The development trend of optical imaging systems today is lightweight, large zoom, and low power consumption. The traditional zoom imaging system is composed of glass lens, mechanical control module and image sensor. Its working principle is to realize zooming by mechanically adjusting the distance between each lens group.The shortcomings of traditional zoom imaging systems are its complex structure, inconvenient operation and discrete variable multiples. The combination of adjustable focus lens and glass lens makes the zoom optical imaging system lighter and easier to obtain image detail information. In this paper, we propose a variable magnification imaging system composed of a combination of a liquid crystal lens and a glass lens. This variable magnification imaging system consists of an optical lens group, a liquid crystal lens array and a CMOS detector. The optical lens group is a telephoto lens composed of traditional glass lenses.The liquid crystal lens is a liquid crystal device that electronically controls the focal length. The object is first imaged through the optical lens group, the liquid crystal lens array then images the image formed by the optical lens group, and finally the image is received by the CMOS. This is the imaging principle of this system;By adjusting the voltage applied to the liquid crystal lens array to adjust its focal length, and then moving the CMOS mechanically, zoom imaging can be achieved.
In this paper, we present a new and practical method for achieving real-time wavefront measurement, dramatically increasing the resolution, dynamic range of Shack-Hartmann wavefront sensor and improving the wavefront reconstruction quality. In proposal method, a liquid crystal display panel (LCD) for the generation of an array of Fresnel microlenses is used instead of the static microlens array of the conventional Shack-Hartmann type sensor
An off-axis holographic microlens array is designed instead of the normal microlens array to increase the effective array and then the dynamic range. The focus properties of the off-axis lens are studied.
In this paper the research of the real-time three-dimensional holographic imaging system which uses liquid crystal panels to display the computer generated Fresnel holograms for reconstructed 3D images is described. The reconstructed effects are related to each step of the process and the characteristics of the devices. The contradictions between the quantization of holographic numerical data and the properties of the display device are the important reasons for the reconstruction errors. A new algorithm for calculating point holograms is proposed for reducing the reconstruction errors. Finally the original experimental result is given.
KEYWORDS: Zone plates, Holograms, Computer generated holography, 3D image processing, Holography, 3D image reconstruction, LCDs, Wavefronts, 3D modeling, Reconstruction algorithms
A new fast algorithm using the “host” Fresnel zone plate was proposed to improve the computational efficiency of computer-generated hologram (CGH) for 3D objects. By reading .3DS files, the spatial position information of each point of the 3D object was obtained directly. With the illumination of plane wave, the “host” Fresnel zone plate of a single point could be equal to all points located in the same depth plane - as the Fresnel zone plate was translated and superimposed along the horizontal and vertical axes. Consequently, the hologram of a 3D object could be built up by superimposing different Fresnel zone plates in the corresponding depth planes. For a digital object composed of 1060 points, it cost about 83s to generate a hologram of 1024*768 pixels. The CGH of 3D objects with the results of the reconstruction was presented in this paper, which proved the feasibility of this algorithm.
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