摘要:
Several possibilities of driving devices (13,14,15) for optical switches, especially displays (1) based on the principle of electrowetting are given. This principle uses optical switches comprising a first fluid (5) and a second fluid (6) immiscible with each other within a space between a first transparent support plate (3) and a second support plate (4), the second fluid being electro˜conductive or polar.
摘要:
An electrophoretic display (1) comprising an electrophoretic medium (5) comprising a plurality of negatively charged black particles (6) and a plurality of positively charged white particles (6) in fluid. The average dc value of the drive voltages is arranged to be non-zero, so as to maximise brightness or contrast ratio of the displayed image, as required. If the average dc value of the drive voltages has a positive polarity, such that a small positive voltage is applied to the pixel electrode (3), although the white level may be less bright, the black level becomes darker, thereby increasing the contrast ratio during the driving sequence, which is obviously advantageous if the contrast ratio is the most important display parameter. If, on the other hand, maintaining or increasing a maximum brightness level is of key importance, then a drive sequence where the average dc value of all drive waveforms has a negative polarity is applied, so as to apply a small, controlled negative voltage to the pixel electrode (3). In this case, although the black level may become less dark, the white level becomes significantly brighter, such that the brightness is increased during the driving sequence, which is obviously advantageous if brightness is the most important display parameter.
摘要:
Electrophoretic display units (1) comprising pixels (11) situated between common electrodes (6) and pixel electrodes (5) need, for shortening the total image update times, increased driving voltages across the pixels (11) which endanger transistors (12) coupled to the pixel electrodes (5). These increased driving voltage (V6) to the common electrode (6). To protect the transistors (12) against these increased driving voltages, a setting signal (S1, S2) is supplied to the pixel electrode (5) via the transistor (12) for reducing a voltage across the pixel (11) resulting from a transition in the alternating voltage signal (V6). During driving frame periods (Fd) data pulses (D1, D2, D3, D4, D5, D6) are supplied, and during setting frame periods (Fs), the setting signals (S1, S2) are supplied.
摘要:
The electrophoretic display panel (1) for displaying a picture has a plurality of pixels (2) and drive means (100). Each pixel (2) has two electrodes (3, 4) for receiving a potential difference and charged particles (6) capable of occupying a number of different positions between the electrodes (3, 4). The drive means (100) are able to supply a sequence of potential difference pulses to each pixel (2), each sequence having, to display the picture, a picture pulse for bringing the particles (6) into one of the positions. For the display panel (1) to be able to display a picture of at least relatively medium quality even shortly after the application of the sequences, with respect to at least a number of the pixels (2) having received picture pulses for bringing their particles (6) into extreme positions, the sequence of each pixel (2) out of said number has an additional picture pulse subsequent to the picture pulse, which additional picture pulse serves to prevent the particles (6) from substantially changing their position.
摘要:
A drive circuit for a bi-stable display comprises: a driver (101, 102) which supplies drive waveforms (DWk) to the pixels (Pij) of the display during an image update period (IUk) wherein the image presented by the pixels (Pij) is updated. A controller (103) controls the driver (101, 102) to supply, during the image update period (IUk) wherein a particular optical transition of a particular one of the pixels (Pij) is required, an associated one of the drive waveforms (DWk) to the particular one of the pixels (Pij). The associated one of the drive waveforms (DWk) comprises a sequence of a particular number of pulse, (SPk), wherein consecutive ones of the pulses (SPk) of the sequence are separated by a separation period of time (SPT). The particular number of said pulses (SPk), and/or a duration of said pulses (SPk), and/or a duration of the separation period (SPT) of the associated one of the drive waveforms (DWk) is determined to obtain the particular optical transition at a desired energy of the associated one of the drive waveforms (DWk) to decrease an average value of the associated one of the drive waveforms (DWk).
摘要:
The electrophoretic display panel (1) for displaying a picture corresponding to image information has drive means (100) which are able to control for each picture element (2) the potentials, thereby being able to change the position of the particles (6) based on the image information. Furthermore, the display panel (1) has monitoring means (101) which are able to generate for each picture element (2) actual position information indicative for the actual position of the particles (6), and control means (103) which are able to control for each picture element (2) the drive means (100) in dependence of the actual position information and the image information to reduce a difference between the position of the particles (6) and the position off the particles (6) corresponding to the image information. For the display panel (1) to be able to provide a picture of relatively high quality even at relatively low or nonuniform intensities of the ambient light, the monitoring means (101) comprise electrical means (102) which are able to generate for each picture element (2) the actual position information based on an electrical property of the respective picture element (2).
摘要:
The electrophoretic display panel (1), for displaying a picture corresponding to image information, has drive means (100) which are arranged 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, and subsequently to be a picture potential difference for enabling the particles (6) to occupy the position corresponding to the image information. For the display panel (1) to be able to provide a relatively high picture quality, the drive means (100) are further arranged for controlling the reset potential difference of each picture element (2) of at least a number of the picture elements (2) to have an additional reset duration.
摘要:
An electrophoretic display comprises a plurality of pixels (18) with an electrophoretic material (8, 9) which comprises charged particles. A first electrode (6) and second electrode (5, 5′) associated with each one of the pixels (18) presents a drive voltage waveform (VD) across each one of the pixels (18). The charged particles are able to occupy, between the first electrode (6) and the second electrode (5), two limit positions and intermediate positions between the two limit positions which are defined by the drive voltage (VD). An addressing circuit (16, 10)generates the drive voltage waveform (VD) by successively applying between the first electrode (6) and the second electrode (5) during an image update period (IUP): (i) a reset pulse (RE) enabling said particles to substantially occupy one of the extreme positions, and (ii) a drive pulse (Vdr) having a level in accordance with an optical state to be reached by the associated one of the pixels (18). The addressing circuit (16, 10) further generates a first shaking pulse (SP1) comprising at least one preset pulse having an energy sufficient to release particles present in one of the extreme positions, but insufficient to enable said particles to reach the other one of the extreme positions. The first shaking pulse (SP1) occurs during a same first shaking time period (TS1) during each image update periods (IUP), independent on the optical state a pixel (18) should reach. The first shaking time period (TS1) precedes the reset pulse (RE) or occurs in-between the reset pulse (RE) and the drive pulse (Vdr).
摘要:
The invention relates to an electrophoretic display device (1) comprising charged particles (8, 9) in a fluid (10) between a pair of electrodes (5, 6). A drive means is arranged and configured to supply a drive waveform to the electrodes (5, 6), the drive waveform comprising a sequence of drive signals for effecting respective optical transitions by causing the charged particles (8, 9) to occupy a predetermined position between the electrodes (5, 6) according to image data required to be displayed, and at least one voltage pulse, preferably prior to each drive signal, for inducing a substantially uniform electric field distribution across the display device (1). This has the effect of significantly reducing edge image retention and/or ghosting.
摘要:
A display device (401) has groups of display elements (118), which are changed from one optical state to another by applying a waveform (330, 331) sequence of potential differences. The waveforms (330, 331) to be applied are stored in a look-up table (445) in a memory of the device (401). The look-up table is ordered so that portions of the waveforms (330, 331) are reused for different groups of display elements (401). The memory requirement for storing the waveforms (330, 331) is reduced.