The orientation lock can be useful when you want to keep the screen from rotating. However, this feature can be very annoying if you forgot about it or accidentally enable it. On iOS devices, the rotation lock can be found by double-tapping on the Home button to bring up the multitasking tray, and then sliding from left to-right on the tray. The rotation-lock icon appears as a circular arrow. When the lock is enabled, the circular arrow will have a small lock in the center. To enable or disable this lock, just tap on the icon. On the iPad, you can also change the mute switch to an orientation lock switch by visiting Settings > General
The small lock in the center of the circular arrow will let you know your device has been locked in portrait or landscape mode.
If this doesn’t fix your locked screen, then there could be a bigger problem. Try doing a hard restart on your iOS device by holding down the Home and Sleep/Wake buttons for a few seconds until the device restarts. Release the buttons when you see the Apple logo. If your device still won’t rotate the image properly, your best bet is a visit to a Genius Bar or a call to AppleCare
