Vehicle display device

A vehicle display device comprising:

• a display that displays an image;
• a vehicle information image generator that generates a vehicle information image indicative of vehicle information;
• an external image obtaining device that obtains an external image, which is an image to be displayed on the display, from an external device connected to the vehicle display device;
• a display controller that displays at least the vehicle information image on the display, and displays the vehicle information image and the external image on the display when the external image obtained by the external image obtaining device needs to be displayed on the display;
• and
• an external image display determination device that determines whether the display controller is going to display the external image which was not displayed at a predetermined past time, wherein:
• when the external image display determination device determines that the display controller is going to display the external image which was not displayed at the predetermined past time, the display controller displays the external image, which the display controller is going to display, on the display with gradually increasing brightness of the external image from the brightness that is lower by a predetermined amount than original brightness of the external image which was not displayed to predetermined brightness that is determined based on the original brightness of the external image which was not displayed;
• the display controller includes a display image generator that generates a display image to be displayed on the display by superimposing images, each of which is arranged on one of a plurality of layers in which an upper layer is displayed on a display screen of the display in front of a lower layer;
• the display image generator generates the display image by arranging the vehicle information image in the upper layer higher than a layer in which the external image is arranged;
• the vehicle information image generated by the vehicle information image generator includes a brightness adjustment filter region, transparency of which is changed according to an instruction from the display controller, to display the external image arranged in the lower layer by changing the brightness of the external image according to the transparency of the brightness adjustment filter region;
• the vehicle information image generator generates the vehicle information image by changing the transparency of the brightness adjustment filter region according to the instruction from the display controller;
• the display controller includes a brightness adjustment filter controller that controls the vehicle information image generator to change the transparency of the brightness adjustment filter region;
• when the external image display determination device determines that the display controller is going to display the external image which was not displayed at the predetermined past time, the brightness adjustment filter controller controls the vehicle information image generator to change the transparency of the brightness adjustment filter region so as to decrease the brightness of the external image in the display image by a predetermined amount, and then to change the transparency so as to gradually increase the brightness of the external image in the display image;
• and
• wherein the brightness adjustment filter region is arranged only in a part of the upper layer.