Patent ID: 7745772
Filing Date: 2010-06-29
Classification: G02B,G03B

Abstract:
1. An image forming state detection device, comprising: a micro-lens array that includes a plurality of micro-lenses arrayed with a predetermined pitch at a position set apart from a predetermined focal plane of an image forming optical system by a specific distance; a plurality of light-receiving element arrays each of which includes a plurality of light-receiving elements, each of the light-receiving elements outputting photoelectric conversion signal, each of the light-receiving element arrays being disposed corresponding to each of the micro-lenses; a first forming circuit that forms a first signal string (a(i):i=1, 2, 3, 4, . . . ) including the photoelectric conversion signals output from the light-receiving element array corresponding to one of the micro-lenses, and a second signal string (b(i):i=1, 2, 3, 4, . . . ) including the photoelectric conversion signals output from the light-receiving element array corresponding to another micro-lens; a second forming circuit that executes a process in which with regard to each of the plurality of the micro-lenses, signals a(i) and b(i) are extracted from the photoelectric conversion signals output from two of the light-receiving elements disposed at a predetermined position among the light-receiving element array corresponding to ith micro-lens, and that forms a first signal string (a(i):i=1, 2, 3, 4, . . . ) including the signals a(i) and a second signal string (b(i):i=1, 2, 3, 4, . . . ) including the signals b(i); and an image forming state calculating circuit that selects one of the first and second signal strings formed by the first forming circuit and the first and second signal strings formed by the second forming circuit based upon a predetermined decision-making criterion, and calculates an image forming state of the image forming optical system at the predetermined focal plane by detecting an offset based upon the selected first and second signal strings.