scholarly journals Three-Dimensional Shape Measurements of Specular Objects Using Phase-Measuring Deflectometry

Sensors ◽  
2017 ◽  
Vol 17 (12) ◽  
pp. 2835 ◽  
Author(s):  
Zonghua Zhang ◽  
Yuemin Wang ◽  
Shujun Huang ◽  
Yue Liu ◽  
Caixia Chang ◽  
...  
2019 ◽  
Vol 9 (7) ◽  
pp. 1444
Author(s):  
Xiaoting Deng ◽  
Nan Gao ◽  
Zonghua Zhang

Phase measuring deflectometry has been widely studied as a way of obtaining the three-dimensional shape of specular objects. Recently, a new direct phase measuring deflectometry technique has been developed to measure the three-dimensional shape of specular objects that have discontinuous and/or isolated surfaces. However, accurate calibration of the system parameters is an important step in direct phase measuring deflectometry. This paper proposes a new calibration method that uses phase information to obtain the system parameters. Phase data are used to accurately calibrate the relative orientation of two liquid crystal display screens in a camera coordinate system, by generating and displaying horizontal and vertical sinusoidal fringe patterns on the two screens. The results of the experiments with an artificial specular step and a concave mirror showed that the proposed calibration method can build a highly accurate relationship between the absolute phase map and the depth data.


1995 ◽  
Vol 7 (3) ◽  
pp. 221-224 ◽  
Author(s):  
Harunobu Kawai ◽  
◽  
Toshihiro Hamada ◽  
Hiroki Nakanishi ◽  
Seiji Hata ◽  
...  

In the case of constructing an inspection system such as extracting the defects of 3-D shape of parts, it is a necessary and indispensable factor that the non-contact shape measurement of an object is automated. However, it is very difficult to measure the shape of an object which has a mirror-like surface. Here, a three-dimensional shape measurement sensor capable of reliably measuring the shape of an object which has mirror-like surface has been developed. The spotlight scanning light-section method is employed in this sensor. The sensor is a compact instrument by which the position of light can scan the object. The output intensity of the light source is controlled according to the detected brightness of light.


2006 ◽  
Vol 37 (4) ◽  
pp. 583
Author(s):  
Michael McGowan

This article examines the relatively new fields of colour and shape trade marks. It was initially feared by some academics that the new marks would encroach on the realms of patent and copyright.  However, the traditional requirements of trade mark law, such as functionality and descriptiveness, have meant that trade marks in colour and shape are extremely hard to acquire if they do not have factual distinctiveness. As colour and shape trade marks have no special restrictions, it is proposed that the combination trade mark theory and analysis from the Diamond T case should be used as a way to make them more accessible. The combination analysis can be easily applied because every product has a three dimensional shape and a fourth dimension of colour.


2017 ◽  
Author(s):  
Tatsuya Kitamura ◽  
Hironori Takemoto ◽  
Hisanori Makinae ◽  
Tetsutaro Yamaguchi ◽  
Kotaro Maki

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