Something

function idcard_settings(){
  $form['IDCARD_BGIMAGE_FILEPATH'] = array(
    '#type' => 'file',
    '#title' => t('Background Image'),
    '#attributes' => array('enctype' => "multipart/form-data"),
    '#description' => t('The background image to use for the ID card'),
    '#default_value' => '',
    );
  return $form
}