Fujinon Corporation

Fuji Photo Optical Co., Ltd.

Fujifilm Corporation

Asahi Glass Company, Limited

Nobuaki Ueki

Hideo Kanda

Koji Otsuka

Hidenori Takahashi

Tsuyoshi Mitarai

Katsuyo Kubo

The first and second optical elements are held so as to be rotatable relative to each other about an optical axis. An aberration, which can cancel an aberration caused by a color separation prism, is generated from a synthesis of aberrations generated by the first and second optical elements in a case in which the second optical element is positioned at a first position with respect to the first optical element. The aberration generated by the first optical element is cancelled by the aberration generated by the second optical element in a case in which the second optical element is positioned at a second position with respect to the first optical element. The second optical element is positioned at the first position in a case in which the lens device is to be used in a 3-CCD type first camera device, and the second optical element is positioned at the second position with respect to the first optical element in a case in which the lens device is to be used in a single-CCD type second camera device.

Lens device, camera system, and aberration correction unit

A low coherent light from a white light source is emitted to a sample surface. A detour distance in a detour section is adjusted such that an optical path difference between a reference light and a sample light is equal to or shorter than a coherence length of interference light. The interference light is incident on an image sensor only when an inclination angle of a diffraction grating plate and a wavelength of the interference light satisfy a predetermined condition. Thus, an interference fringe image is formed. Based on each of the interference fringe images taken on a wavelength-by-wavelength basis of the interference light and an optical distance between a reference surface and the sample surface along an optical path of a measuring light at the time of taking the interference fringe image, a shape of the sample surface is measured.

Apparatus for measuring rotationally symmetric aspheric surface

A relationship between surface decenter of a lensunder test and surface-decenter comatic aberration and a relationship between surface tilt of the lensunder test and surface-tilt comatic aberration are calculated by computer simulation. The surface tilt of the lensunder test is calculated by measuring a transmissive wavefront of a projecting portion, and comatic aberration of the lensunder test is calculated by measuring a transmissive wavefront of a lens portion. The surface-decenter comatic aberration that occurs due to the surface decenter is calculated by subtracting the surface-tilt comatic aberration from the calculated comatic aberration. The surface decenter of the lensunder test is calculated based on the calculated surface-decenter comatic aberration.

Aspheric lens surface-decenter measuring method and apparatus

A moving-object measuring interferometric apparatus comprises: a light beam output section outputting a measuring beam; an interference optical system obtaining interference light by projecting the measuring beam onto an object and by allowing light reflected from the object or transmitted light having passed through the object to interfere with reference light; an image pickup section obtaining image information by receiving the interference light on an image pickup surface; and an image pickup timing control section setting a momentary image pickup period during which the object is regarded as being stationary to be contained in a light reception acceptable period of the image pickup surface and controlling the interference light to enter the image pickup surface only during the momentary image pickup period.

Interferometric apparatus for measuring moving object and optical interferometry method for measuring moving object

The light intensity ratio adjustment filter is placed between the reference surface and the sample surface of the interferometer. This light intensity ratio adjustment filter has a light intensity ratio adjustment film including an optical reflection-absorption layer and a dielectric anti-reflection layer on the surface of a transparent substrate made of glass on the sample side, and an optical anti-reflection film on the reference surface side, and acts so as to reflect part of the incident light from the surface opposite the reference surface, and after absorbing part of the remaining light, transmit the remainder towards the sample, and furthermore, absorb part of the light returned from the sample while controlling reflection, and transmit the remainder in the direction of the reference surface as the sample light.

Light intensity ratio adjustment filter for an interferometer, interferometer, and light interference measurement method

There are carried out a first measurement operation for measuring the shape of a front surface of a sample held in a held state, a second measurement operation for measuring the shape of a back surface of the sample held in the same state, and a third measurement operation for measuring the shape of the back surface of the sample held so as to cause inverse distortion. First data are acquired on the basis of the front surface shape data obtained through the first measurement operation and the back surface shape data obtained through the second measurement operation. Second data are obtained on the basis of the front surface shape data obtained through the first measurement operation and the back surface shape data obtained through the third measurement operation. Holding distortion is determined on the basis of the first and second data.

Method and apparatus for measuring holding distortion

A subject having a test surface is held by a holder so that an axis line of the test surface intersects the direction of gravity and applied with a load, from above and beneath, that is optimized for accurate measurement of surface profile of the test surface. For optimization of the load, the test surface is applied with variable exploratory load strong enough to cause bending deformation in the test surface and a linear-functional relationship existing between more than two different exploratory loads and sizes of surface deformation caused with the different exploratory loads is derived. With the aid of linear-functional relationship, a load that induces the subject to cause surface deformation less than a predetermined size of surface deformation admissible, for example, as a manufacturing en-or is used as an optimized load.

