Novel corrective machining method to fine-tune groove widths

When creating a multi-view image for multi-view 3D display with one camera, the camera has to be moved from one viewpoint to another viewpoint. However, this method takes long time and can not get images of a moving object. In this paper, we proposed the method for capturing a multi-view image by one step. In order to capture a multi-view image, the lenticular lens is used in our proposed system. The captured multi-view image becomes reverse by using the lenticular lens. Before calculating the best observation distance, a reversal processing is performed. To display a multi-view 3D image by the multi-view image, the same lenticular lens is used. As an experiment result, we got the multi-view image by our proposal system. When we laid the multi-view image under the lenticular lens, a multi-view 3D image with deep feeling was confirmed.

The grinding of ceramics with diamond wheels has disadvantages such as low stock removal rates or reduction of the strength of workpieces.This paper describes scratch tests with single point diamond tools and grinding experiments with diamond wheels in order to analyze the grinding mechanism of ceramics and overcome these disadvantages.The following results were obtained.(1) Specific grinding energy of ceramics is strongly correlated with fracture toughness and hardness.(2) Chips are removed as a result of the generation and growth of cracks, so called "fracture machining".(3) Fracture machining is achieved at a high depth of cut, and improves both the stock removal rate and the grinding ratio.(4) The crack layer induced by fracture machining at a 40 pm depth of cut and 20 m/min table speed can be removed by the finished grinding using a # 800 diamond wheel and the bending strength of SiC results in recovering up to that of the base material.

Single point diamond dressing of aluminium oxide grinding wheels and its influence in cylindrical traverse grinding

To create 3D lenticular comics, a lenticular lens and printing output are combined, making various visual effects such as animation and auto-stereoscopic displays possible. 3D lenticular content is created easily by placing a lenticular lens on an image composed especially for viewing in 3D. With lenticular technology, 3D images are created through a lenticular lens that combines two images, one to be viewed by the left eye and the other by the right eye. The type of lenticular lens to be used is selected depending on the purpose, effect, and viewing distance. Although many 3D lenticular comics currently published consist of a single character or a scene, it is expected that normal comics, which include both pictures and text and which have many pages and relatively long stories, will start to be published as 3D lenticular comics. In this case, the readability of the text is essential. Getting a high readability on text containing Chinese characters is especially difficult because the characters are made of complex combinations of thin lines. However, there has been little research reported in this field. Therefore, we conducted experiments and investigated the relationship between readability and the resolution of the lenticular lenses used to create the stereoscopic effect. From the results of these experiments, we propose a guideline for determining the resolution of 3D lenticular comics.

With the flattening of Moore’s law, the growth rate of the consumer electronics industry is slowly decelerating. Additionally, a plethora of applications of silicon in the optics industry has resulted in a boom in its demand in the recent times. There is an inevitable need to come up with manufacturing solutions to process silicon at nanometric scales. This has given rise to the field of ultra-precision machining. Single-point diamond turning (SPDT) tools offer an advantage over other ultra-precision manufacturing techniques regarding speed and scalability. In this paper, the nanometric cutting of single-crystal silicon using a single-point diamond tool has been simulated using molecular dynamic simulation (MDS). The cutting forces experienced by the tool and the temperature of the workpiece were observed for both negative and positive rake angles and depth of cuts. Tersoff potentials were used in a large-scale atomic/molecular massively parallel simulator (LAMMPS) to simulate the machining process. It was observed that the cutting temperature of the workpiece was significantly lower for the tools with negative rake angle as compared to that obtained for positive rake angles. Additionally, it was observed that forces on negative rake angle tools are more sensitive to depth of cut compared to positive rake angle tools.KeywordsMolecular dynamicsNanometric cuttingUltra-precision machining

An investigation into the dressing of grinding wheels using single point diamond tools has shown that-diamond geometry can affect greatly the stability of the dressing process, and thereby influence both the useful life of the dressing diamond and the efficiency of the grinding wheel in operation. Analysis of the forces acting on the diamond during dressing has shown the need for an unambiguous definition of the diamond geometry which at the present time is somewhat inadequately covered by the term “drag angle”. This work shows that three dressing regions exist i.e. stable, critical and unstable, which may be classified according to the angle of presentation between the diamond and the grinding wheel, called the rake angle, and that this angle itself is modified by the onset of diamond wear.

Influence of cutting conditions scaling in the machining of semiconductors crystals with single point diamond tool

Workpiece surface quality when ultra-precision turning of SiCp/Al composites

The reflection and surface-to-bulk wave conversion of a Rayleigh wave incident at a single shallow groove on an elastically isotropic substrate have been studied for various rectangularlike and troughlike groove profiles. It is found that the maximum value of the amplitude reflection coefficient is insensitive to the groove profile, and that the groove width producing maximum reflection or zero reflection of the incident surface wave is independent of the profile for all rectangularlike grooves. In all cases, both P and SV bulk waves are excited, with the latter carrying most of the bulk-wave power. While the angular distribution of the bulk-wave power patterns is strongly dependent on the groove width for a given profile, it is surprisingly insensitive to the profile for a given width. The fraction of the total incident power which is converted to bulk waves has been calculated.

