Method and apparatus for measuring two dimensional plane displacement by moire fringes of concentric circle gratings

Claim 1

An apparatus for measuring two-dimensional displacement by moire fringes of concentric circle gratings, comprising: a light source generating a light beam; a heat absorbing filter absorbing heat of the light beam; an optical fiber transmitting the light beam from the heat absorbing filter; a condensing lens condensing the light beam from the optical fiber; a beam spliter reflecting the light beam from the condensing lens to change a path of the of the light beam by 90°; a microscope objective lens condensing the light beam from the beam spliter; a moving grating attached to a moving body being shone by the light beam from the microscope objective lens; a standard grating on which is formed a real image of the moving grating by a microscope lens and that forms a pattern of moire fringes from the real image of the moving grating; and a photographing means for capturing a virtual image of the moving grating and the standard grating.

Claim 2

An apparatus for measuring two-dimensional displacement by moire fringes of concentric circle gratings, comprising: a light source generating a light beam; a heat absorbing filter absorbing heat of the light beam; an optical fiber transmitting the light beam from the heat absorbing filter; a condensing lens condensing the light beam from the optical fiber; a beam spliter reflecting the light beam from the condensing lens to change a path of the of the light beam by 90°; a microscope objective lens condensing the light beam from the beam spliter; a moving grating attached to a moving body being shone by the light beam from the microscope objective lens; a standard grating on which is formed a real image of the moving grating by a microscope lens and that forms a pattern of moire fringes from the real image of the moving grating; and a photographing means for capturing a virtual image of the moving grating and the standard grating.

Claim 3

A method for measuring two- dimensional displacement by moire fringe of concentric circle gratings, comprising the steps of: absorbing heat from a beam of a light source using a heat absorbing filter, and thereafter transmitting the beam through an optical fiber; condensing the beam from the optical fiber and thereafter transmitting the beam through a beam spliter to be reflected onto a microscope objective lens; shining the beam through the microscope objective lens and onto a moving grating attached to a moving body; and forming an image of the moving grating onto a standard grating through a microscope objective lens, and capturing an overlapped virtual image of the moving grating and the standard grating using a camera.

Claim 4

A method for measuring two- dimensional displacement by moire fringe of concentric circle gratings, comprising the steps of: absorbing heat from a beam of a light source using a heat absorbing filter, and thereafter transmitting the beam through an optical fiber; condensing the beam from the optical fiber and thereafter transmitting the beam through a beam spliter to be reflected onto a microscope objective lens; shining the beam through the microscope objective lens and onto a moving grating attached to a moving body; and forming an image of the moving grating onto a standard grating through a microscope objective lens, and capturing an overlapped virtual image of the moving grating and the standard grating using a camera.