This feature is not on a current W3C standards track, but it is supported on the Firefox OS platform. Although implementations may change in the future and it is not supported widely across browsers, it is suitable for use in code dedicated to Firefox OS apps.
Navigator.requestWakeLock() method of the Wake Lock API is used to request a
MozWakeLock on any resource of the device. This means that you can prevent that resource from becoming unavailable as long as your app holds a lock for that resource. For example, a voice recording app can obtain a lock to keep the screen on during recording so that it can give prover visual feedback to the user that recording is progressing.
Note: When the window that requested one or more wake locks is closed or destroyed, any wake locks it acquired are implicitly released; no manual release is necessary.
lock = window.navigator.requestWakeLock(resourceName);
MozWakeLock object you can use to keep track of or release the lock..