Patent ID: 7075714

Claim:
An image-pickup unit that achieves removable mount on a microscope, comprising: an image-pickup device having an image-pickup element that picks up an image by the microscope; and a dust protection glass arranged in front of the image-pickup device, wherein the dust protection glass is provided with an anti-reflection film having a layered structure having first to sixth layers of films, in order from a surface of the dust protection glass, formed of a high-refractive-index material for each of the first, third and fifth layers, a low-refractive-index material or a middle-refractive-index material for each of the second and fourth layers, and a low-refractive-index material for the sixth layer, with a range of an optical film-thickness nd of each layer in reference to a design wavelength Î» being â€œ(0.13 Ëœ 0.35)Ã—Î»/4â€ for the first layer, â€œ(0.18 Ëœ 0.75)Ã—Î»/4â€ for the second layer, â€œ(0.28 Ëœ 2.31)Ã—Î»/4â€ for the third layer, â€œ(0.26 Ëœ 0.92)Ã—Î»/4â€ for the fourth layer, â€œ(0.20 Ëœ 0.37)Ã—Î»/4â€ for the fifth layer, and â€œ(1.09 Ëœ 1.18)Ã—Î»/4â€ for the sixth layer.