Why does the double tap to wake feature have Lag?

[Harrie-S]

Where is the proximity sensor please?

On the top of your device in the same spot as the camera.

 

[Ali Akbar 7]

Re: Double tap to wake feature has Lag

No it not that because with the power button the screen does not lag.
It's because the phone needs to "determine" if the double tap is really a double tap and that causes the "lag".

Here in my 730,sometimes or like 50% of the time whatever tap i do,it will not unlock the phone.When i double tap,it wont come,when i wait 1 sec and does again,it wont come,then i does a triple tap,it wont come,ten i do a double tap again,it wont come.Comes only when the power button is pressed.Then if i unlocked again and tries,it will come.
So,is this is how we need to use double tap?
It is to wake up the phone without pressing the power button,It is not for first you have to click the power button and unlock.Then lock it again,then you have to try double tap,and then it will unlock.Is this what they mean?
I know they don't ,but this works that way.