Showing papers on "Visual inspection published in 1987"

Machine visual inspection device and method

Abstract: A visual inspection device is disclosed in which a workpiece to be inspected is set onto a holding fixture in a defined position, the holding fixture having a fixed, crosshair target in a defined location on the fixture The fixture is transported into one or more consecutive illuminated video scanned inspection fields having prepositioned therein a calibrated gray scale The piece is then viewed for inspection by a video camera as an addressed data stream containing reflectance values and transmitted to a digitizer and a central processing unit The inspection field of the data stream is shifted algorithmically such that the target is brought into alignment with and matches a target contained in a reference stream in memory The data stream is further corrected algorithmically for ambient light by comparing the gray scale reflectance values in the inspection field to a reference gray scale in memory which has not been affected by ambient light Variations in values cause rejection Totalizing of rejection by address combinations is retained in memory and the inspection device is automatically shut down when defined rejection totals are reached

Auatomatic inspection system for IC lead frames and visual inspection method thereof

Abstract: The a system includes a visual inspection unit, a plating thickness inspection unit, and a shape inspection unit, suitably arranged in combination on the inspection line for automatic inspection of stains, flaws, glossiness or deformation in plated IC lead frames. The system can be used by an inventive method to correct errors in positional relation between a reference image and images input from an inspection camera, to obtain a comparison between a reference luminance curve and the individual luminance curves and the correlation between reflectivity and the corresponding area, and to obtain a comparison between the reference correlation and individual correlations to thereby enhance automation and precision in inspection IC lead frames.

A Rule-Based System for Verifying Engineering Specifications in Industrial Visual Inspection Applications

Abstract: An important step in automatic visual inspection is verifying whether a part is good or bad, by comparing a list of inspection specifications to a list of extracted and measured defects. Our goal is to provide a general, flexible, and efficient solution to this problem. We present a solution following a rule-based approach for the case of specs for visual inspection of disk heads. However, due to the generality of our approach (within the realm of visual inspection), it is easily extendible to verification of specs in other visual inspection applications. While flexibility comes naturally with the rule-based approach, efficiency is still an issue. Therefore, we implemented two techniques to increase the efficiency of our system: one at the rule level, and one at the rule-matching level. We describe our implementation and show experimental results from applying our approach in an experimental system for automatic visual disk head inspection.

Multi-directional mobile inspection system

Abstract: Apparatus for performing inspections in difficult to access locations. The device includes remotely controlled transport apparatus upon which is mounted a camera and illumination lamps. The transport apparatus is maneuvered, through the remote control system, to the location where a visual inspection is to be performed. The associated camera then transmits a picture of the area in the vicinity of the camera back to a remote television monitor where it may be viewed.

Picture processing system and device

Abstract: PURPOSE: To facilitate and to accelerate picture processing by directly using CAD data used for the shape design of a substance and forming a reference picture or an inspection specification. CONSTITUTION: An inspection instrument 1 can input the inspection specification data produced by an inspection specification data producing device 3. Therefore, the inspection device 1 itself does not need the instruction of the inspection specification. The inspection specification data producing device 3 inputs basic design data 14 and detailed design data 15 produced by a CAD system 2. Then, the inspection specification is formed by an operator OP 2. This inspection specification operation can be processed much more easily and quickly than that by making at real model, which is inspected, to a picture on the inspection device and instructing. COPYRIGHT: (C)1988,JPO&Japio

Automation of Solder Joint Inspection Procedures Utilizing Laser Induced Infrared

Abstract: In the rush to automate assembly flow in the fabrication and assembly of electronic equipment, great strides have been made in all areas with the exception of solder joint inspection and rework. This paper focuses on an attempt to automate, at least in part, the inspection of printed wiring assembly (PWA) solder joints. The use of laser and/or X-ray equipment is causing quite a stir in the industry due to the fact that there finally appears to be a technique that may allow for automation of one of the most labor intensive, inexact, and costly tasks in any PWA assembly operation--the visual inspection of solder joint quality. As the complexity of PWA's increase, the number and density of solder joints are increasing. This trend is resulting in decreased efficiency in the inspection process due to the shear number of joints to be inspected, operator fatigue, and the subjectivity of the entire inspection process. In areas where absolute quality is critical, such as military products, this declining inspection effectiveness is being compensated for by the incorporation of multiple inspection-rework loops. These techniques statistically should result in the identification of all defects on a given assembly. However, the impact of this multiple inspection process is one of total disruption to the assembly flow in an automated shop. Laser induced infrared (IR) inspection has been under investigation by Texas Instruments' Defense Systems and Electronics Group for the past several years. Our thrust has been aimed at the incorporation of this technique into the inspection of PWA's that are fabricated for military customers. Extensive efforts have been expended in the determination of the strengths and weaknesses of the technique in an attempt to augment the human element in the inspection process.

