Canon Kabushiki Kaisha

Kazuhiko Momoki

Yutaka Yamaguchi

Keiji Ohtaka

Shingo Hayakawa

Daisuke Sano

Sayoko Amano

Reona Ushigome

Takeharu Okuno

Rie Ishimatsu

Takehiko Nakai

Hirokatsu Miyata

Masahiko Takahashi

Yoshiaki Ida

Kazue Uchida

Kei Ueda

An imaging apparatus includes an optical low-pass filter that includes first, second, third, and fourth optical anisotropic elements configured to separate an incident ray into a plurality of rays, and a retardation plate disposed between two optical anisotropic elements adjacent to each other among the first to fourth optical anisotropic elements, and an image sensor configured to photoelectrically convert an optical image formed by light that has passed the optical low-pass filter. A predetermined condition is satisfied.

Imaging apparatus and optical low-pass filter

The polarization acquisition apparatus is configured to allow an image capturing system including an interchangeable lens and an image capturing apparatus to perform image capturing using polarized light. The polarization acquisition apparatus includes a variable polarization axis element in which a direction of its polarization transmission axis is variable, a driver configured to operate the variable polarization axis element so as to change the direction of the polarization transmission axis, a first mount to which the image capturing apparatus is detachably attachable, and a second mount to which the interchangeable lens is detachably attachable. The driver is configured to operate the variable polarization axis element so as to change the direction of the polarization transmission axis to at least three directions when the image capturing is performed multiple times.

Polarization acquisition apparatus, image capturing apparatus and image capturing system

An image pickup optical system includes an aperture stop, a first apodization filter disposed on an object side of the aperture stop, and a second apodization filter disposed on an image plane side of the aperture stop, each of the first apodization filter and the second apodization filter satisfies a predetermined condition, and a meridional light beam of a maximum angle of view has an optical path not involving at least one of a point of intersection between the optical axis and the first apodization filter and a point of intersection between the optical axis and the second apodization filter when an aperture size of the aperture stop is maximum.

Image pickup optical system and image pickup apparatus

An optical low pass filter includes a first birefringent plate, a second birefringent plate, a third birefringent plate, and a fourth birefringent plate. A conditional expression of 1.15&#x3c;b/a&#x3c;3 is satisfied, in a case where a separation width of an incident light ray in each of the first birefringent plate and the second birefringent plate is set to be a and a separation width of an incident light ray in each of the third birefringent plate and the fourth birefringent plate is set to be b.

Optical low pass filter and, image capturing apparatus and image capturing unit having the same

An optical low-pass filter is arranged on an object side than an image sensor in an image pickup apparatus and has an unevenness shape. The conditions of 5.0 &#x3bc;m&#x2264;&#x394;z&#x2264;80.0 &#x3bc;m and 1.0&#x2264;Ps/&#x3c;Pf&#x3e;&#x2264;20.0 are satisfied where &#x394;z represents a distance between the optical low-pass filter and the image sensor, Ps represents a pixel pitch of the image sensor, and &#x3c;Pf&#x3e; represents an average pitch of the unevenness shape.

Optical low-pass filter and image pickup apparatus

The antireflection coating is a multi-layer film to be formed on a surface of a substrate. The film includes multiple layers including an uppermost layer most distant from the substrate among the multiple layers, and a lower layer including at least one layer other than the uppermost layer. A refractive index nof the uppermost layer for a wavelength of &#x3bb; (nm) satisfies a condition of 1.11&#x2264;n&#x2264;1.3. An optical admittance Y of the lower layer is expressed by Y=a+ib, and a and b in the optical admittance satisfy conditions of (a&#x2212;1.13)+(b&#x2212;0.24)&#x2264;0.45for &#x3bb;=430, (a&#x2212;1.33)+(b+0.05)&#x2264;0.25for &#x3bb;=900 and (a&#x2212;1.14)+(b+0.25)&#x2264;0.29for &#x3bb;=1800.

Antireflection coating, optical element, optical system and optical apparatus

An optical apparatus includes a first retardation plate giving a retardation between polarization components in slow and fast axis directions, a second retardation plate changing a relative retardation between polarization components in slow and fast axis directions, and a polarizer extracting a polarization component guided to the image pickup element. The first and second retardation plates, and the polarizer are disposed in order from an object side. The slow or fast axis direction of the first retardation plate is parallel to a polarization direction of the polarization component extracted by the polarizer. The slow or fast axis direction of the second retardation plate is inclined by 45 degrees with respect to the polarization direction. When a design wavelength is &#x3bb;, a phase change amount being a difference between maximum and minimum values of the relative retardations is in a range from 2&#x3bb;/5 to 3&#x3bb;/5 both inclusive.

Optical apparatus and image pickup apparatus

An optical element having antireflection function includes a substrate including a first relief structure, which includes a plurality of convexes and a plurality of concaves arrayed with a pitch of at most a half of a wavelength &#x3bb;. A thin film layer including at least one thin film on the first relief structure. The at least one thin film each has a refractive index lower than a refractive index of the substrate. The optical element satisfies the following conditional expression: 1/4 &#x2266;h/h&#x2266;and 1/5 &#x3bb;&#x2266;D&#x2266;&#x3bb;, where hrepresents a first height difference between a top and a bottom of the first relief structure in a normal direction of a bottom plane of the first relief structure, hrepresents a second height difference between a top and a bottom of the second relief structure in the normal direction, D represents a maximum thickness of the thin film layer, and the wavelength &#x3bb; is 550 nm.

