OPTICAL ANALOGUE IMAGE PROCESSING OF SHAPES AND/OR SIZES OF PARTICLES DISTRIBUTED THREE-DIMENSIONALLY

摘要

In order to three-dimensionally measure the spatial distributions and the behavior of particles in each shape and/or size, a new technique for determining simultaneously and instantaneously shapes, sizes and positions of particles has been developed by using the technique of the Multiplexed Matched Spatial Filter (MMSF) constructed by the Photo-conductor Plastic Hologram (PPH) processed by solvent vapor. The diffraction patterns generated from particles flowing in the collimated laser beam appear and are superimposed at the back focal plane of the convex lens set in the parallel expanded laser beam as the object beam of the holographic optical system. The particles are discriminated for each shape and/or size by a MMSF which is a holographic filter set at the back focal plane of the lens, and the auto-correlation signals appear skew-symmetrically for the positions of the measured particles. The auto-correlation signals obtained for each shape and/or size of particles which flow in the object beam are focused at the different depth apart from the back focal plane of the imaging lens set on the back of the MMSF. The auto-correlation signals are moving in correspondence with movement of particles in the laser beam. The auto-correlation signals are taken to the photograph three-dimcnsionally by scanning focal point of the signals to the different place, using galvanic scanning mirror. Therefore, 3D behavior of particles is measured simultaneously for each shape and/or size.