Multimedia device and remote control device for synchronizing screen, and method for same

A remote control device for screen synchronization with a multimedia device, the remote control device comprising:

• a display unit;
• a communication unit configured to communicate with the multimedia device;
• and
• a control unit configured to receive a plurality of image data, displayed on a screen of the multimedia device, through the communication unit from the multimedia device, and output the received image data to the display unit.

A screen synchronization method, performed by a multimedia device, between the multimedia device and a remote control device, the screen synchronization method comprising:

• generating a single image with a plurality of image data, wherein when the plurality of image data comprise moving image data, the multimedia device generates the single image with image data except the moving image data;
• storing the generated single image data in a buffer memory;
• outputting the generated single image data to a screen, wherein when there are the moving image data, the multimedia device synthesizes the generated single image data with the moving image data and outputs the synthesized image data to the screen;
• transmitting the generated single image data to the remote control device;
• reflecting, when image data except the moving image data among the image data composing the single image data are changed after the transmitting, the changed image data to generate a new single image;
• comparing the newly generated single image data with the single image data stored in the buffer memory to obtain difference image data;
• and
• transmitting the obtained difference image data to the remote control device.

A screen synchronization method, performed by a multimedia device, between the multimedia device and a remote control device, the screen synchronization method comprising:

• mixing a plurality of image data according to mixing rule information, wherein when the plurality of image data comprises moving image data, the multimedia device mixes moving image data with the plurality of image data according to the mixing rule information;
• outputting the mixed image data to a screen, wherein when there is the moving image data, the multimedia device synthesizes the mixed image data with the moving image data and outputs the synthesized image data to the screen;
• transmitting the image data to be mixed and the mixing rule information to the remote control device;
• and
• transmitting, when the mixed image data is changed, the changed image data and changed mixing rule information to the remote control device.

A screen synchronization method, performed by a remote control device, between a multimedia device and the remote control device, the screen synchronization method comprising:

• receiving single image data, composed of a plurality of image data comprising no moving image data, from the multimedia device;
• outputting the received single image data to a screen;
• storing the received single image data in a buffer memory;
• receiving difference image data from the multimedia device;
• generating a new single image with the received difference image data and the single image data stored in the buffer memory;
• and
• outputting the newly generated single image data to the screen.

A screen synchronization method, performed by a remote control device, between a multimedia device and the remote control device, the screen synchronization method comprising:

• receiving a plurality of image data, comprising no moving image data, and mixing rule information from the multimedia device;
• storing the plurality of received image data in a buffer memory;
• mixing the plurality of received image data according to the received mixing rule information;
• outputting the mixed image data to a screen;
• receiving changed image data and changed mixing rule information from the multimedia device;
• mixing the changed image data with the plurality of image data stored in the buffer memory according to the changed mixing rule information;
• and
• outputting the mixed image data based on the changed mixing rule information to the screen.