1. Field of the Invention
The present invention generally relates to an input device, and more particularly to the input device for transmitting input information by a radio communication.
2. Description of the Related Art
In the current computer system industry, in order to simplify connections to peripheral devices and to improve operability thereof, a wireless communication has been applied to the peripheral devices such as a mouse and a like.
As a wireless communication method, a radio wave method and an infrared ray method have developed. The radio wave method is applied to a coordinate input device such as the mouse because of a wider flexible range of an input position thereof.
In the coordinate input device applying the wireless method, if there is a conductive object around the coordinate input device, an electrostatic capacity (load capacity), which is occurred between the object and the mouse, is applied to an antenna of the mouse. Then, a transmission rate becomes lower. If a radio field intensity of the mouse is set to be stronger and exceeds a predetermined level so that the transmission rate will not be lower, it is required to get a permission in accordance with the radio wave law. Accordingly, in general, the radio field intensity is set to be at a maximum while not requiring the permission in accordance with the Wireless Telegraph Law.
In a conventional input device applying a radio communication, the antenna is formed on a circuit board arranged on a bottom surface of a housing of the mouse. Therefore, for example, when the mouse is operated on a desk made from steel material, an antenna effect is degraded. And an area, in which the radio field intensity output from the input device is degraded, locally occurs.
USPTO Backgrounds
USPTO Backgrounds