Method and device for holding subject and measuring instrument equipped with the device

The light source is a low-coherence light source, and the optical path is regulated so that the reflected light from the upper surface of each metal wire and that from the reference surface interfere with each other during the first measuring operation, and so that the reflected light from the small regional surface of the conductive layer and that from the reference surface interfere with each other during the second measuring operation. The light detecting surface is divided into a plurality of detecting unit regions, and obtains interference fringe information corresponding to the upper surfaces of the metal wires or the general shape of the first or second virtual contact surface engaged with the small regional surfaces of the conductive layer on the basis of the light intensity averaged and detected with respect to the detecting unit regions.

Interferometer for measuring virtual contact surfaces

A Fizeau interferometer apparatus is used for both low and high interference measurement. When irradiating a reference surface and a sample with a low coherent luminous flux, a path-matching passage divides the low coherent luminous flux into first and second paths, while the optical path length difference between the respective luminous fluxes passed through the two paths equals twice the optical distance between the reference surface and the sample. When irradiating the reference surface and the sample with a high coherent luminous flux, the luminous flux is made incident on the sample side of the path-matching passage at a position coaxial with the low coherent luminous flux.

Interferometer apparatus for both low and high coherence measurement and method thereof

In a phase unwrapping method for fringe image analysis, when storing newly calculated numeric data into a storage list, the new numeric data is initially compared with numeric data of a representative rank within each rank block in the storage list, whereby the rank block to store the data is chosen. Subsequently, the new numeric data is compared with each of respective numeric data within thus chosen rank block, so as to determine a rank at which the new numeric data is to be stored, and then is stored into the storage list. Along with the storing of numeric data, rank data is updated.

Phase unwrapping method for fringe image analysis

Respective regional form information items obtained from regional interference fringe images corresponding to partial regions of a spherical surface to be inspected are transformed into regional synthesis form information items corresponding to a common coordinate system set for aperture synthesis by using a relationship among a polar coordinate system of the spherical surface, a plane coordinate system of an imaging plane, and the common coordinate system. Thus obtained regional synthesis form information items are subjected to aperture synthesis processing, so as to determine the overall form information of the spherical surface.

Spherical form measuring and analyzing method

A moving distance of a moir&#xe9; grating in y direction is set with respect to a grating pitch of a moir&#xe9; grating, whereas an imaging magnification of imaging means is set according to the relationship between the pixel pitch of an image pickup device in the imaging means and the size of grating pitch when forming an image on the image pickup device. An image of moir&#xe9; fringes is captured each time when the moir&#xe9; grating is moved by a predetermined distance in the y direction, so as to yield a predetermined number of y-direction positional moir&#xe9; fringe images, which are then averaged. According to thus obtained average moir&#xe9; fringe image, shape information of a surface to be inspected is determined.

Moir&#xe9; grating noise eliminating method

An imaging optical system for an oblique incidence interferometer comprises first and second optical systems and an intermediate imaging surface therebetween. Each of the first and second imaging optical systems comprises two telecentric lenses, arranged afocal to each other, having respective focal lengths different from each other. A first image of a surface to be inspected having a deformed aspect ratio with respect to this surface is formed on the intermediate imaging surface by way of the first imaging optical system. The second imaging optical system is arranged such that the first image is focused onto the imaging surface of the interferometer as a second image corrected so as to have substantially the same aspect ratio as that of the surface to be inspected.

Imaging optical system for oblique incidence interferometer

While the three-flat method is used as background art, a technique for analyzing the difference between two planes by approximating it with symmetry power series polynomials are employed, and measurement is effected at two positions where the reference surface and the sample surface are in a predetermined reference rotation state and where they are rotated from each other by 90 degrees from the former state; whereby the approximate surface form of the whole plane can be determined by a very simple arithmetic operation with a high accuracy. Of three glass sheets, different pairs of two glass sheets 53 and 54 are successively selected three times. The difference between two surfaces to be measured in each pair of the two glass sheets 53 and 54 is measured at a first position where, with respect to one glass sheet 53, the other is set at a predetermined rotational position; and a second position where the two sheets are rotated from each other by 90 degrees from the first position. Then prepared are relational expressions to which sixth-order Zernike polynomials approximating the difference between the surfaces to be measured is applied. These relational expressions are operated so as to determine the form of the surface to be measured in each of the glass sheets.

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Saitama, Japan

Nobuaki Ueki