High Precision Grinding of Large Fresnel Lens Mold

2012 ◽  
Vol 516 ◽  
pp. 629-633
Author(s):  
Tatsuya Furuki ◽  
Hirofumi Suzuki ◽  
Mutsumi Okada ◽  
Yutaka Yamagata ◽  
Shinya MORITA
Keyword(s):  
Tungsten Carbide ◽  
Power Efficiency ◽  
Fresnel Lens ◽  
Rare Metal ◽  
Diamond Wheel ◽  
Precision Grinding ◽  
Form Accuracy ◽  
Grinding Method ◽  
Fresnel Lenses ◽  
Glass Lenses

Demand for glass Fresnel lenses is increasing in solar panel manufacture in order to increase power efficiency. Glass lenses are usually moulded using a glass moulding method with tungsten carbide moulds. In this study, large Fresnel lens moulds made of tungsten carbide are tested to be ground by a simultaneous 2-axis (Y, Z) controlled grinding method. The resinoid bonded diamond wheel is trued with a rare metal truer to increase the sharpness of the wheel edge. In the grinding test of the tungsten carbide mould, a form accuracy of less than 0.8 μm P-V and surface roughness of 18 nm Rz are obtained, and it is clarified that the proposed grinding method is useful for Fresnel grinding.

Precision Grinding of Structured Tungsten Carbide Mold

2012 ◽  
Vol 497 ◽  
pp. 15-19 ◽  
Author(s):  
Hirofumi Suzuki ◽  
Tatsuya Furuki ◽  
Mutsumi Okada ◽  
Yutaka Yamagata ◽  
Shinya MORITA
Keyword(s):  
Tungsten Carbide ◽  
Power Efficiency ◽  
Fresnel Lens ◽  
Rare Metal ◽  
Diamond Wheel ◽  
Precision Grinding ◽  
Form Accuracy ◽  
Molding Method ◽  
Grinding Method ◽  
Glass Lens

Demands of glass Fresnel lens is increasing in solar panel in order to increase power efficiency. Glass lens is usually molded by glass molding method with tungsten carbide molds. In this study, large Fresnel lens molds made of tungsten carbide are tested to be ground by simultaneous 2-axis (Y, Z) controlled grinding method. The resinoid bonded diamond wheel was trued with a rare metal truer to improve the sharpness of the wheel edge. In the grinding test of the tungsten carbide mold, a form accuracy of less than 0.8 μm P-V and surface roughness of 18 nm Rz were obtained, and it is clarified that the proposed grinding method is useful for the Fresnel grinding.

Ultrasonic Vibration Assisted Grinding of Microstructures on Binderless Tungsten Carbide (WC)

2014 ◽  
Vol 625 ◽  
pp. 475-479 ◽  
Author(s):  
Bing Guo ◽  
Qing Liang Zhao ◽  
Yan Hou ◽  
Cheng Ge ◽  
Xin Yu
Keyword(s):  
Surface Roughness ◽  
Tungsten Carbide ◽  
Ultrasonic Vibration ◽  
Ground Surface ◽  
Precision Grinding ◽  
Form Accuracy ◽  
Grinding Method ◽  
Edge Radius ◽  
Microstructured Surfaces ◽  
Ultrasonic Vibration Assisted Grinding

Microstructured optical elements made of glass are generally replicated by hot pressing with super-hard materials, such as binderless tungsten carbide (WC) and precision ceramic. However, in grinding of microstructures, problems frequently occur in terms of rough ground surface, chipping and rounding of micro-structures edges when compared to conventional grinding. In order to overcome these technological constraints, a promising precision grinding method for microstructured surfaces that applies ultrasonic vibration to improve the surface quality, and protect the edges and tips of microstructured surfaces is presented. The experimental investigation of ultrasonic vibration assisted grinding of microstructures on binderless WC is researched. The effects of ultrasonic vibration on surface roughness, form accuracy and edge radius were analyzed. The morphology of surface and array edges was examined with a scanning electron microscope (SEM), while the surface roughness was measured by a laser interferometer. And a contact probe profilometer was used to assess the form of array and radius of microstructured edges. Experimental results showed that the application of ultrasonic vibration leads to significant improvements of the surface roughness and edges of microstructures compared with traditional precision grinding processes. A micro cylinder lens array of binderless WC with surface roughness of 78nm and edge radius of less than 1μm was obtained. The novel grinding method is feasible and applicable in machining higher form accuracy microstructures.

