An automatic particle detection system for patterned wafers has been developed. The system consists of optical image processing and electrical signal processing that enable detection of much smaller particles. A specific area of the wafer is illuminated with 4-lasers at ± 45° diagonal in reference to an orientation-flat shaped on the wafer. The scattered light is detected by an objective lens. The images of the adjacent two-chips are detected with an image sensor. The subtracted signal of the two detected images is transformed into a binary signal with a threshold. This system is performed so as to detect 0.6 μm standard particles on a first photo-process wafer, and 1.0-1.5 μm standard particles on a latter photo-process wafer in 1.5 minutes on 5-inch-diameter wafers.

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Interferometric measurement method is described of long-gauge blocks using a fringe-counting interferometer with a 633-nm wavelength-stabilized He-Ne laser. Two sub-gauges, which are made of usual gauge blocks with V-type graduation lines, are optically-contacted with the both sides of a long-gauge block. Using the NRLM 2-m line standard automatic measuring-machine, several gauge blocks up to 1 m are measured with a resettability of 50 nm, and they are also measured by using a traditional excess-fractions method. The result shows that this new method can determine the length of gauge blocks up to 2 m, within an accuracy of 0.15 μm.

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This paper presents a failure diagnosis of a V-belt thorough vibration monitoring. The belt vibration is monitored at points on a driven bearing. Seven types of basic causes of belt failures are considered. Power spectra of the vibration data are calculated through a noise reduction called a cross-spectrum method. Six parameters characterizing the vibration data are identified, and seventeen typical combinations of basic causes are diagnosed by a Bayes' discriminant function approach. Two types of incorrect diagnoses are considered : type I leaves a failed belt not repaired, and type II causes overmaintenance. Two types of losses are considered accordingly, and the ratio of them is determined so as to minimize the type I error. It turns out that the Bayes' approach using the six characteristic parameters successfully diagnoses the V-belt failure.

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This paper describes a method to represent an intermediate shape in rounding a solid shape as a non-manifold model and to manipulate the model uniformly by Euler operations. Fillet surfaces are generated step by step by a rolling ball method according to generation rules for edges and a data structure is represented by cycle structure extended from half-edge structure. By the method the original shape and the rounded shape can coexist and finally they are separated automatically.

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This paper deals with a method for centerless grinding of light workpieces having a concentric through hole. The machining accuracy for light workpieces tend to be poor compared with that for solid workpieces. This phenomenon was clarified through geometrical and dynamic analysis of a centerless grinding system companing a regulating wheel, a grinding wheel and a supporting blade.
The lead angle of the regulating wheel used to feed a workpiece yields a non-uniform peripheral speed in the axial direction of the regulating wheel. Higher peripheral speed of the regulating wheel induces an upward friction force on the workpiece with a lower peripheral speed. This upward friction force causes an abnormal motion of the workpiece during grinding, which results in inferior machining accuracy. This phenomenon becomes more and more conspicuous on lighter workpieces.

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This paper presents experimental results of ultra-precision diamond turning of stainless steel. The steel cannot be machined normally by diamond tools due to excessive wear, although there are great demands for ultra-precision machining of the steel family. The ultra-precision diamond turning of stainless steel was realized by applying ultrasonic vibration of 40 kHz to the single crystal diamond tool in the cutting direction. An optical quality mirror of stainless steel with surface roughness less than 0.03 μm in R_max was obtained. High quality surfaces with roughness less than 0.1 μm were obtained stably up to a cutting distance of 1 600 m. It is expected that these results will extend the application of ultra-precision cutting, which has been limited to products of light metals and plastics, and will lead to improving the quality and reducing the cost of various precision products.

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This study deals with 5-axis control machining and grinding of workpieces with sculptured surface. The 5-axis control machining and grinding allows sculptured surface to be produced efficiently and accurately. The system developed in the study generates the collision-free tool path for machining and grinding workpieces with sculptured surface, based on the CAD/CAM system P-CAPS employing the solid modeling technique. For grinding, the high speed spindle attachment is used to increase the rotational speed of grinding tool, which consists of rubber pad and diamond abrasive cloth. The system realizes the surface roughness of 0.23 μm for the workpiece with sculptured surface. As a result, the system has potential of producing workpieces with high accuracy and efficiency.

