Patent ID: 9167123
Filing Date: 2015-10-20
Classification: G03B,H04N

Abstract:
1. An image reader apparatus for reading an image on a document being fed and outputting an image signal, comprising: a synchronization signal generator configured to generate a synchronization signal based upon a feed cycle signal outputted from a feeder device, the feed cycle signal representing a feed timing and a feed cycle of the document; an image sensor configured to read the image on the document in synchronism with the synchronization signal; a light source configured to emit light; and a lighting controller configured to turn the light source on in synchronism with the synchronization signal and to turn the light source off so that a lighting period is equalized for each line irrespective of a variation of a cycle of the synchronization signal, wherein the lighting controller is further configured to monitor the cycle of the synchronization signal, to subject the lighting period of the light source to a feedback control, and to maintain the lighting period to be shorter than the cycle of the synchronization signal even if the maximum variation is caused to a feed speed, and wherein the lighting controller comprises a measurement part configured to take in the synchronization signal from the synchronization signal generator and a clock signal having a predetermined cycle and to count a number of clocks of the clock signal over one cycle of the synchronization signal.