Scanning module

DETAILED DESCRIPTION It is an object of the present invention to provide a simple, miniature scanning module allowing its optical path length to be easily adjusted.
A scanning module of the present invention includes a light source for illuminating a document.
A pair of mirrors consist of a first mirror to which light reflected by the document is incident and a second mirror positioned substantially parallel to and spaced by a preselected distance from the first mirror.
The pair of mirrors reflects the light a plurality of times therebetween and then output it as light reflected from the first mirror.
A third mirror reflects the reflected light from the pair of mirror away from the pair of mirrors in substantially parallel to the document.
A fourth mirror reflects the light incident from the third mirror toward a lens in a direction substantially opposite to a direction in which it is reflected from the pair of mirrors to the third mirror.
A fifth mirror reflects the light incident from the lens in a direction substantially opposite to a direction in which it is reflected from the third mirror to the fourth mirror.
A linear sensor is spaced from the fifth mirror by a preselected distance such that the light passed through the lens is focused on the linear sensor.
The pair of mirrors are adjustable in position on a path, extending from the document to the first mirror, while maintaining a positional relation therebetween.
If desired, the pair of mirrors, reflected the light a plurality of times therebetween, may output it as light reflected from the second mirror.