Abstract: A shape measuring apparatus of the present invention measures a variation in a thickness of an object to be measured WA based on an A surface reference interference light and an A surface measuring interference light obtained by performing optical heterodyne interference on a first A surface measuring light and a second A surface measuring light and a B surface reference interference light and a B surface measuring interference light obtained by performing the optical heterodyne interference on a first B surface measuring light and a second B surface measuring light. When the optical heterodyne interference is performed, the shape measuring apparatus makes the first A surface measuring light and the second B surface measuring light equal in frequency and makes the first B surface measuring light and the second A surface measuring light equal in frequency.

Abstract: A shape measuring apparatus of the present invention measures a variation in a thickness of an object to be measured WA based on an A surface reference interference light and an A surface measuring interference light obtained by performing optical heterodyne interference on a first A surface measuring light and a second A surface measuring light and a B surface reference interference light and a B surface measuring interference light obtained by performing the optical heterodyne interference on a first B surface measuring light and a second B surface measuring light. When the optical heterodyne interference is performed, the shape measuring apparatus makes the first A surface measuring light and the second B surface measuring light equal in frequency and makes the first B surface measuring light and the second A surface measuring light equal in frequency.

Abstract: A shape measurement device and a shape measurement method according to the present invention measure, for first and second distance measurement units which are disposed so as to be opposed to each other with a measurement object to be measured interposed therebetween and each measure a distance to the measurement object, first and second displacements of the first and second distance measurement units in an opposition direction, and obtain, as a shape of the measurement object, a thickness of the measurement object in the opposition direction, the thickness being corrected with the measured first and second displacements, based on first and second distance measurement results measured by the first and second distance measurement units, respectively.

Abstract: A shape measurement device and a shape measurement method according to the present invention measure, for first and second distance measurement units which are disposed so as to be opposed to each other with a measurement object to be measured interposed therebetween and each measure a distance to the measurement object, first and second displacements of the first and second distance measurement units in an opposition direction, and obtain, as a shape of the measurement object, a thickness of the measurement object in the opposition direction, the thickness being corrected with the measured first and second displacements, based on first and second distance measurement results measured by the first and second distance measurement units, respectively.

Abstract: A shape determining device includes first and second homodyne interferometers respectively provided for front and back surfaces of an object to be measured and a thickness distribution calculator that calculates a thickness distribution of the object based on intensities of first and second interference light beams respectively detected by the first and second homodyne interferometers for the front and back surfaces of the object at a plurality of measurement sites. The thickness distribution calculator calculates, for each interference light beam for which the intensity is detected by the first and second homodyne interferometers, a phase difference between the polarization components of a corresponding reference light beam and a corresponding object light beam in a corresponding non-interference light beam based on the intensity of the interference light beam, and calculates the thickness distribution based on a distribution of the calculated phase differences.

Abstract: An object of the present invention is to measure thickness distribution with precision by using a simple device configuration without being affected by vibrations of a to-be-measured object. In the present invention, for each of the front and the back surfaces of a to-be-measured object 1, each of light beams obtained by branching into two an emitted light beam from a laser light source 2 is further branched into two. Then, the light beams are reflected in reference surfaces and measurement points 1a and 1b mutually in a front and back relation, so that non-interference light beams Pax and Pbx each of which contains the reference light beam and the object light beam as mutually orthogonal polarization components are acquired. Then, each light beam is branched into a plurality. Onto one or more of the branched light beams, phase shift is performed in which a change is imparted to the phase difference between the orthogonal polarization components by using wavelength plates a261, a263, and a264 and the like.

Abstract: An epoxy optical sheet comprising a hardened sheet of an epoxy resin and another resin layer formed on one side thereof. The sheet has a retardation of 5 nm or less, an average thickness of 500 &mgr;m or less, a thickness accuracy of ±10% or less, a glass transition temperature of 170° C. or above, and a smooth surface. The epoxy optical sheet is made by a continuous process which comprises: successively forming a strippable resin layer on a support having a smooth surface; successively spreading an epoxy resin coating solution comprising an epoxy resin, a hardener, a hardening accelerator, and a leveling agent, on the resin layer in the form of a sheet; followed by a hardening treatment, thereby forming a hardened sheet adhering to the resin layer; and, at the same time, recovering the hardened sheet together with the resin layer from the support.

Abstract: An epoxy optical sheet having a thickness of 500 &mgr;m or less, a high thickness accuracy, a small retardation and an excellent heat resistance; and a process by which the optical sheet can be efficiently produced.

Abstract: An epoxy optical sheet having a thickness of 500 &mgr;m or less, a high thickness accuracy, a small retardation and an excellent heat resistance; and a process by which the optical sheet can be efficiently produced.

Abstract: An epoxy optical sheet having a thickness of 500 &mgr;m or less, a high thickness accuracy, a small retardation and an excellent heat resistance; and a process by which the optical sheet can be efficiently produced.