IMAGE READER

PURPOSE:To eliminate the exposure of a radiograph film terminal part or the influence of light leakage and to realize exact image reading by detecting the width of a radiograph film and adjusting the light generating area of a band- shaped light source corresponding to the detected width. CONSTITUTION:An automatic reading part 1 is constituted by providing a light generating means (light source) such as an LED to be partially turned on for irradiating the radiograph film with light in the case of applying this device for a bone measuring instrument, detecting means such as a CCD for detecting the quantity of light transmitted from the light source to the radiograph film, and automatic film feeding means such as a roller for automatically feeding the radiograph film. On the other hand, a bone measured data processing part 2 is constituted by providing an MPU to be functioned as a film width detecting means for detecting the film width in a direction rectangular to the feeding direction of the radiograph film. Then, the light generating are of the band- shaped light source is adjusted corresponding to the detected result of the radiograph film width calculated by the bone measured data processing part 2.