A diffractive optical element includes: a substrate; a protrusion and recess portion that is formed on one surface of the substrate and imposes predetermined diffraction on incident light; and an antireflection layer provided between the substrate and the protrusion and recess portion. An effective refractive index difference Δn in a wavelength range of the incident light between a first medium constituting a protrusion of the protrusion and recess portion and a second medium constituting a recess of the protrusion and recess portion is 0.70 or more. An exit angle range θ.sub.out of diffraction light exiting from the protrusion and recess portion when the incident light enters the substrate from a normal direction of the substrate is 60° or more. Total efficiency of diffraction light exiting from the protrusion and recess portion in the exit angle range is 65% or more.

Provided is an optical element which significantly reduces arrangement space, has superior durability, and also enables increased costs to be curbed. Functions of a polarizer and a phase difference compensation element are integrated. Specifically, the optical element has a transparent substrate, and a polarizer on one side of the transparent substrate, and has a phase difference compensation element on a side of the transparent substrate opposite from the polarizer.

Provided is an optical element which significantly reduces arrangement space, has superior durability, and also enables increased costs to be curbed. Functions of a polarizer and a phase difference compensation element are integrated. Specifically, the optical element has a transparent substrate, and a polarizer on one side of the transparent substrate, and has a phase difference compensation element on a side of the transparent substrate opposite from the polarizer.

Provided are a composite membrane, a touchpad and a display device. The composite membrane includes a first graded-refractive-index layer, a first dielectric layer and a second graded-refractive-index layer which are stacked in sequence; where the first graded-refractive-index layer includes at least two first sub-layers, and the second graded-refractive-index layer includes at least two second sub-layers; in a direction from the first graded-refractive-index layer to the first dielectric layer, refractive indexes of first sub-layers sequentially increase, and refractive indexes of second sub-layers sequentially decrease; a refractive index of a first sub-layer adjacent to the first dielectric layer is less than or equal to a refractive index of the first dielectric layer; and a refractive index of a second sub-layer adjacent to the first dielectric layer is less than or equal to the refractive index of the first dielectric layer.

Provided are a composite membrane, a touchpad and a display device. The composite membrane includes a first graded-refractive-index layer, a first dielectric layer and a second graded-refractive-index layer which are stacked in sequence; where the first graded-refractive-index layer includes at least two first sub-layers, and the second graded-refractive-index layer includes at least two second sub-layers; in a direction from the first graded-refractive-index layer to the first dielectric layer, refractive indexes of first sub-layers sequentially increase, and refractive indexes of second sub-layers sequentially decrease; a refractive index of a first sub-layer adjacent to the first dielectric layer is less than or equal to a refractive index of the first dielectric layer; and a refractive index of a second sub-layer adjacent to the first dielectric layer is less than or equal to the refractive index of the first dielectric layer.

A camera module includes an imaging lens assembly module and an image sensor. The image sensor is disposed on an image surface of the imaging lens assembly module and includes a photoelectric converting layer, a micro lens arrays layer, a light filtering layer and an anti-reflecting layer. The photoelectric converting layer is for converting a light signal to an electric signal. The micro lens arrays layer is for converging an energy of the imaging light into the photoelectric converting layer. The light filtering layer is for absorbing a light at a certain wavelength region of the imaging light. The anti-reflecting layer is disposed on a surface of at least one of the light filtering layer and the micro lens arrays layer and includes an irregular nano-crystallite structure layer and an optical connecting layer. The optical connecting layer is connected to the irregular nano-crystallite structure layer.

A camera module includes an imaging lens assembly module and an image sensor. The image sensor is disposed on an image surface of the imaging lens assembly module and includes a photoelectric converting layer, a micro lens arrays layer, a light filtering layer and an anti-reflecting layer. The photoelectric converting layer is for converting a light signal to an electric signal. The micro lens arrays layer is for converging an energy of the imaging light into the photoelectric converting layer. The light filtering layer is for absorbing a light at a certain wavelength region of the imaging light. The anti-reflecting layer is disposed on a surface of at least one of the light filtering layer and the micro lens arrays layer and includes an irregular nano-crystallite structure layer and an optical connecting layer. The optical connecting layer is connected to the irregular nano-crystallite structure layer.

Embodiments of articles including a low-contrast anti-reflection coating are disclosed. The coated surface of such articles exhibits a reduced difference in reflectance between a pristine state and when a surface defect is present. In one or more embodiments, the coated surface of such articles exhibits a first average reflectance in the range from about 0.6% to about 6.0% in a pristine condition and a second average reflectance of about 8% or less after removal of a surface thickness of the anti-reflection coating. In other embodiments, the coated substrate exhibits a second average reflectance of about 10% or less, when the coated surface comprises a contaminant. In some embodiments, the coated substrate exhibits a first color coordinate (a*.sub.1, b*.sub.1) in a pristine condition and a second color coordinate (a*.sub.2, b*.sub.2) after the presence of a surface defect such that Δa*b* is about 6 or less.

Embodiments of articles including a low-contrast anti-reflection coating are disclosed. The coated surface of such articles exhibits a reduced difference in reflectance between a pristine state and when a surface defect is present. In one or more embodiments, the coated surface of such articles exhibits a first average reflectance in the range from about 0.6% to about 6.0% in a pristine condition and a second average reflectance of about 8% or less after removal of a surface thickness of the anti-reflection coating. In other embodiments, the coated substrate exhibits a second average reflectance of about 10% or less, when the coated surface comprises a contaminant. In some embodiments, the coated substrate exhibits a first color coordinate (a*.sub.1, b*.sub.1) in a pristine condition and a second color coordinate (a*.sub.2, b*.sub.2) after the presence of a surface defect such that Δa*b* is about 6 or less.

The object of the present invention is to provide an optical laminate capable of reducing reflectance not only with respect to light incident vertically but also light incident obliquely, and further capable of obtaining a neutral reflected color tone even when light is incident obliquely. The optical laminate includes a base material, an antireflection film provided on one surface of the base material, and a light shielding film provided on the other surface of the base material. The optical laminate satisfies all of the following characteristics (i) to (iii):
0.5<R(λ.sub.1a,θ.sub.1a)/R(λ.sub.1b,θ.sub.1b)<1.5;  (i)
Y(θ.sub.2)≤3%; and  (ii)
Y(θ.sub.3)≤10%;  (iii)
in which R (λ, θ) designates reflectance when light of a wavelength of λ nm is incident at an angle of θ, provided that λ.sub.1a=380 nm, θ.sub.1a=60° and λ.sub.1b=650 nm, θ.sub.1b=60°; and Y (θ) designates luminous reflectance at an incident angle of θ, provided that θ.sub.2=5° and θ.sub.3=60°.