Patent attributes
A telescope main body, which is provided with an objective optical system, a focusing system, an imaging device, a beam splitter, and a correcting system that performs a correcting operation for correcting a position shift between an image forming position of an object image and a receiving surface of the imaging device caused by diopter variation of a user. The correcting system includes a focus driving system which relatively moves an image forming position of the object image with respect to the receiving surface, a focus detecting system which detects a status in which the image forming position coincides with the receiving surface, and a controller controlling the focus driving system. The controller has with a learning function of storing correction data of a preceding correcting operation so that the stored correction data of the preceding correcting operation is reflected in a subsequent correction operation.