| 摘要 |
PURPOSE:To obtain the continuous rod shaped back light readily, by providing a light source case which surrounds a side surface and a light diffusing means which covers a light projecting surface on many DC mercury lights which are aligned in the width direction of a material to be measured. CONSTITUTION:Under a conveying path of a sheet bar 10, the back light sources 14 are provided along the width direction of the sheet bar 10. Light receiving elements detect the image formed by the sheet bar 10. One dimensional image sensor 16 is arranged in the width direction of the sheet bar 10. The back light is irradiated along the width direction of the sheet bar 10. The image, which is formed by the sheet bar 10, is detected by the one dimensional image sensor 16. The configuration detecting device 12 detects the width of the end of the sheet bar based on the width data of the sheet bar 10 obtained by the one dimensional image sensor 16 and the movement data of the sheet bar 10. Many back light sources 14 of the configuration detecting device 12 are arranged in the width directions of the sheet bar 10. |