The Reliability of Non-destructive Inspection, Assessing the Assessment of Structures under Stress

Abstract: The inspection of inspection: Introduction. Historical attitudes to non-destructive testing. Recent trends in non-destructive testing. Inspection and those who do it. General plan of the book. Systems reliability: Introduction. Fitness for purpose. Analysis of system failure. Risk analysis and human factors. Legal and economic aspects. Defects and failure: Fracture mechanics - mechanisms of failure. Defects in starting materials - cast metals. Manufactured defects - welding defects. Defects which grow in operation. Defects in non-engineering systems. Methods of non-destructive testing: Introduction. Visual inspection. Ultrasonics. Impact testing. Acoustic emission. Thermal resistivity. Eddy current techniques. Magnetic flux techniques. Electrical resistivity. Penetrating radiations. Proof testing. Summary. Failure of inspection: Reasons for failure of NDT techniques. Is the technique appropriate for the defects sought? Inspection procedures. Automated versus manual scanning. Human error. Magnitude of errors in manual inspection. Equipment malfunction. Estimates of serious human error. Human factors and how to control them. Properties affecting the performance of the technique. A mathematical description of unreliability. Repeating inspections. Summary. Idealised inspection studies: Tests of inherent capability. Idealised inspection studies - test-block trials. An example of the cost of fabrication and sectioning of test-block trials. Manufacture of test blocks. Destructive examination. Realism of test blocks. Results of test-block exercises. Interpolation of results. Probabilistic fracture mechanics. Role of test-block exercises in estimating inspection reliability. Alternatives to test-block exercises. Ultrasonic inspection of thick section steel components - criticism of PISC I. The Defect Detection Trials organised by the UKAEA. Further analysis of the results of the Defect Detection Trials. PVRC-PISC I and other ultrasonic trials in thick section steel. The future of round-robin tests. Inspection of other systems. Summary. Appendix. References. Index.

A real-time image processing algorithm for visual inspection of semiconductor wafer patterns

Abstract: The following general requirements are made in the visual inspection of the semiconductor wafer: (1) the candidates for the defect should automatically be detected from a complex multivalued pattern; and (2) only serious defects to the reliability of the element are extracted from those candidates. Such sophisticated decisions must be made with a high reliability and a high speed. This paper proposes a method for detecting serious defects as a means to cope with those requirements. The method is composed of the following two steps.

Optical Holography Applied To Underwater Visual Inspection

Abstract: In this paper we discuss the application of optical holography to underwater visual inspection with particular regard to the offshore oil and gas industries and outline some optical and physical problems likely to be encountered.

Semiconductor assembling equipment

Abstract: PURPOSE: To reduce inspection time, and prevent inspection omission, by providing a part to determine visual inspection items, charging the inspection items, and inspecting objects only, whose failure possibility is high. CONSTITUTION: A recognition processing part 40 recognizes pellet positions for bonding, and inspects the state after bonding. It is constituted of the followings; a picture image memory 46 to store quantized values of the signal from a TV camera 30, a position detection part 44, an inspecting part 45, an inspection item determining part 43, a communication interface 41, an inspection result storing part 47 and a CPU 42. The inspection item determining part 43 examines the past inspection results with respect to each inspection item, calculates the failure rate expected from said inspection results, and determines that the items of high failure rate should be inspected with high frequency, thereby assembling semiconductors while inspecting them with the highest efficiency in a limited time. COPYRIGHT: (C)1989,JPO&Japio

Method and device for visual inspection

Abstract: PURPOSE:To decrease deciding mistakes by giving an overall inspection to an actual pattern to divide it into blocks for collation and deciding a defect when the degree of difference higher than a standard level. CONSTITUTION:An overall collation is carried out between a standard pattern and an actual pattern thorough the 1st comparison part 10. Then both patterns are divided respectively into blocks and these blocks are collated with each other through the 2nd comparison part 18 to obtain the degree of difference among them. Then a defect of the actual pattern is decided when the degree of difference is higher than a standard level. Thus it is possible to inspect whether the defects are scattered or concentrated.

