34results about How to "Small aberration" patented technology

A holographic projection system with a display screen and an optical wave tracking means for controlling the direction of propagation of a modulated wave uses a position controller and an eye finder. An extremely wide tracking range is realised in the projection system for simultaneous viewing of the reconstruction by multiple observers, which are situated beside one another. The reconstruction of the scene is reconstructed for each eye position of an observer such that the entire scene is visible in the visibility region in a large tracking range with minimal errors. The projection system reconstructs the scene with the help of modulated partial waves. Projection means direct these partial waves with separately holographically reconstructed segments of the scene at the desired eye position through a structure of screen segments which are at least horizontally staggered on the display screen.

An image relay optical system is provided with an optical coupling member before incidence of image light on a light guide member. Among a first light incident surface, a coupling member reflecting surface, and a first light emitting surface provided in the optical coupling member, the coupling member reflecting surface and the first light emitting surface are curved surfaces. Therefore, a large bright virtual image with reduced aberration can be displayed.

A supporting structure for supporting an optical element. The supporting structure includes a first supporting member for supporting the optical element, a second supporting member arranged in an outer diameter side of the first supporting member for supporting the first supporting member, and an elastic member placed between the first supporting member and the second supporting member in the radial direction of the optical element. The inner diameter side of the elastic member is connected to the first supporting member while an outer diameter side of the elastic member is connected to the second supporting member. The elastic member is elastically deformable in the radial direction.

The present invention provides a compact electron lens causing little aberration, and a charged particle beam apparatus such as a scanning electron microscope that is super compact and offers a high resolution. An upper magnetic pole and a sample-side magnetic pole are magnetically coupled to the respective poles of a permanent magnet that is made of a highly strong magnetic material such as a rare-earth cobalt system or a neodymium-iron-boron system, that is axially symmetrical, and that has a hole in the center thereof. An inner gap is created on the side of a center axis. Thus, a magnetic lens is formed axially. Moreover, a semi-stationary magnetic path that shields an outside magnetic field and has the magnetic reluctance thereof regulated is disposed outside. The sample-side magnetic pole and magnetic path defines a region where magnetic reluctance is the highest outside the permanent magnet. A space defined by the permanent magnet, upper magnetic pole, sample-die magnetic pole, and semi-stationary magnetic path is filled with a filling made of a non-magnetic material. Thus, an objective lens is constructed.

A hologram optical element is formed on a substrate so as to make an optical device. The hologram optical element is formed in an area smaller than an irradiation area of a beam for reproduction such as image light or object light on the substrate. Supposing that the beam for reproduction is made of a center beam having intensity higher than 50% of center intensity and other peripheral beam, the hologram optical element is formed on the substrate in a size for diffracting only the center beam so that a flare or a ghost can be relieved without using additional optical elements such as a shading plate.

An electronic imaging apparatus of the present invention comprises a photographing optical system, in order from an object side, a first lens group having negative refracting power, which has a reflecting component having a reflecting surface for bending an optical path of an incident light from the object side and at least two positive lens groups arranged at an image side of the first lens group, wherein the photographing optical system is a zoom optical system and the following condition is satisfied: −1.75<f1 / fw<−0.8 where f1 is a focal length of the first lens group, and fw is a focal length at the wide angle end at the photographing optical system.

A holographic projection system with a display screen and an optical wave tracking element for controlling the direction of propagation of a modulated wave uses a position controller and an eye finder. An extremely wide tracking range is realized in the projection system for simultaneous viewing of the reconstruction by multiple observers, which are situated beside one another. The reconstruction of the scene is reconstructed for each eye position of an observer such that the entire scene is visible in the visibility region in a large tracking range with minimal errors. The projection system reconstructs the scene with the help of modulated partial waves. Projection element(s) direct these partial waves with separately holographically reconstructed segments of the scene at the desired eye position through a structure of screen segments which are at least horizontally staggered on the display screen.

A wide-angle lens system having a long back focal length, disposed in front of a ⅓″ CCD camera and the focal length (f) for all lens groups is 3.0 mm, the F-number is 3.0 and the half-field angle is 46°. The following conditions are met by the first lens group: 1≦d / d3<1.2; R3 / R2=0.99; and d2 / f=0.03. Here, (d) indicates the thickness of the second lens along the normal line at a given distance from the optical axis within the maximum effective diameter of the object side convex surface of the lens. d3 is the thickness of the second lens along the optical axis.

