At least one example embodiment discloses an apparatus for sensing an object, the apparatus including a display, a light source configured to emit light toward the display, a pattern layer on the display, the pattern layer including a first pattern for identifying a position on the display, a camera configured to generate a pattern image based on light reflected off of the pattern layer, and a controller configured to adjust an operation of at least one of the light source and the camera based on a second pattern displayed in the pattern image.