Image display apparatus having plurality of pixels arranged in rows and columns
View Patent ↗In a partial display mode, a source IC outputs a start signal at an “H” level designating the start of vertical scanning by a vertical scanning circuit, over a plurality of cycles from before a time T 1 to after a time T 8 . A plurality of shift registers sequentially shift the start signal in synchronization with a clock signal to sequentially drive a plurality of activation enable signals, respectively, to an “H” level. Then, after time T 8 when first to fourth activation enable signals simultaneously attain an “H” level, the source IC outputs an enabling signal at an “H” level to the vertical scanning circuit. In response, the vertical scanning circuit simultaneously activates first to fourth gate lines corresponding to the first to the fourth activation enable signals, respectively.
1. An image display apparatus, comprising:
an image display portion including a plurality of image display elements arranged in rows and columns;
a plurality of pixel control lines arranged corresponding to the rows of said plurality of image display elements;
a vertical scanning circuit connected to said plurality of pixel control lines; and
a control device generating a scanning start signal for designating start of vertical scanning and an enabling signal for designating activation of a pixel control line of activation target, and outputting each of the generated signals to said vertical scanning circuit,
in a partial display mode partially displaying an image on said image display portion, or in a partial self-refresh operation dividing a self-refresh operation for saving and rewriting data in said plurality of image display elements into a plurality of blocks and performing the self-refresh operation for each block in said image display portion,
said vertical scanning circuit simultaneously placing multiple pixel control lines corresponding in number to an activation period of said scanning start signal at an activation enable state, and simultaneously activating the multiple pixel control lines in said activation enable state in response to activation of said enabling signal, with a region corresponding to the multiple pixel control lines in said activation enable state as a non-display region or a refresh region.
2. The image display apparatus according to claim 1 , wherein said vertical scanning circuit includes:
a plurality of shift registers provided corresponding to said plurality of pixel control lines and connected in series along a scanning direction, and
an output control circuit activating a pixel control line in said activation enable state corresponding to a shift register having an output activated when said enabling signal is activated, and
said plurality of shift registers receive said scanning start signal at a shift register in a first stage, and sequentially shift said scanning start signal to a shift register in a succeeding stage in synchronization with a clock signal.
3. The image display apparatus according to claim 2 , wherein
in a normal operation, said control device activates said scanning start signal for only one cycle of said clock signal and activates said enabling signal in synchronization with said clock signal, and
in said partial display mode, said control device activates said scanning start signal for a plurality of cycles of said clock signal within a frame of the image to be displayed on said image display portion, and activates said enabling signal at a timing of simultaneous activation of outputs of shift registers corresponding to said non-display region.
4. The image display apparatus according to claim 3 , wherein
said image display portion is subject to frame inversion driving, and
said control device activates said scanning start signal for a plurality of consecutive cycles of said clock signal in said partial display mode.
5. The image display apparatus according to claim 3 , wherein
said control device further outputs a reset signal for resetting an internal state of each of said plurality of shift registers, and activates said reset signal after activation of said enabling signal in said partial display mode, and
each of said plurality of shift registers resets the internal state in response to activation of said reset signal.
6. The image display apparatus according to claim 3 , wherein
said image display portion is subject to line inversion driving, and
said control device alternately repeats activation and inactivation of said scanning start signal for a plurality of times in synchronization with said clock signal in said partial display mode.
7. The image display apparatus according to claim 2 , wherein
each of said plurality of pixel control lines includes a control signal line for designating said self-refresh operation at a corresponding image display element,
in a normal operation, said control device activates said scanning start signal for only one cycle of said clock signal and activates said enabling signal in synchronization with said clock signal, and
in said partial self-refresh operation, said control device activates said scanning start signal for a plurality of cycles of said clock signal within a frame of the image to be displayed on said image display portion, and activates said enabling signal at a timing of simultaneous activation of outputs of shift registers corresponding to said refresh region.
8. The image display apparatus according to claim 7 , wherein
said image display portion is subject to frame inversion driving, and
said control device activates said scanning start signal for a plurality of consecutive cycles of said clock signal in said partial self-refresh operation.
9. The image display apparatus according to claim 7 , wherein
said image display portion is subject to line inversion driving, and
said control device alternately repeats activation and inactivation of said scanning start signal for a plurality of times in synchronization with said clock signal in said partial self-refresh operation.