| 摘要 |
PURPOSE:To obtain the ocular which has small distortion and is cable of diopter adjustment by using a plano-convex lens as at least one of positive lenses in two group whose small-curvature-radius surfaces face each other, and moving the positive lenses in the two groups on an optical axis individually. CONSTITUTION:The ocular consists of the positive lenses L1 and L2 in two groups, and they are plano-convex lenses. Those plano-convex lenses L1 and L2 are arranged on the optical axis so that their convex surfaces face each other, and they are independently movable on the optical axis. Consequently, the ocular which has small distortion in a diopter adjustable range as compared with the use of a positive single lens and is capable of diopter adjustment is obtained. When the eye is put closer to the ocular lens, variation in distortion with the distance from the optical axis is less than when the distance between the two group lenses is fixed, and a screen never becomes hard to see even when the eye is shifted in position. |