A high-performance image-forming optical system made compact and thin by folding an optical path using reflecting surfaces arranged to minimize the number of reflections. The image-forming optical system has a single prism. When image-side three surfaces of the prism are defined as a surface A, a surface B and a surface C in order from the image plane side thereof, at least one of the surfaces B and C has a rotationally asymmetric curved surface configuration that gives a power to a light beam and corrects aberrations due to decentration. The optical system leads light rays from an object to the image plane without forming an image in the prism and has a pupil in the prism. The surface A is a transmitting surface through which rays exit from the prism. The surfaces B and C are internally reflecting surfaces, which are positioned to face each other to form a Z-shaped optical path.

The present invention has an object to provide a cold cathode field-emission electron gun with low aberration, to thereby provide a high-brightness electron gun even in the case of a large current. The present invention provides a field-emission electron gun which extracts an electron beam from a cathode and converges the extracted electron beam, the field-emission electron gun including: a magnetic field lens which is provided such that the cathode is disposed inside of a magnetic field of the lens; and an extraction electrode for extracting electrons from the cathode, the extraction electrode being formed into a cylindrical shape without an aperture structure. The present invention can provide an electron gun having a function of converging an electron beam using a magnetic field, the electron gun which is capable of reducing an incidental electrostatic lens action and has small aberration and high brightness.

A method for compensating an aberration of a variable focus liquid lens is configured to compensate the aberration associated with a first lens surface and a second lens surface of the liquid lens. The first lens surface is of a first radius of curvature. The second lens surface is of a second radius of curvature.

A variable magnification optical system consists of, in order from an object side, a first optical system remaining stationary during changing magnification and a second optical system including a plurality of lens groups moving during changing magnification. The first optical system includes a first mirror and a second mirror having reflective surfaces arranged to face each other. The first mirror has a reflective surface concave toward the object side. The second mirror has a reflective surface convex toward the image side. An intermediate image is formed between the second mirror and the second optical system. Predetermined conditional expressions relating to the partial dispersion ratios of the lenses included in the second optical system are satisfied.

An imaging lens includes an optical system having in order from an object side to an image side a first lens group having a positive refractive power and a second lens having a positive refractive power to image an optical image of an object, the first lens group and the second lens group being displaced in an extending amount different from one another to be focused on an object of a finite distance, the first lens group including a negative meniscus lens having a convex surface on the object side, a lens having a weak refractive power, and a lens having a positive refractive power, and the second lens group including four lenses or less or five lenses or less having at least one pair of a cemented lens.

An optical recording medium tilt compensation device having a tilt compensation unit is disclosed that is able to compensate for a tilt error in servo control when recording or reproducing data in an optical recording medium. The optical recording medium tilt compensation device includes an object lens that condenses light from a light source on a recording surface of an optical recording medium; an object lens tilt actuator that controls a tilt of the object lens; an object lens tilt sensor that detects a tilt of the object lens; an optical recording medium tilt sensor that detects a tilt of the optical recording medium; a control unit that controls the tilt of the object lens in accordance with a tilt value from the optical recording medium tilt sensor so that an aberration of the spot condensed on the recording surface is minimum by driving the object lens tilt actuator; a gain variable unit that changes the magnitude of an output signal from the object lens tilt sensor or the optical recording medium tilt sensor.

The invention provides a quasi-periodic optical metasurface imaging element. The quasi-periodic optical metasurface imaging element comprises a substrate and a plurality of cuboid nanorods generated on the substrate, the nanorods are divided into a first size and a second size which respectively correspond to a first wavelength lambda 1 and a second wavelength lambda 2; the first size of nanorodsand the second size of nanorods are alternately arranged in a gold spiral shape at intervals; the length and the width of the nanorod are coupled with the wavelength of an incident light beam; and therotation angle of the nanorod is coupled with the wavelength, focal length, additional phase modulation value and position of the incident light beam, so that the focal length of the element to the parallel incident light with two wavelengths is the same. By adjusting the length, the width and the rotation angle of the nanorod, adaptation to incident beams with various wavelengths can be achieved, the incident beams are focused at the same point and have the quasi-periodic characteristic, and the universality of the design scheme is greatly higher than that of an existing scheme.

