A clean room is used for adjusting the concentration of suspended particles using an air-conditioner. It has a fan-filter unit combining a centrifugal fan and a high-efficiency particulate air filter that purifies the outside air and directly affects its cleanliness. Defects in these systems are typically detected using special sensors for each fault, which can be costly. Therefore, this paper proposes a system for diagnosing defects in the fan-filter unit using a single differential sensor and deep learning. The fan-filter unit is part of the air-conditioning system, and it is usually defective in bearings, filters, and motors. These faults include ball wear, internal bearing contamination, filter contamination, and motor speed changes. Each defect was artificially induced in experiments, and the differential pressure data of each defect was learned using a long short-term memory (LSTM) deep learning algorithm. The results of deep learning experiments generated by randomly mixing data five times were presented using a confusion matrix, and the results showed an accuracy of 87.2±2.60%. Therefore, the possibility of diagnosing defects in the fan-filter unit using a single sensor was confirmed.

This paper presents a construction method regarding a tubular nano-mesh for which the anodic oxidation of aluminum (Al) wire is used. The first step of tubular-nano-mesh production is Al-wire anodization. A new anodizing device was made for the wire-based uniform anodization for this study, and a high-purity (99.999%) Al wire with a 2 mm diameter was used. Also, an electrolytic solution was used as a 0.07 M oxalic acid, while the electrolytic-solution temperature was maintained at -3℃. While the applied voltage and the process time were varied, the AAO (Anodic Aluminum Oxide) characteristics of the Al wire were observed. When 60 V was applied to the wire, alumina cracks were not evident, whereas the application of 100 V produced alumina cracks; this is because the growth rate of the nano-pore voltage affected the alumina shape. For the subsequent construction of the tubular alumina structure, an Al-etchant (HCl + H2O + CuCl2 + 2H2O) etched-Al portion of the anodized wire was employed. The final step is a pore-widening process that is implemented through the hole channel. The anodized wire was dipped in the alumina etchant, and the pore-wall removal was checked over time.

Pyramid shape of micro pattern is applied to the light guide panel (LGP) to enhance the uniformity of the brightness of the LCD. The micro pyramids are molded in intaglio on the surface of the LGP. The size of each pyramid is 5㎛ × 5㎛ on bottom and the height is about 3.5㎛. The pyramids are distributed on the LGP surface randomly to be sparser where the light comes in and denser at the opposite side as a result of a simulation using lightools™. Based on this design, a silicon pattern master and a nickel stamper are fabricated by MEMS process and electro plating process. Intaglio micro pyramids are fabricated on the 6" of silicon wafer from the anisotropic etching using KOH and the process time, temperature of the KOH solution, etc are optimized to obtain precise shape of the pattern. A Ni stamper is fabricated from this pattern master by electro plating process and the embossed pyramid patterns turns out to be well defined on the stamper. Adopting this stamper to the mold base with two cavities, 1.8" and 3.6" LGPs are injection molded.

The automatic assembly system of micro optical filter is a key technology in the development of optical modules with high functionality. In order to develop an automatic assembly system of optical fiber and filter, we have firstly developed the system and program capable of characterization of 30 ㎛-thick film filters as well as conventional optical filters. Moreover, we have carried out the characterization of optical filter using the developed system and program, and compared experimental results with by conventional handwork. The measurement of optical filters using the present system is faster, more precise and more reliable than those based on the conventional handwork.

From the Beckmann's reflection model of wave incident, reflected light from a surface is known to have not only specular but also diffuse components. The specular component dominant a surface for a mirror-like surface is distributed on the almost the same area as the spot on the surface, but the diffuse component region dominant for a rough surface spreads scattered on the larger areas than the spot. Therefore, statistic parameters from the scattered light distribution are more meaningful in the diffuse region, while the magnitude of rather meaning in the specular region. In usual, there need two sensors to acquire two kinds of information: Photo-detector for light intensity magnitude and image sensor for light intensity distribution. But dual sensor scheme requires a beam splitter usually to feed light to each sensor, and moreover there is not a combination rule to relieve the different sensor characteristics. In this study a new method is proposed for acquisition of the dual information using only an image sensor. Specular region is established on an image area being distinguished from a diffuse component, and laser power is adjusted so that no pixel of the image sensor in the specular region is saturated. Simulation based on the light reflection theory and the experimental results are quite well matched, and thus the proposed method was proved to be very useful for mirror-like surface measurement.

The light pattern reflected from a machined surface contains some information like roughness and profile on the projected surface as expected in the Beckmann-Spizzichino model. In applying the theory into a real reliable measuring device, many parameters such as incident light power, wave length, spot size shoud be kept a constant optical value. However, the reflected light power is likely to change with the environmental noise, the variations of the light source, the reflectivity of the surface, etc. even though the incident light power is constant. In this study, a method for adjusting the incident light power to keep the reflected light power projected on a CMOS image sensor constant was proposed and a simple adjustment algorithm based on PI digital control was examined. Experiments verified that the proposed method made the surface roughness measurement better and more reliable even under variations of the height of light source.