Scanner and scanner data generating method

A scanner comprising:

• a first mirror having multiple concavities configured to reflect light from a document;
• a sensor configured to sense light reflected by a concavity of the first mirror;
• and
• a wall disposed to the first mirror and protruding from between the multiple concavities,
• the sensor including multiple sensor chips corresponding one-to-one with the concavities of the first mirror,
• light from a defined range of a main scanning line of the document being reflected by a first concavity of the first mirror and incident to a first sensor chip corresponding to the first concavity, and being reflected by a second concavity of the first mirror and incident to a second sensor chip corresponding to the second concavity,
• the first concavity and the second concavity being aligned adjacently in a main scanning direction;
• the sensor chips being aligned in the main scanning direction, and
• the wall protruding from between the first concavity and the second concavity to a height Hdm equal to (0<Hdm<L−(q+Wdm)/(2 tan θ2)) where
• L is a distance to the first mirror from a virtual plane, which is a position where an image formed through the first mirror on the sensor chip is in focus,
• q is the length of the defined range on the main scanning line in the virtual plane,
• θ2 is the angle, in a plane including a principal ray from an end of the defined range and the main scanning line, between a perpendicular to the main scanning line and the principal ray, and
• Wdm is a width in the main scanning direction of the wall disposed to a position equidistant from the first concavity and the second concavity.