Patent ID: 8699104
Filing Date: 2014-04-15
Classification: G03G,H04N

Abstract:
1. An image scanner comprising: a plate-shaped transparent member for placing a document thereon; a light source for irradiating a document with light through the transparent member; an image scanning section having a plurality of pixel detecting elements for scanning an image of the document irradiated with light from the light source, in the form of a plurality of pixels each having brightness represented by a pixel value; a first dew-condensation determination member and a second dew-condensation determination member provided on a part of the transparent member in adjacent relation to each other in one of a main scanning direction and an auxiliary scanning direction, the first and second dew-condensation determination members being different from each other in terms of light reflectance; a first dew-condensation determination data acquisition section operable to perform a first dew-condensation determination data acquisition processing for acquiring a first adjacent pixel value and a first distant pixel value, in such a manner that it causes the image scanning section to scan the first dew-condensation determination member at a position adjacent to a boundary line between the first dew-condensation determination member and the second dew-condensation determination member to obtain a pixel as a first adjacent pixel and acquire a pixel value of the first adjacent pixel as the first adjacent pixel value, and further causes the image scanning section to scan the first dew-condensation determination member at a position distant from the boundary line with respect to the first adjacent pixel to obtain a pixel as a first distant pixel and acquire a pixel value of the first distant pixel as the first distant pixel value; a second dew-condensation determination data acquisition section operable to perform a second dew-condensation determination data acquisition processing for acquiring a second adjacent pixel value and a second distant pixel value, in such a manner that it causes the image scanning section to scan the second dew-condensation determination member at a position adjacent to the boundary line to obtain a pixel as a second adjacent pixel and acquire a pixel value of the second adjacent pixel as the second adjacent pixel value, and further causes the image scanning section to scan the second dew-condensation determination member at a position distant from the boundary line with respect to the second adjacent pixel to obtain a pixel as a second distant pixel and acquire a pixel value of the second distant pixel as the second distant pixel value; an inter-adjacent pixel difference value calculation section operable to calculate a difference between the first adjacent pixel value and the second adjacent pixel value, as an inter-adjacent pixel difference value; an inter-distant pixel difference value calculation section operable to calculate a difference between the first distant pixel value and the second distant pixel value, as an inter-distant pixel difference value; and a dew-condensation determination section operable, when evaluation information indicative of a level of a difference between the inter-adjacent pixel difference value and the inter-distant pixel difference value shows that the difference between the inter-adjacent pixel difference value and the inter-distant pixel difference value is greater than a predetermined difference level, to determine that dew condensation occurs around the boundary line on the transparent member.