摘要 |
<p>An electro-optical sensor senses marks on a sheet (14) which travels longitudinally with respect to a printed circuit board (32), carrying linear arrays of light sources (LEDs) (40) and photodetectors (44) and optics (70) which define zones displaced laterally across the width of a sheet of paper, longitudinal columns of which can contain marks, the presence and absence of which marks is detected by the sensor. The sensor is especially adapted for use in detecting marks which indicate votes on paper ballots in electronic, computerized vote counting apparatus.</p> |