Abstract: A catalyst used to manufacture a biodegradable polyester resin, in particular, an organic titanium catalyst which does not contain a heavy-metal component, and a method of manufacturing a polyester resin using the same. Accordingly, the method of manufacturing a polyester resin can be useful in attaining desired physical properties without using a catalyst harmful to environments and a human body. The biodegradable resin, which can be safely used in the field of applications in which the use of harmful components is a sensitive issue without using the components harmful to environments and a human body during the manufacture of a resin, can be prepared.

Abstract: Provided are an optical sheet for high resolution, a filter comprising the same, and a display device having the optical sheet for high resolution or the filter. The optical sheet for high resolution includes: a plurality of external light absorption units that are disposed separate from each other at a predetermined interval and comprise a light absorbing material; a plurality of light transmission units optically separated from each other by the external light absorption units, wherein the refractive index of the light transmission unit is smaller than the refractive index of the external light absorption unit. Thus, the optical sheet for high resolution, the filter comprising the same, and the display device having the optical sheet for high resolution or the filter can maintain high resolution by reducing generation of ghost images and moiré phenomenon and improving the contrast ratio.