• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.2
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• pp.141-146
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• 2014

This paper describes the implementation and algorithm of handwritten character recognition using mobile touch screen. The system is consisted of PXA320 processor, capacitive touch panel and QT4 interface. The proposed algorithm extracts pattern characteristics with straight, left circle, right circle on the inputting character. The definition of character is determined by 3-way tree searching method. The performance of proposed algorithm is verified using alphabet character. It is suitable to apply the mobile touch screen because of simple algorithm.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.3
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• pp.1-12
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• 2011

Large-sized multi-touch screen is usually made using infrared rays. That is because it has technical constraints or cost problems to make the screen with the other ways using such as existing resistive overlays, capacitive overlay, or acoustic wave. Using infrared rays to make multi-touch screen is easy, but is likely to have technical limits to be implemented. To make up for these technical problems, two other methods were suggested through Surface project, which is a next generation user-interface concept of Microsoft. One is Frustrated Total Internal Reflection (FTIR) which uses infrared cameras, the other is Diffuse Illumination (DI). FTIR and DI are easy to be implemented in large screens and are not influenced by the number of touch points. Although FTIR method has an advantage in detecting touch-points, it also has lots of disadvantages such as screen size limit, quality of the materials, the module for infrared LED arrays, and high consuming power. On the other hand, DI method has difficulty in detecting touch-points because of it's structural problems but makes it possible to solve the problem of FTIR. In this thesis, we study the algorithms for effectively correcting the distort phenomenon of optical lens, and image processing algorithms in order to solve the touch detecting problem of the original DI method. Moreover, we suggest calibration algorithms for improving the accuracy of multi-touch, and a new tracking technique for accurate movement and gesture of the touch device. To verify our approaches, we implemented a table-based multi touch screen.

• Journal of Korean Institute of Industrial Engineers
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• v.36 no.1
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• pp.52-58
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• 2010

The level of competition has reached the limits in cellular phone market and the cellular phone manufacture companies started to focus their solution in user interface. Design issues with controllability led the development and renovation of such products to the use of the touch-screen phone. Depending upon the readability, technical advances, portability and controllability, user satisfaction of touch-screen phones could vary significantly. In this research, the controllability was dealt in regard to various grip postures, in order to improve menu layout which fits for using the thumbs of both hands and a thumbs of single hand. Regression models are found to the suggest the location of buttons on the screen by redesigning the menu layout, it is expected to improve both controllability and satisfaction of the user. This result can be applicable not only to mobile phone design, but also to the design of various hand-held devices using a touch screen.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.173-178
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• 2008

Due to a rapid increase in demand for bigger-screen-equipped mobile phones in recent years, many big-name-manufactures have been releasing touch-screen-enabled devices. In this paper, various touch-screen-input methods have been summarized into 6 different categories. How? By tracing each user's finger print path, user's input pattern and behavior have been carefully recorded and analyzed. Through this analysis, what to be considered before designing UI is presented in great details.

• Journal of Korea Multimedia Society
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• v.17 no.12
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• pp.1430-1436
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• 2014

We propose an algorithm which detects the touch of the fingertip on a general wall using the shadow information. Nowadays, there is a demand for presentation systems which can perceive the presenter's action so that the presenter can use natural movements without extra interface hardware. One of the most fundamental techniques in this area is the detection of the fingertip and the recognition of the touch of the fingertip on the screen. The proposed algorithm recognizes the touch of the fingertip without using the depth information, and therefore needs no depth or touch sensing devices. The proposed method computes the convex hull points of both the fingertip and the shadow of the fingertip, and then computes the distance between those points to decide whether a touch event has occured. Using the proposed method, it is possible to develop a new projector device which can perceive a fingertip touch on a general wall.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.4
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• pp.246-250
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• 2014

Large mutual capacitance touch screen panels (TSP) are susceptible to display and ambient noise. This paper presents a multi-touch detection algorithm using an efficient noise compensation technique for large mutual capacitance TSPs. The sources of noise are presented and analyzed. The algorithm includes the steps to overcome each source of noise. The algorithm begins with a calibration technique to overcome the TSP mutual capacitance variation. The algorithm also overcomes the shadow effect of a hand close to TSP and mutual capacitance variation by dynamic threshold calculations. Time and space filters are also used to filter out ambient noise. The experimental results were used to determine the system parameters to achieve the best performance.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.4
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• pp.71-79
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• 2015

This paper proposes a new touch screen sensing method that improves the drawback of conventional single-line sensing methods for mutual capacitance touch screen panels (TSPs). It introduces a dual sensing and voltage shifting method, which reduces the ambient noise effectively and enhances the touch signal strength. The dual sensing scheme reduces the detection time by doubling the integration speed using both edges of excitation pulse signals. The voltage shifting method enhances the signal-to-noise ratio (SNR) by increasing the voltage range of integrations, and maximizing the ADC's input dynamic range. Simulation and experimental results using a commercial 23" large touch screen show an SNR performance of 43dB and a scan rate 2 times faster than conventional schemes - key properties suited for a large touch screen panels. We implemented the proposed method into a TSP controller chip using Magnachip's CMOS 0.18um process.

• Journal of Korea Multimedia Society
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• v.14 no.7
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• pp.924-932
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• 2011

Though the spread of the touch screen devices is now revitalized, the Korean input methods in the touch screen devices are mostly the button input methods using keypads. Even though the button input methods are used with a touch screen, they still adopts the existing qwerty keyboard. It means that the existing methods can not be improved. This research suggests that the Korean input method which can be used in the portable terminals and the touch screen devices, for example, a smart phone which has a limited sized screen. It assigns every vowel a process which corresponds with the Korean invention theory and the vowel input method is to drag it. Through the mock experiments, we confirmed that the simplification of the Korean alphabet is more efficient than the existing methods, in the point of the speed of the Korean input.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.2
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• pp.319-324
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• 2012

This paper introduces a 2-dimensional touch screen panel driver based on an improved capacitive sensing circuit. The improved capacitive sensing circuit based on charge pump can eliminate the remaining charges of the intermediate nodes, which may cause output voltage drift. The touch screen panel driver with mixed-mode circuits was built and simulated using Cadence Spectre. Verilog-A models the digital circuits effectively and enables them to interface with analog circuits easily. From the simulation results, we can verify the reliable operations of the simple structured touch screen panel driver based on the improved capacitive sensing circuit offering no voltage drift.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.2
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• pp.1-13
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• 2011

The recent spotlight on electronic touch-screen display, a rapid breakthrough in the information society is evolving. Touch panel input device such as a keyboard or mouse without the use of, the on-screen character or a specific location or object on the person's hand touches a particular feature to identify the location of a panel is to be handled. The touch screen on the touch panel is used in the Ag paste is used mostly for low-curable paste. The thermal-curing paste according to the drying process of thermal energy consumption and improve the working environment of organic solvents have problems. In this study, Ag paste used in the non-thermal curing friendly and cost-effective UV curable paste was prepared. Current commercially available thermal-curable binder, was used instead of the flow characteristics of UV-curable oligomers and monomers with functional groups to give a single conductive Ag paste with the addition of a pattern could be formed. Ag paste as a result, thermal-curing adhesive, hardness, resistance and excellent reproduction of fine patterns and was available with screen printing environmentally friendly could see its potential as a patterning technology.