Patent ID: 7834869

Claim:
A display panel driver for displaying an image on a display panel divided into a first display area and a second display area abutting the first display area, the display panel driver comprising: a first driver circuit; and a second driver circuit; wherein each of the first driver circuit and the second driver circuit has respective facilities for receiving, storing, and displaying image data, generating and displaying a screen saving image, and generating a timing signal that causes the screen saving image to move; each of the first driver circuit and the second driver circuit has a normal mode and a screen saving mode, and is operable as master and slave in the screen saving mode; the first driver circuit and the second driver circuit are disposed in separate integrated circuit chips that are connected in parallel between a system bus and the display panel, each integrated circuit chip having an external master/slave terminal that receives a voltage having a first logic level if the respective driver circuit is to operate as the master in the screen saving mode or having a second logic level if the respective driver circuit is to operate as the slave in the screen saving mode; the second driver circuit is identical in structure to the first driver circuit; the first driver circuit has a first oscillator and a first external terminal that is directly connected to the first oscillator; the second driver circuit has a second oscillator and a second external terminal that is directly connected to the second oscillator, the first and second external terminals being directly connected to one another; and in the normal mode, the first driver circuit receives first image data from the bus, and stores and displays the first image data in the first display area, and the second driver circuit receives second image data from the bus, and stores and displays the second image data in the second display area; and in the screen saving mode, the first driver circuit generates, as said screen saving image, a first screen saving image that moves in synchronization with a clock signal generated by one of the first and second oscillators and displays the first screen saving image in the first display area, and the second driver circuit generates, as said screen saving image, a second screen saving image that moves in synchronization with the clock signal generated by said one of the first and second oscillators and displays the second screen saving image in the second display area, the second screen saving image moving in the second display area in coordination with the movement of the first screen saving image in the first display area so as to depict a coordinated screen saver that is displayed on the first and second display areas.