| 摘要 |
PURPOSE:To read all pieces of color information by arranging plural light emitting element groups having a different light emitting wavelength on the same line and lighting up them respectively one time or above in the time to read at least one line, in a light source device for reading an image. CONSTITUTION:LED (light emitting diode) groups 1 and 2 as two types (green and red) of the light emitting element group having different light emitting wavelengths are respectively arranged on the same line at an interval (s). The LED groups 1 and 2 are selected to the wide directivity close to the non- directivity, sandwiched by mirror surfaces 3 and 4, and then, on the line from which a distance (d) is away, an equal illumination can be executed by a ripple number % while only one side LED group lights up. The relation between the interval (s) and the distance (d) is d/s 0.6. LED drivers 7 and 8 light up the internal part of one accumulating time through current-limiting resistors 5 and 6 with a 50% duty, the LED groups 1 and 2 divide the internal part of one line reading time of an original 10 into five, light it up alternately and the transmitting light of the original 10 is read by a sensor 12.
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