Inspecting device for printed character or the like

Abstract: PURPOSE:To generate no fatigue of an eye without dropping the inspection accuracy, by combining a visual inspection and an optical inspection. CONSTITUTION:When executing the learning, at the time of an inspection for correcting a total value of addition of an adding circuit 12 by collating with the naked eye an image of a printed character part drawn on a video surface of a monitor 19 and an image of a printed character part in a standard pattern, a data signal corresponding to a pattern to be inspected is binary-coded, based as a reference on a set digital value in a digital value setting circuit 16 in case when an added value of an adding circuit 13 has coincided with the total value of addition of the adding circuit 12, an equivalent area is corrected automatically in accordance with variable density of the printed character. Further, binary-coding signals which have been read in a memory 18 and 20 are compared successively, by which the pattern to be inspected is inspected by position information. In this way, a result of inspection being extremely similar to an inspection by the naked eye can be obtained.

Method for handling through-hole part at time of comparative inspection of pattern of printed circuit board

Abstract: PURPOSE:To perform inspection on a basis proper from a practical aspect, by performing visual inspection by recognizing the result of characteristic comparing inspection as a through-hole without rejecting the same when a through- hole recognition signal is issued from at least one of channel images. CONSTITUTION:A-channel image input 1 and B-channel image input 2 are respectively guided to a characteristic comparing inspection circuit 3 to be subjected to mechanical characteristic comparison. These inputs 1, 2 are simultaneously sent to through-hole recognition parts 4a, 4b and, in such a case that a through- hole is recognized from at least one of images of channels A, B, the presence of the through-hole is recognized when the position of the through-hole and the peripherals pattern thereof are simultaneously confirmed. In this case, even if a flaw signal is outputted as the result of the characteristic comparison, said signal is not outputted from an one-input negation AND gate 6 through an OR gate 1 and the confirmation of the through-hole is entrusted to visual inspection.

A Rule-BasedSystemforVernfying Engineerng Specifications inIndustral VisualInspection Applications

Abstract: An important stepinautomatic visual inspection isveri- fying whether apartisgoodorbad,bycomparing alist ofinspection specifications toalist ofextracted andmeasured defects. Ourgoalis toprovide ageneral, flexible, andefficient solution tothis problem. We present asolution following arule-based approach forthecaseofspecs forvisual inspection ofdiskheads. However, duetothegenerality of ourapproach (within therealmofvisual inspection), itiseasily exten- dible toverification ofspecsinothervisual inspection applications. Whileflexibility comesnaturally withtherule-based approach, efficiency isstill anissue. Therefore, weimplemented twotechniques toincrease theefficiency ofoursystem: oneattherulelevel, andone attherule-matching level. We describe ourimplementation andshow experimental results fromapplying ourapproach inanexperimental system forautomatic visual diskheadinspection. IndexTerms-Disk headinspection, efficiency, inspection specifica- tions, rule-based approach, visual inspection. I.INTRODUCTION A COMMON building blockinalgorithms forauto- matic industrial inspection isacomparison ofalist ofextracted defects withengineering specifications (specs), todetermine whether apart isgoodorbad.These specs areoften given asacomplex, context-dependent set

Visual Inspection for Multiple Flaws: Effects of Long-Term Inspector Experience

Abstract: In a simulation of industrial quality control inspection, performance was tracked over a period of three months using target conditions which had previously been shown to produce performance decrements with multiple flaws. Feedback on performance was supplied to inspectors at the end of each day's work. Results showed that by the end of the period, multiple fault inspection performance was equal to or slightly better, in both accuracy and latency, than previous data obtained with single fault conditions. This finding raises concerns over previous studies which have attempted to address the issue of the supposed performance decrement associated with increasing the size of the target set.