Fabrication of Thin-Film Fresnel Optics by Combining Diamond Turning and Photolithographic Processes

2013 ◽  
Vol 7 (4) ◽  
pp. 385-390 ◽  
Author(s):  
Jiwang Yan ◽  
◽  
Kenta Watanabe ◽  
Yutaro Nakagawa ◽  
Keyword(s):  
Thin Film ◽  
Crystalline Silicon ◽  
Fresnel Lens ◽  
Diamond Turning ◽  
Fabrication Process ◽  
Single Crystalline Silicon ◽  
Form Accuracy ◽  
Metal Thin Films ◽  
X Ray ◽  
Fresnel Lenses

A novel fabrication process is proposed for manufacturing thin-film metal Fresnel lenses for X-ray applications. This process combines diamond turning technology and photolithographic processes. To prevent thin-film lens substrates from deflection during diamond turning, films were prepared on single crystalline silicon wafers by electrolytic plating. After the Fresnel lens structure is generated on the metal thin films by diamond turning, the silicon substrate was then removed selectively by reactive ion etching. Experimental results demonstrated that the proposed hybrid fabrication process achieves submicron form accuracy and nanometer surface roughness.

Basic Study on High Efficiency Ultra-Precision Grinding of the Optical Glass Lens

2014 ◽  
Vol 1017 ◽  
pp. 21-26 ◽  
Author(s):  
Rei Sekiguchi ◽  
Shun Yoshikawa ◽  
Yasuhiro Kakinuma ◽  
Katsutoshi Tanaka ◽  
Masahiko Fukuta
Keyword(s):  
Surface Quality ◽  
High Efficiency ◽  
Optical Glass ◽  
High Surface ◽  
Precision Grinding ◽  
Form Accuracy ◽  
Large Aperture ◽  
Highly Efficient ◽  
Ultra Precision ◽  
Glass Lenses

The demand for large aperture lenses with high surface quality and form accuracy used for single-lens reflex cameras has been increasing. Generally, large aperture glass lenses are produced by ultra-precision grinding. Considering the increasing global competition, the grinding process has to be improved. However, highly efficient grinding causes worse surface quality, which leads to much polishing and ultimately results in lower form accuracy. Thus in this study, aiming at the realization of highly efficient and precise grinding of glass lenses, cross grinding of optical glass BK7 is carried out. As a first step of the study, the influence of grinding conditions on the surface quality is investigated experimentally.

scholarly journals Precision Grinding of Micro Fresnel Lens Molding Die. Feasibility Study on Precision Grinding of Tungsten Carbide.

1999 ◽  
Vol 65 (8) ◽  
pp. 1163-1168 ◽  
Author(s):  
Hirofumi SUZUKI ◽  
Toshiro HIGUCHI ◽  
Naoshi WAJIMA ◽  
Takayuki KITAJIMA ◽  
Shigeki OKUYAMA ◽  
...  
Keyword(s):  
Tungsten Carbide ◽  
Feasibility Study ◽  
Fresnel Lens ◽  
Precision Grinding ◽  
Lens Molding

Study on Precision Grinding Technique for Large Size Optical Aspheric Lens

2013 ◽  
Vol 395-396 ◽  
pp. 1015-1019 ◽  
Author(s):  
Xiao Long Ke ◽  
Jian Chun Liu ◽  
Hai Bin Huang
Keyword(s):  
Diamond Wheel ◽  
Surface Measurement ◽  
Machining Accuracy ◽  
Precision Grinding ◽  
Aspheric Lens ◽  
Grinding Method ◽  
Large Size ◽  
Grinding Technique ◽  
Measurement And Evaluation ◽  
Grinding Machine

Large size optical aspheric lens is an important component in optical engineering. Aiming at the demand of precision processing for optical aspheric lens, this paper develops a precision grinding technique for large size optical aspheric lens. Based on precision surface grinding machine (MGK7160), grating-type parallel grinding method is put forward to realize grinding paths planning for optical aspheric lens. An on-machine measurement system is built to obtain surface measurement and evaluation after grinding. In order to ensure machining precision and efficiency, a diamond truer which self-developed is adopted to precision dress for arc diamond wheel. Finally, the experiment of precision grinding and error compensation validates machining accuracy for large size optical aspheric lens.

Dressing of Grinding Wheels for Ultra Precision Grinding of Diffractive Structures in Tungsten Carbide Molds

2014 ◽  
Vol 625 ◽  
pp. 161-166 ◽  
Author(s):  
Thomas Bletek ◽  
Fritz Klocke ◽  
Martin Hünten ◽  
Olaf Dambon
Keyword(s):  
Tungsten Carbide ◽  
Grinding Wheel ◽  
Geometric Features ◽  
Grinding Wheels ◽  
Precision Grinding ◽  
Form Accuracy ◽  
Fine Grained ◽  
Diffractive Structure ◽  
Ultra Precision ◽  
Diffractive Structures

The manufacturing of molds with diffractive structures requires new approaches in terms of grinding wheel geometry and preparation. To be able to manufacture small geometric features such as widths and depths in the micron range on the mold, ideally sharp edged grinding wheels should be used. This paper will present dressing procedures to create sharp edged grinding wheels by using metal alloy blocks. The results and achieved tip radii of the dressed resin bonded and metal bonded fine grained grinding wheels will be presented. Finally, grinding tests of a tungsten carbide mold with a diffractive structure are conducted and the results of the achieved form accuracy and surface roughness are presented.

