Development of Parallel Grinding System of Aspheric Optics

2007 ◽  
Vol 339 ◽  
pp. 365-370
Author(s):  
L.J. Li ◽  
Fei Hu Zhang ◽  
S. Dong
Keyword(s):  
Tool Path ◽  
Aspheric Surface ◽  
Key Factors ◽  
Factors Affecting ◽  
Optical Instruments ◽  
Grinding Method ◽  
Aspheric Optics ◽  
Profile Accuracy ◽  
Grinding System ◽  
Parallel Grinding

The roughness and profiles accuracy of aspheric surface are two key factors affecting the resolution and other characteristics of optical instruments. In this paper a new grinding system-parallel grinding system was built, and an CNC system controlled by PMAC (programmable multi-axis controller) was developed, the parallel grinding system can realize Arc Envelope Grinding Method (AEGM) only through controlling 2-axis and the wear of wheel was diminished, the tool path calculation was simplified. Using this system, the roughness and profile accuracy of aspheric surface are improved.

Surface Quality Improvement of Aspheric Pressing Mould Using Parallel Grinding Method

2005 ◽  
Vol 291-292 ◽  
pp. 133-138
Author(s):  
Fei Hu Zhang ◽  
L.J. Li ◽  
Shen Dong
Keyword(s):  
Surface Quality ◽  
Optical Glass ◽  
Cost Effective ◽  
Optical Quality ◽  
Grinding Method ◽  
Mould Surface ◽  
Aspheric Optics ◽  
Grinding System ◽  
Parallel Grinding

It is a cost-effective technology to obtain aspheric optics made from optical glass and other brittle materials using pressing mould. The optical quality of molded optics is determined mostly by the surface quality of the mould, which means poor mould surface with lots of cutter marks will result in adhesion phenomena and error replication between the optics and mould. [1] In this article, a chatter model about parallel grinding system was presented, and the reasons of chatter induced by velocity feed back was analyzed and simulated. By using parallel grinding system integrated ELID technology, and wheel with greater cross-section radius in rough grinding and constant grinding velocity in fine grinding, the amplitude of cutter marks in the surface of mould was minimized and the quality of the mould surface was improved.

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.

A Study on the Grinding to Improve Profile Accuracy of Aspheric Lens

2007 ◽  
Vol 364-366 ◽  
pp. 1168-1173
Author(s):  
Seung Yub Baek ◽  
Eun Sang Lee ◽  
Jong Koo Won
Keyword(s):  
Surface Roughness ◽  
Tool Path ◽  
Production Costs ◽  
Total Production ◽  
Precision Grinding ◽  
Aspheric Lens ◽  
Ultra Precision ◽  
Grinding Technique ◽  
Profile Accuracy ◽  
Grinding System

This study presents the development of an ultra-precision grinding system based on a new grinding technique called the “In-Process Grinding Method (IPGM)”. IPGM which is used for grinding aspheric lens increases both the production and grinding performance, and significantly decreases total production costs. To enhance the precision grinding productivity of ultra-precision aspheric lens, we present here an ultra-precision grinding system and process for the aspheric micro-lens. The tool path was calculated and CNC program generation and tool path compensation were performed for aspheric lens. Using this ultra-precision grinding system, aspheric lens, 4mm in diameter, were successfully performed. The profile error after the first grinding without any compensation was less than 0.6μm, and surface roughness Ra was 0.01μm. In-process grinding was performed with compensation. Results of the profile accuracy P-V 0.3μm and surface roughness Ra 0.006 μm were obtained.

Arc Envelope Grinding of Non-Axisymmetric Aspheric Surface Using Equal-Envelope Height

2006 ◽  
Vol 532-533 ◽  
pp. 189-192 ◽  
Author(s):  
Jin Xie ◽  
Wei Wei Xu
Keyword(s):  
Tool Path ◽  
Curve Surface ◽  
Ground Surface ◽  
Smooth Curve ◽  
Grinding Wheel ◽  
Aspheric Surface ◽  
Tool Paths ◽  
Grinding Method ◽  
Generate Curve ◽  
Grinding Efficiency

An arc envelope grinding method for non-axisymmetric aspheric surface was proposed in order to achieve the mould core used for the precision injection molding of optic reflector. In grinding, the arc-shaped diamond grinding wheel trued on CNC grinder was used to envelope workpiece and generate curve surface, and the spacing distance between tool paths is controlled by the equal-envelope height between wheel and workpiece. In this paper, arc envelope grinding principle was investigated in connection with wheel coordinate calculation and tool path number. The theoretical analysis and grinding experiment showed that arc envelope grinding may improve form grinding efficiency especially for large curvature and smoothness of ground surface and a smooth curve surface can be produced when the equal-envelope height is less than a certain value.

