This study is about the design and simulation of an f-theta lens, one of the main components used in laser printers and laser scanning systems. To design an f-theta lens, the optical paths of the components of the laser scanning unit, the ftheta lens, the cylinder lens, and the collimator lens must be identified. Simulations were performed on the performance of aspherical and beam size optical systems while considering the f-theta lens optical design and optical properties. And while considering the optical design and optical characteristics of the f-theta lens, simulation was conducted on the performance of the optical system for aspherical surface and ray aberrations by location, point spread function, spot diameter, and beam size. Optical system simulation was implemented by applying the collimator lens, polygon mirror, and cylinder lens to the design formula of an f-theta lens using the Code-V and design verification was performed with these results.

In this study, the fracture characteristics of structural adhesives were investigated according to the shape of a DCB and TDCB by using the FEM. First, to obtain the reliability of the finite element method, the experimental and FEM analyses were compared, and the reliability was secured. When the graph of reaction force to displacement on the TDCB test specimen was examined, it was found that the smaller the slope, the stronger the exhibited property sustaining the load to the end of the adhesive surface. Maximum reaction force occurred was just before the adhesive was removed. The shear stress of the specimen exhibited the same characteristics and an equivalent stress. Thus, the data of this study resulting in the fracture characteristics of the structural adhesives for each shape can be applied to the design with durability.

Majority of deformation and ruptures as a result of severe deformation of mechanical structures are due to the existence of cracks or cracks generated through specific situations. These cracks causes stress concentration and eventually ruptures under lower load conditions than they are designed to withstand. In this study, simulation tensile analysis was done by designing compact tension specimen models with the number of holes that existed inside and the materials of the test specimens by focusing on the effects of the cracks. The study results from all the analysis (deformations, equivalent stress and strain energy) confirmed that the specimen models having two holes had better strength characteristics than those with only one hole. Additionally, the durability and strength characteristics of specific mechanical structures against the load improved through appropriate arrangement of holes thereby reducing stress generation. As such the results of this study could be utilized as the basic data for future researches on composite materials and sandwich type homogenous materials. Furthermore, the study results can assist in designing more durable products.

Ball screw system is widely used as a precision mechanical linear actuator that translates rotational motion to linear motion for its high efficiency, great stiffness and long life. Recently, according to the requirements of high accuracy and stiffness, the pre-load on the ball screw which means of remove the backlash in the ball screw is usually used. Because of the preload which means the frictional resistance between the screw and nut, becomes a dominating heat source and it generates thermal deformation of ball screw which is the reason for low accuracy of the positioning decision. There are several methods to solve the problem that includes temperature control, thermal stable design and error compensation. In the past years, researchers focused on the error compensation technique for its ability to correct ball screw error effectively rather than the capabilities of careful machine design and manufacturing. Significant amounts of researches have been done to realtime error compensation. But in this paper, we developed a series of cooling methods to get thermal equilibrium in the ball screw system. So we find the optimum cooling type for improving positioning error which caused by thermal deformation in the ball screw system.

This study deals with the correction of gear tooth profile error by finish roll forming. First, we experimentally confirmed that the tooth profile error is a synthesis of the concave error and the pressure angle error. Since various types of tooth profile errors appear in the experiments, we introduced evaluation parameters for rolling gears to objectively evaluate profile quality. Using these evaluation parameters, we clarified the relationship among the tooth profile error, the addendum modification factor (A. M. factor), and the tool loading force.
We verified the character of concave error, pressure angle error, tool loading force and number of cycles of finish roll forming by using a forced displacement method. This study makes clear that tool loading force and number of cycles of finish roll forming are very important factors that affect involute tooth profile error.
The results of the experiment and analysis show that the proposed method reduces concave and pressure angle errors.