A display system comprising: a control apparatus having a display unit; and a display apparatus comprising: a communication unit configured to communicate with the control apparatus; and a display unit; and characterised in that the control apparatus is configured to determine the on or off status of the display unit of the control apparatus and to transmit a corresponding status signal to the display apparatus; the display apparatus further comprises a controller configured, in response to receiving the status signal indicating an on or off status of the display unit of the control apparatus from the control apparatus via the communication unit, to select a user interface display limit mode if the status signal indicates that the display unit of the control apparatus is on and a UI display mode if the status signal indicates that the display unit of the control apparatus is off, wherein the UI display limit mode limits displaying a UI on the display unit of the display apparatus by displaying only part of the UI so that the display apparatus does not output a UI provided for the manipulation of the display apparatus and the UI display mode does not limit displaying the UI on the display unit of the display apparatus, and to operate the display unit of the display apparatus in the selected mode; and the display unit of the control apparatus is configured to display the UI for manipulation of the display apparatus when the display unit of the display apparatus is in the UI display limit mode. a control apparatus having a display unit; and a display apparatus comprising: a communication unit configured to communicate with the control apparatus; and a display unit; and a communication unit configured to communicate with the control apparatus; and a display unit; and characterised in that the control apparatus is configured to determine the on or off status of the display unit of the control apparatus and to transmit a corresponding status signal to the display apparatus; to determine the on or off status of the display unit of the control apparatus and to transmit a corresponding status signal to the display apparatus; the display apparatus further comprises a controller configured, in response to receiving the status signal indicating an on or off status of the display unit of the control apparatus from the control apparatus via the communication unit, to select a user interface display limit mode if the status signal indicates that the display unit of the control apparatus is on and a UI display mode if the status signal indicates that the display unit of the control apparatus is off, wherein the UI display limit mode limits displaying a UI on the display unit of the display apparatus by displaying only part of the UI so that the display apparatus does not output a UI provided for the manipulation of the display apparatus and the UI display mode does not limit displaying the UI on the display unit of the display apparatus, and to operate the display unit of the display apparatus in the selected mode; and to select a user interface display limit mode if the status signal indicates that the display unit of the control apparatus is on and a UI display mode if the status signal indicates that the display unit of the control apparatus is off, wherein the UI display limit mode limits displaying a UI on the display unit of the display apparatus by displaying only part of the UI so that the display apparatus does not output a UI provided for the manipulation of the display apparatus and the UI display mode does not limit displaying the UI on the display unit of the display apparatus, and to operate the display unit of the display apparatus in the selected mode; and the display unit of the control apparatus is configured to display the UI for manipulation of the display apparatus when the display unit of the display apparatus is in the UI display limit mode.