A drawing processing apparatus for performing tessellation processing, comprising a pixel shader and a texture unit. The touch panel includes an upper electrode sheet and a lower electrode board having respective transparent electrodes face to each other, and both of the sheet and the board are made of respective materials containing an identical main component to each other. The same process is then repeated for the elevation adjustment. The first reference surface corresponds with a second reference surface of the second mounting flange. According to the present invention, the apparatus is characterized in that the incident-light illumination device and the imaging device each have associated with them a polarizing means whose transmission axes are oriented at a predetermined angle to one another.