EP0000696B1 - Fingerkey arrangement for generating signals by means of keys arranged by pairs or quadratically and forming part of an and circuit - Google Patents

Description

The invention relates to a key arrangement for triggering certain symbols of the key surface respectively assigned switching functions or switching signals.

Key arrangements in the form of keypads or rows of keys are generally known, in which, for example, a switch contact is assigned to each individual key, which is closed to implement a switching function when the relevant key is pressed, or which emits a switching signal to a user group as soon as the associated key is depressed.

Known key arrangements of this type can only be reduced within certain limits, since the individual keys must always be of such a size that the fingertip of an operator's hand can be safely placed on the relevant key without a neighboring key being depressed and a malfunction being triggered.

In order to avoid incorrect operation with comparatively small dimensions of the individual keys, it is known that either, for example in the case of miniaturized computers, an actuating pin was used to depress the individual keys or, for example in typewriters or the like, the individual keys were designed as island keys, in which those with the Actuating finger touching button surface was mushroom-like raised, so that a neighboring key was practically only pressed simultaneously with or instead of the desired key if the actuating finger was placed very eccentrically to the center of the desired key.

In many cases, however, it is desirable to have a large key labeling area and to provide the actuating finger with a contact surface which is at least the same as the projection of the fingertip for a convenient key actuation. This cannot be achieved with the known key arrangements, since the miniaturized key arrangements, which can only be depressed with an actuating pin, can no longer be clearly labeled and require a separate component to be actuated, while the so-called island keys, which likewise only have an extremely limited labeling area, give the operator due to the visual appearance Confuse the impression and result in an undesirably low ease of use if the key top is sufficiently small for the intended purpose.

German patent specification 737 039 discloses a key arrangement for triggering switching functions or switching signals which are assigned to specific symbols of the key surface, with a plurality of keys which are each assigned a specific labeling field for a symbol and can be depressed together by a finger, the output actuating movement signals of which form the the switching function or the switching signal mentioned are subjected to an AND operation. The number of keys required to generate a certain number of switching functions or switching signals is reduced in the known arrangement by providing a total of four keys in roughly square groups in pairs on different levels, one of the four keys being designed in such a way that it is different from the one Fingers of an operating hand can not only be operated alone, but also optionally together with one or two of the buttons on the other level.

If one proceeds from key to key in a row of keys in this known key set, a pair of adjacent keys are assigned to one of the labeling fields in this row of keys, or several keys are assigned to a labeling field in an essentially square grouping in the key field. The output actuator signals from at least two of these grouped keys are ANDed.

Furthermore, from the publication “IBM, Technical Disclosure Bulletin”, Volume 18, No. 12, May 1976, it is known per se for a keypad to assign four square-grouped touch keys to each labeling field, of which the four output actuating signals of the AND and Linkage.

In contrast, the object of the invention is to achieve a mechanical key set for triggering switching functions or switching signals assigned to specific symbols of the key surface, with a plurality of keys, each assigned to a specific labeling field for a symbol and which can be depressed together by a finger, and whose output actuating movement signals to form the switching function or the switching signal mentioned are subjected to an AND operation, whereby, despite a restriction on the labeled key surface, the operating finger nevertheless offers a relatively large and in each case the same surface, which exerts a uniform and in each case the same counterpressure on the operating finger .

This object is achieved in that progressively from key to key in a row of keys each pair of adjacent keys or in a key field of each group of four square-grouped adjacent keys, of which the output positioning movement signals of at least two diagonally opposite keys of the AND link be subjected to a label field is assigned without individual Keys have independent functional meaning.

If the keys of the key arrangement are located in a key field, then the output positioning movement signals are preferably used only from every second key of each key row and each key column to derive the switching function or the switching signal.

The output actuation movement signals of a key group to be subjected to an AND linkage can be coupled to a mechanical AND switching element, the mechanical AND switching element in each case from a switching pin coupled to the respective output output signals to be linked in the direction of the rest position is formed, by means of which the switching function or the switching signal is generated and which is biased towards the actuating position with a force which is less than a respective force biasing the keys in the rest position, such that the biasing force of the switching pin only in this Actuating position is able to pull when all of the keys of the relevant key group are actuated.

It is also possible to supply the output actuation movement signals to be subjected to an AND link in each case to a mechanical-electrical AND switching element, which in each case emits an electrical signal as a switching function or switching signal.

According to a further development of such a key arrangement, a driver pin is provided, with which the keys of a key group delivering the respective output positioning movement signals are coupled in such a way that when the driver pin is also depressed, the keys of the relevant key group are fully depressed.

Since the keys of a key group each have a common label field, divided by the column between the keys, there is sufficient space available for attaching one symbol each, and at the same time there is a high level of security against incorrect operation.

• Fig. 1 eine schematische, teilweise perspektivische Abbildung einer Tastenanordnung in Gestalt eines Tastenfeldes,
• Fig. 2a bis 2d Aufsichten auf Tastenanordnungen der hier vorgeschlagenen Art und einer bisher bekannten Bauart zum Vergleich der Grössenverhältnisse,
• Fig. 3 eine schematische, teilweise perspektivische Ansicht einer anderen Ausführungsform einer Tastenanordnung und
• Fig. 4 eine schematische, perspektivische Ansicht einer nochmals anderen Ausführungsform einer Tastenanordnung der vorliegend angegebenen Art.

