| 摘要 |
PURPOSE:To use two lead wires irrespective of the number of detecting positions by detecting a position of a moving body by a difference of voltage. CONSTITUTION:Fixed contacts 63-66 for detecting one return position, for detecting a read start position, for detecting a stop position, and for detecting the other return position are provded respectively on the upper face of a printed board 62, and fixed resistors R1-R3 are provided in series between the contacts 63 and 64, between 64 and 65, and between 65 and 66, respectively. The contact 63 is connected to an electric power source through a lead wire 67 and a fixed resistor R4, a contact 61 is connected to one end of a fixed resistor R5 in a signal processing part 69 through a lead wire 68, and a voltage level of this connected part is inputted to an A-D converter 70. When an original placing platen 2 moves in the directions as indicated with arrows A, B, a movable contact 61 slides along a part shown by an alternate long and short dush line on the printed board 62, and in case when it contacts with the contacts 63-66, since voltage inputted to the A-D converter 70 is different from each other, a digital signal to be outputted is different in accordance with it, by which a position of the original placing plate 2 is discriminated. |
