BroadcastReceiver画面がオフになったときに通知を受け取り、再度オンにしたいのですが、何もしません。何が問題ですか?
public class SplashScreen extends SherlockActivity {
PowerManager.WakeLock mWakeLock;
BroadcastReceiver rec = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
            WakeLock screenLock = ((PowerManager) getSystemService(POWER_SERVICE))
                    .newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK
                            | PowerManager.ACQUIRE_CAUSES_WAKEUP, "TAG");
            screenLock.acquire();
        }
    }
};
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(com.sensounlock.R.layout.rotation);
    IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_OFF);
    registerReceiver(rec, filter);
}