Windows 8.1 : Opening the application launches on-screen keyboard even when physical keyboard is connected

Question

I have a Windows 8.1 Application

In my tablet "Lenovo Ideapad", I have physical keyboard attached.

When I launch my app using the touch screen, as soon as the app launches, the on-screen keyboard also gets launched in the numeric keyboard mode. This is happening in spite of physical keyboard being connected.

How do I stop the on-screen keyboard from appearing automatically. I tried wrapping up my MainPage.xaml completely with a

<ContentControl IsTabStop="true">
<!-- MY CONTENT -->
</ContentControl>

I would be very glad if you can point me in the right direction. Thanks in advance.