• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.152-154
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• 2005

This paper proposes the new subfield method to erase reverse gray levels and low gray level contour in AC plasma display panel(PDP). In the conventional method, it is supposed that output luminance levels of a PDP increase regularly. But actual output luminance levels of a PDP increase irregularly. Therefore, conventional methods are unable to effectively reduce low gray-level contours and reverse gray levels. Accordingly, a new subfield method is applied to improve the low gray-level expression in PDP. Conclusively this paper clear proof that a new subfield method can suppress low gray-level contours and reverse gray levels more effectively than conventional methods.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.647-650
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• 2005

A new driving scheme, Address and Display Period Complex Driving for Expanding Gray Scale(ACE), is proposed by mixing Address Display period Separated(ADS) and Address While Display(AWD). In this method scan lines are divided in blocks driving by AWD and scan lines in block progress sequential high speed addressing. ADS driving get accomplished in low gray level for expanding gray scale. Scan time is reduced and the number of subfields is increased by high speed addressing of ACE. That expands the gray scale and decreases the dynamic false contour. Also, that improves contrast by using ramp reset.

• 전자공학회논문지B
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• 제32B권11호
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• pp.1445-1454
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• 1995

In this study, we have developed a prototype of the automatic defects detection system for capsule inspection using the computer vision techniques. The subjects for inspection are empty hard capsules of various sizes which are made of gelatine. To inspect both sides of a capsule, 2-stage recognition is performed. Features we have used are various lengths of a capsule, area, linearity, symmetricity, head curvature and so on. Decision making is performed based on average value which is computed from 20 good capsules in training and permission bounds in factories. Most of time-consuming process for feature extraction is computed by hardware to meet the inspection speed of more than 20 capsules/sec. The main logic for control and arithmetic computation is implemented using EPLD for the sake of easy change of design and reduction in time for developement. As a result of experiment, defects on size or contour of binary images are detected over 95%. Because of dead zone in imaging system, detection ratio of defects on surface, such as bad joint, chip, speck, etc, is lower than the former case. In this case, detection ratio is 50-85%. Defects such as collet pinch and mashed cap/body seldom appear in binary image, and detection ratio is very low. So we have to process the gray-level image directly in partial region.