A hologram optical element is formed on a substrate so as to make an optical device. The hologram optical element is formed in an area smaller than an irradiation area of a beam for reproduction such as image light or object light on the substrate. Supposing that the beam for reproduction is made of a center beam having intensity higher than 50% of center intensity and other peripheral beam, the hologram optical element is formed on the substrate in a size for diffracting only the center beam so that a flare or a ghost can be relieved without using additional optical elements such as a shading plate.

An optical recording medium tilt compensation device having a tilt compensation unit is disclosed that is able to compensate for a tilt error in servo control when recording or reproducing data in an optical recording medium. The optical recording medium tilt compensation device includes an object lens that condenses light from a light source on a recording surface of an optical recording medium; an object lens tilt actuator that controls a tilt of the object lens; an object lens tilt sensor that detects a tilt of the object lens; an optical recording medium tilt sensor that detects a tilt of the optical recording medium; a control unit that controls the tilt of the object lens in accordance with a tilt value from the optical recording medium tilt sensor so that an aberration of the spot condensed on the recording surface is minimum by driving the object lens tilt actuator; a gain variable unit that changes the magnitude of an output signal from the object lens tilt sensor or the optical recording medium tilt sensor.

Provided is a zoom lens including, in order from an object side to an image side: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power; a third lens unit having a negative refractive power; a fourth lens unit having a positive refractive power; and a rear lens group including at least one lens unit, the first lens unit, the second lens unit, the third lens unit, the fourth lens unit, and the rear lens group having an interval between each pair of adjacent lens units changed for zooming. The third lens unit is configured to move for focusing, and at least a part of the fourth lens unit forms a lens system IS, which is configured to move in a direction including a component of a direction perpendicular to an optical axis for image stabilization.

A catadioptric objective system used for storage and / or reproduction of information by use of an optical near field. The catadioptric objective system is composed of a catadioptric objective lens and a light transmitting plate. The lens has a first surface and a second surface. The first surface has a positive optical power and transmits incident rays. The second surface has a positive optical power and reflects incident rays, and a plane portion is formed in the center of the second surface. The light transmitting plate has a third surface and a fourth surface which are substantially parallel to each other, and the third surface is bonded to the second surface. Incident rays pass through the first surface and are reflected by the second surface. Thereafter, the rays enter into the first surface again and are reflected by the first surface. Then, the rays pass through the plane portion of the second surface, and the rays are converged in vicinity of the fourth surface.

An electronic imaging apparatus of the present invention comprises a photographing optical system, in order from an object side, a first lens group having negative refracting power, which has a reflecting component having a reflecting surface for bending an optical path of an incident light from the object side and at least two positive lens groups arranged at an image side of the first lens group, wherein the photographing optical system is a zoom optical system and the following condition is satisfied:−1.75<f1 / fw<−0.8where f1 is a focal length of the first lens group, and fw is a focal length at the wide angle end at the photographing optical system.

A zoom lens includes, in order from the object side: a positive first lens group; a negative second lens group; a positive third lens group; a negative fourth lens group; and a positive fifth lens group. The distance between the first and second lens groups constantly increases, the distance between the second and third lens groups constantly decreases, the distance between the third and fourth lens groups constantly changes, and the distance between the fourth and fifth lens groups constantly increases when changing magnification from the wide angle to the telephoto end. The first lens group includes, in order from the object side, a negative lens, a positive lens, and a positive lens. The fourth lens group includes, in order from the object side, a negative lens, a negative lens, and a positive lens, and moves toward the image side when focusing from a far distance to a close distance.