A Novel High Concentration Fresnel Lens as a Solar Concentrator

2021 ◽  
pp. 1-29
Author(s):  
Kuldeep Awasthi ◽  
Desireddy Shashidhar Reddy ◽  
Mohd. Kaleem Khan
Keyword(s):  
Optical Axis ◽  
Spherical Aberration ◽  
Spherical Surface ◽  
Fresnel Lens ◽  
High Concentration ◽  
Aperture Diameter ◽  
Convex Lens ◽  
Flat Base ◽  
Fresnel Lenses ◽  
Outer Vertex

Abstract This paper describes the design methodology for a novel Fresnel lens. The original Fresnel lens is obtained from a plano-convex lens, whose spherical surface is split into a number of divisions (called facets), collapsed onto the flat base. Thus, all the facets of the original Fresnel lens have the same radius as that of the plano-convex lens. The proposed design aims to achieve better ray concentration and reduced spherical aberration than the original Fresnel lens by constructing spherical facets with unequal radii. The centers and radii of facets are constrained so that the ray refracted from the bottom vertex of each facet on one side of the optical axis and the ray refracted from the outer vertex of the corresponding facet on the other side of the optical axis must intersect at the focal plane. The proposed lens design has resulted in a 275% gain in the concentration ratio and a 72.5% reduction in the spherical aberration compared to the original lens of the same aperture diameter and number of facets. The performance of both novel and original Fresnel lenses when used as solar concentrators with a conical coil receiver is evaluated. The novel Fresnel lens led to increased heat gain and resulted in a compact solar collector design.

scholarly journals The effectiveness of a mini photovoltaic cell by using light LED bulbs as a source of photon energy

2021 ◽  
Vol 926 (1) ◽  
pp. 012090
Author(s):  
Mustofa ◽  
Iskandar ◽  
Muchsin ◽  
S Suluh ◽  
T M Kamaludin
Keyword(s):  
Energy Source ◽  
Output Power ◽  
Electrical Energy ◽  
Photovoltaic Cell ◽  
Fresnel Lens ◽  
Test Results ◽  
Light Spectrum ◽  
Pv Cell ◽  
Fresnel Lenses ◽  
Cell Module

Abstract Muxindo’s LED bulb is one of the brands that are widely used by Indonesian people as lighting in the home. This study aims to look at the effectiveness of the light spectrum of the 10, 15 and 20 Watt LED power bulbs as an energy source to generate electrical energy in monocrystalline mini photovoltaic (PV) cell module. The light spectrum is compared with and without the Fresnel lens before being transmitted to the PV surface. The test results show that the PV output power is much better with a Fresnel lens (4.06> 1.67) mW. The efficiency of PV with lens displays slightly different figures, 3.77% at 15 Watt bulb power, while without Fresnel lenses, PV efficiency is 4.86% with a 20 Watt bulb. Need further research, for example, with Philips brand LED bulbs

Research on the 3-Axis CNC Ultra-Precision Grinding of Aspheric Mould

2009 ◽  
Vol 69-70 ◽  
pp. 39-43 ◽  
Author(s):  
Li Jun Li ◽  
Fei Hu Zhang ◽  
Shen Dong
Keyword(s):  
Influence Factors ◽  
Grinding Wheel ◽  
Aspheric Surface ◽  
Precision Grinding ◽  
Form Accuracy ◽  
Form Errors ◽  
Machining Test ◽  
Ultra Precision ◽  
Grinding System ◽  
Parallel Grinding

Parallel grinding is an effective method of aspheric moulds machining which is usually made of industrial ceramic such as silicon carbide (SiC) or tungsten carbide (WC), but if the spherical grinding wheel is not being with precision truing and dressing, the roughness and form accuracy of the ground aspheric surface should get worse, for this reason, in this paper, the influence factors of thoroughness and form accuracy induced by the wheel truing and dressing are studied firstly, and a new 3-axis CNC Ultra-precision grinding system which is based on the PMAC (Programmable Multi-axes Controller) is developed, through simultaneous motion of the controlled X, Z and B axis, the form errors which is induced by the grinding wheel can be improved theoretically, and the aspheric mould machining test shown that the surface roughness of Ra 0.025μm and the form accuracy of P-V 1.15μm are achieved.

Sign in / Sign up

Export Citation Format

Share Document