Patent ID: 6278436
Filing Date: 2001-08-21
Classification: G09G,H04N

Abstract:
A brightness controlling apparatus for adjusting a brightness level of a video signal inputted thereto and outputting the video signal having the adjusted brightness level to a display apparatus so that said display apparatus displays a video image corresponding to the video signal on the basis of the video signal having the adjusted brightness level, said brightness controlling apparatus comprising:an average brightness level detecting device for detecting average brightness levels of the video signal in a plurality of blocks respectively, said blocks being obtained by dividing the video signal to be displayed on a picture plane by said display apparatus into the blocks;an average brightness level adding device for adding to each other the average brightness levels of the video signal in at least two of the blocks at a vicinity of each other for each of the blocks, which are detected by said average brightness level detecting device;a brightness level setting device for setting the brightness level of the video signal on the basis of the added average brightness levels added by said average brightness level adding device; andan outputting device for outputting the video signal having the brightness level set by said brightness level setting device to said display apparatus as the video signal having the adjusted brightness level;said brightness level setting device limiting the brightness level of the video signal for each frame of the video image on the basis of the added average brightness levels,wherein groups each including the at least two of the blocks adjacent to each other are defined as block groups respectively,said average brightness level adding device adds to each other the average brightness levels in the blocks within respective one of the block groups for each of the block groups, to thereby calculate the added average brightness level for each of the block groups, andsaid brightness level setting device compares each of the added average brightness levels with a predetermined reference value, to thereby limit the brightness level if the added average brightness level in at least one of the block groups is larger than the predetermined reference value.