Apparatus and method for measurement of aspheric surface with hologram and concave surface

• Main Authors: KIM, TAE HUI, BURGE, JAMES H
• Format: Patent
• Language: English; Korean
• Published: 27.06.2003
• Edition: 7
• Subjects: MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; PHYSICS; TESTING; TESTING STATIC OR DYNAMIC BALANCE OF MACHINES ORSTRUCTURES; TESTING STRUCTURES OR APPARATUS NOT OTHERWISE PROVIDED FOR

PURPOSE: An apparatus and a method for measuring an aspheric surface are provided to precisely measure an optical device having the aspheric surface by using an optical device having a hologram, in which a lattice interval is finely formed. CONSTITUTION: An aspheric surface measuring apparatus includes an interferometer(31) for creating incident light. A test member(39) having an aspheric surface is provided to form test light by reflecting incident light created by the interferometer. A first optical device(32) is aligned in an optical path of incident light. The first optical device(32) has at least one plane, in which a hologram(34) for diffracting incident light is formed. A second optical device(36) is aligned at a rear portion of the first optical device(32) so as to guide incident light towards the aspheric surface. The second optical device(36) has a concave surface for reducing an incident angle of test light reflected from the aspheric surface. 비구면 측정장치 및 측정방법이 개시된다. 개시된 비구면 측정장치는, 입사광을 생성하는 간섭계와, 입사광을 반사시켜 시험광으로 형성하는 비구면을 가지는 시험부재와, 입사광의 광경로상에 위치하며 시험부재로 입사광을 회절시키는 홀로그램이 형성되는 적어도 하나의 면을 가지는 제1광학소자 및, 제1광학소자의 후방에 정렬되어 입사광을 비구면으로 진행시키며 비구면에서 반사된 시험광의 홀로그램에 대한 입사각을 감소시키는 오목면을 가지는 제2광학소자를 구비한다. 본 발명은 홀로그램과 오목면을 가지는 광학소자를 이용하여 비구면정도가 심한 렌즈를 정밀하게 측정할 수 있다.