| 摘要 |
PURPOSE:To accurately stabilize the light quantity of a light source in a short time, by providing a reference body and irradiating the light of the light source upon the reference body, and then, discriminating whether the light quantity of the light source is stabilized or not on the basis of the reflecting light quantity from the reference body whether the light quantity reaches a set value or not. CONSTITUTION:When electric power is supplied to the main body of this exposing and scanning device, a main control section 41 makes a fluorescent lamp 23 to light and, at the same time, turns on a heater 43. A carriage 22 is moved to the scale 13 side of an original placing table 12 and rays of light are irradiated upon a reference body provided on the backside of the scale 13. The rays of light reflected by the reference body 32 are stored in a line memory 47 after they are converted into digital data through a line sensor 25 and AD converter 29. Then the mean value of the data stored in the memory 47 is calculated and whether or not the mean value exceeds a preset value is discriminated. When the mean value does not reach the preset value, whether a prescribed time has passed or not is discriminated. When the prescribed time has not passed, discrimination of the mean value is continued. When it is discriminated that the mean value exceeds the preset value, it is discriminated that the light quantity of the light source is stabilized. Thus the light quantity of the light source can accurately be stabilized in a short time. |