Research on the Roughness Model of Aspheric Surface with Parallel Grinding Method

2012 ◽  
Vol 472-475 ◽  
pp. 2338-2343
Author(s):  
L.J Li ◽  
W.T Bai ◽  
W Sun ◽  
Fei Hu Zhang
Keyword(s):  
Mathematical Model ◽  
Surface Roughness ◽  
Grain Size ◽  
Ground Surface ◽  
Aspheric Surface ◽  
Grinding Method ◽  
Proportional Relation ◽  
Roughness Model ◽  
The Mathematical Model ◽  
Parallel Grinding

This paper deals with the roughness forming mechanics of aspheric surface, and based on the subsequent abrasive blade theory, which will form the final ground surface, the mathematical model of maximal valley height of ground surface during aspheric parallel grinding was established. Through simulation study, the influences of grain size, the speed of wheel and workpieces on the aspheric surface roughness were analyzed, and furthermore, through test, the proportional relation between the maximal valley height and the roughness was found.

A Study on the Manufacturing System of the Axes Linked Ultra-Precision Grinding of Aspheric Surface

2011 ◽  
Vol 487 ◽  
pp. 500-504
Author(s):  
Li Jun Li ◽  
Y. Jiang ◽  
Fei Hu Zhang
Keyword(s):  
High Speed ◽  
Manufacturing System ◽  
High Strength ◽  
Maximum Speed ◽  
Aspheric Surface ◽  
Precision Grinding ◽  
High Speed Grinding ◽  
Ultra Precision ◽  
Grinding System ◽  
Parallel Grinding

The manufacturing system developed in this paper is mainly used for the ultra-precision grinding of the hard-cutting materials, such as high strength steel and carbonized tungsten, which are characteristics with axisymmetric aspheric surface. Under the priority of accuracy and grinding rigidity to design the key components of multi-axis linked parallel grinding system of aspheric surface, such as high speed grinding spindle, B axis grinding rotary table, clamps and center high adjusting system. Maximum speed of the grinding spindle is 90,000rpm, spindle rotating accuracy is 0.1μm, rotation-angle-accuracy of B axis is , center height adjusting accuracy is 0.1μm, using the system can realize parallel grinding of aspheric surface[1].

EVALUATION OF FINANCIAL SECURITY OF THE REPUBLIC OF CRIMEA

2020 ◽  
pp. 56-67
Author(s):  
Elena Evgenevna Mashyanova ◽  
Elena Aleksandrovna Smirnova
Keyword(s):  
Financial Markets ◽  
Negative Impact ◽  
Gradual Increase ◽  
Financial System ◽  
Financial Security ◽  
Key Factors ◽  
Factors Affecting ◽  
External Threats ◽  
The Republic ◽  
Global Financial System

In modern conditions of development, financial security is an integral part of the overall security of the region and is formed on the basis of the functioning of the financial system. The complication of relationships between key segments of international financial markets, as well as the limited ability to accurately predict future trends in the development of the global financial system, lead to a gradual increase in the risks that accompany the activities of economic entities, and an increase in the number and scale of internal and external threats that have a negative impact on the financial security of the state. This formulation of the issue requires generalization of approaches to determining the financial security of the region in order to further formalize this issue and determine the key factors affecting it. The article considers the types of financial security, as well as certain areas of ensuring the financial security of the region and their priority. In work the assessment of the level of socio-economic development of the region with a view to ensuring financial security on the basis of which offers the main activities and priority areas of implementation of the investment policy that will ensure financial security of the Republic of Crimea.

scholarly journals Comparison of the sensitivity of Western blotting between PVDF and NC membranes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yufang Xiang ◽  
Yuanyuan Zheng ◽  
Shaobo Liu ◽  
Gang Liu ◽  
Zhi Li ◽  
...  
Keyword(s):  
Western Blotting ◽  
Polyvinylidene Fluoride ◽  
Staining Intensity ◽  
Detection Sensitivity ◽  
Key Factors ◽  
Post Translational Modifications ◽  
Factors Affecting ◽  
Molecular Weights ◽  
Direct Blue ◽  
The Relationship

AbstractWestern blotting (WB) is one of the most widely used techniques to identify proteins as well as post translational modifications of proteins. The selection of electroblotted membrane is one of the key factors affecting the detection sensitivity of the protein which is transferred from gel to membrane in WB. The most common used membranes are polyvinylidene fluoride (PVDF) and nitrocellulose (NC) membranes. Which membrane of these two is more suitable for WB has not been reported so far. Here, by incubating proteins which were transferred to PVDF or NC membranes with a series of antibodies and different types of lectins, we investigated the relationship between the binding ability of these two membranes to proteins or glycoproteins and the molecular weight of the target protein. The antibody re-probed ability of the two membranes was also explored. Moreover, we verified the above results by directly incubating proteins having different molecular weights onto PVDF or NC membranes. Bound proteins were stained with direct blue-71, and the staining intensity was quantitated by scanning and densitometry.

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