| 摘要 |
A projection lens for enlargedly projecting the image of a cathode ray tube onto a screen comprises, in succession from the screen side, a first lens having a positive refractive power, a second lens having a positive refractive power and having its surface of sharper curvature facing the screen side, the second lens being disposed at or near the entrance pupil position of the entire system, a biconvex third lens having a positive refractive power, and a fourth lens having a negative refractive power and having its surface of sharper curvature facing the screen side.
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