The quality of edge detection is related to detection angle, scale, and threshold. There have been many algorithms to promote edge detection quality by some rules about detection angles. However these algorithm did not form rules to detect edges at an arbitrary angle, therefore they just used different number of angles and did not indicate optimized number of angles. In this paper, a novel edge detection algorithm is proposed to detect edges at arbitrary angles and optimized number of angles in the algorithm is introduced. The algorithm combines singularity detection with Gaussian wavelet transform and edge detection at arbitrary directions and contain five steps: 1) An image is divided into some pixel lines at certain angle in the range from 45° to 90° according to decomposition rules of this paper. 2) Singularities of pixel lines are detected and form an edge image at the certain angle. 3) Many edge images at different angles form a final edge images. 4) Detection angles in the range from 45° to 90° are extended to range from 0° to 360°. 5) Optimized number of angles for the algorithm is proposed. Then the algorithm with optimized number of angles shows better performances.

This paper reviews architectures and topologies for column-parallel analog-to-digital converters (ADCs) used for CMOS image sensors (CISs) and discusses the performance of CISs using column-parallel ADCs based on figures-of-merit (FoM) with considering noise models which behave differently at low/middle and high pixel-rate regions. Various FoM considering different performance factors are defined. The defined FoM are applied to surveyed data on reported CISs using column-parallel ADCs which are categorized into 4 types; single slope, SAR, cyclic and delta-sigma ADCs. The FoM defined by (noise)2(power)/(pixel-rate) separately for low/middle and high pixel-rate regions well explains the frontline of the CIS' performance in all the pixel rates. Using the FoM defined by (noise)2(power)/(intrascene dynamic range)(pixel-rate), the effectiveness of recently-reported techniques for extended-dynamic-range CISs is clarified.

This paper presents the design and implementation of a quadrature voltage-controlled ring oscillator with the improved figure of merit (FOM) using the four single-ended inverter topology. Furthermore, a new architecture to prevent the latch-up in even number of stages composed of single-ended ring inverters is proposed. The design is implemented in 0.18 µm CMOS technology and the measurement results show a FOM of -163.8 dBc/Hz with the phase noise of -125.8 dBc/Hz at 4 MHz offset from the carrier frequency of 3.4 GHz. It exhibits a frequency tuning range from 1.23 GHz to 4.17 GHz with coarse and fine frequency tuning sensitivity of 1.08 MHz/mV and 120 kHz/mV, respectively.

In this paper, Poly(3,4-ethylenedioxythiophene): Poly (Styrenesulfonate) (PEDOT:PSS) thin films for application in a bolometer, a type of uncooled infrared image sensor, are presented. In addition, the TCR and 1/f noise dependencies of PEDOT:PSS thin films on the thermal treatment conditions are demonstrated. It is also shown that an appropriate thermal treatment can suppress the 1/f noise of PEDOT:PSS thin films while maintaining the resistivity and TCR. A high TCR value over -4%/ (within 10 ohmcm) through chemical treatment is also presented. The results of this study show that PEDOT:PSS thin films have potential for use as a bolometric material.

A design of a low-power CMOS ring oscillator for an application to a 13.56 MHz clock generator in an implantable RFID tag is proposed. The circuit is based on a novel voltage inverter, which is an improved version of the conventional current-source loaded inverter. The proposed circuit enables low-power operation and low sensitivity of the oscillation frequency, fOSC, to decay of the power supply VDD. By employing a gm-boosting subcircuit, power dissipation is decreased to 49 µW at fOSC=13.56 MHz. The sensitivity of fOSC to VDD is reduced to -0.02 at fOSC=13.56 MHz thanks to the use of composite high-impedance current sources.

A low-power high-frequency sinusoidal quadrature oscillator is presented through a new RC technique using only CMOS current mirrors. The technique is relatively simple based on (1) internal capacitances of CMOS current mirrors and (2) a resistor of a CMOS current mirror for a negative resistance. Neither external capacitances nor inductances are required. As a particular example, a 2.4 GHz-0.4 mW, 0.325-fT, CMOS sinusoidal quadrature oscillator has been demonstrated. The power consumption is very low at approximately 0.4 mW. Total harmonic distortions (THD) are less than 0.3%. The oscillation frequency is current-tunable over a range of 540 MHz or 22%. The amplitude matching and the quadrature phase matching are better than 0.035 dB and 0.15, respectively. A figure of merit called a normalized carrier-to-noise ratio (CNRnorm) is 158.79 dBc/Hz at the 2 MHz offset from 2.46 GHz. Comparisons to other approaches are also presented.

A number of Tonpilz piezoelectric transducers generally form a large matrix array. They may be required to be only light in weight, or both miniaturized and light in weight as well as to have high-power capability, according to their use. This paper describes the results obtained in an investigation of miniaturized, light-weight Tonpilz piezoelectric transducers with high-power capability. An electromechanical energy conversion system and mechanical vibration system for the transducer are theoretically investigated on transducer configuration, using a Martin equivalent circuit and distributed-constant equivalent mechanical circuits. For simplification of the theoretical analysis, the transducer was considered as being divided into a front-half section, from the head mass end to the vibration nodal section, and a rear-half section, from the vibration nodal section to the tail mass end. Figures of merits, FMm for the front-half section and FM'm for the rear-half section, are calculated to achieve lightening as well as high-power capability. In addition, figures of merits FMml for the front-half section and FM'ml for the rear-half section are calculated to achieve miniaturization and lightening as well as high-power capability. To corroborate the theoretical results obtained, three kinds of Tonpilz transducers having the same 30 kHz resonant frequency but different configurations were built. Then, three kinds of 33 matrix arrays composed of nine Tonpilz transducers with the same configuration were fabricated. To evaluate the high-power characteristics for the arrays, a water tank to which high hydraulic pressure can be applied was adopted and a high-power test was carried out. As a result, it was found that transducers with high FMm and FM'm figures of merits are light in weight and exhibit high performance in high-power handling capability. Also, it was found that transducers with high FMml and FM'ml figures of merits are miniaturized and light in weight and exhibit high performance in high-power handling capability.

The nonlinear optical properties of organics with unsaturated bonds were compared with those of inorganics including semiconductors and dielectrics. Because of the mesomeric effect, namely quantum mechanical resonance effect among configurations, aromatic molecules and polymers have larger optical nonlinear parameters defined as δ(n)=X(n)/(X(l))n both for the second (n=2) and third-order (n=3) nonlinearities. Experimental results of ultrafast nonlinear response of conjugated polymers, especially polydiacetylenes, were described and a model is proposed to explain the relaxation processes of photoexcitations in the conjugated polymers. Applying the model constructed on the basis of the extensive experimental study, we propose model polymers to obtain ultrafast resonant optical nonlinearity.

The nonlinear optical properties of organics with unsaturated bonds were compared with those of inorganics including semiconductors and dielectrics. Because of the mesomeric effect, namely quantum mechanical resonance effect among configurations, aromatic molecules and polymers have larger optical nonlinear parameters defined as δ(n)X(n)/(X(1))n both for the second (n2) and third-order (n3) nonlinearities. Experimental results of ultrafast nonlinear response of conjugated polymers, especially polydiacetylenes, were described and a model is proposed to explain the relaxation processes of photoexcitations in the conjugated polymers. Applying the model constructed on the basis of the extensive experimental study, we propose model polymers to obtain ultrafast resonant optical nonlinearity.