| 摘要 |
PURPOSE:To produce the title lens easily by selecting the radius of curvature of the vertexes of far and near conjugate point side lens surfaces, the conical of the far conjugate point side lens surface, and the image forming magnification, refractive index and center thickness of the single lens within specific ranges. CONSTITUTION:The single lens forms the image of an object O on an image plane I. When it is defined that X is a distance from the tangential plane on the vertex of the lens surface to a point on an aspheric surface, (h) is the height from the optical axis, C is a value relating to the curvature of the vertex of the aspheric surface, K is a conical constant, and A2 is the coefficient of the aspheric surface, the aspheric surface shape is expressed by the equation I and satisfies the conditions of formulas II-IV, and when the center thickness of the single lens is (d), the aspheric surface shape satisfies the condition of the formoula V. In this case, the relation of R=1/(C+2A2) is formed between the radius R of curvature of the vertex of the lens surface and the value C relating to the curvature of the vertex of the aspheric surface. Said condition II is a condition for miniaturization, and if the condition II is not satisfied, the whole length of the lens is extended and miniaturization is made difficult.
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