The movement of point of gravity of hairspring is so known as the one as far as of it's central area which will cause the vertical positional error at the amplitude 220° in vertical positions, has been once resolved with the famous condition known as the Phillips condition written in 1860 by Edouard Phillips. But it's mathematical formula has not been translated into a helpful form for the actual practice of adjustment of internal curve shape, and has not contributed for the improvement of actual adjustment of vertical positional errors. Then, as the consequence, we have not yet been informed any new researches about this area in these 150 years. Thus the actual method of adjustment of shape of internal curve of hairspring has been long lead with arbitrary ways, almost no method. In this report here is presented the new understanding and the adaptation of the theory above for Archimedes curves used in modem watches. Furthermore here are shown very precise results of adjustment of internal curve of hairspring by following the method in this report. The maximum positional error at 220° amplitude reached to 1.3s/day in case of gentle wrist watches tried here.

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The hands of the analog watch can be thrown off by exposure to strong magnetism or impact. So we developed a new mechanism and algorithm of auto hand position correction for the analog watch. It detects the position of the hands periodically and adjusts them to the correct position if it discovers any discrepancy, and it corrects all three hands (hour, minute, and second hand) position by using one set of detection device.

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Acrylic adhesives with short curing time for packaging of electronics parts have been developed. The technology is based on experiences with development of lubricants and polymer materials for precision machineries like watches. Experiments on various acrylmonomers have shown that cure shrinkage depends on molecular weight and molecular structure, and some additive agents will further reduce the shrinkage. Mechanism of cure shrinkage is discussed in terms of molecular structures of the acrylmonomers.

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A simulation method for stepping motors has been developed. This method is based on the experimental data for instance friction loss, the finite element method (FEM) data, the theory of the permeance method and the genetic algorithm. Pareto-optimal solutions are obtained in a short time by using this method.

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Citizen has developed electorophoretic display (EPD) based on E-INK technology, which has many advantages; low power consumption, thin, flexible, good readability. To drive easier and to get high contrast ratio, we developed original EPD driver IC. And to achieve high reliability, we also developed new barrier films and new cell structure. We will explain our EPD structure and the EPD application for Marathon EPD display system and for mobile phones sub-display and key pad.

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We would like to introduce our newly developed small portable pedometer (WZ700/750/800). The detecting circuit to count steps is designed by two single-axis acceleration sensor bisected at right angles, in order to detect the touchdown impact (landing impact). Also the software to count steps is designed to ignore the signal of touchdown impact for certain period after detecting it. Furthermore, we were able to achieve the small portable pedometer by adopting the structure to reduce substrate strain and by preventing error count from the stress to the product.

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