Delay Compensation for Synchronization Signal in Rotating Laser-Scanning Measurement System

2021 ◽  
Vol 58 (3) ◽  
pp. 0312002-312002171
Author(s):  
郭同闯 Guo Tongchuang ◽  
任永杰 Ren Yongjie ◽  
林嘉睿 Lin Jiarui ◽  
金云超 Jin Yunchao ◽  
张振宇 Zhang Zhenyu
Keyword(s):  
Measurement System ◽  
Laser Scanning ◽  
Delay Compensation ◽  
Synchronization Signal

An Automated Procedure for the Geometrical Characterization of Root Canals

2008 ◽  
Author(s):  
Giovanni Tani ◽  
Leonardo Orazi ◽  
Gabriele Cuccolini
Keyword(s):  
Measurement System ◽  
Laser Scanning ◽  
Original System ◽  
Maximum Amount ◽  
Computer Design ◽  
Geometrical Characterization ◽  
Statistical Population ◽  
Root Canals ◽  
Best Fit

In this work an original system for the geometrical characterization of root canals for dental implants was developed and tested. The aim of this work is to determine the shape and the size of the posts that best fit a statistical population of root canals with a defined maximum amount of removed tissue. The task is performed by an accurate acquisition of the shape of a statistically significant batches of root impressions: the geometry are then processed to obtain the post geometry. The acquisition is carried out using a conoscopic laser scanning device mounted on a 4 axis controlled CNC measurement system. The shape of the root canals were measured for each type of tooth, obtaining an average 3-D computer design of the canal profiles. Several comparisons between the acquired geometry and the representative forms of commercial posts are finally presented.

Error Analysis and Improvement of Equal Precision Frequency Measurement

2014 ◽  
Vol 687-691 ◽  
pp. 841-846 ◽  
Author(s):  
Rong Xiang Wang ◽  
Xia Zhang
Keyword(s):  
Error Analysis ◽  
Measurement System ◽  
Measurement Accuracy ◽  
Frequency Measurement ◽  
Frequency Count ◽  
Frequency Multiplication ◽  
Circuit Performance ◽  
Standard Frequency ◽  
Synchronization Signal ◽  
Precision Frequency

In accordance with the principle of equal precision frequency measurement and theory of errors, in this paper, the problems are discussed that the equal precision frequency measurement eliminates the standard frequency count error. In order to reduce the relative error and improve the measurement accuracy, a method is proposed for phase coincide detection between standard frequency multiplication and measurement frequency demultiplication to open or shut the gate, at the same time, a signal selector is also used to improve circuit performance. This method can effectively solve the problem that the frequency can not be detected without the synchronization signal and improve the performance of the frequency measurement system.

Soft Defect Localization Techniques without a Synchronization Signal to the Laser Scanning Module

2005 ◽  
Author(s):  
Diana M. Mitro ◽  
Dawn Glaeser ◽  
Clifford Howard
Keyword(s):  
Liquid Crystal ◽  
Hot Spots ◽  
Laser Scanning ◽  
Threshold Temperature ◽  
Support Design ◽  
Analysis Technique ◽  
Defect Localization ◽  
Localized Heating ◽  
Synchronization Signal ◽  
Race Conditions

Abstract Soft Defect Localization (SDL) is an analysis technique where changes in the pass/fail condition of a test are monitored while a laser is scanned across a die.[1,2,3,4] The technique has proven its usefulness for quickly locating failing nodes for functional fails that are temperature, frequency, and/or voltage dependant. The localized heating from the laser can toggle the pass/fail condition as it sweeps over failing nodes with the aforementioned sensitivity. The technique is instrumental in identifying latent defect locations on conditional fails even though they seldom produce light emissions or liquid crystal hot spots. These fails often manifest themselves after reliability stress or at the customer. The technique can also be applied to support design groups with first silicon analysis of timing race conditions and identification of signals that are speed path limiters. The main challenges associated with the technique are in synchronizing the tester with the Laser Scanning Module (LSM) and ensuring the laser can heat the device enough to overcome the pass/fail threshold temperature of the failing node.

Measurement System for BGA Coplanarity

2003 ◽  
Author(s):  
Yu Qiu ◽  
Changku Sun ◽  
Shenghua Ye ◽  
Yilan Kang
Keyword(s):  
Measurement System ◽  
Laser Scanning ◽  
Experimental Studies ◽  
Assessment Method ◽  
Optical Image ◽  
Scanning System ◽  
Laser Scanning System

This paper presents a line-structured laser scanning system for measuring the coplanrity of BGA chip leads. The corresponding methematics model of the system is gived. And also a study of optical image splitting and splicing technique is constructed and used to improve the resolution of the system. Furthemore, a contact-datum-plane assessment method is established to evaluate the coplanarity of BGA chip leads. The experimental studies on a 20 × 20 array of BGA chip is carryed out, the inaccuracy error of the measurement system is 2σ= 0.033μm.

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