number of first reading elements 224 in the signal line 137 is a value u201c 4 u201d all the reading enables 2241 to 2244 for the two input selectors 611 to 614 are the value u201c 1 u201d thereby the values of the signal lines 1481 to 1484 are output to the signal lines 1681 to 1684 respectively as they are similarly when the number of second reading elements 225 in the signal line 137 is a value u201c 1 u201d only the reading enable 2251 for the two input selector 621 is a value u201c 1 u201d and the other signals are a value u201c 0 u201d thereby the value of a signal line 1491 is output to a signal line 1691 and the value u201c 0 u201d is output to signal lines 1692 to 1694 when the number of second reading elements 225 in the signal line 137 is a value u201c 2 u201d the reading enables 2251 and 2252 for the two input selectors 621 and 622 are the value u201c 1 u201d and the other signals are the value u201c 0 u201d thereby the values of the signal line 1491 and a signal line 1492 are output to the signal lines 1691 and 1692 respectively and the value u201c.