We propose a novel excimer laser machining using a multiple imaging system employing a holographic optical element (HOE). The HOEs that we used were computer generated phase holograms. We calculated the HOE by with three-step optimization using a direct binary search algorithm. The optimized HOE pattern was 4-level, and the matrix size was 1024×1024 with 1 micron pixels. With the use of this HOE, the 95 holes whose diameter was 0.1 mm were drilled in a 10×10 mm area. The energy availability was 19.4%.
There are various ways to binarize images automatically. Our study is how to binarize character images which were taken under bad lighting conditions with CCD camera. We propose a linear equation for threshold and the adaptive image segmentation. The dynamic thresholding by this method makes these shading images well binarized in quality.
Handwritten character recognition has been increasing for its importance and has been expanding its application areas. In this paper, we propose the recognition system of musical score, and as one of the applications we tried to perform the Okinawan syamisen by the recognized data. The recognition system is composed of a simple, fast feature extraction method, and as an efficient way we used both the fast recognition method (Three-Dimensional Table Method) and the exact recognition method (Euclid Distance). In recognition experiments using musical score (2010 Characters), we have obtained a recognition rate of 95.3 [%], which is the efficient combination method.
The recognition by computer of handwritten characters has been the subject of discussion for many years, because of being increasing its importance. In this paper, we propose the simple character recognition system of free handwritten characeters. This system is given by a structure analytic techique, and we used end points, corner points, 3 fork points, and crossing points as its features. As the result of the recognition experiments using 7800 characters, we have obtained a recognition rate of 85.4 [%].
The back illumination type photosensitive field emitter was fabricated by depositing p-type a-SiC : H/intrinsic a-Si : H photodiode on the back surface of nongated n-type cone-shaped Si emitters by using plasma CVD methode. The emission current corresponding with illumination intensity was observed and the quantum efficiency of about 0.7. However, the emission current has tendency to be saturated at high illumination level. To expand the dynamic range of the photodetector, the photosensitive field emitter composed of gated field emitter and p-type a-SiC : H/intrinsic a-Si : H photodiode film was demonstrated.
We studied a MOSFET which suits with a readout transistor on a solid-state imager in which MOS scanner is combined with an avalanche photoconversion layer. The MOSFET requires high endurance voltage because high voltage is applied between the scanner and the photoconversion layer to get high multiplication gain using avalanche phenomenon. In this paper, a new MOSFET structure, which can increase the endurance voltage by attaching an electric field relaxation layer to the drain contact of the MOSFET, is described. The device parameters for fine readout operation were decided by calculations using a process-device simulator. The electric field relaxation layer was confirmed to work effectively because endurance voltage of 60V was obtained on fabricated test devices.
To develop small, high-quality cameras, we have been studying an imaging method for NTSC using a single-chip HDTV CCD. The arrangement of the color filter array is the key issue for reproducing color images and improving color image quality for both HDTV and NTSC. Since two-pixel and four-pixel mixing are required to generate signals for both scanning systems, there are only a few choices for the color filter arrangement. The vertical stripe filter array is one possibility that satisfies the operational requirements, but it has poor horizontal resolution characteristics. In this paper, we propose a new color filter array and color separating method. The new filter array has a quincunx sampling structure for different color signals, which improves the color resolution, and it is easy to separate color signals for NTSC. Using simulations, we compare the quality of images from our filter to that of images reproduced by a vertical stripe filter array.