Moiré pattern

About: Moiré pattern is a research topic. Over the lifetime, 1917 publications have been published within this topic receiving 27176 citations. The topic is also known as: moiré fringes & moire pattern.

Coaxial illumination mirror image Moire measuring device and method

Abstract: The invention relates to a coaxial illumination mirror image Moire measuring device and method. The coaxial illumination mirror image Moire measuring device comprises a camera, a telecentric light path lens set, a spectroscope, an LCD optical grating, a diffusion light source and a computer system, wherein the spectroscope has a half-permeating and half-reflection characteristic, the included angle between the spectroscope and the central axis is 45 degrees, and the spectroscope can reflect light of the diffusion light source to a mirror object to be detected, so that coaxial illumination is formed. The LCD optical grating is connected with the computer system, and the frequency and direction of grid lines can be changed through programming. The coaxial illumination mirror image Moire measuring method includes the step of device adjustment, wherein the mirror object to be detected is put behind the optical grating, the step of data collection, wherein the camera and the telecentric light path lens set are used for permeating the optical grating and shooting a Moire fringe graph formed by the grid lines of the optical grating and a virtual image of the optical grating in an overlapping mode, and the step of data processing, wherein the computer system is used for processing the Moire fringe graph, and a three-dimensional shape of the mirror to be detected is rebuilt.

Assigning fringe order in moire profilometry using colors

Abstract: A side illumination based approach capable of assigning fringe order to moire topography is proposed. Along with the three basic components used to generate moire fringes (camera/observer, grating and light source), current proposal uses additional light source which rules the object parallel to the grating plane with colored bands. This article deals with the theory, simulations and experimentation of the proposed method. This analysis is not only useful to assign fringe orders to Moire phase map, but also helps one to reliably extract object surface profile in the presence of surface discontinuities (which will leads to 2Nπphase jumps).

Moiré pattern reduction by using special designed parallax barrier in an autostereoscopic display

Abstract: The moire pattern is caused by the spatial interference of two regular pattern structures. In the case of an autostereoscopic display, it's caused by the overlap of the parallax barrier and the black matrix among pixels of FPD. To minimize the moire effect, we simulate the relationship of brightness distribution and various design parameters of the parallax barrier. According to the simulation results, a combination of multiple parameters was chose to obtain a moire free autostereoscopic display based on the concept of mutual compensation among the design parameters. After the detailed simulation, experiments of the final design were made to verify the performance of the display.

Anti-parallax device for observation of moiré fringes

Abstract: A parallax corrected grating system, consisting of two coarse plane gratings close together, enables relative displacements of 0?0005 in to be observed visually by use of the moir? effect, in ambient light conditions.

Focusing point detecting method of optical device

Abstract: PURPOSE:To detect focusing of an optical device promptly and accurately from the appearing moire image interference fringe, by placing first and second charts having regular pattern on the imaging lens focal plane and subject position. CONSTITUTION:A first chart 6 and a second chart 7 are placed on a focal plane 4 of an imaging lens 2 and a subject position 5. The respective charts are provided with regular patterns 61, 71, which should cause moire interference phenomenon when they are overlapped. A moire image 9 of good contrast appears when the two regular patterns to be overlapped are formed in the same pitch. There fore, since the moire image 9 appears only when correctly focused, the range finding precision similar to the required precision of the imaging lens may be obtained, so that the focusing of the optical device may be detected promptly and accurately.