| 摘要 |
An imaging lens having four lenses is provided to perform a stabilized performance by arranging an iris diaphragm between a first lens and a second lens. An imaging lens includes a first lens(110), a second lens(120), a third lens(130), and a fourth lens(140). The first lens, the second lens, and the third lens have a positive refractive index. The fourth lens has a negative refractive index. An infrared filter(200) filters an infrared ray. An iris diaphragm(150) is positioned between the first lens and the second lens, controls a light amount, and blocks an unnecessary light. The first lens, the second lens, and the third lens are meniscus lens. The fourth lens is biconcave.
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