1. Field of the invention
This invention relates to an electronic apparatus which can store data, and more particularly to a small electronic apparatus such as a so-called electronic memo or electronic data book.
2. Description of the prior art
Recently, small electronic apparatuses which can store various types of information such as telephone numbers and schedule data have been developed. As a typical example of such apparatuses, a so-called electronic memo or electronic data book will be described. When a telephone number of a person is to be entered in an electronic memo, keys are operated so that the name and telephone number of the person are displayed on a display device such as an LCD, and then the name and telephone number are stored in a RAM backed up by a battery. In this way, a many number of combinations of person names and telephone numbers can be stored in the RAM. A company name may be stored instead of a person name. When a telephone number of a person is to be displayed, the name of the person is called on the LCD by operating keys, and then the telephone number of the person is also displayed on the LCD. In an electronic memo, a many number of combinations of a numeric string (such as a telephone number) and a character string (such as a person name, company name) can be written in the RAM, and any one of the combinations can be arbitrarily called. Hereinafter, the term "call" means to read data from a memory and display the data on a display device.
As described above, when data is to be stored in such an electronic memo, keys are operated to display the data to be stored on a display device, and the displayed data is transferred into a memory. Generally, an electronic memo is required to have a reduced size. In an electronic memo, therefore, the size of a display device is restricted. In order to reduce the total size of a display device, it has been proposed that the display device is separated into two sections, one is a dot-matrix type display unit which is suitable for displaying a character string, and the other a seven-segment display unit which is adequate for displaying a numeric string. In an electronic memo having such a two-sectioned display device, when a telephone number is stored, only one of a person name and company name is displayed on the dot-matrix type display unit, and the telephone number on the seven-segment display unit.
In a prior art electronic memo, therefore, a telephone number combined with one of a person name and company name can be stored. In other words, a prior art electronic memo cannot store a combination of a telephone number and two or more character strings. Consequently, the kind of data which can be memorized in combination with a telephone number is restricted. When calling a telephone number, only one of a person name and company name is used as a search key, with the result that it is not easy to call the desired telephone number.
The methods of calling data in such electronic memos of the prior art can be generally classified into the sequential search and the direct search. In the former, data stored in memory are sequentially accessed in the order they have been stored therein. In the latter, for example, a name which is to be used as a search key is input, and then data in memory is searched for a name field which matches the input name, and the searched data is displayed. Electronic apparatuses have been known in which the initial character matching search which retrieves data in the name field beginning with the input name can be performed.
In the direct search, a search key is the data which has been input by a user. While conducting a data call in which one character is used as the search key, it is impossible to change the search key to a character string which begins with another character. Namely, when the contents of a search key are to be modified, the user must input the whole of the new search key.
For data in a prior art electronic memo, either the sequential search or the direct search is performed independently of each other, or the process automatically proceeds to the sequential search mode upon completion of the direct search. Therefore, the user cannot use the results obtained by the sequential search for the direct search, and the user must re-input the name and other search contents again for the direct search. Moreover, when changing from the direct search to the sequential search, the user must wait until the direct search has been completed.
In the majority of prior art electronic apparatuses, the contents of a search key cannot be changed during a direct search. In other electronic apparatuses, the direct search ends automatically when one datum is accessed by the direct search, thereby preventing the user from using the intermediate results in a direct search in subsequent searches. usually, the only way to access all the data stored after a certain datum is to sequentially search the data from beginning to end.