| 摘要 |
PURPOSE:To reduce the size and cost of a lens array optical system by partially and mutually superposing respective lenses constituting the lens array to compensate for the nonaniformity of light distribution on the center and periphery of the lenses. CONSTITUTION:A ring pattern 6 of micro-Fresnel lenses is obtained by forming a resist layer on an array base 5 and transferring a pattern directly to the resist layer or forming the pattern unitedly with the array base 5 by using a plastic molding method such as an injection method. Since respective lenses constituting the lens array are partially and mutually supersposed, the unbalance of light distribution on the center and periphery of the lenses can be compensated. Even if the expansion of a visual field is required by shortening a focal distance to reduce the size, a peripheral image is not defocused and the quantity of light is not reduced. In addition, the molded part can be mass-produced under low cost.
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