| 摘要 |
PURPOSE:To provide a laser plotter which is small in size and high in accuracy by providing a means for correction a surface inclination error from the information on the correction of the surface inclination error of a rotary polyhedral mirror. CONSTITUTION:A voltage comparator 4 compares the reference voltage from a reference voltage generator Vsg and the scanning position voltage inputted to the voltage comparator 4 and detects the surface inclination error. Such a memory 8 which corresponds to the respective faces of the rotary mirror 5 is used in a feedback system. The reading/writing (R/W) signals of the memory are generated in accordance with the information on the rotating position of the rotary mirror sent from an encoder 7 and the error is managed for each face in a memory R/W signal generating circuit 6. The error of a short period is, therefore, absorbed by the correction value stored in the memory 8 and the error of a long period is slight in the change rate of amplitude and can, therefore, be corrected by repeating the feedback operation several times. The compact laser plotter of the high accuracy is obtd. in this way. |
