1. An apparatus for sensing an object, the apparatus comprising: 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 determine whether an operation of at least one of the light source and the camera is appropriate based on whether a criterion pattern is identifiable from the pattern image and adjust the operation of the at least one of the light source and the camera based on a second pattern in the pattern image according to the result of the determination.