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This paper deals with influence of cutting force on machining accuracy and improving method of the accuracy in corner cut by end mill. Errors by corner cut are extremely greater than that of steady state cutting. When a cutter radius is equal to a radius of curvature of the corner, maximum machining error becomes 13 to 22 times as large as that of steady state cutting. Describing the position of maximum error by rotating angle φ from start point of corner cut, the position by the angle is φ=10° in down milling and φ=0°in up milling. And also cutting forces in corner cut are measured, and machining accuracy is analysed by a simple error generating model that depends upon cutting force vector and resulting stiffness of machine-tool-workpiece system. Calculated values or shape errors are almost coincident with that of experimental values. To improve machining accuracy, plunge and twice looped path cutting are recommended. But under the experimental conditions, difference of accuracy between steady state cutting and corner cut is smaller by diameter 17 mm in down milling and 14 mm in up milling.

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This paper describes the roughness of flank surface by tapping for a large size threads with a geometrical analysis and experiments. The behavior of roughness is experimentally studied by the turning test using the imitated cutting edges and every variety of cutting oils and the tapping test using M 42×4.5 tap. The results are as follows. (1) The roughness of flank surface is affected by the depth of cut per one cutting edge in tapping. It becomes small as the cutting depth is finer. (2) There are three effective methods to make the cutting depth thin, that is, to select smaller pitch thread, to make the chamfer angle small by reducing a percentage of thread engagement, and to increase the number of tap grooves. (3) In order to improve the roughness of flank, it is effective to use the lower effervescent oil and the slower tapping speed. (4) The excellence of soy sauce as the cutting oil for tapping was revealed through the cutting test. However, the rate of salt and stink are questionable so that it is necessary to develop a new tapping oil containing the lower effervescent oil. (5) If the cutting edge of a current manufactured tap is sharpened the sweep edge on a whetstone, the roughness of flank surface can be improved.

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An optical profile NC machining for a free formed surface has been developed by using an automatic non-contact measuring system of 3-dimensional model shapes and an NC milling machine. The principle of this system and the results of machining a free formed doll's face and an abutment tooth with accuracy of 80 μm were reported in the 1st report. In this study, it is attempted to apply this system to a dental CAD/CAM system developed by authors to machine a crown. Then, it was done to machine an abutment tooth and inside of the crown with free formed surface by this system. As a result, it could machine the whole shape of the abutment tooth with an under-cutting side. Consequently, it is verified that this system is applicable to the dental CAD/CAM system.

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Effects of internal cooling for a cutting tool have been analyzed using the finite element method. Contact pressure at the tool-chip interface is so high that cutting fluid, which is normally supplied, does not work sufficiently for reducing crater wear. Internal cooling is aimed at enforcing heat transfer into the coolant which is introduced within a cutting tool, resulting in the decrease of tool temperature. Supposing the use of a heat pipe as a cooling device, which potentially has a coefficient of heat transfer more than 10⁴ Wm^-2K^-1, optimum shape and position of a coolant path as well as the cooling characteristics were analyzed. It shows that tool temperature is decreased by 30 to 200°C by means of the internal cooling and there is no influence upon the strength of the tool. Besides, thermal displacement of the internally cooled cutting edge is found to decrease by a factor of 2 compared to that of a normal tool. This suggests that an internally cooled cutting tool is effective for precision machining.

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This report deals with the formation mechanism of grooves overlapped in the direction of a groove width in order to make clear the generation process of ground surface which is formed by the accumulation of overlapped grooves with abrasive grains. Remarkable phenomena observed in the formation process of overlapped grooves are as follows ; (1) A meandering phenomenon of overlapped grooves takes place and has a close relation to the axial cutting force. (2) A modification phenomenon of overlapped grooves, which dominates the variations of pile-up height and groove angle, exists at the beginning and the ending of the overlapped region. (3) A tearing phenomenon, which makes the pile-up height lower, exists in the cutting process of overlapped grooves.

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On the previous paper, it have been described that the same motion as the cam displacement curves can be obtained by applying the feedforward control method, that is, the inverse to DC motor driving system. In this paper, it was clarified that the velocity feedback for the motor driving system reduces the effect of the real motor parameter deviation from the setting values of the inverse, even if including the displacement feedback. Moreover, the residual vibration characteristics of one degree of freedom vibration load connected to the motor axis compensated by the above-mentioned means were studied. The numerical and experimental results in case of the basic motion curves as the parabolic and harmonic motion cam curves were similar to the mechanical cam behaviour. Then the availability of the inverse system method for the motor output was assured also dynamically. And the possibility of the open control positioning by the motor was obtained.

