The present invention generally relates to a data input apparatus and more particularly to a data input apparatus for a data display system capable of producing a plurality of logic pictures, such as windows, frames or the like on a display screen.
In recent years, a so-called multi-window function, i.e. the function which allows a plurality of logic pictures (frequently referred to as window) to be simultaneously displayed in parallel on a single display screen is widely favored. In that case, the multi-window function can be classified into two categories. First, a plurality of logic pictures are displayed in an overlapping relation to one another. Second, they are displayed discretely, being separated from one another. In the display apparatus imparted with the multi-window function of either one of the above mentioned types, data entry into a first one of the plural logic pictures or windows is effected by moving a cursor therein. When a data is next to be entered in a second logic picture, he cursor has to be moved therein. In this manner, when data are to be inputted sequentially to the first and second logic pictures or windows, the cursor must be moved alternately in the first and second logic windows by correspondingly manipulating the arrow-imprinted cursor keys. This procedure is very troublesome. Further, when data are to be inputted alternately into more than two windows displayed simultaneously, an operator is forced to perform much complicated manipulation of the cursor keys for moving the cursor. In an extreme case, the cursor moving manipulation will require a greater time consumption than the data input operation itself, to a serious problem.
In the hitherto known data entry at locations designated by a cursor, there has been known a method of reducing the time taken for the cursor key manipulation, according to which method the cursor is moved skipwise in a predetermined manner upon inputting of data, as disclosed in JP-A-58-219639 (Japanese Patent Application No. 57-101860 on titled "Buffer Memory Device For Image Processing" filed June 14, 1982) and published Dec. 21, 1983. More specifically, the cursor is moved in a predetermined sequence among simultaneously displayed regions of an image or among logic pictures by skipping a certain region or picture upon every inputting of data. However, this known method suffers a drawback in that the inputting sequence is fixedly predetermined. In other words, data inputting in other sequence than the fixed one is impossible, thus involving a lot of time in the inputting operation. When the sequence of the data inputting of logic pictures is fixed, a problem will then arise in respect that the advantage of independency among the logic pictures or windows will be lost.