Display device and display system of injection molding machine

A display device of an injection molding machine, capable of displaying two or more windows, comprising:

• a display having at least a main display and a sub-display;
• an input device that receives an input related to selection of a window to be displayed on the display;
• a processor that,
• stores a selection order that indicates an order in which windows have been selected for displaying on the main display, and
• selectively controls the window to be displayed on the display based on the input to the input device;
• and
• a counting unit that counts a number of selection times of a window selected to be displayed on the main display subsequently to a window being displayed on the main display, wherein
• the processor switches the window to be displayed by,
• determining a first window that is displayed on the main display,
• determining, based on the selection order, a second window for which the number of selection times of displaying the second window on the main display subsequently to displaying the first window on the main display is the largest among the windows, and
• displaying the second window on the sub-display.