摘要:
Electrophoretic display units (1) are driven with a reduced amount of power by efficiently clocking a data signal into the data driving circuitry (30) only once and then supplying this data signal subsequently to two or more pixels (11) in two or more different lines. This can be done in case the pixels (11) in a same column require the same data pulse, like a shaking data pulse (Sh1, Sh2) or a reset data pulse (R). As a result, time is saved, which allows frame periods to be shorter. Even more time can be saved and even shorter frame periods are possible when combining the efficient clocking with the parallel driving of groups of lines (70-72).
摘要:
An electrophoretic display panel and a method for driving an electrophoretic display panel in which the drive pulse, i.e. the grey scale pulse, to bring an element from a preceding optical state to an optical state is split in more than one sub-pulses. A more gradual introduction of the grey scale is thereby achieved reducing the suddenness of the transition form one image to another. Preferably application of the grey scale potential differences is preceded by application of reset pulses in which case the preceding optical state is an extreme optical state.
摘要:
A display device (1) comprises two or more groups of display elements having electrophoretic particles (8,9), a pixel electrode (5) and a counter electrode (6). Drive signals (50, (V,t)drive, (V,t)reset) are supplied to the electrodes to bring the display elements in a predetermined optical state. The drive signals are preceded by preset signals (53, (V,t)preset) to release the electrophoretic particles but too low in intensity to enable the particles to change the optical state significantly. The preset signals supplied to the groups show differences in phase. This reduces flicker. The preset and drive signals are, in operation, so supplied that the phase of the preset pulse preceding the drive pulse is, in respect of the drive pulse, substantially the same for all groups. The combination of a drive and preceding preset pulse is then for the groups substantially the same, reducing grey level variations.
摘要:
An electrophoretic display panel (1), comprises drive means (100), for controlling the potential difference of each picture element (2) to be a reset potential difference having a reset value and a reset duration for enabling particles (6) to substantially occupy one of the extreme positions. The reset pulses are applied in two or more pulses separated by a non-zero time interval during a reset period (Preset).
摘要:
Image quality is improved when updating a display image (310) in a bi-stable electronic reading device (300, 400) such as one using an electrophoretic display, by providing both monochrome and greyscale images. When an update mode of a pixel (2) of the display changes from a monochrome to greyscale, a compensating pulse (805, 825, 845, 865) is applied. The compensating pulse represents an energy based on the energy difference between: (a) an over-reset pulse (815, 835, 855, 875) used during the greyscale update mode and (b) a standard reset pulse (610, 660) used during the monochrome update mode. Also, a monochrome update waveform (600, 650) includes a standard reset pulse (610, 660) whose duration is substantially less than a duration of an over-reset pulse (815, 835, 855, 875) used in a greyscale update waveform (800, 820, 840 and 860). The monochrome update mode is used in combination with the greyscale update mode when possible.
摘要:
An electrophoretic display panel (1) comprises: an electrophoretic medium (5) comprising charged particles (6); a plurality of picture elements (2); electrodes (3,4) associated with each picture element (2) for receiving a potential difference; and drive means (100). The drive means (100) are arranged for application of a grey scale potential difference to enable the particles (6) to occupy the position corresponding to the image information. The drive means are further arranged for application of grey scale potential differences during an update period to only a sub-assembly of the picture elements of the display, without addressing the remainder of the picture elements of the display during said update period. More grey scales are obtained.
摘要:
A display device comprising electrophoretic particles, a display element comprising a pixel electrode and a counter electrode between which a portion of the electrophoretic particles are present, and control means for supplying a drive signal to the electrodes to bring the display element in a predetermined optical state corresponding to the image information to be displayed, characterized in that control means are further arranged for supplying a preset signal preceding the drive signal comprising a preset pulse having an energy sufficient to release the electrophoretic particles at a first position near one of the two electrodes corresponding to a first optical state, but too low to enable the particles to reach a second position near the other electrode corresponding to a second optical state, and in that the control means are further arranged for supplying the preset signal, in anticipation of or upon receipt of a power-up or image change operation.
摘要:
Electophoretic display units (1) are driven with a relatively low amount of power and more efficiently by addressing the pixels (11) only once during a sequence of frame periods. Compared to addressing a pixel (11) each frame period, for signals having a duration of more than one frame period, a large amount of power is saved. During a sequence of frame periods formed by a time-interval (T1-T8), one or more reset pulses (R) or one or more driving pulses (Dr) are provided. The addressing of a line of pixels (11) can be skipped during a sequence of frame periods if all pixels (11) of the line of pixels (11) have to remain unchanged. Signals having a duration of two or more frame periods do not need to be supplied to the pixels (11) each frame period, but need to be supplied only once by addressing the pixels (11) only once during a sequence of frame periods.
摘要:
Electrophoretic display units (1) having fixed frame times are driven relatively unflexibly. By introducing line driving signals having timing parameters, the frame rates can be made variable. With variable frame rates, the optical disturbance from shaking pulses (Sh) is reduced and the number of gray values is increased. The timing parameters comprise delays of starts of line driving signals and/or comprise durations of line driving signals. The lines preferably comprise rows. All possible column driving signals and, per column driving signal or per frame, a row delay parameter defining a row delay time, are stored in a memory coupled to the controller (20). Shaking pulses (Sh) are supplied at minimum row delay time, reset pulses (R) are supplied at maximum row delay time, and driving pulses (Dr) are supplied at flexible row delay time, which corresponds with a product of a predefined timeinterval and a step value defined by a number of bits.
摘要:
An image is updated on a bi-stable display (310) such as an electrophoretic display by providing separate scaling functions (SF1, SF2) for scaling a duration of a reset pulse (R) and a duration of a driving pulse (D) in a drive waveform based on temperature (335). An absolute value of a slope with varying temperatures of the scaling factor (SF 1) for the reset pulse (R) is significantly greater than that of the scaling factor (SF2) for the driving pulse (D), while both scaling factors increase with decreasing temperature. Image update time (IUT) is significantly reduced at lower temperatures, while a range of variation of IUT across all temperatures is also reduced. Scaling functions (SF3, SF4) may also be used for scaling a duration of a help reset pulse (H) and/or a duration of one or more shaking pulses (SH1, SH2).