How do I turn on the screen programmatically during call while proximity sensor's value is zero in Android?

I just want to develop a background service for android in which i can disable the functionality of proximity sensor.i dont want to turn off the display during call.

following codes samples are not working.

1.

PowerManager powerManager;
    PowerManager.WakeLock wakeLock;
    int field = 0x00000020;
    try {
        // Yeah, this is hidden field.
        field = PowerManager.class.getField("PROXIMITY_SCREEN_OFF_WAKE_LOCK").getInt(null);
    } catch (Exception e) {

    }
    powerManager = (PowerManager) context.getSystemService(context.POWER_SERVICE);
    wakeLock = powerManager.newWakeLock(field, "MyWakeLock");
    wakeLock.acquire();

2

PowerManager mPowerManager;
     PowerManager.WakeLock mWakeLock;
    mPowerManager = (PowerManager) getSystemService(Context.POWER_SERVICE);
    KeyguardManager km = (KeyguardManager) getSystemService(Context.KEYGUARD_SERVICE);
    final KeyguardManager.KeyguardLock kl = km.newKeyguardLock("MyKeyguardLock");
    kl.disableKeyguard();

    PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
    mWakeLock = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP
            | PowerManager.ON_AFTER_RELEASE, "MyWakeLock");
    // mWakeLock = mPowerManager.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP, "Service");
    mWakeLock.acquire();

Is there any solution?