3–85OPERATIONS AND TIMINGCOPYRIGHT © 1998 CANON INC. CANON NP6621 REV.0 FEB. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON)H. Identifying the Size of theCassetteSpecific photointerrupters (Q651, Q652, Q653,Q654) turn OFF or ON when a cassette is slid intoa cassette holder.Specific combinations of the states (ON/OFF) ofthe photointerrupters are used by the microprocessoron the DC controller PCB to identify the presence/absence of a cassette and the size of the cassette(if any) and to control scanner reversal and blankexposure. (See Table 3-402.)Cassette sizeNo cassetteB5R (182 × 257)A4 (297 × 220)A3 (297 × 420)Mini (STMTR) 5.5" × 8.5"(148 × 216)Legal 8.5" × 14"(356 × 216)Letter 11" × 8.5"(279 × 216)A4R (210 × 297)Letter R 8.5" × 11"(216 × 279)A5R (149 × 218)A5 (218 × 149)Mini-R (STMT) 8.5" × 5.5"(216 × 148)B5 (257 × 182)B4 (364 × 257)Ledger 11" × 17"(182 × 257)*U(182 ~ 283 × 198 ~ 354)Configuration000000001111111100001111000011110101010101010101(left)0011001100110011(right)(unit: mm)Table 3-4021: Photointerrupter blocking the light.0: Photointerrupter not blocking the light.* Sizes may be stored in memory within dimensions given (in mm; see the Service Handbook for details).Q654Q653Q652Q651
