Nec Engineering, Ltd.

Nec Platforms, Ltd.

Hiroshi Hoshimiya

Tetsuichiro Yamamoto

Kouji Okada

An image reading device includes: a CCD for reading an image on a document to output an image signal; a light source for switchingly emitting visible light and non-visible light; and lighting control means for controlling lighting periods of the light source. The lighting control means is adapted to perform control such that a first light source lighting period for applying non-visible light is longer than a second light source lighting period for applying visible light. The image reading device also includes splitting means for splitting the image signals outputted from the CCD into an image signal upon application of visible light and an image signal upon application of non-visible light.

Image reading device for reading document images with visible light and non-visible light being switchingly applied

The present invention provides an image reader apparatus capable of obtaining an image having stable brightness while suppressing an increase of the cost of the apparatus. The image reader apparatusfor reading an image on a documentbeing fed and outputting an image signal includes a synchronization signal generation circuitfor generating a synchronization signal SS synchronous with a feed timing and a feed cycle of the document, a CCDfor reading an image on the documentin synchronism with the synchronization signal SS, an LEDfor emitting white light, and a lighting control circuitfor turning the LEDon in synchronism with the synchronization signal SS and turning the light source off so that a lighting period is equalized for each line irrespective of a variation of the feed cycle of the documentThe lighting control circuitturns the LEDoff so that the lighting period of the LEDis equal to a predetermined preset period.

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Tokyo, Japan

Hiroshi Hoshimiya