The recent study of digital X-ray detectors in medical diagnostics has focused on high-resolution image acquisition. Digital X-ray detectors use either a direct or an indirect method of converting X-ray into an electric charge. Indirect systems have low resolution due to blurring of light from the scintillator. In contrast, direct systems have higher resolution than indirect systems, but they are expensive, and systems that have large areas are difficult. This paper proposes a new structure for a non-pixel detector in order to resolve these problems by constructing multiple layers, including photoconductor and liquid crystal (LC) cell layers. First, simulations were conducted to measure changes in the transmittance and electric field of the LC cell under different applied voltages and different thicknesses of a glass layer between the LC and the photoconductor. Subsequently, non-pixel X-ray films having an optimized structure were fabricated using the optimal glass thickness and voltage obtained from the simulation results. In a previous study, X-ray film was fabricated from an LC and a photoconductor by a single integrated production process. In this study, the fabrication process was divided into two steps to prevent damage to the X-ray conversion materials caused by the high temperature used to manufacture the LC cell. The photoconductor layer was fabricated by screen-printing at room temperature on the LC cell. HgI 2 was used as the photoconductor material and an aluminum reflective layer was then deposited. The photoconductor was approximately 150-250µm thick. The linear range of LC twisting was acquired by measuring the transmittance-voltage curve; when a voltage of 1.3V to 2.2V is applied to the LC

We investigated nanophosphor materials that exhibit high resolution and emission efficiency for use in X-ray medical imaging. Rare-earth phosphor material has long been used due to its high atomic number and emission efficiency, but these materials tend to exhibit lower resolution and emission efficiency when manufactured in bulk. In this study, we synthesized nanometer-scale phosphors of Gd 2 O 3 :Eu and Y 2 O 3 :Eu using the solution-combustion method, and we evaluated the dependence of the optical properties of these nanophosphors on europium concentration and synthesis atmosphere. The nanophosphors were characterized by X-ray diffraction (XRD), fieldemission scanning electron microscopy (FE-SEM), and photoluminescence (PL) spectroscopy. Characterization of the optical properties revealed that both Gd 2 O 3 :Eu and Y 2 O 3 :Eu exhibited peak emission intensity at 611 nm, which corresponded to that for commercial bulk phosphors. These results imply that manufacturing nanophosphors can achieve thin and compact displays that have enhanced performance, and that improvements in emission efficiency of nanophosphors could reduce the required patient dose for medical imaging.