Electrophoretic display device and driving method thereof

An electrophoretic display device, comprising:

• a display unit which comprises a first substrate in which switching elements and pixel electrodes are arranged in matrix, a second substrate in which a counter electrode is formed, an electrophoretic layer including at least a single color of electrophoretic particles and being inserted between the first substrate and the second substrate, and pixels arranged in matrix by corresponding to the pixel electrodes;
• and
• a voltage applying unit which updates a display state of the display unit from a current image to a next image by applying a prescribed voltage waveform to the electrophoretic particles between the pixel electrode and the counter electrode for each display gradation when updating the image, wherein
• when a state where all the electrophoretic particles of at least the single color are migrated to the first substrate or the second substrate by a stirring pulse for stirring the electrophoretic particles is defined as a base state, periods for updating the image include:
• a reset period that is a combination of a stirring period where all the pixels of the display unit are set to the base state at least once and a compensation period where accumulation of a residual direct current component is suppressed by the compensation pulse;
• and a set period that includes a set pulse for transiting the display state to a state according to the next image, and
• the compensation pulse is applied after all the pixels of the display unit are in the same base state by at least one of the stirring pulses, and the display state does not change before and after applying the compensation pulse.

An electrophoretic display device, comprising:

• a display unit which comprises a first substrate in which switching elements and pixel electrodes are arranged in matrix, a second substrate in which a counter electrode is formed, an electrophoretic layer including at least a single color of electrophoretic particles and being inserted between the first substrate and the second substrate, and pixels arranged in matrix by corresponding to the pixel electrodes;
• and
• a voltage applying unit which updates a display state of the display unit from a current image to a next image by applying a prescribed voltage waveform to the electrophoretic particles between the pixel electrode and the counter electrode for each display gradation when updating the image, wherein:
• the display unit is constituted with the pixels of a first region and the pixels of a second region;
• when a state where all the electrophoretic particles of at least the single color are migrated to the first substrate by a stirring pulse for stirring the electrophoretic particles is defined as a first base state and a state where all the electrophoretic particles are migrated to the second substrate is defined as a second base state, periods for updating the image include:
• a reset period that is a combination of a stirring period where all the pixels in the first region are set to the first base state and all the pixels in the second region are set to the second base state at least once and a compensation period where accumulation of a residual direct current component is suppressed by the compensation pulse;
• and a set period that includes a set pulse for transiting the display state to a state according to the next image;
• and
• the compensation pulse is applied after all the pixels in the first region are in the first base state and all the pixels in the second region are in the second base state by at least one of the stirring pulses, and the display state does not change before and after applying the compensation pulse.

An electrophoretic display device, comprising:

• a display unit which comprises a first substrate in which switching elements and pixel electrodes are arranged in matrix, a second substrate in which a counter electrode is formed, an electrophoretic layer including at least a single color of electrophoretic particles and being inserted between the first substrate and the second substrate, and pixels arranged in matrix by corresponding to the pixel electrodes;
• and
• a voltage applying unit which updates a display state of the display unit from a current image to a next image by applying a prescribed voltage waveform to the electrophoretic particles between the pixel electrode and the counter electrode for each display gradation when updating the image, wherein:
• when a state where all the electrophoretic particles of at least a single color are migrated to the first substrate by a first stirring pulse for stirring the electrophoretic particles is defined as a first base state and a state where all the electrophoretic particles of at least a single color are migrated to the second substrate by a second stirring pulse for stirring the electrophoretic particles is defined as a second base state, periods for updating the image include:
• a reset period constituted with a stirring period where all the pixels are set to the first base state and the second base state;
• and a set period that includes a set pulse for transiting the display state to a state according to the next image;
• and
• in the reset period, a first timing occurs where all the pixels of the display unit are aligned to one of the first base state and the second base state by applying one of the first stirring pulse and the second stirring pulse, and after the first timing, a second timing occurs where all the pixels of the display unit are aligned to the other one of the first base state and the second base state by applying the other one of the first stirring pulse and the second stirring pulse containing an extension period of the pulse width according to the display gradation, and the display state of the display unit does not change during a longest extension period among different extension periods according to the display gradation.

