Konica Minolta Opto, Inc.

Canon Kabushiki Kaisha

Konica Minolta, Inc.

Kentarou Nakamura

Eiji Nomura

Kohei Ota

Nobuyoshi Mori

Takashi Koyanagi

Kiyono Tateyama

Minoru Ito

Sosuke Yamaguchi

Shohei Urushihara

Takahiro Miyazawa

Tohru Kimura

Minoru Nakamura

Kazutoshi Ishida

Shinichiro Saito

Takeshi Kojima

Junji Hashimura

Norihide Yamada

Yuji Sakurai

Ryo Sugiyama

Kyu Takada

Shogo Yamamoto

Kenta Matsunaga

Jinichi Kasuya

Hiroshi Morishita

Kenichi Ishii

Hideki Tanaka

Yuki Ono

Shinichiro Saitou

The developing member includes a substrate having an electroconductive outer surface; an insulating resin layer on the outer surface of the substrate; and electrically insulating domains on an outer surface of insulating resin layer, and has an outer surface including a surface of the insulating resin layer and surfaces of the domains, wherein a potential decay time constant of each of the surfaces of the domains is &#x2265;60.0 seconds, and a potential decay time constant of the surface of the electrically insulating resin layer is &#x3c;6.0 seconds, and assuming that the electrically insulating domains are orthographically projected onto the outer surface of the substrate, to obtain projection images of the respective domains, each of areas of the projection images is defined as S, and each of areas of convex envelopes of the projection images is defined as H, at least one of the domains satisfies 0.05&#x2264;S/H&#x2264;0.80.

Developing member, electrophotographic process cartridge, and electrophotographic image forming apparatus

Provided is a developer carrying member that enables stable formation of images of high quality even on recording paper having a high talc content. The developer carrying member includes a conductive base member and a surface layer, wherein the surface layer includes a urethane resin, and the urethane resin has a carbonate bond and a tertiary amine structure.

Developer carrying member, process cartridge, and electrophotographic apparatus

An object of the present invention is to provide a virtual image display optical system that is capable of substantially simultaneously displaying virtual images at a plurality of distances even with a simple configuration, and an image display device using the virtual image display optical system. A virtual image display optical system () according to the present invention is provided with: a display element (); a projection optical system () that enlarges an image formed on the display element (); a diffusing screen () that has a diffusing function, and is positioned on the light emission side of the projection optical system (); and a virtual image forming optical system () that converts an image on the diffusing screen () into a virtual image, wherein the virtual image display optical system () is further provided with a positioning changing device () that changes a position of the diffusing screen ().

Virtual image display optical system and image display device

The developer carrying member, includes: an electroconductive substrate; and a surface layer containing a resin, on the substrate, in which a thickness of the surface layer is 1.0 &#x3bc;m or more and 100.0 &#x3bc;m or less, a Martens hardness at an indentation depth of 0.1 &#x3bc;m that is measured by infiltrating a Vickers indenter in a thickness direction of the surface layer from an outer surface of the surface layer is 50.0 N/mmor more and 100.0 N/mmor less, an Asker C hardness that is measured from the outer surface of the surface layer is 75&#xb0; or more and 90&#xb0; or less, and a value of a work function of the outer surface of the surface layer is 5.6 eV or more and 6.0 eV or less.

A wide-angle optical system including, in order from an object side: a negative first lens that is a glass lens having a convex shape on the object side, a concave shape on an image side, and a spherical surface on either side; a negative second lens that has an aspherical surface on at least one side, and a concave shape on the image side; a positive third lens; an aperture; a fourth lens that has an aspherical surface on at least one side; and a fifth lens that has an aspherical surface on at least one side.

Wide-angle optical system, lens unit, and imaging apparatus

The developing member includes a substrate, and an electroconductive layer on the substrate, wherein the electroconductive layer has electrically insulating domains on an outer surface thereof, the domains being independent from each other, the developing member has an outer surface including a surface of the electroconductive layer and surfaces of the domains, and wherein, when each of the domains is orthographically projected onto the surface of the electroconductive layer, defining respective areas of projected images of the domains as S, and defining respective areas of convex envelopes of the projected images as H, at least one domain satisfies the relation represented by 0.05&#x2264;S/H&#x2264;0.80.

Developing member having outer surface with independent electrically insulating domains, electrophotographic process cartridge, and electrophotographic image forming apparatus

An optical pickup apparatus including an objective lens capable of enhancing temperature characteristics and wavelength characteristics, and which enables compatibility for three types of optical discs of BDs, DVDs, and CDs by using the objective lens in common, an optical information recording and reproducing apparatus, and an objective lens suitable for it. In a first optical path difference providing structure in which at least a first basic structure and a second basic structure are superimposed on each other, an amount of a level difference in an optical axis direction can be reduced, whereby it becomes possible to suppress the lowering of a diffraction efficiency when wavelength changes. Further, in the first basic structure and the second basic structure deterioration of the spherical aberration due to the change of the refractive index of the objective lens can be corrected by utilizing a phenomenon that the wavelength of the light source rises similarly due to a rise in the environmental temperature.

Objective lens for optical pickup apparatus, optical pickup apparatus, and optical information recording reproducing apparatus

An objective lens a first optical path difference providing structure in which a first basic structure and a second basic structure are overlapped with each other. The first basic structure is a blaze-type structure which emits a Xth-order diffracted light flux, when the first light flux passes through the first basic structure, where the value of X is an odd integer. At least a part of the first basic structure arranged around an optical axis includes a step facing an opposite direction to the optical axis. The second basic structure is a blaze-type structure which emits a Lth-order diffracted light flux, when the first light flux passes through the second basic structure, where the value of L is an even integer. At least a part of the second basic structure arranged around the optical axis includes a step facing the optical axis.

