At present, there are many different keypad designs, all of which are aimed at making the tool equipped with the keypad practical and easy to use. However, a common feature of all these designs is that the keypad has keys which are generally of the same shape and which are arranged in an essentially rectangular pattern. This arrangement means that when keying in a number or a let- ter combination, the user is always obliged to look at the keypad in order not to risk entering the wrong num- ber. If, simultaneously, the user must keep his attention fully focused in a different direction, which, for exam- ple, is the case when driving a car, the keying-in of the number or letter combination will necessarily be more difficult and thus slower.

Furthermore, when keying in a number on an ordinary keypad only the logical, left cerebral hemisphere is uti- lised. Users find this troublesome in situations where the left cerebral hemisphere is already being used, for example in connection with motoring or logical thinking.

The object of the invention is to simplify the keying-in operation in connection with the use of mobile telephones, electronic locks, and the like. This has been achieved by the invention in such a way that the function keys for entering the numerals zero to nine and/or a num- ber of letters are arranged in a group forming a pattern across a surface, where each key differs in its shape and orientation from adjacent keys to such a degree that it becomes possible with a finger, preferably the thumb of one hand, to orientate oneself among the group and to determine which key one is touching without looking at

the key. Orientation does not primarily refer to the position of the key, but, for example, to its rotation in relation to other keys of essentially the same shape.

When the control device is used in connection with a mobile telephone, for example, it is then only neces- sary to quickly check the display of the mobile tele- phone, where the inputted number is displayed, to ensure that the correct number has been keyed in. However, this operation only requires a moment of observation and can be carried out in connection with the transmission of the telephone number.

Since the keypad by virtue of its design links nume- rals and symbols to a certain geometry and texture, it enables use of the right cerebral hemisphere when input- ting a number to a greater extent than is the case with an ordinary keypad. This makes it much easier to learn a certain number, since one learns the spatial attributes of the numerals, just like an experienced typist.

An embodiment of the invention arranged on a mobile telephone will be described in more detail below with reference to the accompanying drawing, in which Fig. 1 is a front view of a mobile telephone provided with func- tion keys according to the invention and Fig. 2 is an enlarged scale perspective view of the complete keypad of the mobile telephone.

As seen in Fig. 1, the mobile telephone has a front face 1 with a keypad 2 for operating the mobile telephone for the purpose of ordinary telecommunications. Various number and letter combinations are shown on a display 3.

According to the invention, on the keypad 2, the function keys intended for inputting the numerals zero to nine and/or a number of letters (not shown) are arranged in a group 4 forming a pattern across a surface, where each key differs in its shape and orientation from adja- cent keys not only visibly but to such a degree that it is possible with a finger to feel the difference between one key and the next without having to look at the keys.

Fig. 2 schematically shows in more detail how the keys in the group 4 differ from each other. According to an additional feature of the invention, some of the keys are connected in pairs by bars 5 extending straight across the group 4. Suitably, the user can place the thumb of one hand across the bars 5 and fairly quickly, i. e. after a relatively short learning period, find the correct sequence of numerals when keying in a number by searching with the thumb across the bars 5 in order to find the keys at the end of the bars 5 and the keys located between the bars 5. By quickly checking the dis- play 3, the user can ensure that he has inputted the cor- rect number.

Accordingly, by virtue of the device according to the invention it is no longer necessary for the user to find his way to the keys in a keypad by looking at the keys. The learning process is relatively short because the user quickly learns to position his thumb in an ini- tial position, from which he then searches for the diffe- rent keys.

The invention is not limited to what has been shown and described above. Naturally, the keys in group 4 may have many different appearances within the scope of the inventive idea.

Furthermore, the invention can be applied in many contexts in addition to the described use in connection with a mobile telephone. Examples of applications include button-type electronic locks, pocket calculators, or remote controls for televisions and VCRs.