1. Field of the Invention
The present invention relates generally to a key input method to implement multiple functions in a portable phone, and in particular, a method for using a multi-function key for implementing in a portable phone multiple functions such as input of telephone numbers and characters with a single key.
2. Description of the Related Art
Various practical electronic appliances of original design have recently been put on the market along the trend toward consumer convenience and respect for individuality. Among them, a mobile radio terminal such as a portable phone is designed and fabricated in such a manner that the consumer demands for originality and practicality combined are satisfied. Generally, a communication service provider offers a mailbox service (voice/data mailbox service) as an additional service to a mobile subscriber of a cellular phone or a PCS (Personal Communication Service). The mail box service notifies a calling party that a called party is not available when the portable phone of the called party is in a power-off mode or located in a non-service area, stores a voice message or data of the calling party in a mail box of a base station, and informs the called party of receipt of the voice message or data stored in the mail box when the called party is available.
Electronic appliances are equipped with multiple functions to enhance consumer's satisfaction. To invoke the multiple functions, a plurality of keys are provided with the electronic products. For example, a mobile terminal includes a plurality of keys such as the conventional 3×4 alphanumeric keys, function keys, an up/down key, and a menu key to perform functions like dialing and name registering.
From the user's perspective, many keys in a portable phone give rise to manipulation confusion and inconvenience rather than user-friendliness because users are obliged to learn what functions each of the multiple keys are used for. Multiple keys are not favorable to manufacturers since a large area occupied by the keys imposes constraints on product design and makes it difficult to satisfy various consumer tastes.
Though the idea of using the 3×4 keys for input of digits/characters and dialing has been fixedly accepted, a new and simple digit/character input method is needed.