| 摘要 |
PURPOSE: To provide an LED array head having the small dispersion of light quantities and the small variation of the diameters of beam spots. CONSTITUTION: In an LED array head performing optical writing on the image plane 5 of a photosensitive body by using an LED array source arranged with plural numbers of LED(light emitting diode) array chips 1 having plural light emitting sources in an arrayed manner, an image forming optical system composed of a microlens array 2 corresponding to a period for every LED array chip 1 is arranged and each microlens 2a is constituted by an image forming lens composed of a single lens including an aspherical surface whose aberrations of the curvature of field, etc., are excellently compensated. Consequently, the LED array head having the small dispesion of light quantities and the small variation of the diameters of beam spots is realized by using the inexpensive microlens array. |
