IMAGE-READING DEVICE THAT ELIMINATES SHOW-THROUGH FROM ORIGINAL

摘要

In an image-reading device, a controller is configured to: control a reading unit to read a reference plate to generate reference image data and to read a first and second faces of an original to generate first and second image data; identify a show-through line including a show-through region in which the first face depicts a first background color and the second face has a highest density value and a non-show-through region in which the first face depicts the first background color and the second face depicts a second background color; calculate an image data ratio of the show-through and non-show-through regions in the first image data; calculate a reference data ratio of the show-through and non-show-through regions in the reference image data; and determine a show-through removal light intensity such that a difference between the image data ratio and the reference data ratio falls within a prescribed range.

主权项

1. An image-reading device comprising:
a light source configured to irradiate light toward an original having a first face and a second face, the light irradiated theretoward having a light intensity; a reading unit configured to read the original on a line-to-line basis in a main scanning direction by receiving the light reflected off the original; a reference plate disposed in a position confronting the reading unit; an adjusting unit configured to adjust the light intensity of the light source; and a controller configured to:
control the light source to irradiate the light toward the reference plate and control the reading unit to read the reference plate to generate reference image data;control the light source to irradiate the light toward the first face of the original and control the reading unit to read the first face of the original to generate first image data corresponding to the first face of the original;control the light source to irradiate the light toward the second face of the original and control the reading unit to read the second face of the original to generate second image data corresponding to the second face of the original;acquire a first background color from the first image data and a second background color from the second image data;identify a first background color region in the first image data and a second background color region in the second image data, the first background color region defining a region in which the first face of the original depicts the first background color, the second background color region defining a region in which the first face of the original depicts the first background color and the second face of the original depicts the second background color;acquire a highest density value in the first background color region from the second image data;identify a show-through line including a show-through region and a non-show-through region in the second image data based on the second background color and the highest density value, the show-through region corresponding to the highest density value, the non-show-through region defining a region in which the first face of the original depicts the first background color and the second face of the original depicts the second background color;control the light source to irradiate the light toward the first face of the original and control the reading unit to read the show-through region and the non-show-through region in the first face of the original to generate third image data and fourth image data;calculate an image data ratio of the third image data to the fourth image data;calculate a reference data ratio of first reference data to second reference data, the first reference data being image data corresponding to the show-through region in the reference image data, the second reference data being image data corresponding to the non-show-through region in the reference image data;calculate a difference between the image data ratio and the reference data ratio and determine a show-through removal light intensity such that the difference falls within a prescribed range; andcontrol the adjusting unit to adjust the light intensity of the light source to the show-through removal light intensity.