This paper reports characterization and simulation of wet etching of grooves on Langasite (La <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">14</sub> ) wafers using phosphoric acid (H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> PO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> ) and polymer mask layers. Wafers with orientation (0°,138.5°,26.7°), which are commonly used for SAW(Surface Acoustic Waves) devices, were investigated. 85% H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> PO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> was chosen as the etchant and photoresist AZ nLOF 2070 was decided as the mask material. The experiments show that the groove profiles are governed by the anisotropic etch properties of the material in this etchant (H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> PO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> ) as well as an anomalous etch along the LGS-mask interface that leads to large undercuts. Wet etching at different temperatures, groove orientations and groove widths were explored. For the (0°,138.5°,0°) plane, the etch rate vs. etch temperature fits well to the Arrhenius equation with an activation energy of 0.84 eV. A simulator was programmed in MATLAB. The simulation shows good agreement with experiments and confirms that the etching is well described by the anisotropic etch properties of the exposed surfaces and a constant interface etch rate.

This study presents new information on single grit interaction behaviour and its brittle–ductile transition in micro-grinding single crystal silicon using a single grit diamond tool. A model to describe the energy interaction between the cutting behaviour of a single grit and the workpiece in micro-grinding is established based on the single grit geometry model, which was indicated in Fig. 1a, the critical condition of the volume of material removed and the conservation of energy. The tip angle of the single-point diamond tool has been considered. To reveal the material removal mechanism of micro-grinding, a series of scratching experiments, which conducted with a low cutting speed (0.036 to 0.6 m/s), have been performed in this study. The fractures of the micro-grooves machined using single-point diamond tools have been examined by a microscope and a surface profilometer, thus revealing different processing modes (brittle and ductile). The variation curves of the fracture length c have been presented on the condition of different tool tip angles θ (60° and 120°). It is found that the fracture size of grooves machined by a grit with a blunt angle is comparatively larger than that of a grit with a sharp angle for the same scratching parameters. The scratching speed v and penetration depth p0 have a direct effect on the fracture length c, which increases obviously with the rising of v and p0. The critical condition has been investigated based on the experimental results; the blunt grit (with a larger tip angle: θ = 120°) and the sharp grit (with a smaller tip angle: θ = 60°) have different brittle–ductile transitions and different critical cutting depths, which are 334 nm (θ = 60°) and 607 nm (θ = 120°), respectively. The effects of the scratching speed v are investigated. The brittle–ductile transitions of the different scratching speeds have been compared. The relationship between the fracture length c and the volume of material removed in unit time V has been discussed; V is an important measuring constant for the fracture formation and critical ductile cutting condition. This study reveals the mechanism of the single grit interaction in micro-grinding with an ultra-small grinding tool and provides theoretical and experimental validation for ductile micro-grinding of single crystal silicon.

Fabrication of optical quality freeform surfaces using ultra-precision machining technologies enables to achieve sub-micrometric form accuracy and nanometric surface finish. In this paper, ultra-precision machining of large aluminium alloy optical components has been conducted to investigate the machining performance and machined surface integrity. An ellipsoidal mirror surface and a lenticular lens array have been machined out using slow slide servo (SSS) turning, grooving and milling techniques with a single crystalline diamond tool on an ultra-precision machine centre. It was found that there are some striations on one segment of the machined ellipsoidal mirror surface. Through data density optimisation of angular increment dθ and arc length increment dc in C -axis positioning, the striation problem has been successfully solved, and surface roughness Ra of the machined ellipsoidal mirror surface has been achieved less than 10 nm. Work material microstructure and thermal stability of the machining centre significantly affected the machined lenticular lens surface quality. Compared with grooving process, milling process could produce a better surface integrity and form accuracy of large aluminium lenticular lens array.

Is it possible to distinguish cells with minimally invasive methods according to the characteristics of cells when moving through flow paths in vitro? A microflow-channel with microgrooves 45 deg diagonal to the mainstream direction has been manufactured by photolithography technology. The flow path between the two transparent polydimethylsiloxane disks (0.05 mm high, 1 mm wide, and 25 mm long) has rectangular microgrooves (4.5 μm deep, 0.2 mm long) at the bottom with variations in groove widths (0.03 mm, 0.04 mm, and 0.05 mm). Deformation and orientation of floating mouse-myoblasts (C2C12) during passage over the microgrooves were measured. Experimental results show that the larger the shape change of the two-dimensional projected image in the groove, the smaller the angle change tends to be. This method may be applicable to classification by cell deformation.

Nowadays computer 3D technologies are topic of present and are field of state-of-the-art research and dynamical development. Their main goal is to provide the observers of computer simulated environments with 3D perception. 3D computer display technologies play base role in this three-dimensional visualization. This report presents the results from the investigations into a multiview autostereoscopic 3D display technology developed by Philips 3D Solutions with the purpose of creating images and video for these kind devices. This paper is financed by project: Creative Development Support of Doctoral Students, Post-Doctoral and Young Researches in the Field of Computer Science, BG 051PO001-3.3.04/13, European Social Fund 2007--2013, Operational Programme Human Resources Development.

Single Pointe Diamond Turning (SPDT) of silicon can be an extremely abrasive process due to the hardness of this material. In this research SPDT is coupled with the micro-laser assisted machining (μ-LAM) technique to machine an unpolished single crystal silicon (Si) wafer. Si is increasingly being used for industrial applications as it is hard, strong, inert, light weight and has great optical and electrical properties. Manufacturing this material without causing surface and subsurface damage is extremely challenging due to its high hardness, brittle characteristics and poor machinability. However, ductile regime machining of Si is possible due to the high pressure phase transformation (HPPT) occurring in the material caused by the high compressive and shear stresses induced by the single point diamond tool tip. The μ-LAM system is used to preferentially heat and thermally soften the workpiece material in contact with a diamond cutting tool. Different outputs such as surface roughness (Ra, Rz) and depth of cuts (DoC) for different set of experiments with and without laser were analyzed. Results show that an unpolished surface of a Si wafer can be machined in two passes to get a very good surface finish.