A method of dynamically creating a list of operating systems for a target device in communication with a server prior to executing an operating system on the target device is provided. A hinge connects the front panel to the rear panel, creating a pocket between the front panel and the rear panel for receiving an associated label. This process of calculation is complex, giving rise to a problem of reduced processing speed and complicated circuit. According to this arrangement, the medical device conserves energy by drawing the additional electrical power needed to activate the additional processing power only when needed. The mixed level is stored in a look-up table memory as table data corresponding to each of a plurality of luminance levels.