| 摘要 |
PROBLEM TO BE SOLVED: To provide a configuration in which a short-circuited LED can be detected with high probability in an image reading device using a plurality of LEDs as a light source for reading.SOLUTION: An image scanner device includes a light source, and a control unit. The light source is for reading a document, and is configured by including a plurality of LEDs arranged in series. The control unit measures brightness of the light source while decreasing a current or a voltage supplied to the light source lower than that during reading of a document, and determines the presence of a short-circuited LED on the basis of whether or not a locally bright part is present. As decreasing a current or a voltage supplied to the light source makes a distribution of brightness of the light source clear, a short-circuited LED can be detected with high probability. |