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This paper describes a study of an interferometer utilizing an optical fiber for highly accurate measurement of thermal deformation of a mechanical part in out-of-plane direction. This interferometer utilizes a polarization-preserving optical fiber. Two signal lights pass the same optical paths of the fiber, and the influence of the external disturbance (for example, temperature changes) to the optical paths of the fiber can be cancelled by the differential detection of the interference signals of these lights. A reference plane is set near an object plane, and an optical probe with the reference plane is composed of the materials with small thermal expantion coefficient. The experiment verified that the present interferometer worked in the same way as the theory. The present interferometer was applied to a measurement of thermal expantion, and its measuring dispersion of this interferometer was within ±60 nm.

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How to record and judge the direction of tilt in the interferogram is described in this paper.It was theoretically and experimentally shown that the interferograms obtained in a Twyman-Green interferometer without imaging lens had the tilt information of a mirror under test in their edges. The measurement errors introduced in such interferograms were discussed.

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This paper describes a measuring method based on Fraunhofer diffraction which can estimate quantitatively the size parameters of fine grooves, for example the LSI pattern, the grating and the tracking pre-groove of optical memory disks. Theoretical analysis of the relation between a rectangular groove model and diffraction intensity pattern is performed. Equations which can estimate the size parameters of grooves such as pitch, width and depth from diffraction intensity patterns are derived. From the equations, the duty ratio (width/pitch) in the range of 0.1 to maximum 0.8 and depth 1 nm to maximum 150 nm are determined within 10% errors. In order to verify the validity of the proposed method, computer simulations and fundamental experiments are carried out. It is shown by the computer simulations that this method is useful for measuring the size parameters of the fine grooves without the influences of noise on diffraction intensity and random roughness on the surface of the groove. From the measurement of the size parameters of the grooves of a high precision grating plate with pitch of 2.0 μm, width of 1.0 μm and depth of 100 nm, it is found that this method makes it possible to measure pitch, width and depth of a fine groove with consistency.

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On the one-dimensional table unit driven by a friction drive using a position feedback control, it was reported in the 2nd and 3rd reports that the slip between the driving pinion roller and the slider made the settling time long. Therefore, in order to obtain a shorter settling time, a counterplan using a kind of feedback control for the velocity control is considered by decreasing the slip between them. The following results can be obtained for a 24 mm step response in the PTP method : (1) The mean settling time in 100 positioning trials is 299 ms when the table of 15.7 kg reaches the range of ±1 μm of the desired position, and this time is 100-200 ms shorter than that of the previous results. (2) A positioning accuracy is surely within ± 0.158 μm of the desired position (0.158 μm = the resolution of the laser measuring system).

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To realize an infinite-stiffness aerostatic bearing, a new type of active restrictor is proposed. The proposed restrictor controls the air volume exhausted from the bearing surface. Therefore, the restrictor is called an exhaust control restrictor (ECR). Conventional active restrictors should be placed very close to the bearing surface for suppressing pneumatic hammer. Without the occurrence of pneumatic hammer, the ECR can be placed apart from the bearing surface. Consequently, the limitation for the design of an aerostatic bearing with the ECR is much less than that of with conventional active restrictors. The ECR is incorporated into an aerostatic radial bearing. The displacement of the bearing shaft is detected by an electric micrometer, and fed back to a micro computer. The micro computer controls a piezoelectric actuator which changes the restriction gap of the ECR. Radial load is applied to the bearing shaft, however, the ECR suppresses the displacement of the shaft. Thus, it is shown that the bearing stiffness can be infinite.

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This paper is mainly concerned with the cross-talk of a torsional vibration pickup, which was developed to measure the torsional ground motion with a minimum of cross-talk. The causes of the cross-talk considered in this paper are : (1) the static intrinsic errors of cross-spring pivot and (2) the unbalance of the mass element of seismic system. The cross-talk generation due to these causes is investigated in detail. Description of a balancing method utilising a rectilinear vibration table, which was devised to minimize the unbalance of the mass element under actual operating condition of the pickup, is included, together with the construction and performance characteristics of the pickup.

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