Some advantageous embodiments are explained in more detail below with reference to the attached drawing. They represent:

• 1 is a schematic, partially perspective illustration of a key arrangement in the form of a keypad,
• 2a to 2d top views of key arrangements of the type proposed here and a previously known type for comparing the size relationships,
• Fig. 3 is a schematic, partial perspective view of another embodiment of a button arrangement and
• Fig. 4 is a schematic, perspective view of yet another embodiment of a key arrangement of the type specified here.

1 shows a keypad 1, by means of which only four symbols are to be signaled by pressing keys or switching functions or switching signals assigned to the individual symbols are to be generated. In contrast to a known key arrangement, which is shown in plan view in FIG. 2a, which contains a total of four keys assigned to the individual symbols, the key field according to FIG. 1 has a total of nine keys, which have a total of four labeling fields b ₁ , b on their surface wear _z , b ₃ and b ₄ . Each of these labeling fields takes up part of the key surface of four keys in a square arrangement, which represent a key group. The labeling fields b ₁ to b ₄ are thus divided crosswise by the column located between the keys of a key group.

It can be seen, however, that in the embodiment according to FIG. 1, only the keys of the overall keypad located at the corners are assigned to only a single labeling field, while the other keys belong to two different or four different labeling fields.

From different of the individual keys, mechanical transmission means 2 or 3 or 4 or 5 lead to contact sets 6 or 7 or 8 or 9, the individual switching contacts of contact sets 6 to 9 being connected in such a way that the contact sets are connected via the mechanical transmission means 2 to 5 supplied output actuation movement signals of the keys of the keypad 1 are subjected to a certain AND operation.

If, therefore, those keys of the keypad 1 that belong to the labeling field b ₁ and are to signal the symbol “1” are depressed, the mechanical transmission means 2 and 4 effect those which are the first key of the second key line and the first key of the second Key columns include that the respective upper contacts of the contact sets 6 and 8 are closed and the respective associated signal line is turned on. If the four keys of the keypad 1, which belong to the labeling field b _2, are depressed, the mechanical transmission means 4 and 5, which are coupled to the first key of the second key column and the last key of the second key row, cause the lower contact of the Contact set 8 and the upper contact of the contact set 9, so that the signal line connected to it creates a lead connection.

If the keys belonging to the labeling field b ₃ are further depressed, the mechanical transmission means 2 and 3 cause the lower contact of the contact set 6 and the upper contact of the contact set to close due to the depression of the first key of the second row of keys and the last key of the second key column 7, so that the signal line 3 becomes continuous. Finally introduces Depressing the keys belonging to the labeling field b ₄ , closing the lower contact of the contact sets 7 and 9 and thus connecting the signal line 4. To clarify the illustration, those keys to which the mechanical transmission means 2 to 5 are connected are also included marked with a dot on the button surface.

If one compares the representations according to FIGS. 2a and 2b, it can be seen that the key surface of the keys that belong to the fingertip of an actuating hand, the keys belonging to an inscription field approximately the inscription field b ", with the surface of a single key of a known type due to the coding of the output The AND combination of the output positioning movement signals of the selected keys of a key group enables certain portions of the key surface, which is also assigned to a neighboring symbol, to be used simultaneously as an effective operating surface for a specific one With a small keypad for only four symbols, this means a reduction in the required surface area of the entire key arrangement in accordance with the factor 9 /. 16, whereby this value becomes considerably more favorable for increasing symbol numbers.

This can be seen from FIGS. 2c and 2d. Figure 2c shows a keypad with sixteen keys in a square arrangement of four rows and four columns. This conventional keypad has symbols 1 to 16 each associated with switching elements, so that a total of sixteen switching elements are required for the output of signals corresponding to the individual symbols.

In contrast, in the keypad shown in Figure 2d of the type proposed here, a total of only twelve switching elements are assigned very specific keys, in such a way that only every second key of each row of keys and every second key of each key column serves to actuate such a switching element, the output signal of which a decoder D having twelve inputs and sixteen outputs is input. The decoding device can be designed as an integrated circuit and can be produced in a simple manner. It should also be noted that, as in FIG. 1, those individual keys are marked with a dot in the illustration according to FIG. 2d, which serve to actuate a switching element whose output signal line leads to a specific input of the decoding device D. In the schematic illustration according to FIG. 2d, the part of the signal lines running under the keypad is indicated by a broken line. A comparison of FIGS. 2c and 2d shows on the one hand the reduction in the space requirement with the same operating safety and the possible saving of switching elements with the same number of symbols in each case, the additional effort caused by the decoding device not being important, particularly in the case of electronic designs of this part.

