BOKEH FILTER MEMBRANE, IMAGING OPTICAL LENS ASSEMBLY, IMAGING APPARATUS AND ELECTRONIC DEVICE

A bokeh filter membrane, which is disposed on a surface of a substrate, includes a gradient thickness absorbing membrane and an anti-reflection membrane. The anti-reflection membrane includes a high-and-low refraction membrane and a gradient refraction membrane. A transmittance of the substrate at a center thereof is greater than a transmittance of the substrate at a peripheral region thereof. The high-and-low refraction membrane includes a first high-and-low refraction membrane and a second high-and-low refraction membrane, the gradient thickness absorbing membrane is farther away from the substrate than the first high-and-low refraction membrane, the second high-and-low refraction membrane is farther away from the substrate than the gradient thickness absorbing membrane, and the gradient refraction membrane is farther away from the substrate than the second high-and-low refraction membrane. The gradient refraction membrane includes a plurality of pores. A main material of the gradient refraction membrane is metal oxide.