POSITION DETECTION PEN

PURPOSE:To detect handwriting on a paper without using a special baseplate by permitting the paper to diffuse and reflect a laser beam which is emitted from a laser beam source in a pen-axis and which is in a wavelength region beyond visibility near the tip of the pen-axis, counting the number of repetition times for the cycle of diffused light and detecting the relative moving quantity of the pen-axis and the paper. CONSTITUTION:When the tip of the writing part 9 of the pen-axis 8 is abutted on the paper 13 so as to relatively move it, the laser light of a frequency proportional to relative speed components which is parallel to a virtual plane formed between a laser beam L3 passing through the beam splitter 12a of a first optical system and a reflected laser beam L4 from a beam direction conversion means (mirror) 14a is diffused and reflected, and a light-receiving element 15a receives the light. Then, a counter 17a counts the number of repetition times for the cycle of the laser light. The counted result shows the moving quantity of the pen-axis and the moving position of one component is detected. A second optical system similarly detects the moving position of the pen-axis of the component orthogonal to one component, and the coordinates of respective moving positions of the pen-axis can be obtained from both detected results. Thus, the pen does not need to be fitted to a special device such as the baseplate.