Digital halftoning algorithm is a method for representing a continuous tone image with a few discrete level of output-device. Most representative two methods of halftoning are screening (or dithering) and error diffusion. Specially, clustered screening has a fast processing speed and robustness to printer distortion and laser bean printer uses it generally. But, it has a poor quality in detail region, because of screen table's LPI geometry. In general, screen table mostly have 150∼200 LPI. That LPI is not sufficient to represent a good quality at image edge. Our proposal improves the quality of detail region by using edge map and edge-optimized table at edge region differentiated from non-edge region. Edge-optimized screen is not a simple higher LPI screen than non-edge region. We have investigated the best dot-addition position for good edge image quality in visually at each screen table. And then, we composed the edge optimized screen table that makes it. If the image is edge region, edge-optimized screen is used. If not, we use default screen. We show the result screening images in simulated output and scanned image of real hard copy output in laser printer compared with previous methods.