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US 6,958,745 B2Granted
Display device, method for driving the same, and portable terminal apparatus using the same
AssigneeSony Corporation
InventorsMasaki Murase, Yoshiharu Nakajima
Life of this patent
Estimating the term…
Abstract
A selection-addressing-type liquid crystal display selectively addresses a signal line of a pixel unit using groups of three selectors of a selector circuit in a time-division manner. A level converter level shifts selector pulses having a voltage swing corresponding to the external-circuit power supply to selector pulses having a voltage swing corresponding to the internal-circuit power supply. In a non-display region in partial display mode, the level converter is deactivated under the control of a control signal to reduce direct current consumption therein.
Claims8
A display device comprising:
- a pixel unit comprising:
- an array of pixels;
- and
- signal lines disposed in groups of columns of the array;
- level converting means comprising x stages of level shifters, wherein x is an integer of at least two, each level shifter for:
- when activated, converting x selection signals having a first voltage swing to selection signals having a second voltage swing, which are output, said x selection signals, corresponding to every x signal lines of the pixel unit, being input in a time-series manner, every x signal lines of the pixel unit being grouped;
- and
- when deactivated, outputting a signal having a voltage swing, which is latched;
- selecting means comprising a group of x select switches for sequentially selecting said every x signal lines in accordance with said x selection signals that were subjected to level conversion at the level converter to provide a display signal;
- and
- control means for, when partial display mode for displaying only part of a display screen is requested and when pixel writing is performed in a non-display region in which no displaying is performed:
- feeding an activating signal to the level shifter at a first stage when the select switch of the selecting means corresponding to the level shifter at a second stage is not selected;
- feeding an activating signal to a level shifter at one of the second to (x−1)th stages when the select switch of the selecting means corresponding to the level shifter at the previous stage of said one of said second to (x−1)th stages is selected and when the select switch of the selecting means corresponding to the level shifter at the following stage of said one of said second to (x−1)th stages is not selected;
- and
- feeding an activating signal to the level shifter at the xth stage when the select switch of the selecting means corresponding to the level shifter at the (x−1)th stage is selected.
12 more elements
A method for driving a display device, the display device comprising:
- a pixel unit comprising:
- an array of pixels;
- and
- signal lines disposed in groups of columns of the array;
- level converting means comprising x stages of level shifters, wherein x is an integer of at least two, each level shifter for:
- when activated, converting x selection signals having a first voltage swing to selection signals having a second voltage swing, which are output, said x selection signals, corresponding to every x signal lines of the pixel unit, being input in a time-series manner, every x signal lines of the pixel unit being grouped;
- and
- when deactivated, outputting a signal having a voltage swing, which is latched;
- and
- selecting means comprising a group of x select switches for sequentially selecting said every x signal lines in accordance with said x selection signals that were subjected to level conversion at the level converter to provide a display signal, the method for driving the display device, wherein:
- when partial display mode for displaying only part of a display screen is requested and when pixel writing is performed in a non-display region in which no displaying is performed:
- an activating signal is fed to the level shifter at a first stage when the select switch of the selecting means corresponding to the level shifter at a second stage is not selected;
- an activating signal is fed to a level shifter at one of the second to (x−1)th stages when the select switch of the selecting means corresponding to the level shifter at the previous stage of said one of said second to (x−1)th stages is selected and when the select switch of the selecting means corresponding to the level shifter at the following stage of said one of said second to (x−1)th stages is not selected;
- and
- an activating signal is fed to the level shifter at the xth stage when the select switch of the selecting means corresponding to the level shifter at the (x−1)th stage is selected.
12 more elements
A portable terminal apparatus comprising a display device comprising:
- a pixel unit comprising:
- an array of pixels;
- and
- signal lines disposed in groups of columns of the array;
- level converting means comprising x stages of level shifters, wherein x is an integer of at least two, each level shifter for:
- when activated, converting x selection signals having a first voltage swing to selection signals having a second voltage swing, which are output, said x selection signals, corresponding to every x signal lines of the pixel unit, being input in a time-series manner, every x signal lines of the pixel unit being grouped;
- and
- when deactivated, outputting a signal having a voltage swing, which is latched;
- selecting means comprising a group of x select switches for sequentially selecting said every x signal lines in accordance with said x selection signals that were subjected to level conversion at the level converter to provide a display signal;
- and
- control means for, when partial display mode for displaying only part of a display screen is requested and when pixel writing is performed in a non-display region in which no displaying is performed:
- feeding an activating signal to the level shifter at a first stage when the select switch of the selecting means corresponding to the level shifter at a second stage is not selected;
- feeding an activating signal to a level shifter at one of the second to (x−1)th stages when the select switch of the selecting means corresponding to the level shifter at the previous stage of said one of said second to (x−1)th stages is selected and when the select switch of the selecting means corresponding to the level shifter at the following stage of said one of said second to (x−1)th stages is not selected;
- and
- feeding an activating signal to the level shifter at the xth stage when the select switch of the selecting means corresponding to the level shifter at the (x−1)th stage is selected.
12 more elements
Dependencies are inferred from the claim text.