JPS57200004A - Centering method for eyepiece part - Google Patents

Abstract

PURPOSE:To align the center of an eyepiece optical system to the center of a light guide with high precision, by forming an image of an index provided in the eyepiece optical system and each image of the end surface of the light guide on the same surface, and thus performing centering adjustment. CONSTITUTION:An image of an index 16 provided to a lens 8a of an eyepiece optical system 8 is reflected by a luminous flux split prism 20 to reach a luminous flux composing prism 21 through the 1st reflecting mirror 23, an image- forming lens 25, and the 2nd reflecting mirror 24, and it is reflected by the prism and also projected on an image-forming plate 22 through the image-forming operation of the image-forming lens 25. Images of a mask 13 and the index 16 are projected on the same image-forming plate 22 one over another. The shift in center between those images corresponds to the shift in center between the eyepiece optical system 3 and mask 13. For this purpose, while both images on the image-forming plate 22 are observed directly, an adjusting screw 12 is moved forth or back to align the centers of the images to each other, thus performing adjustment so that the center of the mask 13 of an image guide 5 coincides with the center of the index 16.