Showing csv file in media library window

Hi
I have a file selector field in my new plugin to select a csv file. I want to show uploaded csv files when media window is opened, but it shows ‘No items found’ after opening. I use following code for defining media selector field in my plugin:

           image_frame = wp.media({
                           title: 'Select CSV file',
                           multiple : false,
                           library : {
                                type : 'csv',
                            }
                       });

I changed type value to ‘text/csv’, but it did not solve the problem. Please help me.

Thanks