A method for driving an electrophoretic display device which comprises:

• a display unit which comprises a first substrate, a second substrate, and electrophoretic particles inserted between the first substrate and the second substrate;
• and
• a voltage applying unit which updates a display state of the display unit from a current image to a next image by applying prescribed voltage waveforms constituted with a stirring pulse, a compensation pulse, and a set pulse to the electrophoretic particles, the method comprising:
• setting the display state to a state where the electrophoretic particles are migrated to either the first substrate or the second substrate by the stirring pulse according to polarity of the electrophoretic particles;
• then
• applying a voltage for suppressing a residual direct current component that may be generated after applying the set pulse without causing a change in the display state by the compensation pulse, and updating the image to the next image by the set pulse.

A method for driving an electrophoretic display device which comprises:

• a display unit which comprises a first substrate in which switching elements and pixel electrodes are arranged in matrix, a second substrate in which a counter electrode is formed, an electrophoretic layer including at least a single color of electrophoretic particles and being inserted between the first substrate and the second substrate, and pixels arranged in matrix by corresponding to the pixel electrodes;
• and
• a voltage applying unit which updates a display state of the display unit from a current image to a next image by applying prescribed voltage waveforms constituted with a stirring pulse, a compensation pulse, and a set pulse to the electrophoretic particles between the pixel electrode and the counter electrode for each display gradation when updating the image, the method comprising, during update of the image:
• when a state where all the electrophoretic particles of at least a single color are migrated to the first substrate or the second substrate by the stirring pulse for stirring the electrophoretic particles is defined as a base state,
• setting all the pixels of the display unit in the same base state by at least one of the stirring pulses;
• then
• suppressing accumulation of a residual direct current component without causing a change in the display state of the base state by the compensation pulse;
• and then
• transiting the display state to a state according to the next image by the set pulse.

A method for driving an electrophoretic display device which comprises:

• a display unit which comprises a first substrate in which switching elements and pixel electrodes are arranged in matrix, a second substrate in which a counter electrode is formed, an electrophoretic layer including at least a single color of electrophoretic particles and being inserted between the first substrate and the second substrate, and pixels arranged in matrix by corresponding to the pixel electrodes;
• and
• a voltage applying unit which updates a display state of the display unit from a current image to a next image by applying prescribed voltage waveforms constituted with a stirring pulse, a compensation pulse, and a set pulse to the electrophoretic particles between the pixel electrode and the counter electrode for each display gradation when updating the image, wherein:
• the display unit is constituted with the pixels of a first region and the pixels of a second region;
• the method comprising, during update of the image:
• when a state where all the electrophoretic particles of at least a single color are migrated to the first substrate by the stirring pulse for stirring the electrophoretic particles is defined as a first base state and a state where all the electrophoretic particles are migrated to the second substrate is defined as a second base state,
• setting all the pixels in the first region to the first base state and setting all the pixels in the second region to the second base state by the stirring pulse;
• then
• suppressing accumulation of a residual direct current component without causing a change in the display state of the first base state and the display state of the second base state by the compensation pulse;
• and then
• transiting the display state to a state according to the next image by the set pulse.

A method for driving an electrophoretic display device which includes a display unit which includes a first substrate in which switching elements and pixel electrodes are arranged in matrix, a second substrate in which a counter electrode is formed, an electrophoretic layer including at least a single color of electrophoretic particles and being inserted between the first substrate and the second substrate, and pixels arranged in matrix by corresponding to the pixel electrodes;

• and a voltage applying unit which updates a display state of the display unit from a current image to a next image by applying prescribed voltage waveforms to the electrophoretic particles between the pixel electrode and the counter electrode for each display gradation when updating the current image to the next image, the method comprising:
• updating the current image to the next image
• wherein when a state where all the electrophoretic particles of at least a single color are migrated to the first substrate by the first stirring pulse for stirring the electrophoretic particles is defined as a first base state and a state where all the electrophoretic particles of at least a single color are migrated to the second substrate by the second stirring pulse for stirring the electrophoretic particles is defined as a second base state, periods for updating the image including:
• a reset period constituted with a stirring period where all the pixels are set to the first base state and the second base state, and a set period that includes a set pulse for transiting the display state to a state according to the next image,
• in the reset period, a first timing occurs where all the pixels of the display unit are aligned to one of the first base state and the second base state by applying one of the first stirring pulse and the second stirring pulse, and after the first timing, a second timing occurs where all the pixels of the display unit are aligned to the other of the first base state and the second base state by applying the other one of the first stirring pulse and the second stirring pulse containing an extension period of the pulse width according to the display gradation, and the display state of the display unit does not change during a longest extension period among different extension periods according to the display gradation.