Table of whole input filed can't use input search

I have a table,when user login, each column has a input, if not, columns are read-only.
When I search input value use example i found(individual column search input), it can't find a thing.
I guess it's because column().search() only accept string inside of td instead of input or other html tag?
My search function $(table.table().container()).on('keyup', 'thead tr.th_inp input', function () { table .column($(this).data('index')) .search(this.value) .draw(); });