| 摘要 |
To provide a compact and low-cost projector lens capable of appropriately performing temperature correction and obtaining excellent image quality although using a plurality of plastic lens elements, a first lens unit having negative refractive power and a second lens unit having positive refractive power are provided from the screen side, the first lens unit includes a negative meniscus lens element 1b being a plastic lens element, being convex to the screen side and having an aspherical surface, the second lens unit includes: a negative lens element 2b being a plastic lens element and having an aspherical surface; and at least two positive lens elements having anomalous dispersibility and a temperature coefficient of a negative refractive index, and an image plane fluctuation by a temperature change due to a temperature coefficient of a negative refractive index of the plastic lens elements 1b and 2b of the first and second lens units is corrected by the temperature coefficient of the predetermined negative refractive index of the positive lens elements.
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