Pen-type computer input device

DETAILED DESCRIPTION In view of the aforesaid problems of the conventional computer input devices, it is an object of the present invention to provide a pen-type computer input device which is small in size, can easily be handled just like a writing implement, and hence can be used to enter figures, letters, numerals, etc.
into a computer to which the input device is connected, in the exact pattern followed by the input device.
To achieve the above object, there is provided a pen-type computer input device comprising a shank having a tip end, a ball rotatably supported on the tip end, the ball having a plurality of identifiable regions on an outer peripheral surface thereof, and means including a sensor unit for detecting the identifiable regions in response to rotation of the ball, and for detecting the directions in which the ball rotates and the distances by which the ball moves two perpendicular directions in a plane, and producing an output signal representative of the directions and distances.
Since the sensor unit can detect the distance by which the pen-type computer input device moves without any mechanical motion transmitting mechanism incorporated in the shank, the pen-type computer input device may be small in size and can be handled with ease.
The above and other objects, features and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which preferred embodiments of the present invention are shown by way of illustrative example.