An imaging optical system wherein the number of lenses is three to seven, one to four lenses, each of which is an aspheric lens in which radius of curvature of each of both surfaces is infinity in the paraxial region and which has a power of the third-order aberration region in the peripheral area are provided, the first lens from the object side is a negative lens or the aspheric lens, the relationship0.1⁢8<(∑i=1i=n<semantics definitionURL="">❘<annotation encoding="Mathematica">"\[LeftBracketingBar]"< / annotation>< / semantics>1fi<semantics definitionURL="">❘<annotation encoding="Mathematica">"\[RightBracketingBar]"< / annotation>< / semantics>)·fn<0.9is satisfied where i represents a natural number, fi represents focal length of the i-th lens from the object side, f represents focal length of the whole system and n represents the number of the lenses, and the relationship40°<HFOV<80°is satisfied where HFOV represents angle that the principal ray of bundle of rays that enters the imaging optical system and reaches the maximum value of image height forms with the optical axis.

The present invention has an object to provide a cold cathode field-emission electron gun with low aberration, to thereby provide a high-brightness electron gun even in the case of a large current. The present invention provides a field-emission electron gun which extracts an electron beam from a cathode and converges the extracted electron beam, the field-emission electron gun including: a magnetic field lens which is provided such that the cathode is disposed inside of a magnetic field of the lens; and an extraction electrode for extracting electrons from the cathode, the extraction electrode being formed into a cylindrical shape without an aperture structure. The present invention can provide an electron gun having a function of converging an electron beam using a magnetic field, the electron gun which is capable of reducing an incidental electrostatic lens action and has small aberration and high brightness.

A method for compensating an aberration of a variable focus liquid lens is configured to compensate the aberration associated with a first lens surface and a second lens surface of the liquid lens. The first lens surface is of a first radius of curvature. The second lens surface is of a second radius of curvature.

A high-performance image-forming optical system made compact and thin by folding an optical path using reflecting surfaces arranged to minimize the number of reflections. The image-forming optical system has a single prism. When image-side three surfaces of the prism are defined as a surface A, a surface B and a surface C in order from the image plane side thereof, at least one of the surfaces B and C has a rotationally asymmetric curved surface configuration that gives a power to a light beam and corrects aberrations due to decentration. The optical system leads light rays from an object to the image plane without forming an image in the prism and has a pupil in the prism. The surface A is a transmitting surface through which rays exit from the prism. The surfaces B and C are internally reflecting surfaces, which are positioned to face each other to form a Z-shaped optical path.

A catadioptric objective system used for storage and / or reproduction of information by use of an optical near field. The catadioptric objective system is composed of a catadioptric objective lens and a light transmitting plate. The lens has a first surface and a second surface. The first surface has a positive optical power and transmits incident rays. The second surface has a positive optical power and reflects incident rays, and a plane portion is formed in the center of the second surface. The light transmitting plate has a third surface and a fourth surface which are substantially parallel to each other, and the third surface is bonded to the second surface. Incident rays pass through the first surface and are reflected by the second surface. Thereafter, the rays enter into the first surface again and are reflected by the first surface. Then, the rays pass through the plane portion of the second surface, and the rays are converged in vicinity of the fourth surface.

Sensitivity error, image distortion, and background noise upon synthesizing images obtained by an imaging apparatus, and lack of resolution upon reading the entire area of a sample at a time are solved. While moving the sample by the distance that corresponds to the resolution, the sample is read using all the scanning lines of the imaging apparatus, and then an entire image is obtained by synthesizing each line. The imaging apparatus is located such that the scanning lines are parallel to the short side of the sample, and the short side direction is resolved by the maximum resolution of the imaging apparatus.

Provided is a zoom lens including, in order from an object side to an image side: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power; a third lens unit having a negative refractive power; a fourth lens unit having a positive refractive power; and a rear lens group including at least one lens unit, the first lens unit, the second lens unit, the third lens unit, the fourth lens unit, and the rear lens group having an interval between each pair of adjacent lens units changed for zooming. The third lens unit is configured to move for focusing, and at least a part of the fourth lens unit forms a lens system IS, which is configured to move in a direction including a component of a direction perpendicular to an optical axis for image stabilization.

A zoom lens has, in order from an object, a first lens group (G1) having positive refractive power; a second lens group (G2) having negative refractive power; a third lens group (G3) having positive refractive power; and a fourth lens group (G4) having positive refractive power. Zooming is performed by changing an air gap between the lens groups. The fourth lens group (G4) includes, in order from the object, a lens component (La) having positive or negative refractive power, a positive lens component (Lb), and a positive lens component (Lc) having a convex surface facing the object. Specified conditional expressions are satisfied.