Input device for arabic letters

Abstract

The invention is an input device for Arabic letters installed on key pads of the electrical devices. Arabic letters are divided into the main letters which are the common letter parts or bases of each Arabic letters and the subscripts to be added on the main letters, and inputting operation is implemented in a way that the main letters is inputted first, and the subscripts is inputted later, so the consistency of the input method is maintained, and the number of key operating could be minimized without increasing the number of key.

1 . An input device for Arabic letters including Arabic, Farsi and Urdu, which comprises;
 a key pad which includes a main letter area on which plural main letters being common letter parts commonly included in Arabic consonant letters are assigned in a fixed position of key pad and a subscript area on which plural subscripts being added on each main letter to form complete consonant letters are assigned in a fixed position of key pad, and outputs the corresponding letter input signal according to the user's touch operation;   a controller which outputs display control signals to display the complete consonant letters combined by the selected main letter and the selected subscript according to the letter input signal; and   a display which displays each Arabic consonant letter on the display window according to the display control signal from the controller,   wherein the subscripts are divided into the upper subscripts which are added on the upper part of the main letter and the lower subscripts which are added on the lower part of the main letter, and the subscript area includes the upper subscript key on which plural upper subscripts are assigned and the lower subscript key on which plural lower subscripts are assigned, and the controller controls so that the upper subscripts change sequentially according to the predetermined order based on the number of key operating for the upper subscript key and controls so that the lower subscripts change sequentially according to the predetermined order based on the number of key operating number for the lower subscript key,   wherein the upper subscripts comprises a plurality of upper subscripts including the three point upper subscript of ( ), and the lower subscripts comprise a plurality of lower subscripts including the three point lower subscript of ( ), and the subscript area includes a three point subscript key on which the three point upper subscript of ( ) and the three point lower subscript of ( ) are assigned, a general upper subscript key on which the upper subscripts other than the three point upper subscript of ( ) are assigned, and a general lower subscript key on which the lower subscripts other than the three point lower subscript of ( ) are assigned.   
     
     
         2 . An input device for Arabic letters of  claim 1 , wherein the key pad further includes a language selection key to select any one among Arabic language, Farsi language and Urdu language, and the main letters extracted from the scope of the Arabic letters used in the Arabic language selected by the language selection key are assigned in the main letter area.