Abstract: An information apparatus comprises a main apparatus and a subsidiary apparatus which are separable. The main and subsidiary apparatuses has electrical connectors which are connected substantially automatically when the two apparatuses are attached. The connectors are provided with covers which are movable in association with the attaching procedure. Thereby, the connectors can be kept clean and free from dust contamination or breakage, and the reliability of the information apparatus can be enhanced.

Abstract: A hand-held computer with an input pen capable of handwriting recognition. Characters are inputted by a user's manual operation with the input pen on a transparent coordinate input plate in front of a display screen. The computer discriminates pen-input characteristic of the user, and selects a character-recognition dictionary based on the discrimination result.

Abstract: A power managing apparatus in an electronic apparatus using a battery comprises a residual power quantity detector for detecting a residual quantity of the battery; a time setter for setting a time; a judging unit for judging whether the electronic apparatus can be driven until the set time or not on the basis of the detected residual quantity of the battery; and an alarm display for notifying the result of the judgment. The set time is an operable time of the electronic apparatus or an operable time obtained from the next charging time or can be input by a pen.

Abstract: A parent node transmits a third specific message to child nodes as a broadcast message if a first specific message indicating the start of the child node collides with another message so that normal receiving cannot be performed. Then, the parent node sequentially transmits second specific messages to each child node and then receives responses to recognize the states of the children nodes. The parent node transmits a specific message indicating a realization of a sleeping state as a broadcast message to the children nodes, followed by transmitting a specific message when data to be transmitted from the child node has been generated. The parent node cancels the sleeping state when it receives the specific message.

Abstract: A communication apparatus transmits a test message in one direction by the transmitting unit having narrow directivity capable of changing the transmitting direction, and an indication message which indicates that the test message is being transmitted by a transmitting unit having non directivity. Accordingly, the indication message is transmitted at least to the communicating party's apparatus. Subsequently, the transmitting direction of the test message is sequentially changed, and a similar process is performed. When the communicating party's apparatus detects a reception of the indication message, information indicating a level of the test message is transmitted to the transmitting apparatus as a response. The communication apparatus at the transmitting side detects the direction where the communicating party exists by receiving the information indicating the level. Hereinafter, the information communication is performed to adjust the transmitting unit of narrow directivity to the determined direction.

Abstract: A communication apparatus which can communicate by a proper light intensity and can prevent excessive electric power consumption without providing light intensity measuring means on the reception side is provided. There are also provided communication apparatus and method, in which after a CPU issued a first message, a light emission intensity of an infrared LED is changed by the CPU so as to become the optimum state in accordance with the presence or absence of the response of a second message that is performed in response to the first message.