While the AND combination of the output positioning movement signals of the keys belonging to a labeling field is carried out by a mechanical AND switching element in the form of series-arranged switching contacts in the key arrangement according to FIG. 1, the AND combination is carried out in the key arrangement according to FIG. 3 a mechanical AND switching element in the form of a switching pin 10 in cooperation with the keys belonging to a labeling field, which are grouped in a square arrangement around the relevant switching pin. Each of the switching pins is provided with a head 11 which is received in a recess at the abutment of the keys of a group of keys. The switch pin has a shaft which extends through a bore provided along the butt joint of the keys of a key group. At the lower end of the pin 10, a tension spring 12 engages, which attempts to pull the switching pin 10 downward against the force of compression springs 13, which in turn bias the individual keys upward in the rest position. The tensile force exerted by the spring 12 is less than the compressive force of each of the compression springs 13, so that the switching pin 10 can only be pulled down into the actuating position when all of the keys belonging to a key group or to a labeling field are depressed. It goes without saying that the head 11 of the stylus 10 can also be accommodated within the keys in a recess or chamber provided therein, so that the labeling areas are each self-contained except for the column between the individual keys.

Pushbutton switches 15 are connected to the individual switching pins 10 via mechanical transmission means or actuating linkages, which switch switches 15 generate or implement the switching functions or switching signals identified by the symbols.

The embodiment according to FIG. 4 again corresponds essentially to that according to FIG. 1, the switch contacts which establish the connections in the course of the signal lines 1 to 4 being represented by a block symbol and designated by the reference number 16. The mechanical transmission means 2 to 5 lead to the contact sets, which are coupled to those of the keys of the keypad 1 which have a dot to clarify the representation on the key surface. It should be noted here that FIG. 4 shows, compared to FIG. 1, an enlarged keypad in the direction of the key columns, which is shown broken away, in order to make it clear that the keys shown here showed thoughts applicable to keypads of any size.

In the embodiment according to FIG. 4 there are driver pins 17 similar to the switching pins 10 of the embodiment according to FIG. 3 between the joints of the keys belonging to a labeling field. The driver pins 17 are biased downwards by small tension springs 18, while the compression springs 13 Preload the individual keys of keypad 1 in the rest position. If the buttons belonging to a labeling field are hit by the tip of the actuating finger in such a way that the head of the driving pin 17 is depressed at the same time, the driving pin has the effect that all buttons of a button group are actuated synchronously and that the contact sets are properly actuated via the button mechanical transmission means 2 to 5 comes. The driver pins 17 are thus effective as synchronization means. It should be pointed out that the embodiments according to FIGS. 3 and 4 offer the essential advantage over known key arrangements with island keys that on the one hand a considerable size of the labeling field is available for each individual symbol and on the other hand the actuating finger is offered a self-contained actuating surface .

The person skilled in the art recognizes from the above that the size of the heads of the switching pins 10 or of the driving pins 17, insofar as these heads are exposed on the button surface, is to be kept as small as possible in order to obtain the greatest possible operational safety. From this point of view, the embodiment according to FIG. 1 is to be regarded as preferred.

Claims (8)

1. A key array for initiating switching functions or switching signals which are each associated with respective symbols of the key surfaces, comprising a plurality of keys which are each allocated to a predetermined legend field for one symbol and which are depressable conjointly by one finger and the initial control movement signals of which are subjected to an AND correlation operation for forming said switching functions or said switching signals, characterized in that, progressing from key to key, a legend field is allocated to each pair of adjacent keys in a key row or, respectively, to each groupe of four adjacent keys which are grouped in square shape in a key board and by which the initial control movement signals of at least two diagonally opposite keys are subjected to the AND correlation operation without any independent functional value of individual keys.

2. A key array according to claim 1, characterized in that in a keyboard (1), the initial control movement signals are used only by alternate keys in each row of keys and in each column of the keys for deriving said said switching functions or switching signals.

3. A key array according to claim 1 or 2, characterized in that the initial control movement signals to be subjected to an AND correlation operation are each coupled to a mechanical AND-switching element (10, 11, 12, 13).

4. A key array according to claim 3, characterized in that said mechanical AND-switching element comprises a switching pin (10, 11) which is coupled to the keys producing the respective initial control movement signals to be linked for a movement toward the position of rest and by which the switching function or switching signal is produced and which is biassed toward the actuation position by a force (12) which is smaller than any force (13) biassing the keys toward their position of rest so that the bias force of the switching pin can move the latter to its actuated position only when all of the keys associated with said switching pin have been actuated.

5. A key array according to claim 1 or 2, characterized in that the initial control movement signals to be subjected to an AND correlation operation are each applied to a respective mechanical-electrical AND-switching element which correspondingly delivers an electric signal as a switching signal.

6. A key array according to claim 5, characterized by an entraining pin (17) to which the keys producing the respective initial control movement signals to be combined are coupled in respect to the direction of actuation in a manner such that, when also the entraining pin has been depressed, then the respective group of keys will be completely depressed.

7. A key array according to claim 6, characterized in that the diameter of a head of said entraining pin that is exposed on the surface of the keys is less than 30% of the length of one side of a key.

8. A key array according to any of claims 1 to 7, characterized in that the keys of a group of keys each have a common legend field (b₁, b₂, b₃, b₄) which is subdivided by the gaps between the keys.

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