Your PC can be in only three states: on, sleep or off (also called standby)-each of which draws some level of electric current. If you want it to consume zero energy, you're going to have to unplug it.
If you want your PC to consume as little energy as possible when not in use, shut it down. Sleep mode itself, once a pretty unreliable option-you never knew if you would be able to wake your PC without having to reboot it-has been vastly improved with newer operating systems. So your PC will likely slip into sleep mode anyway, even if you leave it on overnight. They are also energy efficient: Such efficiency has reached the point where most PCs place themselves in sleep mode if they remain idle for a certain period of time. Rest easy, your computer is more likely to be damaged by a virus picked up from the Internet than by being turned off and on too much. How you end a computer session depends on how often you use the computer, your views on energy conservation (the amount of juice it uses while sitting idle), and what you have been told about how your decision will affect your investment's longevity: Will frequent starting and stopping cause its circuits to burn out sooner? But before you exit cyberspace, a decision must be made: Should you shut the machine down, place it into "sleep" mode or do nothing at all? Covering the entire display area with pure white for an extended period of time is also a useful proactive solution.You take a deep breath, rub your tired eyes and prepare to push away from your personal computer after a lengthy instant message exchange, video viewing or analysis of your monthly budget-maybe all three. Another strategy is the usage of a screensaver to help during times the computer is left unattended.
One strategy for users looking to avoid image persistence artifacts is to vary the activities performed on a computer to avoid static colors and hide elements on the screen which are displayed perpetually (such as an OS's Taskbar). For most minor cases, simply continuing to use the computer as usual (and thus allowing other colors to "cover" the affected regions) or turning off the monitor for the night is more than enough. Image persistence can be reversed by allowing the liquid crystals to relax and return to their relaxed state, such as by turning off the monitor for a sufficiently long period of time (at least a few hours).
It might be due to accumulation of ionic impurities inside the LCD, electric charge building up near the electrodes, parasitic capacitance, or "a DC voltage component that occurs unavoidably in some display pixels owing to anisotropy in the dielectric constant of the liquid crystal". In fact, the root cause of LCD image persistence is the same as phosphor burn-in, namely, non-uniform usage of the display's pixels. This ever-so-slight tendency to stay arranged in one position can throw the requested color off by a slight degree, which causes the image to look like the traditional "burn-in" on phosphor based displays. displaying a pointer or the Taskbar in one place, or showing a static picture for extended periods of time), the liquid crystals can develop a tendency to stay in one position. If left with the same voltage for an extended period of time (e.g. When a voltage is applied they rearrange themselves to block certain light waves. Liquid crystals have a natural relaxed state.