Optical element with antireflection function and optical apparatus including the same

Provided is an anti-reflection film, which is formed on substrate, the anti-reflection film having a laminated layer structure including, in order from the substrate: a first layer to a sixth layer each formed of a dielectric thin film; and a seventh layer formed by a wet process, in which the first to the sixth layers are formed of three kinds of mediums having different refractive indices from one another, and in which, when refractive indices of the three kinds of mediums at wavelength of 550 nm are defined as nL, nM, and nH, the first layer is formed of a medium having nM, the sixth layer is formed of a medium having nH, a layer formed of a medium having nL and a layer formed of a medium having off are spaced away from each other, and nL, nM, and nH are appropriately set.

Anti-reflection film, optical element including the same, and optical system

An anti-reflection film includes first through ninth layers. Regarding light having a wavelength of 550 nm, where the refractive indexes of the first through ninth layers are nthrough nrespectively, the optical film thicknesses dthrough d(nm) respectively, and the maximum value of the difference in the refractive index between adjoining layers for layersthroughis &#x394;n, the following conditions are satisfied.1.60&#x2266;n1&#x2266;1.70, 15 nm&#x2266;d1&#x2266;140 nm,2.00&#x2266;n2&#x2266;2.40, 20 nm&#x2266;d2&#x2266;120 nm,1.60&#x2266;n3&#x2266;1.70, 11 nm&#x2266;d3&#x2266;70 nm,2.00&#x2266;n4&#x2266;2.40, 20 nm&#x2266;d4&#x2266;165 nm,1.60&#x2266;n5&#x2266;1.70, 15 nm&#x2266;d5&#x2266;45 nm,2.00&#x2266;n6&#x2266;2.40, 90 nm&#x2266;d6&#x2266;175 nm,1.60&#x2266;n7&#x2266;1.70, 50 nm&#x2266;d7&#x2266;110 nm,2.00&#x2266;n8&#x2266;2.40, 20 nm&#x2266;d8&#x2266;50 nm,1.20&#x2266;n9&#x2266;1.28, 140 nm&#x2266;d9&#x2266;160 nm, and0.40&#x2266;&#x394;n&#x2266;0.67.

Anti-reflection film and optical element having the same

The image capturing apparatus includes an optical low-pass filter configured to separate one incident ray into multiple rays to form multiple point images, and an image sensor configured to photoelectrically convert the multiple point images. The optical low-pass filter satisfies a condition of 0.4&#x3c;2&#xd7;&#x3c3;/P&#x3c;0.9. P represents a pixel pitch of the image sensor, and &#x3c3; represents a standard deviation of a distribution of the multiple point images.

Image capturing apparatus

The optical element of the present invention has an anti-reflection film formed on a substrate. The anti-reflection film comprises a low refractive index layer that is formed by mutually binding hollow fine particles, each of which has a vacancy therein, using a binder, and the low refractive index layer consists of a first layer serving as an outermost layer and a second layer which is adjacent to the first layer and is located on the substrate side. Here, the filling ratio of the binder to the first layer is lower than the filling ratio of the binder to the second layer, the refractive index of the first layer is 1.1 or more but not more than 1.25 and the refractive index of the second layer is 1.26 or more but not more than 1.35.

Optical element, and optical system and optical apparatus using same

The anti-reflection structure includes a graded refractive index layer that is disposed on a substrate and whose refractive index decreases as a distance from the substrate increases, and a homogeneous layer that is disposed on the graded refractive index layer and whose refractive index is homogeneous. The structure satisfies a condition of nb&#x2212;na&#x3e;0.10 where na represents the refractive index of the homogenous layer, and nb represents a homogenous layer side effective refractive index of the graded index refractive index layer.

Anti-reflection structure with graded refractive index layer and optical apparatus including same

Provided is an optical system with an excellent anti-reflection effect and ghost suppression effect including an aspherical lens having at least one of an incident surface and an exiting surface of an optical glass formed of an aspherical surface, in which: the aspherical surface includes an anti-reflection structure formed thereon, the anti-reflection structure having an anti-reflection function and including multiple inorganic structural parts finer than a used wavelength; and the aspherical surface has a point that satisfies the following expression: |(1/Rm&#x2212;1/Rs)/Rm|&#x3e;5.0&#xd7;10, where Rm denotes a radius of curvature in a meridional direction at an arbitrary point, and Rs denotes a radius of curvature in a sagittal direction at the arbitrary point.

Optical system and optical equipment including the same

An image projection apparatus includes light sourcestoemitting at least two colored lights whose wavelengths are different from each other, a polarization conversion elementcontrolling a polarization direction of the colored light, at least two light modulation elementsandmodulating incident light, a light guide optical systemguiding the at least two colored lights from the polarization conversion element to the at least two light modulation elements in accordance with the polarization direction, and a projection optical system. One of the at least two colored light and the other are emitted as lights whose polarization directions are different from each other from the polarization conversion element. A drive unitturns on the light sources so that the one of the colored lights and at least one of the other enter the at least two light modulation elements at the same time.

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Koshigaya, Japan

Kazuhiko Momoki