terminal in this query sequence.

When a third pulse from the detector D1 is fed to the counter AAI , this counter is in the position: "Three keys pressed", and this key is only stored once. The process is now as follows:

Depressed
so A5 Keys Exit now
asked
Keys Saved
Fi Fl AS Codes
Fi A5 AS / 45 AS * A3 .45 A3 AS A3 A3 * AS / 15 A3 A5 A5 AS AS A3 ⁵⁵ A3 A5 Al A3 A3 A3 / 45 A3 Al Al AS AS AS / 45 A3 Al Al Al Al * A3 / 43 60 A3 A3 A3 Al Al A3 Al Al A3

In addition to the three versions shown, others can also be used. So it is possible increase the number of keys or the number of keys that can be pressed simultaneously. Furthermore, a parallel or series connection can be used both when comparing the stored code data

609532/202

as well as with the supply to the output terminal or with the generation of the code data by the decoder use. It is also possible that the calculating machine is currently performing another function, whereby the function keys are mechanically locked, while information (e.g. numbers) is stored in an auxiliary register can be introduced.

It may also be necessary to arrange an additional detector that determines whether 2 buttons are simultaneously be released. The last-mentioned process can also be used in combination with a continuous one

10

Queries are applied. Furthermore, the keyboard door can be divided into two parts, which are operated by different * operators; there can also be several, possibly identical keyboards, which are connected to a calculating machine for optimal use. It is also possible that measures must be taken for the event that the calculating machine is still performing processing steps. This is possible because the main pulse generator Cbzw. Cl is blocked by a corresponding: signal.

For this purpose 3 sheets of drawings

Claims (7)

Patent claims: 1. Data input device with a keyboard, in particular for calculating machines, the keys of which are sequentially queried at least when the switching state of keys is changed by a query arrangement, whereby when a key is queried at an output of the keyboard, the code data of the key pressed appear after the bouncing process has subsided and this The output is connected to the input of a memory arrangement with first memory elements which store the code data of a pressed key appearing at the output of the keyboard and the outputs of which are connected via an output arrangement to a release input with an output terminal, characterized in that the memory arrangement (F1-F4 ) contains second memory elements [Fl-FA) , the capacity of which corresponds to the code data of a key (A 1- / 47) and whose input is connected to the output of the first memory elements (Fl), that the output of the first memory elements (Fl) as well the output or outputs e of the second memory elements (F2-F4) with inputs of a comparison arrangement (Jl, Jl, 73. K \, Kl, A3, Ql, Ql, Ql) are connected, which once per query sequence before querying the next key on the one hand if the content does not match of the first memory element with any of the second memory elements during the simultaneous actuation of the keys and on the other hand when only a single key is actuated emits a release signal to the release input, whereby the content of the first memory elements (Fl) appears at the output terminal (H) , and that after each Query of a pressed key (Al-Al) before querying the next key, the contents of the first memory elements (F1) are transferred to the second memory elements (F1-FA) when their oldest contents are deleted. 2. Data input device according to claim 1, characterized in that a pulse generator (O the keys (A l-Al) automatically asks repeatedly. 3. Data input device according to claim 1 or 2, characterized in that the query is not pressed keys is faster than the query of pressed keys. 4. Data input device according to claim 1 or one of the following, characterized in that the second memory elements (I ⁷ I-FA) are connected in series and that when code data appear of a pressed key (A 1- / 47) at the output of the keyboard ( B, E) a transfer of the content of each memory element (Fl, Fl ...) takes place in the respective following memory element. 5. Data input device according to claim 1 or one of the following, characterized in that the pressing of each key (Al-Al ) triggers a Zcitgeberschaltung (D) and that pressing a key during the duration of the timer circuit generates an error signal. 6. Data input device according to claim 1 or one of the following, characterized in that that an error signal is generated if the number of simultaneously actuated keys is greater than the storage capacity of the second memory elements. 7 data input device aach claim 1 or one of the following, characterized in that a fixed code generator is provided as a rest key (A 8), which corresponds to a continuously pressed key and when queried an enable signal and an error signal is suppressed, and that the capacity of the second memory elements (Fl-FA ) corresponds to the code data of at least two keys (Al-Al)