| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical low-pass filter capable of separating an incident light beam into plural lines of light beams such that both of their optical energy amounts become uniform when it is emitted from the filter even when the incident beam is polarized by a beam splitter or the like and the image pickup optical system provided with the filter. SOLUTION: This optical low-pass filter is an optical low-pass filter in which pixels are regularly arranged and which is to be used in a solid-state imaging device and is made to have constitution in which, when the separation width to a horizontal direction, in which the pixel are arranged, of a light beam which is made incident on the LPF and the separation width to a vertical direction in which the pixels are arranged are defined respectively asδh,δv, the optical LPF has a first birefringent plate separating the incident light into an ordinary ray and an extraordinary ray with a separation widthδv×sinθin a prescribed angleθdirection by making the horizontal direction a reference and a second birefringent plate separating the incident light into the ordinary ray and the extraordinary ray with a separation widthδv×cosθin a prescribed angle (θ-90 deg.C) by making the horizontal direction the reference and a third birefringent plate separating the incident light into the ordinary ray and the extraordinary ray with the separation widthδh in a 0 deg. direction by making the horizontal direction the reference in an order in which the incident light is made incident on the LPF filter.
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