1.  Technical Field of the Invention
The present invention relates to an attaching mechanism for a GPS (global positioning system) antenna which is used for attaching the GPS antenna to a portable personal computer. 
2.  Description of the Related Art
The GPS system having been spread as a positioning system requires a GPS antenna for receiving radio wave transmitted from satellites.  High-grade calculation function is required in order to accurately calculate the current position on the basis of the signals received by the GPS antenna.  If such a calculation can be performed by a personal computer, in particular, a portable personal computer such as a note book personal computer, the field to which the GPS system can be applied will be spread rapidly. 
In general, the GPS antenna is disposed with reference to the horizontal plane so as to optimize the receiving sensitivity thereof.  The GPS antenna to be mounted on a vehicle is disposed most suitably at the time of mounting it on the vehicle since the horizontal plane is defined by the vehicle body.  In contrast, the portable GPS antenna is always required to adjust its position with respect to the horizontal plane. 
In a system where the signal received by a GPS antenna is subjected to calculation processing by a portable personal computer, there arises a problem as to where the GPS antenna is to be disposed.  That is, since an operator operates a key board disposed on the front side of a display panel in a state that the display panel is opened, there is no place where the GPS antenna is to be disposed.  This is a problem to be obviated by the present invention.