Objective lens, optical pickup apparatus, and optical information recording reproducing apparatus

There are provided an optical pickup device which can satisfactorily record and/or reproduce information on different kinds of optical information recording medium in spite of compactness, and an objective optical element used for the optical pickup device. The optical functional surface of the objective optical element includes at least two areas of a central area including an optical axis and a peripheral area surrounding the central area. An optical path difference providing structure in the central area is a structure obtained by overlapping a first central basic structure and a second central basic structure which are in a shape of ring-shaped zones divided by step differences, with each other. An optical path difference providing structure in the peripheral area is a structure obtained by overlapping a first peripheral basic structure and a second peripheral basic structure which are in a shape of ring-shaped zones divided by step differences, with each other.

Optical pickup device and objective optical element

Provided are an objective lens with enhanced transmittance and an optical pickup apparatus which can record and/or reproduce information properly for three kinds of discs with different recording densities, even if a single lens is used as the objective lens. When all the expressions (1) to (3) are satisfied, excellent aberration characteristics can be obtained for the three kinds of discs: &#x2212;0.02&#x2266;m&#x2266;0.02 (1); 0&#x2266;(WD&#x2212;WD)&#x2266;1.57 m+0.123 or 1.57 m+0.24&#x2266;(WD&#x2212;WD)&#x2266;0.7 (2); and 0&#x2266;(WD&#x2212;WD)&#x2266;1.79 m+0.333 or 1.66 m+0.508&#x2266;(WD&#x2212;WD)&#x2266;0.7 (3).

Objective lens and optical pickup device

Provided is an optical pickup device capable of ensuring the compatibility among three types of optical discs, i.e., BDs, DVDs, and CDs, with a common objective lens and, in addition, capable of ensuring a sufficient working distance for CDs, and also provided are an optical information recording and reproducing device and an objective lens suitable for the optical information recording and reproducing device. On the objective lens, there is arranged a first optical path difference providing structure formed such that: the direction of step differences of a basic structure wherein the diffraction order of a blue-violet laser light flux become an odd order faces toward the opposite direction of the optical axis; the direction of step differences of a basic structure wherein the diffraction order of the blue-violet laser light flux become an even order faces toward the optical axis; and both the basic structures are overlapped together.

Objective lens for optical pickup device, optical pickup device, and optical information recording and reproducing device

Provided is an objective optical element which can appropriately correct degradation from spherical aberration upon fluctuation of a light source wavelength while maintaining light use efficiency, just by changing the magnification of the objective optical element, and which can record/reproduce information to/from different optical discs. Also provided is an optical pickup device using the objective optical element. When a light flux having two different wavelengths &#x3bb;, &#x3bb;(wherein &#x3bb;&#x3c;&#x3bb;and &#x3bb;&#x2212;&#x3bb;=5 nm) within a range of wavelength &#x3bb;is introduced to the objective optical element to measure the wavefront aberration, the following third order and fifth order spherical aberrations in unit of &#x3bb;rms are obtained: SA3(&#x3bb;), SA5(&#x3bb;), SA3(&#x3bb;), SA5(&#x3bb;). If &#x394;SA3=|SA3(&#x3bb;)&#x2212;SA3(&#x3bb;)|, &#x394;SA5=|SA5(&#x3bb;)&#x2212;SA5(&#x3bb;)|, the following expression is satisfied: 0.18&#x3e;&#x394;SA3&#x3e;&#x394;SA5&#x3e;0 (1).

Objective optical element and optical pickup device

An objective lens relating to the present invention includes a first optical path difference providing structure in which a first basic structure and a second basic structure are overlapped with each other. The first basic structure is a blaze-type structure which emits a Xth-order diffracted light flux, when the first light flux passes through the first basic structure, where the value of X is an odd integer. At least a part of the first basic structure arranged around an optical axis includes a step facing an opposite direction to the optical axis. The second basic structure is a blaze-type structure which emits a Lth-order diffracted light flux, when the first light flux passes through the second basic structure, where the value of L is an even integer. At least a part of the second basic structure arranged around the optical axis includes a step facing the optical axis.

An optical pickup apparatus according to the present invention includes: a first light source for emitting a first light flux; a second light source for emitting a second light flux; a third light source for emitting a third light flux; and an objective optical element. The objective optical element has an optical surface including at least two areas provided with optical path difference providing structures. The objective optical element converges the first to third light fluxes each passing through the predetermined areas on the objective optical element onto respective information recording surfaces of the first to third optical disks. The optical pickup apparatus provides a wavelength dependency of a spherical aberration so as to correct a change in a spherical aberration due to a refractive index change with a temperature change of the objective optical element.

Optical pickup apparatus, objective optical element and optical information recording reproducing apparatus

Provided is an objective lens for an optical pickup apparatus. The objective lens collects diffracted light generated by an optical path difference giving structure onto the information recording surface of an optical information recording medium as a spot and suppresses fluctuation of diffraction efficiency due to a change of using wavelength. The optical pickup apparatus using such objective lens is also provided. The total diffraction efficiency can be improved by adjusting a wavelength at which the diffraction efficiencies of a plurality of basic structures forming the optical path difference giving structure in the objective lens are maximum, in accordance with a basic structure.

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Hachioji, Japan

Kentarou Nakamura